Week 3 Day 3 Flashcards
Topic: Feline Pancreatitis
The correct answer is feed a regular commercial diet if eating. Cats do not require a low-fat nor a low-protein diet and usually do not require a period of being NPO. Withholding food for an extended period may be likely to induce hepatic lipidosis in some cats.
Additionally, some studies suggest that stimulation of pancreatic enzymes via feeding is actually necessary in affected cats. A jejunostomy feeding tube may be occasionally recommended in severe cases of pancreatitis with dogs, but is less likely necessary in cats. If anorectic, usually an esophagostomy feeding tube is sufficient.
Topic: Tick Borne Diseases in Cats
Cytauxzoon felis is a protozoal organism and transmission to cats is through tick bites. Cats usually show clinical signs 1-3 weeks after
infection. Signs can be non specific and include anorexia, lethargy, dyspnea, and icterus. Cats will also commonly have a marked pyrexia.
The organism invades the reticuloendothelial cells of the lungs, spleen, liver, lymph nodes, and other organs so cranial organomegaly can
often be present. The bone marrow can be affected causing pancytopenias. Thrombocytopenia is likely related to the development of
disseminated intravascular coagulation, which can cause spontaneous bleeding. There is no effective therapy and prognosis is poor to
grave. Current treatment recommendations include the antimalarial drug atovaquone combined with the antimicrobial azithromycin as
well as fluids, heparin and supportive care.
You found Heartworm microfilaria on a feline blood smear. How do you treat the patient?
The correct answer is corticosteroids. Treating with any agent that is an adulticide may potentially result in embolization, release of antigen, and acute death, making this a controversial choice. Corticosteroids work well in reducing inflammation associated with infection and will help alleviate clinical signs. Cats are different than dogs in that heartworms cannot survive as long and the cats are sometimes able to eliminate the worm. Surgical removal has been attempted but is not a common practice and may also result in acute death.
The correct answer is an acute blood loss with a PCV of 15. Usually, a blood transfusion is indicated in a dog or cat with a PCV of less than
20. However, an animal with chronic blood loss will have compensated and adapted to the state of anemia and is not as critical. An animal that undergoes acute blood loss is much more critical as they have not had an opportunity to compensate.
Feline mammary hyperplasia, or fibroadenomatous hyperplasia, is a benign, often drastic enlargement of the mammary glands typically seen in younger cats. This syndrome classically has a rapid onset and is seen in pregnant and non-pregnant, unspayed females. It is uncommonly seen in males and spayed females.
In cycling females, this condition is caused by hormonal stimulation from a
functional ovary producing progesterone. Megesterol acetate is a synthetic progesterone that can cause this side effect.
It is generally treated by ovariohysterectomy. If the mammary gland has become severely infected or ulcerated, a mastectomy may be required.
There are different Fleet enemas, some of which contain hypertonic sodium phosphate and are contraindicated in cats. Cats develop an electrolyte disturbance caused by the absorption of sodium and phosphate from the colon. This results in hypernatremia and hyperphosphatemia.
The high phosphorus leads to precipitation of serum calcium and thus hypocalcemia. This hypocalcemia can cause weakness, lead to shock, and cause muscle tremors or seizures. The treatment for this toxicity is to correct the electrolyte disturbance and correct the dehydration. IV fluid therapy and calcium gluconate are the initial treatments, and many times phosphorus binders are helpful to more quickly decrease the serum phosphorus.
Unless the cat is actively seizing, diazepam would not be indicated. The administration of calcium should help to stop the tremoring this cat is exhibiting. Potassium phosphate is clearly contraindicated, since the phosphorus is already too high. Insulin and dextrose are sometimes used in severe cases of hyperkalemia, which is not suspected in this case.
A 5-year old male castrated domestic short haired cat presents for pollakiuria, hematuria, and dysuria. Which of the following is the least likely differential diagnosis in this cat?
Urethral obstruction by uroliths
Feline lower urinary tract disease
Cystitis
Pyelonephritis
The correct answer is pyelonephritis. Pollakiuria and dysuria are lower urinary tract signs that are not consistent with pyelonephritis alone.
Pyelonephritis causes systemic signs such as fever, anorexia, and depression.
Cat scratch disease, caused by Bartonella henselae, results in fever and lymphadenopathy, particularly in immunocompromised people.
Cats typically do not display any clinical signs of disease, so monitoring the cat would not be helpful. Fleas are implicated in disease
transmission with the bacteria seen in flea feces. It is thought that typically, cats with infected flea feces on their claws scratch and
inoculate the bacteria into people. Cats can also be bacteremic and have bacteria present in their saliva.
Topic: Hyperthyroidism in Cats
An elevated free T4 by equilibrium dialysis is a way to support the diagnosis of occult hyperthyroidism. In a small subset of cats, the free
T4 is elevated due to non-thyroidal illness. Therefore, hyperthyroidism should not be diagnosed on a free T4 measurement alone. Most
older cats have a thyroid level that is in the lower end of the normal range. The T4 in this cat is in the high end of the normal range. In
combination with the exam findings and clinical signs, this raises suspicion for hyperthyroidism.
There is marked osteolysis of the proximal tibia with a pathologic fracture. This fracture will not heal with either rest or with rigid fixation due to the presence of underlying disease that resulted in the osteolysis. The most likely cause is a tumor of the bone. In cats, unlike dogs, many bone tumors do not have a high metastatic rate and do not necessarily require adjunct chemotherapy although histopathology would be needed to confirm the tumor type and grade.
Topic: Feline GI Lymphoma
70-90% of all feline mammary tumors are malignant. Spaying a cat before 6 months of age reduces the risk for mammary tumors by 7 fold.
The statistics for dogs is a 50:50 chance of malignancy for a single mammary mass.
A kitten presents with watery diarrhea. On fecal examination, a wet mount shows motile protozoal trophozoites and a centrifugal zinc sulfate fecal flotation shows cysts of the parasite. Which of the following is the most acceptable treatment?
The diagnostic test findings for this cat are consistent with Giardia infection. Metronidazole has been shown to be effective at clearing the
pathogen and reducing cyst shedding of this zoonotic disease. Care should always be taken with metronidazole in kittens due to potential
side effects. Fenbendazole, or Panacur, is another treatment option for Giardia, especially for dogs, but efficacy has not been extensively
evaluated in cats. Albendazole has greater hematologic toxicity than fenbendazole and should not be used in cats. Pyrantel is used to treat
hookworms and roundworms. Praziquantel is used to treat tapeworms.
Maine Coon cats are predisposed to development of hypertrophic cardiomyopathy at a young age. Consequently, left atrial enlargement predisposes to atrial thrombus formation, and these clots frequently lodge in the arterial supply to the hindlimbs. The trifurcation is where the aorta divides into the two external iliac arteries and the common origin of the internal iliac arteries. Classic findings due to a clot at the aortic trifurcation include posterior paresis/paralysis, hindlimb pain, cyanotic nailbeds, absent femoral pulses, and a firm leg musculature.
Other signs of cardiac disease/failure (murmur or pulmonary edema) are often but not always evident at presentation.
Neither cord lesions, tetanus, nor toxicities should cause the vascular compromise evident on this cat’s physical exam.
The correct answer is serology and 7B protein ELISA test. Some FIP viruses do not have the 7B protein. So, this test is not sensitive for FIP virus. Immunohistochemistry or RT-PCR can be used to demonstrate virus on biopsy specimens (RT-PCR does not work on serum or feces). However, this is not always necessary because histopathology (gold standard for antemortem diagnosis) can show characteristic lesions of disseminated pyogranulomatous and fibrinonecrotic reaction around small veins. If you can’t remember any of these at least remember that corona titers are completely useless! They will only tell you if the cat has been exposed to a corona virus. Most cats have been exposed to a corona virus at some point in their lives. So the best choice is serology and the 7B protein ELISA test since neither of these are efficacious.
The correct answer is ovariohysterectomy. Ovariohysterectomy is the treatment of choice for pyometra. Ovariectomy alone does nothing therapeutically for the pyometra. Prostaglandin therapy can be attempted in open pyometras in which the owners insist on keeping the animal intact with the intent to breed the animal in the future. Prostaglandin therapy is contraindicated in closed pyometras due to possible uterine rupture. Antibiotic therapy alone is not enough to treat a pyometra. Uterine lavage is sometimes attempted in open pyometras along with medical therapy with prostaglandins.
EG toxicity in dogs
The correct answer is 4-Methylpyrazole (4-MP). It is used to inhibit alcohol dehydrogenase and is considered the preferred treatment for treating ethylene glycol toxicoses in dogs. 4-MP does not cause hyperosmolality, metabolic acidosis, and CNS depression like ethanol treatment can. 4-MP is given to dogs IV over a 36-hour period. The initial dose is 20 mg/kg (slow IV over 15-30 minutes), then 15mg/kg (slow IV) at 12 and 24 hours, and then 5mg/kg is given at 36 hours. 4-MP is not effective in cats.
Lesions at L4-S3 would manifest as normal thoracic limbs and LMN signs in the pelvic limbs, anus, and bladder.
Alfaxalone (Alfaxan) is FDA registered for induction and maintenance of anesthesia for dogs and cats. It is given slowly at one-fourth the dose every 15 seconds and has minimal dose-dependent effects on cardiopulmonary function.
Hypertrophic osteopathy is visible as periosteal proliferation in the diaphyses of affected
bones. Usually the metacarpal and metatarsal bones are affected first, and it may progress to the long bones. Lameness, pain, and
swelling are usually evident. Joints are unaffected. The cause is usually primary or metastatic pulmonary neoplasia, although other diseases
in the thorax including bronchopneumonia, Spirocerca infection, or congestive heart failure, may also be associated. Less commonly,
abdominal neoplasia may be seen with this condition.
Which drug is a worse vesicant and what should be done to the injection site?
Doxorubicin is worse compared to Vincristine. Cold compress to contain the spread of drug
Intravenous chemotherapy drugs can cause severe tissue necrosis (doxorubicin) or irritation (vincristine) if extravasation occurs. Treatment for both should begin immediately. In both cases, the catheter should be left in place and as much of the drug should be aspirated as possible. Treatment for doxorubicin extravasation involves cold compressing the site to promote vasoconstriction, however perivascular necrosis may still occur and may progress days to weeks later. In severe cases involving doxorubicin, debridement or limb amputation may be needed.
Vincristine extravasation should be treated with warm compresses to disperse the drug and enhance systemic absorption.
Extravasation should be prevented through patient restraint training, use of catheters that have been placed on the first stick, and careful monitoring during administration. The peripheral veins should be avoided for blood draws if possible on all patients receiving chemotherapy.
This is a nasal adenocarcinoma. The classification scheme for tumors by cell of origin and cytologic description is:
Carcinoma- These tumors come from epithelial cells including cells of glandular tissues such as salivary glands, mammary glands, and cells lining most tissues including squamous cells or transitional cells. The cytologic appearance is that of COHESIVE CLUSTERS of cells.
Here, you can see some of the tight cellular junctions in the cluster which is typical. Cells are often polygonal in shape.
Sarcoma- These tumors come from mesenchymal cells and are named by the specific cell type such as fibroblasts (fibrosarcoma) and osteoblasts (osteosarcoma). Cytologically, they tend to appear as isolated spindle-shaped cells with elongated cytoplasm and often oval nuclei.
Round cell tumors- There are 5 round cell tumors and most but not all come from blood cells. They are lymphoma, mast cell tumors, plasma cell tumors, histiocytic tumors, and transmissible venereal tumors. Remember, these are also sometimes also referred to as sarcomas (i.e. lymphosarcoma or histiocytic sarcoma). Cytologically, they appear usually as large populations of cells that are not in defined clusters. The cells have a round shape, often with unique identifiable features such as the purple granules in mast cell tumors.
The correct answer is these are most likely pulmonary contusions; your dog needs to be carefully monitored for the next day as they may
worsen and lead to breathing problems. Pulmonary contusions can cause respiratory deterioration in the apparently stable patient for up
to 24 hours after trauma. They usually then improve over the next 24-48 hours. In this case, careful monitoring is probably indicated for
24 hours followed by recheck radiographs. These are indicated to detect possible abscesses, early pneumonia, cysts, or other related
injuries.
The correct answer is before first estrus. Development of mammary tumors in the dog is hormone dependent. As such, ovariohysterectomy before a heat cycle prevents the hormonal effects on the mammary glands that predispose them to developing tumors. Dogs spayed prior to an estrus are 0.05% times as likely to develop a mammary tumor as an intact dog. That risk rises to 8% and 26% after one and two heats respectively, with no decrease in risk if they are spayed subsequent to a third heat.
The correct answer is struvite. Struvite or magnesium ammonium phosphate crystals form in alkaline urine, whereas most other crystal
types form in acidic urine. The cocci present are urease positive bacteria that cleave urea to ammonia causing the urine pH to rise and
making the environment more favorable for struvite crystals to form. Cysteine crystals form as a result of a genetic defect of the renal
tubules, and are almost exclusively seen only in males. Urate crystals only form in Dalmatians (due to a genetic defect in urate
metabolism) and animals with portosystemic shunts or liver dysfunction. Urates are less likely in this patient, since it is not a Dalmatian
and shows no signs of liver disease.
Which of the following is most likely to be the vector for Lyme disease?
Dermacentor andersoni
Rhipicephalus sanguineus
Amblyomma americanum
Ixodes pacificus Core Answer
Dermacentor variabilis
Explanation
The correct answer is Ixodes pacificus. Ticks acquire the infection at any stage and are most likely to get it from the white-footed mouse, Peromyscus leucopus. Dermacentor variabilis and Dermacentor andersoni are known to transmit Rocky Mountain Spotted Fever.
Amblyomma americanum may transmit canine granulocytic ehrlichiosis which is caused by E. ewingii and Anaplasma phagocytophila.
Rhipicephalus sanguineus is known to transmit Ehrlichia canis.
A dog presents to your clinic with tenesmus and swelling near the anus as seen in the image. On examination, there is a fluctuant swelling lateral to the anus, and on rectal exam, you note lateral dilatation of the rectum. Which of the following is the most common signalment for dogs presenting with this problem?
This is a case of a perineal hernia. Older intact male dogs are most commonly affected. Overrepresented breeds include Boxers, Collies, Kelpies, Pekingese, and Boston terriers. The hernia results from a weakened pelvic diaphragm. It is thought that there may be a hormonal component which results in weakening with time.
This is a common presentation for cutaneous lymphoma (mycosis fungoides). Patients with this cancer will often be worked-up for allergies because many are pruritic. However, most cases of allergies will not have lesions affecting the oral mucosa or foot pads. It is important to have cutaneous lymphoma on your list of differentials for older patients with skin disease who are not responding to conventional therapy.
Look at tumors of the skin PDF
What is the most common cause of pyometra in dogs older than 8 years of age?
The correct answer is cystic endometrial hyperplasia (CEH). Older intact females develop CEH from repeated exposure to progesterone.
Progressive thickening occurs and glands become hypertrophied. This sets up the uterus for development of pyometra.
Pressures above 20cm H20 may result in barotrauma. In an otherwise healthy patient it is not recommended to exceed this pressure. In patients with chronic atelectasis, anesthetists will be much more apprehensive about over ventilating or ventilating the lungs too quickly, as acute expansion can trigger re-expansion pulmonary edema, which may then lead to acute respiratory distress syndrome and death.
The mass described is classic for transmissible venereal tumor (TVT) in dogs. TVT is a sexually transmitted tumor found throughout the world, particularly in areas with high populations of stray dogs. The tumor cells are transferred from one dog to the next by physical contact, which typically consists of sniffing, licking, and copulation. The tumor is often curable with vincristine chemotherapy.
What is the tx of choice for nasal aspergillosis in dogs?
Topical antifungals (more efficacious than systemic).
The currently recognized treatment of choice is clotrimazole, a synthetic imidazole that has an 80% cure rate with single administration. The main potential complication is CNS exposure to the drug if there has been erosion of the cribriform plate.
What is the diagnostic test of choice for exocrine pancreatic insuffiency in dogs?
Trypsin like immunoreactivity
Chlorheadine is a topical drug implicated in ototoxicity and peripheral vestibular disease.
Another excellent choice would be aminoglycosides including neomycin, kanamycin, tobramycin, amikacin and gentamicin.
