RykuPrep Study Guide
General Cat & Dog Notes
Heartworm disease is caused by Dirofilaria immitis.o The adult worms produce L1 larvae (microfilariae) inside the bloodstream. L1 microfilariae mature to L3 larvae inside mosquitoes.
L3 larvae are the infective stage inside cats and dogs.
Heartworm preventives kill L3 & L4 larvae that have accumulated in the animal’s subcutaneous tissue the past month.
o Heartworm antigen tests and microfilariae tests only work about 6 months post-infection
It takes ~6 months for the L3s to mature into adults.
o Occult infection has adult worms only. Patent infection has microfilariae and can transmit to mosquitoes.
Occult infection would have positive antigen test and negative Knott’s test.
o No need testing puppies or kittens for heartworm until 6 months after given preventive.
Use heartworm antigen test in dogs.
o Most common sequela of heartworm disease is thromboembolism.
Glomerulonephritis is also common due to Ag-Ab complex deposition in kidneys. o Larvae are more likely to migrate to ectopic locations in cats than in dogs.
o Treatment for heartworms in dogs includes exercise restriction, doxycycline, monthly preventive, and melarsomine.
Doxycycline kills the Wolbachia bacteria associated with Dirofilaria
immitis.
o Cats are not the true end-stage host for heartworms and will often kill off any L3s they are exposed to.
Use heartworm antibody test in cats.
Treatment for cats is prednisolone, preventives, and possibly doxycycline. The two types of microfilariae that can be seen in dog blood are Dirofilaria immitis
(heartworm) and Acantheilonema reconditum.
Acantheilonema reconditum is non-pathologic and does not need to be treated.
Systemic inflammatory response syndrome (SIRS) is associated with the cytokine Interleukin-1.
Doberman Pinschers are predisposed to type III hypersensitivity reactions to sulfa drugs (such as TMS).
Air bronchograms on a radiograph indicate uniform lung consolidation. Isotonic crystalloid shock dose in dogs is 90 mL/kg.
o Give 1/3 shock dose and then reassess. Most cats prefer clumping litter.
Feline hairballs are treated with Laxatone.
Anticoagulant rodenticides will cause an increase in PT (prothrombin time) before other coagulation times.
Lembert, Cushing, & Connell patterns are inversion patterns used to close hollow viscera. o The Bunnel pattern is used to close severed tendons.
o The Ford interlocking pattern is used to appose tissues with increased tension. o The horizontal and vertical mattress patterns are eversion patterns.
An alveolar radiographic pattern shows areas of consolidation with air bronchograms. Non-cardiogenic pulmonary edema can be caused by electrocution, pulmonary
thromboembolism, head trauma, and upper airway obstruction.
o Non-cardiogenic pulmonary edema is not caused by hypertension. Blood makes up 8% of body weight in most species.
o Cat blood makes up about 6% of body weight.
o In order to raise a PCV by 1%, give 1 ml/kg of packed red blood cells.
A 100% solution is 1 g/mL.
o A 1% solution is 10 mg/mL.
2/3rds of body weight is water.
o Intracellular fluid makes up 2/3rds of body water (40% of weight) & extracelluar
fluid makes up 1/3rd of body water (20% of weight).
RER = 70 x BWkg0.75
o Another equation is RER = 30 x BWkg + 70
Standard chemotherapy affects neutrophils the most because neutrophils have short half-lives and replicate quickly.
o Chemotherapy targets cells that replicate quickly.
The most common intussusception in small animals is ileocolic. A 1st degree burn involves the epidermis.
o A 2nd degree burn can go down to the dermis.
o A 3rd degree burn involves the adnexal structures.
o A 4th degree burn involves muscle and bone.
The round ligament of the bladder is a remnant of the umbilical arteries. o The urachus becomes the middle ligament of the bladder.
o The umbilical vein becomes the falciform ligament.
In dogs, the dead space associated with aural hematomas are closed with mattress sutures parallel to the blood vessels.
Actinomyces (a filamentous, gram-positive, rod bacteria) is associated with plant awn
migration.
In utero infection with feline panleukopenia virus can cause cerebellar hypoplasia. o Feline panleukopenia virus is caused by a parvovirus.
o In utero infection with canine parvovirus causes nonsuppurative myocarditis. Canine parvovirus affects the GI tract and bone marrow (rapidly dividing tissues).
o Caused by Canine parvovirus-2
o The most affected age group of puppies is 6 weeks to 6 months. o A key finding of Parvovirus is leukopenia.
Bordatella bronchispetica is a cause of primary bacterial pneumonia in dogs.
o Causes infectious canine tracheobronchitis (kennel cough).
Cryptococcus neoformans causes mucopurulent nasal discharge and a proliferation on
the nose (Roman nose) in cats.
o Can also cause neurologic signs and uveitis (aqueous flare). o Spread via pigeon droppings.
o Diagnose with latex agglutination titer or by seeing small yeasts with large capsules on CSF tap.
Hemorrhagic gastroenteritis causes bloody diarrhea and an elevated PCV. o Most important therapy is aggressive IV fluids.
Rabies protocol for dogs is vaccinate at 3 months, booster one year later, then vaccinate every 1 – 3 years.
Rattlesnake bites can cause echinoctyes, thrombocytopenia, prolonged PT/PTT, and unilateral painful muzzle swelling.
Perineal hernias are usually seen in older intact male dogs.
Keratoconjunctivitis sicca is caused by autoimmune destruction of the lacrimal glands. Causes decreased tear production and mucoid ocular discharge.
o Treat with topical cyclosporine and steroids.
o A side effect of sulfa drugs is keratoconjunctivitis sicca.
Cats can exhibit cervical ventroflexion due to weakness, which is most often caused by hypokalemia.
In a dog that has had a parathyroid adenoma removed, monitor the serum calcium daily for a week to check for hypocalcemia.
The definitive host for Sarcosystis cruzi is the dog. Vitamin D causes high calcium and high phosphorous.
o PTH causes high calcium and low/normal phosphorous.
Fleet enemas are high in sodium and phosphate, which causes a hypocalcemia.
o Fleet enemas cause hyperphosphatemia, hypernatremia, and hypocalcemia. o Treat with calcium gluconate, IV fluids, and phosphorous binders.
Hyperkalemia (increased K+) causes bradycardia, absent P waves, prolonged PR interval,
wide QRS complexes, and tented (spiked) T waves. o Can be seen with renal failure.
o Treat with:
Calcium gluconate and Calcium chloride are cardioprotective; it does not reduce K+.
NaHCO3 causes an intracellular exchange of H+ for K+.
Glucose and insulin cause a K+ transferwith glucose.
Acromegaly is caused by excessive growth hormone release due to a pituitary tumor. Causes enlarged head, abdomen, and paws, as well as insulin-resistant diabetes mellitus due to growth hormone causing a defect in insulin receptors.
o Diagnose with an MRI.
o Best way to treat a pituitary tumor (as seen with acromegaly) is with external beam radiation therapy.
The most predisposed breed to perianal fistulas is German Shepherds.
o Causes hematochezia, tenesmus, mucopurulent discharge near anus, and
ulcerations around perineum.
o Probably immune-mediated and treated with cyclosporine.
Acetaminophen toxicity causes muddy mucous membranes, tachycardia, methemoglobinemia (brown blood), and Heinz body formation.
o Cats lack glucuronyl transferase, which is needed to metabolize acetaminophen. o Treat with N-acetylcysteine and abscorbic acid.
Mothballs can cause Heinz body anemia.
Pythium is an aquatic organism common in ponds in the southeast United States.
o Extremely difficult to treat. Treat with amputation and systemic antifungal
therapy.
Myasthenia gravis causes occasional weakness and megaesophagus. Caused by deficiency of acetyl choline receptors on postsynaptic membrane.
o Treat with elevated feedings and pyridostigmine (an acetylcholinesterase
inhibitor).
o Diagnose with a Tensilon response test. (Tensilon is an anticholinesterase that
prolongs the effect of the available acetylcholine.)
o Can be seen with a thymoma (which is a cranial mediastinal mass).
Feline asthma can present with panting, episodic respiratory distress, exercise intolerance, wheezing, and coughing (which sounds like getting rid of hairballs).
o Feline asthma is due to allergens causing a type I hypersensitivity response. o
Causes eosinophil infiltration into the lungs. o Causes an expiratory push.
o Diagnose with a bronchoalveolar lavage, which show seosinophilic inflammation with mucus.
Radiographs will show hyperinflation of the lungs, a bronchiolar pattern, and atelectasis of the right middle lung lobe.
o Treat feline asthma with prednisolone on an anti-inflammatory dose (not immunosuppressive). Use nebulizers or inhalors
Beta-two agonists such as terbutaline would be useful.
Atropine is contraindicated because it thickens bronchial secretions. Pulmonary thromboembolism can cause dyspnea and split second heart sounds with
normal radiographs.
Distemper virus infection in young dogs can lead to enamel hypoplasia.
Major differentials for feline upper respiratory tract disease include Chlamydophila felis, Feline calicivirus, & Feline herpesvirus.
Classic lesion for Feline Infectious Peritonitis is pyogranulomatous vasculitis.
o Diagnose FIP with biopsy and histopathology.
Serology for FIP is unreliable due to cross-reaction with feline coronavirus. 7B protein ELISA test is also unreliable.
o Rivalta’s test has the highest negative predictive value (best for ruling out FIP).
Linear foreign bodies such as string cause intestinal plication.
Lead toxicity has neurologic signs and basophilic stippling of erythrocytes. Treated with Ca-EDTA.
o Do not use sodium EDTA. EDTA binds calcium and can cause a hypocalcemia; Ca-EDTA is needed to prevent hypocalcemia.
Taurine deficiency in cats cause dilated cardiomyopathy and central retinal degeneration.
Lipomas look like this: .
o Lipoma fine needle aspirates typically have a clear and oily appearance.
The most common cause for hypercalcemia in dogs is T-cell lymphoma.
Sertoli cell tumors are endocrinologically active. Sertoli cell tumors make estrogen, cause prostatic metaplasia, and cause contralateral testicular atrophy.
Peripheral nerve sheath tumors (and other soft tissue sarcomas) are locally aggressive and often recur after surgical removal.
In dogs, 50% of mammary tumors are malignant. Only 50% of malignant mammary tumors will metastasize.
o In cats, > 90% of mammary tumors are malignant.
Single solitary liver masses are usually hepatocellular carcinomas.
o Remove with surgery and have a long-term survival (~1400 days). Histiocytic neoplasia is most common in Bernese Mountain Dogs.
Perianal adenomas respond to testosterone and often regress with castration. Cutaneous lymphoma causes pruritic lesions of the oral mucosa and foot pads.
o Intestinal lymphoma is treated with chlorambucil and prednisolone.
Apocrine gland sac adenocarcinoma commonly causes polyuria & polydipsia, secondary to hypercalcemia of malignancy.
Stargazer lily toxicity causes renal failure in cats.
General Horse Notes
Horse’s dry matter should be 12% protein. Normal horse lactate should be < 2.5 mmol/L. Fescue ingestion causes reproductive problems.
o Red maple causes Heinz body anemia.
o St. John’s wort & pyrrolizidine alkaloids causes photosensitization and
hepatotoxicity.
Pyrrolizidine alkaloids cause megalocytosis, fibrosis, & bile duct hyperplasia.
o Cantharidin from blister beetles causes colic.
o Yellow star thistle toxicity causes nigropallidal encaphelomalacia.
This causes lips to pull back and the tongue to tremor when a horse attempts to eat.
o Black walnut contains jugulone, which causes laminitis. o Onions cause hemoglobinuria & Heinz body anemia.
Horses are predisposed to gastric ulcers because they constantly secrete gastric fluid. Arabian horses are predisposed to cerebellar abiotrophy.
Peritoneus tertius ruptures let you extend the hock and flex the stifle simultaneously. o Ringbone is osteoarthritis of the pastern or coffin joints.
o Stringhalt is spastic hyperflexion of the hindlimb and is treated with a lateral digital extensor tenectomy.
o Sweeney is shoulder atrophy.
o Sweet itch is a type I allergic reaction to Cullicoides. Causes pruritus. Summer sores are caused by Habronema & Draschia stomach worms. Causes
eosinophilic granulomas on skin.
In horses, the muscle responsible for inspiration is the diaphragm. Proud flesh is exuberant granulation tissue formation at a wound site. African Horse Sickness is spread by Cullicoides flies.
Purpura hemorrhagica in the horse is an immune complex disorder associated with high levels of Streptococcus equi ssp. equi antigens and antibodies.
o Disrupts endothelial integrity, which causes leaked blood and plasma. o Causes an aseptic necrotizing vasculitis and can cause tissue sloughing. o Treat with dexamethasone and penicillin.
o Gray horses are predisposed to melanoma, which normally appear in the perineal region.
The most sensitive test for Strangles (Streptococcus equi subsp. equi) is PCR of guttural pouch wash for the S. equi M protein gene.
o For Strangles, reintroduce horses 30 days after resolution of signs, then 3 consecutive weekly negative nasopharyngeal cultures (after all that). o Strangles has a similar presentation to the foreign disease Glanders.
Glanders is diagnosed with a Mallein test.
Abdominal paracentesis in horses is performed to the right of the midline and normally retrieves yellow fluid.
Premature foals have short silky hair coats, pliant floppy ears, soft muzzle, incompletely ossified carpal & tarsal bones, and laxity of flexor tendons.
Equines develop marked hyperbilirubinemia from fasting.
Nephrosplenic entrapment causes the left kidney to be obscured on abdominal ultrasound. o The spleen may also be difficult to see.
o Can use phenylephrine to help treat.
Equine eosinophilic granulomas are nodular, non-ulcerative, and are not pruritic. o Treat with systemic antibiotics, sublesional steroids, and surgical excision.
Equine Herpes Virus-1 (EHV-1) can cause mares to abort. Future breeding possibilities should be unaffected, although the mare does not have permanent immunity and may be infected again.
o Vaccinate against EHV at 5, 7, & 9 months gestation.
Tyzzer’s disease is caused by Clostridium piliformis in mice and foals. o Causes acute necrotizing hepatitis.
Laryngeal hemiplegia is due to a damaged recurrent laryngeal nerve. o Usually affects the left side.
o Causes an audible whistling sound on inspiration.
Culicoides flies can cause a type I allergic reaction, extreme pruritus, and self-trauma.
Hyperkalemic periodic paralysis is due to a heritable defect in voltage-gated sodium channels.
o This is an autosomal dominant trait.
An auriculopalpebral nerve block lets you examine the eyes of a horse.
o This blocks the auriculopalpebral branch of cranial nerve VII (facial nerve). This
disrupts the motor innervation to the orbicularis oculi, which closes the eye.
o Does not offer any anesthesia.
Foal heat diarrhea causes very mild diarrhea in 7 - 14 day old foals. Associated with post-foaling estrous in the mare.
o Rhodococcus equi causes diarrhea and respiratory signs in 1 - 4 month old foals.
Rhodococcus equi is gram positive pleomorphic rods.
Causes pulmonary abscesses and an alveolar lung pattern. Treat with erythromycin and rifampin.
o Clostridium perfringens Types A, B, & C causes severe and fatal diarrhea in foals.
Most will die within 2 days if not treated.
o Rotaviruses are the most common cause of viral diarrhea in foals.
Miniature horses are predisposed to hyperlipemia and hepatic lipidosis secondary to anorexia.
o Miniature horses are also predisposed to colic due to small colon impaction. This
causes a dilated gas-filled colon.
In horses, subsolar abscess result from penetrating wounds or poor farrier work. Causes severe lameness, heat and pain in the affected foot, and edema of the pastern & fetlock.
o Treat with adequate drainage, disinfectants, and poultices.
Gastric reflux with a pH > 5 indicates small intestinal obstruction or ileus. The most common equine tumors are sarcoids.
o Sarcoids are locally aggressive fibroblastic tumors of the dermis and subcutis with a variable proliferative epithelial component.
o Caused by Bovine papillomavirus types 1 & 2.
The most common equine bladder and gastric tumor is squamous cell carcinoma.
o The most common equine intestinal neoplasia is a lymphosarcoma.
Equine influenza is an orthomyxovirus spread via aerosol.
Choke (esophageal obstruction) is not an emergency; you have time to act.
o Most cases of choke resolve within 24 hours without treatment.
o Treat by sedating and passing a nasogastric tube to move the obstruction aborally
(away from mouth).
Meconium impactions in foals are treated with acetylcysteine enemas. Windswept foals have valgus of one limb and varus of the contralateral limb. Normal pCO2 in a horse is 40.
General Ruminant Notes
Normal somatic cells in cows are < 200,000 cells/mL.If you puncture your finger with the RB51 brucellosis vaccine, see a physician and request 3 weeks of doxycycline.
o Brucella ovis can cause epididymitis and infertility in rams. Test with ELISA. Salt poisoning, lead poisoning, polioencephalomalacia, and vitamin A deficiency will all
o Vitamin A deficiency is the only disease that will cause absent pupillary light reflexes.
Bighead (Clostridium novyi Type A) causes edema of the head and neck. o Treat with wound debridement and penicillin.
o No need to cull or isolate affected animals because it is part of the native flora. Contagious ecthyma is caused by a parapoxvirus. Affects lambs and kids.
o Scabs fall off within 1 month.
o Can cause low-grade fever and make animal not want to eat. o Microscopically resembles proliferative granulation tissue.
Bovine papular stomatitis (BPS) is a parapox virus is similar to contagious ecthyma.
o Causes fever and raised oral lesions that will resolve in a few weeks.
Ovine Progressive Pneumonia (OPP) is a lentivirus of the family Retroviridae and is the most common cause of pneumonia in sheep.
Hydroallantois is a disorder of the placenta that results in accumulation of fluid during the last trimester. The cow is clinically affected.
o Calf usually dies and the cow usually becomes infertile.
Hydramnios is a disorder of the fetus with thick viscous fluid accumulated. The cow is not clinically affected and has a good prognosis for future pregnancies.
Blue tongue is an RNA orbivirus that mainly affects sheep, but also cattle.
o Causes fever, widespread multisystemic vasculitis, oral lesions, mucopurulent nasal discharge, pulmonary edema, white streaks in muscle, and lameness.
Causes loss of epithelium and edema in the tongue. This can turn the tongue blue.
Blue tongue is a teratogen and can cause abortions.
Causes hydranencephaly (destroyed cerebrum) in lambs born from sheep infected with blue tongue.
Cattle may suffer reproductive losses but rarely show signs of the systemic disease. Aborted or live weak calves can have white eyes due to cataracts. o Spread by the midge Culicoides sonorensis.
o Appears similar to Foot and Mouth Disease.
Johne’s disease (Mycobacterium avium spp paratuberculosis) usually affects cows 2 – 5 years old.
o Causes enlarged mesenteric lymph nodes and granulomatous bowel. o Johne’s disease is associated with Crohn’s Disease.
Bovine spongiform encephalopathy is associated with Creutzfeldt-Jakob disease.
Caseous lymphadenitits is caused by Corynebacterium pseudotuberculosis, which is a pleomorphic, gram positive, intracellular, facultative anaerobic rod.
o Best method of prevention is a Corynebacterium pseudotuberculosis vaccine. o Treatment is not usually recommended, so cull.
o If treating a valuable animal, surgically drain or remove the abscess. Then isolate and give antibiotics.
Clostridium hemolyticum (renamed Clostridium Novyi type D) causes bacillary
hemoglobinuria, internal hemorrhage, and acute death with bloody urine.
o Liver flukes (Fasciola hepatica) are often associated with the disease. You can
control flukes by controlling snails.
o Treat with penicillin or oxytetracycline.
Infectious Bovine Rhinotracheitis is caused by 3 types of bovine herpes virus (BHV).
o BHV-1.1 causes respiratory and ophthalmic infections. o BHV-1.2 causes respiratory and genital infections. o BHV-1.3 causes neurologic infections.
Malignant Catarrhal Fever causes acute arteritis, diarrhea, cloudy cornea, fever, respiratory signs, and gastrointestinal lesions.
o Wildebeest are the reservoir for the African form & sheep are the reservoir for the
North American form.
Enzootic pneumonia is the major respiratory disease of 3 – 8 month old calves.
o Multifactorial, but most common cause is Pasteurella multocida. o Causes cranioventral consolidation.
o Commonly seen with coccidiosis.
Coccidiosis is a parasitic infection that causes destruction of the intestinal mucosa.
o Caused by the protozoa Isospora or Eimeria.
In chickens, coccidiosis is caused by Eimeria.
o Causes bloody diarrhea, tenesmus, and dehydration. o Treat with amprolium.
Amprolium has a 0 day meat withdrawal time.
o Nervous coccidiosis affects cattle less than 1 year of age due to a neurotoxin.
E. coli O157:H7 is an enterohemorrhagic strain of E. coli that produces Shiga-like
toxins.
o Causes no symptoms in cows but has zoonotic potential.
Diagnose carriers with stool culture or PCR.
Mycoplasma bovis causes otitis media, respiratory disease, mastitis, arthritis, and
abortion.
o Cull all cows with Mycoplasma bovis mastitis.
o Growth medium for Mycoplasma bovis is Hayflick’s agar.
Mannheimia hemolytica causes fibropurulent bronchopneumonia.
Trichomoniasis (Tritrichomonas foetus) in a herd of cows is normally asymptomatic but causes poor calving percentage.
o Mature bulls are usually the reservoir for a herd. o Most common cause of pyometra in cows.
E. coli is the major cause of diarrhea in 3 – 5 day old calves.
Clostridium chauvoei causes blackleg in cattle.
Campylobacter fetus cannot be spread to humans via milk.
o Campylobacter fetus primarily causes early embryonic death and infertility in
cows, but it can cause abortion.
Left displaced abomasums occur in the first 4 weeks after parturition and are heard from the last to the 8th rib.
o Normally have normal vital signs. Cattle have 11 blood groups.
o Horses and sheep have 7 blood groups. o Goats have 5 blood groups.
White muscle disease is caused by selenium deficiency. Causes white streaks in muscle and can cause sudden death due to myocardial abnormalities.
o Check for selenium deficiency by testing for glutathione peroxidase.
Moldy sweet potatoes have 4-Ipomeanol, which causes atypical interstitial pneumonia. o Perilla mint has perilla mint ketones, which are toxic to the respiratory system. o Brassica plants (associated with lush pasture) have D,L-tryptophan, which is
converted in the rumen into 3-methylindole. This causes pulmonary edema and emphysema
o Moldy sweet clover contains slaframine, which causes hypersalivation. It also causes a coagulopathy via inhibiting vitamin K.
o Castor bean results in hemolysis.
o Yellow bristle grass has barbs that cause oral ulcerative damage.
o Amaranthus contains nitrates, which causes chocolate brown blood and weakness.
o Cottonseed has gossypol, which can cause dyspnea, weakness, reproductive
problems, and death in calves via cardiomyopathy.
Spider lamb syndrome is a genetic disease of sheep that causes carpal valgus. Postparturient hemoglobinuria is due to hypophosphatemia below 2.0 mg/dL. Float tanks are the most effective way of managing down cows without underlying
fixable problems.
Milk liners last at least 500 milkings.
Streptococcus agalactiae is not an environmental mastitis organism; it is contagious. o This is the only mastitis organism that responds to treatment during lactation.
Best way to combat failure of passive transfer in calves past effective colostral supplementation (older than 2 days) is to give IV bovine plasma.
o Best way to test for failure of passive transfer is ELISA (SNAP) test.
Obese cows are predisposed to fatty liver syndrome when they encounter a negative energy balance.
Spastic paresis is a hereditary disease that causes continuous stiffness of the hocks (tibiotarsal joint).
o Treat with gastrocnemius tenectomy.
Volcanic soils often cause copper deficiency.
Sheep are very prone to copper toxicity, which causes a hemolytic crisis.
o Cattle feed is a common source of copper toxicity.
Uterine prolapses occur immediately postpartum.
o Vaginal prolapses occur late in pregnancy.
o Rectal prolapses are associated with straining to defecate.
Femoral nerve paralysis in calves causes the inability to bear weight on pelvic limbs and dog sitting without bony abnormalities.
o Prevent in the future with delivery via Cesarean section.
In order to do a standing laparotomy in a cow, you must perform a paravertebral nerve block to desensitize nerves T13, L1, & L2.
Pododermatitis circumspripta involves a lesion in the sole/bulb junction.
With sole abscesses in cows, put wooden hoof block on claw that is not affected. Lice are usually species-specific and have 6 legs.
o Mallophaga are biting lice.
o Anoplura are sucking lice that can cause anemia.
Poloxalene will destabilize froth and help cure bloat.
The most common ocular tumor of cattle is squamous cell carcinoma. Ocular squamous cell carcinoma has a heritable and sunlight component.
o Euthanize beef cattle with lymphoma or squamous cell carcinoma because they
cannot be eaten.
o If you do surgically remove the eye, use a five-point orbital block using lidocaine.
General Pig Notes
Pseudorabies is reportable, transmitted via inhalation, and causes these signs: o Neurological signs in piglets.
o Neurological & respiratory signs in weaned pigs. o Respiratory signs in older pigs.
o Reproductive failure in pregnant sows. Inguinal hernias in pigs are heritable.
o Inguinal hernias are most common in males after castration. o Umbilical hernias are slightly more common in female pigs.
Staphylococcus hyicus causes greasy pig disease in piglets under 2 months old.
Streptococcus suis causes polyserositis and sometimes pneumonia.
o Causes pink and frothy oral and nasal discharge. o Immediately treat all pigs in herd with enrofloxacin. Classic Swine Fever causes splenic infarcts.
o African Swine Fever is similar to Classic Swine Fever.
Herpes viruses become latent in the trigeminal ganglia where they become incorporated in the host genome.
o There is no antibody response during latency.
Salt poisoning causes neurological signs in pigs. Major indicator is perivascular infiltration of eosinophils.
Swine tuberculosis is associated with materials contaminated by birds. Vitamin A deficiency can cause ataxia, head tilt, and middle ear infections. Fusobacterium necrophorum contributes to necrotic rhinitis in pigs.
Rectal strictures and large intestinal ulcers are a common sequela to salmonellosis. Vesicular stomatitis is caused by a Rhabdovirus. Vesicular stomatitis is a reportable
disease with signs similar to foot-and-mouth disease. Is present in the U.S.
o Foot-and-mouth disease is caused by a picornavirus.
Zearalenone is a mycotoxin that causes hyperestrogenism, pseudopregnancy, and rectal prolapse in pigs.
o Alfatoxins cause hepatic necrosis and fibrosis.
Enterotoxogenic E. coli produces a heat-stable Shiga toxin. This causes facial edema, diarrhea, dyspnea, and circling.
Hemolytic E. coli is treated with ceftiofur injections for sick pigs and gentamycin in the water.
o F18 E. coli is associated with edema disease in swine.
Brucellosis causes abortion at all gestational stages without placental lesions.
o Brucellosis is present in feral swine and spread venereally and through aborted fetuses.
Parvovirus causes mummies and stillborns, not abortions.
Atrophic rhinitis is caused by Bordatella bronchiseptica & Pasteurolla multocida. o Bordatella causes non-progressive atrophic rhinitis.
o Pasteurella causes progressive atrophic rhinitis. o No treatment, just cull.
Pityriasis rosea causes raised circular lesions on the ventral abdomen of 3 – 14 week old pigs.
o No treatment required.
Erysipelothrix rhusiopathiae causes diamond-shaped lesions, is treated with penicillin, and has 3 forms:
o The peracute form causes sudden death.
o The acute form causes lethargy, painful joints, abortion, and diamond-shaped skin lesions.
Clostridium perfringens type C enteritis causes acute hemorrhagic diarrhea and death in
piglets up to 1 week-old.
o High morbidity and mortality.
Enteric colibacillosis (enterotoxogenic E. coli) causes diarrhea in piglets up to 2 weeks-old, but is not bloody and does not cause death.
Coccidiosis in pigs (Isospora suis) causes high morbidity and low to moderate mortality. o Affects 1 – 3 week old piglets.
o Not responsive to antibiotics.
o Best prevention is improved sanitation.
Transmissible gastroenteritis is caused by a Coronavirus. It causes diarrhea and complete mortality in piglets less than 2 weeks-old.
o Causes mild diarrhea in older pigs.
Swine dysentery (Brachyspira hyodysenteriae) causes bloody diarrhea and death in grower and finisher pigs.
General Exotic Notes
The best site for tuberculosis testing in monkeys is intradermally in the 3rd eyelid.
Raccoons carry the zoonotic diseases Rabies & Baylisascaris.
o Baylisascaris is a roundworm that can cause CNS signs in humans.
Choanal atresia in alpacas is a congenital disorder causing a lack of an opening between the nasal and pharyngeal regions.
o Causes respiratory signs.
o Commonly seen with other congenital abnormalities such as extra digits. BIRDS:
o Marek’s disease in chickens is caused by a herpes virus. Causes sciatic nerve paralysis and brain edema.
o Metabolic dystocia in birds (egg binding) can be caused by hypocalcemia. Treat
with calcium gluconate.
Diagnose with radiographs.
o In birds, the pectin is a normal black structure from the retina to the vitreous humor.
o Budgerigars that look like this
have the genetic disorder Chrysanthemum disease. Continuous growth of feathers all over body.
o In birds, progressive unilateral paralysis is usually due to renal neoplasia (due to
pressure on sciatic nerve).
Diagnose with abdominal radiographs.
o Egg drop syndrome is caused by an adenovirus.
Causes healthy birds with soft-shelled or no-shelled eggs that are eaten by other birds.
o Hypovitaminosis A in birds is seen with all-seed diets. Causes squamous metaplasia and white plaques in the oral cavity.
All-seed diets can also cause hypocalcemia, which can lead to cloacal prolapse.
o Chickens commonly develop Candidiasis (Candida albicans) after the use of antibiotics.
Causes thickened mucosa and circular oral ulcers. Treat with copper sulfate or nystatin.
o The best treatment for feather cysts is surgical removal of cyst and follicle.
Feather cysts are like ingrown hairs.
o Heavy metal toxicosis causes PU/PD, severe dehydration, and hemoglobinuria.
Liver disease can present similarly but has green-tinged feces.
o Eclectus parrots are sexually dimorphic.
Males are green & females are yellow. o Male birds are ZZ and female birds are ZW.
Male mammals are XY & female mammals are XX.
o Toucans and mynah birds are susceptible to hemochromatosis (iron storage
disease). Causes poor feathering, overgrown beak, and elevated liver enzymes & bile acids.
Diagnose with liver biopsy.
o Psittacine beak and feather disease usually affects psittacine birds <3 years old. Causes feather loss and beak abnormalities.
o The best place to draw blood from in a bird is the right jugular vein.
Intraosseus catheters in birds should be placed in the ulna or tibiotarsus.
o The bird esophagus is on the right side of the neck.
o In birds, vitamin A deficiency causes submandibular abscesses and squamous
metaplasia.
o Female poultry can lose feathers on the base of their tale due to normal mating
behavior with roosters.
o Organophosphates can cause bone abnormalities and problems with embryonic
development in ducks.
Organophosphates inhibit acetylcholinesterase causing incoordination, salivation, & bloat. Treat with atropine.
o Vitamin E deficiency in chicks causes nutritional encephalomalacia.
o A xanthoma is a benign growth in birds that is composed of lipids and cholesterol. Will have macrophagic inflammation with multi-nucleate giant cells.
FISH / TURTLES / REPTILES:
o The only approved anesthetic for fish is MS-222.
o The causative agent of “Ich” in fish is Ichthyopthirius multifillis. Causes erratic swimming and white spots on skin & gills.
o The most common bacterial pathogen of fish is Aeromonas salmonicida. o All reptiles are carriers of Salmonella. Strict hygiene and handling is advised. o Ivermectin is highly neurotoxic in turtles.
o Hypovitaminosis A is more common in turtles than other reptiles.
Causes respiratory disease, renal disease, squamous metaplasia of epithelium, & palpebral edema.
o Septicemic cutaneous ulcerative disease (SCUD) in turtles is caused by
Citrobacter freundii.
Causes sloughing skin with purulent exudate. Treat with chloramphenicol.
o Abnormal beak growth in turtles is usually due to primary malocclusion
secondary to hypocalcemia.
Supplemental calcium won’t help once the distortion occurs; patient will require long-term trimmings.
o Iguana tongues are normally very dark red.
o The best treatment for tail trauma in iguanas is tail removal.
o White chalky nodules in lizard joints are due to gout (uric acid deposition).
Gout can cause shifting leg lameness and spindle-shaped crystals in birds. Treat with systemic allopurinol therapy.
Cat food is too high in protein for reptiles and can cause gout.
o Raw fish diets contain thiaminase, which can lead to neurologic signs.
o Inclusion body disease causes snakes to regurgitate and become unable to right
themselves.
Associated with the snake mite Ophionyssus natricus.
o Dysecdysis is abnormal shedding. o Snakes do not have urinary bladders.
o Snakes have incomplete cartilaginous rings around their tracheas.
Turtles and birds have complete cartilaginous rings around their tracheas. RABBITS & GUINEA PIGS:
o “Snuffles” in rabbits causes mucopurulent nasal discharge and sneezing. Caused by Pasteurella multocida.
o Rabbits frequently get caudal lumbar vertebral fractures, especially L7. o Gastric trichobezoars (hairballs) cause weight loss.
o Rabbits have 2 uterine horns and 2 cervices.
o Intact rabbits are extremely prone to developing uterine adenocarcinoma, which can cause alopecia.
o Daily water requirement for rabbits is 120 mL/kg (higher than most species). o Treponema cuniculi causes rabbit syphilis.
o Encephalitozoon cuniculi causes head tilt and torticollis (twisted neck).
o Guinea pigs are frequently deficient in vitamin C, which can cause rough hair
coat, loose teeth, petechial, and lameness. FERRETS:
o Ferrets are carnivores and need a diet low in fiber and carbohydrates.
o Ferrets commonly get mast cell tumors, lymphoma, insulinoma, and adrenal tumors.
o Ferret adrenal disease is not like other small animal hyperadrenocorticism. Ferrets have increases in sex hormones but not cortisol.
o Ferrets should be vaccinated for rabies at 3 months and then annually.
o The most common cause of seizures in adult ferrets is hypoglycemia secondary to an insulinoma.
Treat insulinomas with prednisone and diazoxide.
o Lawsonia intracellularis causes proliferative bowel disease in ferrets, which is treated with chloramphenicol (antibiotics).
o
RODENTS:
o Transmissible murine colonic hyperplasia is seen in mice 2 – 4 weeks old. Highly contagious but self-limiting; causes anorexia and diarrhea. Treat with Neomycin or tretracyclines.
o Average lifespan of a rat is 2.5 years.
Average lifespan of a hamster is 2 years.
Business Management Questions
Most general practitioners are paid 20 - 25% of gross production. A payroll service will not file and send tax returns to the IRS.The most common reason for a client choosing a veterinary practice is location. Guardian and teacher styles of veterinarians dominate the conversation, whereas
collaborator styles of veterinarians do not dominate the conversation. The USDA is responsible for meat and poultry products.
o The FDA regulates other food and drugs.
A profit and loss statement is a report of income and expenses over a period of time. o A balance sheet is a report on the financial position of a company at a certain
o A cash flow statement involves the sources of cash and uses of cash over a period of time.
o A net book value is the same as equity, which equals assets minus liabilities. Cohort studies are best for examining the temporality of disease (exposure precedes
disease).
When using drugs extra-label, legally you should not do so if there is a legal alternative. However, if a specialist would do it then you are unlikely to be sued.
Pathology
ALT is a hepatocellular leakage enzyme increased with liver inflammation and necrosis.
o AST is a hepatocellular leakage enzyme increased with liver inflammation and
necrosis. Also seen with muscle damage.
If AST >>> ALT, consider muscle damage and evaluate creatinine kinase (which is muscle specific).
o ALP is increased with cholestasis. More specific for cholestasis but not as
elevated in cats.
Glucocorticoids cause an increase in ALP in dogs.
o GGT is increased with cholestasis. More specific for cholestasis in dogs. o Albumin is only made in the liver. Liver failure will have hypoalbuminemia. o BUN is decreased with liver failure.
o Hypocholesterolemia will be seen with liver problems.
Hypercholesterolemia will be seen with decreased biliary excretion of cholesterol (extrahepatic obstruction).
o Unconjugated bilirubin is processed from heme and conjugated in the liver.
Pre-hepatic hyperbilirubinemia will have increased conjugated bilirubin. Hepatopathy will have increased unconjugated bilirubin.
o Sorbital dehydrogenase (SDH) is the most liver-specific enzyme in ruminants and
horses.
Tuberculosis is an infectious granulomatous disease that primarily affects the lungs. o It is usually caused by Mycobacterium species.
o The most important diagnostic test is the intradermal tuberculin test.
False positives are expected because there is cross-reactivity with other mycobacteria.
Antigens are injected into the skin. If an animal has experienced the bacteria than they should mount an immune reaction.
o Humans usually get an airborne infection.
There is not good zoonotic transfer from animals because the infection is not usually spread via aerosols.
Most common primary brain tumors in dogs are oligodenrogliomas & astrocytomas. o The most common primary brain tumors in cats are meningiomas.
Agglutination of erythrocytes is due to immune-mediated hemolytic anemia (IMHA). o Spherocytes are small and round erythrocytes that also indicate IMHA.
Reticulocytes are large, dark blue, young erythrocytes.
o
o Indicate a regenerative anemia. o Horses do not release reticulocytes. Heinz bodies indicate oxidative damage.
o (new methylene blue stain)
Howell-Holly bodies are nuclear remnants and may indicate increased erythropoiesis.
o
o
Macrocytosis is large erythrocytes and is usually seen with regenerative anemias.
o Microcytosis is usually seen with hepatic disease, portosystemic shunts, and iron deficiency.
Toxic neutrophils indicate intense neutrophil production and shortened maturation time. A left shift is an increase in immature (band) neutrophils.
o A regenerative left shift is a mature neutrophilia with smaller numbers of band neutrophils.
o A degenerative left shift means there are more immature band neutrophils than mature neutrophils.
Glucocorticoids cause SM¡LE.
o Increased segmented neutrophils and monocytes. o Decreased lymphocytes and eosinophils.
Epinephrine causes increased in neutrophils and lymphocytes.
Disseminated Intravascular Coagulation (DIC) is not a primary disease but secondary to underlying diseases.
o The underlying disease causes an uncontrolled systemic inflammatory response characterized by massive activation and consumption of coagulation proteins, endogenous inhibitors, fibrinolytic proteins, and platelets.
o Usually induced by exposure to tissue factor and activation of the extrinsic pathway of coagulation.
o DIC causes a decrease in fibrinogen because it is utilized. Normal cavity fluid should be a transudate (low protein and cells).
o To distinguish a septic exudate from a normal exudate, look for intracellular bacteria.
Pathogenic hemorrhage is indicated by phagocytosis of erythrocytes by macrophages. Benign neoplasms have uniform cell appearance, whereas malignant neoplasms have
variable cell appearance.
Carcinomas are malignant neoplasms that arise from epithelial cells of glandular tissue. o Cytologically, carcinomas appear as clusters of epithelial cells.
Sarcomas are malignant neoplasms of mesenchymal cells. o Cytologically, sarcomas appear as solitary spindle cells.
Round cell tumors include mast cell tumors, lymphoma, plasma cell tumors, histiocytic tumors, and transmissible venereal tumors.
o Cytologically, round cell tumors appear as large populations of cells not in defined clusters.
o Lymphomas are malignant neoplasms of lymphocytes.
Cytologically, lymphoma contains many immature lyphoblasts. Plasma cells are lymphocytes that secrete large volumes of antibodies.
A canine platelet has a circulating lifespan of 5 - 7 days.
o Canine leukocytes have a circulating lifespan of 5 - 9 hours. o Canine erythrocytes have a circulating lifespan of 110 days. o Feline erythrocytes have a circulating lifespan of 68 days. Large amounts of fibrin in fluid indicate the fluid is inflammatory.
Parasites
Lice have 6 legs; ticks and mites have 8 legs.Fecal sedimentation is good for testing for eggs that sink, like most fluke (flatworm) eggs.
o A direct fecal smear can find any egg or larva passed in feces, but it doesn’t increase the concentration of the parasites.
Haemonchus contortus is the most important goat parasite.
o The “barber pole” nematode that causes anemia.
Strongyloides stercoralis is a roundworm that causes mucoid diarrhea and anemia in
puppies and kittens.
o Diagnose with the Baermann fecal technique. Moniezia are tapeworms of cattle.
o rectangular or triangular eggs
Trichomoniasis (Tritrichomonas foetus) in cats is a protozoal infection that causes large bowel diarrhea.
o Affects young cats who will grow out of the infection without treatment. o Treat with Ronidazole.
Aerostrongylus abstrusus is the lungworm of cats and is treated with ivermectin or
fenbendazole.
Neospora caninum is a protozoan parasite that causes abortion in cows and neurologic &
Urinary System
The upper urinary tract consists of the kidneys and ureters.o The lower urinary tract consists of the bladder and urethra.
A nephron is the functional renal unit. A nephron consists of a glomerulus and a tubule. o Glomerular diseases result in proteinuria and eventual tubular disease.
o Tubular diseases result in loss of concentrating ability & eventually azotemia. Uremia is not a laboratory value. It is a set of clinical signs seen with kidney disease.
Includes vomiting, lethargy, anorexia, weight loss, dehydration, diarrhea, and oral ulceration.
o One possible sign of uremia is gastric ulceration. Treated with: Famotidine - H2 blocker (blocks HCl acid production) Omeprazole - proton pump inhibitor
Sucralfate - cytoprotective agent (binds to ulcer site)
Dogs must lose 65% renal function to become unable to concentrate urine & 75% renal function to see azotemia.
o In cats, 75% of renal function must be lost to lose concentrating ability. Polydypsia is > 100 mL/kg/day.
o Polyuria is > 50 mL/kg/day.
Pollakiuria (frequent urination with small volume), dysuria, and stranguria (straining drop by drop) are signs of lower urinary tract disease.
The kidneys excrete H+, phosphorous, potassium, and BUN / creatinine.
o
Problems with urinary excretion result in metabolic acidosis, hyperphosphatemia, hyperkalemia, azotemia, and hypocalcemia (secondary to hyperphosphatemia). o With chronic renal failure, the body’s compensatory mechanism to
hyperphosphatemia is secondary hyperparathyroidism.
Parathyroid hormone (PTH) increases calcium and decreases phosphorous. Blood Urea Nitrogen (BUN) is formed in the liver from metabolism of ammonia.
o BUN is the best measure of liver function and also shows kidney function. High BUN means GFR is low and kidneys are not working. Low BUN
means liver is not producing it.
BUN does not exceed normal value until 75% of kidney function is lost.
Azotemia is high levels of BUN and/or Creatinine in the blood.
o Azotemia can be due to decreased GFR (prerenal, renal, or postrenal), high protein diet, GI hemorrhage, steroids, or tetracyclines.
o Elevated creatinine is more specific for decreased GFR than elevated BUN. The only other cause of elevated creatinine is well-muscled dogs.
Proteinuria can be due to glomerular disease, post-renal hemorrhage or inflammation, or protein overload.
Amyloidosis is accumulation of inappropriately folded proteins in glomerulus.
Amyloidosis results in a gray and waxy kidney. Shar-Peis are predisposed to amyloidosis.
o Protein itself is damaging to renal tubules, so proteinuria is a sign of ongoing renal damage.
The best measure of glomerular filtration rate is serum creatinine. Urine specific gravity evaluates renal tubular function.
o In healthy hydrated animals, the USG can vary widely from 1.015 – 1.050 in dogs to 1.015 – 1.060 in cats.
o Consistent isosthenuria (USG 1.008 – 1.012) indicates renal dysfunction.
o In the presence of azotemia, the USG should be >1.030 in dogs & > 1.040 in cats. This indicates the kidneys can concentrate urine in the face of decreased blood flow and the azotemia is likely pre-renal.
In the presence of azotemia, a lower than normal USG indicates the kidneys cannot concentrate urine and the azotemia is renal in nature. (Pre-renal azotemia may still contribute.)
o Cannot evaluate USG once patient is on fluid therapy. One sign of chronic renal disease is a non-regenerative anemia.
Ethylene glycol in transformed in liver by alcohol dehydrogenase into the toxic glycolic acid.
o Treatment is 4-MP or ethanol, which inhibit alcohol dehydrogenase.
o 3 stages of disease: neurological signs improvement fatal kidney failure o Will see calcium oxalate crystalluria.
Leptospirosis spreads through urine and causes acute renal failure. o Not clinically important in cats.
o Diagnosis is via urine PCR or microscopic agglutination test (MAT). Can be viewed under dark field microscopy.
o Vaccination reduces clinical signs but does not prevent infection. o Treat with doxycycline or penicillins.
o The most important problem of Leptospirosis in pigs is reproductive failure.
All aminoglycosides are nephrotoxic.
o Decrease risk with larger single doses.
Most common cause of chronic renal failure in small animals is tubuloinsterstitial nephritis.
o The most common cause of chronic renal failure in horses is glomerulonephritis. In horses, glomerulonephritis is treated with corticosteroids, plasma
transfusion, & low-protein diet. Glomerulonephritis usually causes polyuria, so furosemide is not needed.
Furosemide is indicated for oliguric renal failure. Treatment for chronic kidney disease includes:
o renal diet with decreased protein and phosphorous o Phosphorous binders such as aluminum hydroxide.
o give calcitriol (activated vitamin D) because the kidneys activate vitamin D o Give angiotensin converting enzyme (ACE) inhibitors (Enalapril) to reduce
proteinuria.
o Reduce hypertension with ACE inhibitors in dogs and Amlodipine in cats. o erythropoietin to correct anemia
o Famotidine, omeprazole, or sucralfate to correct gastritis and gastric ulceration o Metoclopramide, dolasetron, ondansetron, or maropitant if vomiting a lot. Renal failure can cause PU/PD, decreased appetite, and weight loss.
Protein-losing nephropathies (such as glomerulonephritis and amyloidosis) is treated with dietary protein restriction, ACE inhibitors, and aspirin.
o Dietary protein restriction obviously decreases proteinuria.
o ACE inhibitors decrease proteinuria by causing dilation of the efferent arterioles. o Aspirin decreases platelet function to help alleviate the hypercoagulable state
from lost antithrombin III.
Unless obstructed, lower urinary tract disease (LUTD) rarely results in systemic signs or bloodwork changes.
o Most common cause of LUTD in dogs is bacterial infections.
o Most common cause of LUTD in cats is Feline Idiopathic Cystitis (FIC)
Acute and chronic FIC will usually resolve on own without treatment but may recur.
Treat acute FIC with high-moisture urinary diets and short-term opioids for analgesia.
Treat chronic FIC with same as acute, but also Amitriptyline.
The terminal urethra is not sterile; finding microbes in the terminal urethra does not mean there is a urinary tract infection (UTI).
o Bacteriuria and pyuria (leukocytes in urine) does not by themselves necessarily mean there is a UTI.
o The most common cause of a UTI is E. coli.
Staphylococcus, Enterococcus, Streptococcus, Proteius, Pseudomonas, and Klebsiella are other common pathogens.
o Dipsticks are not appropriate for diagnosing a UTI. You must examine a urine sediment and ideally perform a urine culture.
o 2 weeks of Amoxicillin is best initial therapy for UTIs.
Fanconi syndrome is a form of renal failure normally only seen in Besenji dogs. o Due to a proximal tubule dysfunction.
Polycystic Kidney Disease is the most common genetic renal disorder. o Primarily seen in Persian cats and will cause chronic renal failure. o Diagnose with ultrasound.
Struvite uroliths are normally sterile in cats and normally associated with bacterial infection in dogs.
o You want an acidifying diet to treat struvite uroliths.
o Other types of uroliths require an alkalinizing diet to prevent. o Dalmatians are prone to ammonium urate stones.
Dalmatians have a genetic defect in making allantoin from urates in the liver. This predisposes them to forming urate stones and getting urinary tract obstructions.
Treat stones with allopurinol and a low-purine diet to alkalinize the urine. Allopurinol therapy in turn predisposes Dalmatians to Xanthine stones. o Struvite and calcium stones can be seen on radiographs. Urate and cysteine
stones cannot.
o Most equine uroloiths are calcium carbonate and calcium phosphate. The most common urolith in ferrets is sterile struvite.
Phenylpropanolamine is an alpha-adrenergic agonist that treats urethral sphincter mechanism incontinence.
o Phenylpropanolamine is used to treat dogs who leak urine. Phenoxybenzamine is used to treat hypertonicty of urethral muscle.
A uroabdomen will have hyponatremia, hypochloremia, hyperphosphatemia, and azotemia.
o Urine is high in potassium and low in sodium & chloride; the electrolytes equilibrate with the blood.
A key finding of pyelonephritis is bacterial or leukocyte casts in urine.
Urethral obstruction commonly causes hyperkalemia. 0.9% NaCl is the best fluid to treat this.
o During the immediate post-obstructive period, cats may develop hypocalcemic tetany.
Urohydropropulsion is the expulsion of cystic calculi after anesthetizing an animal by application of manual pressure to the bladder to expel the stone through the urethra.
o Best done in thin female dogs. Not done in male dogs because their long, narrow urethras and os penis increase the likelihood of obstruction.
Protein-losing nephropathies are treated with ACE-inhibitors, low protein diets, & aspirin (to decrease hyper-coagulable state). No antibiotics are given.
Treatment for urethral prolapse is urethropexy and castration. Most often seen in English bulldogs.
Myoglobinuria is characterized by brownish urine that does not clear on centrifugation with normal-colored plasma.
o Myoglobin doesn’t bind to serum proteins, so it is cleared to the urine before it builds up and discolors the plasma.
Check if fluid is urine by comparing creatinine to serum. Fluid:serum creatinine ratio of greater than 2:1 is indicative that the fluid is urine.
Hypoproteinemia can cause low serum calcium but is not associated with clinical signs of hypocalcemia.
o Serum chemistry measures calcium bound to proteins. o The accurate measure of calcium is ionized calcium (iCa).
Iguanas in renal failure can have episcleral injection, swelling of the pharyngeal region, and painful abdominal palpation.
Cardiology
Blood pressure = total peripheral resistance * cardiac output o Cardiac output = heart rate * stroke volume
Eccentric hypertrophy is an increase in cardiac mass with an increase in chamber size. Seen with diastolic stress.
o Concentric hypertrophy is an increase in cardiac mass with no change or a decrease in chamber size. Seen with systolic stress.
Patients with compromised cardiac output have exercise intolerance, decreased growth, or muscle wasting. Pale mucous membranes, weak pulses, cold extremities, low temperature.
o Patients with right-sided backward failure (congestive failure) have ascites (in dogs) or pleural effusion.
Will see ventral or brisket edema, true jugular pulse, and bottle jaw in large animals.
o Patients with left-sided backward failure (congestive failure) have coughing, exercise intolerance, and sleeps in sternal recumbency.
Heart sounds:
o S1 is closure of AV valves (ventricles are filled with blood). S1 indicates beginning of systole.
o S2 is closure of semilunar valves (aortic and pulmonary valves; ventricles are empty of blood).
S2 indicates beginning of diastole.
o A gallop rhythm is when you hear either S3 or S4, which are diastolic sounds. This is normal in large animal species but indicates pathology in small animal species.
S3 is passive ventricular filling (mid-diastole). S4 is active atrial contraction (end of diastole). On the left side, remember P-A-M
o 3rd intercostal space you can hear the pulmonic valve (right ventricle pumping into
the pulmonary artery)
o 4th intercostal space you can hear the aortic valve
On the right side, you can hear the tricuspid valve.
There is a weak (but existent) relationship between murmur grade and clinical severity. o Innocent puppy murmurs go away by 4 months.
o Diastolic murmurs are uncommon; the most common diastolic murmur is aortic regurgitation.
Aortic regurgitation is flow of blood from aorta into left ventricle during diastole.
Will not have effect on athletic performance of a horse.
o Holosystolic murmurs are heard throughout all of systole. Indicate mitral regurgitation, tricuspid regurgitation, or ventricular septal defect.
Most common holosytolic murmur is mitral regurgitation. This is heard at the left apex. Due to endocardiosis, degeneration, dysplasia, or dilated cardiomyopathy.
Tricuspid regurgitation is heard on the right. Can be due to endocardiosis, dysplasia.
Mitral or tricuspid valve regurgitation is when blood flows back into the atrium when the ventricles contract.
o These lead to eccentric hypertrophy because the chamber must get bigger to pump more blood (because some is wasted). Puts patient at risk for congestive heart failure. Ventricular septal defect is heard on the right and a little cranial.
Ventricular septal defects are the most common congenital cardiac anomaly in all species except dogs.
o Ejection murmurs are heard at the left base.
Indicate aortic stenosis, pulmonic stenosis, or atrial septal defect. o A continuous murmur is usually a patent ductus arteriosus.
o Don’t give corticosteroids to patients with undiagnosed heart murmurs. Steroids can push patients with heart disease into heart failure. Blood flow shunts (such as a ventricular septal defect) go from high pressure to low
pressure. So, they are normally left right.
Patent Ductus Arteriosus (PDA) is commonly seen in small, white, female dogs. o The ductus arteriosus directs blood from the pulmonary artery to the aorta in the
fetus.
o A PDA has blood flowing from the aorta to the pulmonary artery (due to higher pressure in the aorta).
o Causes enlarged pulmonary vasculature and left side of the heart, continuous murmur at left base, bounding arterial pulses, and increased QRS amplitudes. o Treated with catheter-based occlusion or surgical ligation.
Surgical ligation is preferred for cylindrical PDAs. Subaortic stenosis is seen in large breed dogs.
o Fair prognosis, increased risk for infective endocarditis, and sudden death may occur at any time.
o Treated medically with Atenolol (beta-blocker). Pulmonic stenosis is seen in smaller breed dogs.
o Has a systolic murmur at left base with normal pulses. o May cause right heart enlargement.
o Treat with balloon valvuloplasty +/- Atenolol (beta blockers) Carina elevation is the best radiographic estimation of cardiomegaly.
o Carina should be 1/3rd - 1/4th of the chest width from the spine.
On radiographs, the cranial part of the heart is the right side. The caudal part of the heart is the left side.
A vertebral heart score measures the heart cranio-caudal and dorso-ventral. Measure the lines against the T4 vertebrae. Should be < 10.5.
When looking at pulmonary vasculature:
o big pulmonary arteries = pulmonary hypertension
o big pulmonary veins = left-sided congestive heart failure o big pulmonary arteries and veins = left-to-right shunt
o small pulmonary arteries and veins = right-to-left shunt or hypovolemia Tetralogy of Fallot is the most common defect that produces cyanosis. It has four
components: pulmonic stenosis, large ventricular septal defect, right ventricular hypertrophy, & dextropositioning (overriding) of the aorta.
o Results in a right-to-left shunt, hypoxemia, cyanosis, and polycythemia. o Treat with surgery and non-selective beta blockers.
An ECG measures electrical, not mechanical, activity: o P wave is atrial depolarization.
QRS is ventricular depolarization T wave is ventricular repolarization.
o When positioning leads, remember Green & White are always right. Also red and green go at the end of the dog (Christmas colors at end of the year).
White is right front leg. Green is right rear leg. Black is left front leg. Red is left rear leg.
o Tall p waves indicate right atrial enlargement.
Wide p waves indicate left atrial enlargement.
Deep S waves indicate right ventricular enlargement. Tall R waves indicate left ventricular enlargement.
o Pericardial effusion can cause electrical alternans, which is varying height of every other R wave.
Pericardial effusion also causes pulsus paradoxus, which is a much stronger pulse on expiration.
o Hyperkalemia (increased K+) causes bradycardia, absent P waves, prolonged PR
interval, wide QRS complexes, and tented (spiked) T waves.
Often seen with hypoadrenocorticism or urinary-blocked animals.
o Sick sinus syndrome is sinus arrest (arrest of SA node) that lasts several seconds and can cause syncope.
Will see several seconds of absence of electrical activity. Treat with Theophylline or Terbutaline.
o 1st degree AV block has a prolonged PR interval.
Normal PR interval in cats is 0.05 – 0.09 seconds.
2nd degree AV block has more P waves than QRS complexes.
Mobitz I 2nd degree AV block has the PR interval progressively
lengthen.
o Better for patient and normal in horse.
Mobitz II 2nd degree AV block has the PR interval constant.
o
o Don’t treat type II AV block unless patient is clinical. 3rd degree AV block has dissociation between P waves and QRS
complexes.
Treat high-grade AV block with a pacemaker.
Never give lidocaine because it may abolish the ventricular escape rhythm.
o Ventricular Premature Complexes have wide and bizarre QRS complexes with AV dissociation (no associated P waves).
Wide and bizarre QRS complexes are almost always VPCs.
VPCs are more deadly in the short-term than supraventricular VPCs. Narrow QRS complexes with associated P waves are
supraventricular premature complexes. Arise from irritated regions of ventricles.
Ventricular rhythms are more life-threatening than supraventricular rhythms.
Treat ventricular arrhythmias with lidocaine (Sodium channel blocker). Lidocaine is not useful for supraventricular tachycardia
A string of VPCs in a row is called ventricular tachycardia.
Treat ventricular tachycardia with procainamide, lidocaine, or defibrillation in drug-resistant cases.
The “N”s above are some normal beats.
o Atrial Premature Complexes look normal but have short R-R intervals. The beat comes earlier than other beats.
A string of APCs is called atrial tachycardia. Not concerning in a horse.
o Atrial fibrillation causes tachycardia, sounds like “tennis shoes in a dryer,” and has an irregular ECG with absent P waves.
Causes “flutter-like” waves.
Causes a rapid irregular heart rate with no atrial sounds or compensatory pause.
Treated with Quinidine (Na+ channel blocker).
Sinus arrhythmia is a gradual increase and decrease in heart rate associated with respiration.
Atrio-Ventricular Valve Dysplasia
o Mitral valve dysplasia is the most commonly affected valve in cats.
o Tricuspid valve dysplasia is the most commonly affected valve in dogs, especially Labrador retrievers.
o Often causes regurgitation, but can also cause stenosis. systolic murmurs are heard with regurgitation diastolic murmurs are heard with stenosis o Can cause atrial hypertrophy
o No easy treatment for stenosis. Treat regurgitation with diuretics, ACE-inhibitors, and beta-blockers.
Dilated Cardiomyopathy mainly affects larger dogs like Dobermans. o Patient may be syncopal or have congestive heart failure.
o Causes markedly dilated ventricles with thin walls that can’t contract well; usually the left ventricle.
Commonly has secondary mitral regurgitation.
o Commonly causes premature ventricular contractions and/or atrial fibrillation. o If patient is hypotensive, treat with dobutamine.
o In cats, DCM is due to taurine deficiency and cats can also present with retinal lesions.
o Treat with ACE-inhibitors even in asymptomatic animals. Treat symptomatic patients with Pimobendan.
Pimobendan is a positive inotrope and a vasodilator.
o Makes the heart beat more efficiently and reduces vascular resistance against the heart.
Boxer Cardiomyopathy is similar to dilated cardiomyopathy but has severe and life threatening PVCs or ventricular tachycardia.
o Patient may have fainting.
o Treat with Solatol and Mexilitene.
Hypertrophic Cardiomyopathy is a genetic feline disease seen often in Maine Coons. o Unlike with dilated cardiomyopathy (systolic disease), hypertrophic
cardiomyopathy is a diastolic disease that has problems filling.
o Aim of treatment is to improve diastolic filling by decreasing heart rate. o Usually have left ventricular concentric hypertrophy.
o Usually seen in cats < 3 years-old
o Will have systolic murmur and gallop heart sounds.
o Treat symptomatic cats with Atenolol (beta-adrenergic blocker), ACE-inhibitors, diltiazem (calcium channel blocker), and heparin (to prevent thromboembolism)
