Week 3 Day 5 Flashcards
What is a major adverse side effect of doxorubicin?
In addition to the usual side effects of chemotherapeutic drugs such as myelosuppression and Gl side effects, a major concern with adriamycin administration is dose dependent cardiotoxicity. The drug that causes ileus is vincristine. The drug that causes anaphylaxis is L-asparaginase. The drug that causes nephrotoxicity is cisplatin. The drug that causes cystitis is cyclophosphamide.
The correct answer is central nervous system on the right. This dog has paradoxical vestibular disease. This disease is usually caused by a
destructive lesion in the CNS in which there is loss of inhibition of the vestibular output on the side of the lesion. There is therefore a
relative increase in vestibular output on the side of the lesion, causing vestibular signs on the side opposite the lesion (yes, this can be
confusing). In this case, the right sided lesion has vestibular signs that would normally localize the lesion to the left side. When the lesion
causes vestibular signs and proprioceptive deficits, the lesion is ipsilateral to the side with the proprioceptive deficits.
The correct answer is hemangiosarcoma. This tumor accounts for approximately 2/3 of malignant splenic masses and will have metastasized in >90% of cases by the time they are diagnosed. Chemotherapy would be recommended for adjunct therapy after surgical removal of the spleen. Lymphoma is not as commonly found in the spleen in dogs, and you would have expected enlarged lymph nodes to be mentioned in the question. Mast cell tumors occur with some frequency in the spleen of cats but not so often in dogs. Transitional cell carcinomas are typically found in the urinary bladder, since that is where transitional cells are located.
Given that Manny is lame after intense exercise and is an older, overweight, large-breed dog, he is probably dealing with degenerative joint
disease (DJD). It is not uncommon for owners to decline diagnostics when they just think their dog is getting old. Unfortunately this makes
treating the patient appropriately a bit more difficult. Ideally you would like to rule out evidence of a primary bone tumor, cruciate
ligament tear, and see evidence of DJD on a radiograph. In certain regions of the country Lyme disease is a common cause of lameness,
and a simple blood test can screen for exposure to this disease. Prior to starting Manny on long-term medications, you would recommend
blood work to make sure there are no underlying diseases that could be worsened from medications like NSAIDs. Management of DJD or
osteoarthritis consists of weight management, controlled exercise, and neutraceuticals that decrease inflammation such as
glucosamine/chondroitin, Omega-3 fatty acid supplementation or diets that contain these nutrients. Some patients will show dramatic
improvements with these simple changes, saving the pain medications for later. Physical therapy and swimming can also be helpful to
strengthen the muscles, but punishing activities like sprinting, jumping and rough play should be avoided.
The correct answer is HO occurs in association with a thoracic mass. There is no breed or age predisposition for HO. The disease usually starts at the distal extremities and develops proximally. HO is characterized by periosteal proliferation near joints, not sclerosis of the subchondral bone.
‘Chronic’ describes the clinical course of the disease, which is considered indolent or slowly progressive. The neoplastic cells of chronic
leukemias are well differentiated or mature cells; therefore, CLL is considered a chronic or indolent form of leukemia made up of small,
mature lymphocytes. These are difficult to distinguish from normal lymphocytes. The mildly prominent lymph nodes and prominent
spleen are classic findings for chronic leukemias. The large disease burden within the bone marrow and relatively less affected lymphoid
tissues (relative to lymphoma) makes this a lymphocytic leukemia as opposed to a small cell or low grade lymphoma.
This is seasonal nasal hypopigmentation. Season associated lightening of the nasal planum occurs during winter months and can darken in the spring and summer. Complete depigmentation is not noted. Hypopigmentation and discoloration of the nose and mucocutaneous junctions can vary from benign immune-mediated diseases, such as vitiligo that lower the amount of melanocytes in the skin to seasonal variations in coloring, commonly called a “Dudley Nose” or “Snow Nose”. Certain breeds are more predisposed than others, such as Siberian Huskies, Golden and Labrador Retrievers, and Bernese Mountain Dogs. This can be seen in any breed.
With vitiligo, which is a benign immune related depigmentation, antimelanocyte antibodies can be found in circulation and a biopsy will show decreased melanocytes. Typically multiple areas will be affected, including ear tips, footpads, claws, and hair coat. Breeds predisposed to vitiligo can include German Shepherd Dogs, Collies, Rottweilers, Doberman Pinschers, and Giant Schnauzers
There are no treatments to prevent these disorders, and they typically cause no harm to the animals.
The correct answer is Coccidioides (fungal) infection. SLE causes many signs, but anterior uveitis is not considered one of them. The causes of uveitis include infection (bacterial, viral, fungal, rickettsial), immune-mediated (lens-induced uveitis), neoplasia, hypertension, and trauma. Over 50% of the time, the cause is not found, and the uveitis is termed idiopathic. Chronic uveitis can lead to cataract formation, glaucoma and other eye issues.
How are folate and cobalamin levels affected in cases of SIBO?
The correct answer is increased folate, decreased cobalamin. The reason for this is that bacteria synthesize folate leading to decreased absorption of cobalamin.
Transitional cell carcinoma of the bladder in dogs can be palliatively managed with non-steroidal anti-inflammatory drugs such as piroxicam. Progression-free interval and survival can be extended with the addition of chemotherapy. The most commonly used agents are carboplatin, cisplatin, and mitoxantrone. Although cisplatin is effective against TCC, it has increased nephrotoxicity with piroxicam and is less commonly used these days in the author’s experience. Secondary infections can be treated with appropriate antibiotics.
Patients with Addison’s disease have hypoadrenocorticism. This means that the patient is not producing an adequate amount of glucocorticoids. During times of stress Addisonian patients require additional amounts of glucocorticoids or else they are at risk of going into a crisis. The exact amount of additional glucocorticoid to administer is not known but it is generally accepted that patients should receive 2-10 times a physiologic dose of prednisone. The physiologic dose of prednisone is considered by many to be 0.1 mg/kg/day but there is some variation depending on the source. Therefore the best answer is to give a dose of dexamethasone that is approximately 5 times the physiologic dose of prednisone followed by twice the regular dose of prednisone the following day.
The patient is likely receiving deoxycorticosterone pivalate (Percorten) which is given at approximately 25-28 day intervals and is a means of providing the necessary mineralocorticoids. An alternative treatment for mineralocorticoid replacement is fludrocortisone acetate (Florinef). This medication needs to be administered daily.
Weaning the patient off of prednisone is contraindicated and will result in an Addisonian crisis as the patient is unable to produce its own cortisol.
Angiography is the gold standard for diagnosing PTE. If positive, there are sudden interruptions in blood and contrast flow. Plain radiographs are often normal or have mild changes. Cytology samples would mainly show blood and would not be considered diagnostic or definitive. Blood gas changes typical for PTE are hypoxemia and hypocapnia, but these are not specific for PTE. CT angiography is also a reasonable test to confirm PTE.
Pythium is an aquatic organism that inhabits ponds of the Southeast United States. These organisms have different cell walls than regular
fungi, which makes them difficult to treat since most antifungal treatments target fungal cell wall synthesis. Prognosis is extremely poor
with this disease and amputation (if the lesions are localized to an affected limb) is currently the best option. Amputation should always
be followed with multiple long-term antifungal therapies. Owners should be warned that local postoperative recurrence is common. Dogs
are most commonly affected, but this disease can also occur in cats. It has also been reported in humans and horses.
What IVF choice would you use for a post-op feline urethral obstruction and why?
The most common electrolyte disturbance from a urethral obstruction is hyperkalemia. This occurs from an impaired urinary excretion of
potassium. This can cause life-threatening arrhythmias and needs to be quickly addressed, especially if potassium exceeds 7 mEq/L. 0.9%
Sodium chloride is the fluid of choice to treat this disturbance. If this fluid is not available, then Lactated Ringer’s would be a good
alternative due to the low potassium concentration in those fluids. In extreme cases, dextrose may need to be added to the fluids because
this stimulates insulin secretion and helps to move the potassium intracellular. Sodium bicarbonate and calcium gluconate can also help
this shift of potassium in extreme cases.
This cat likely has a tapeworm infection. Tapeworm segments are typically flat and white and small, resembling a grain of rice. The most common tapeworms in cats are Taenia taeniaeformis and Dipylidium caninum. The only medication that will treat both types is praziquantel.
Praziquantel is in the products Drontal Plus and Profender, approved for the use in cats. Drontal Plus also contains pyrantel. Profender also contains emodepside. Both are also effective against roundworm and hookworm.
Pyrantel is not effective against tapeworms and treats hookworm and roundworm infection. Fenbendazole (or Panacur), treats Taenia but not Dipylidium, and also treats hookworm, roundworm, and whipworm infection.
Revolution treats and prevents hookworm, roundworm, heartworm, fleas, and ear mites in cats. Frontline treats and prevents fleas and
ticks. A flea control should be recommended since Dipylidium is transmitted by ingestion of an infected flea. Taenia is transmitted through eating an infected prey.
Enalapril is an angiotensin-converting enzyme (ACE) inhibitor used as a vasodilator, antihypertensive agent, and heart failure treatment. It works by preventing the conversion of angiotensin I to angiotensin Il, thus reducing aldosterone concentrations and causing diuresis. Its dilatory effects on the efferent arterioles of glomeruli help to palliate protein losing nephropathies. It is often used in conjunction with diuretics.
The correct answer is atenolol. Atenolol is a beta blocker and will decrease contractility and heart rate thus allowing for better chamber filling before contraction. Other treatments include ACE inhibitors, calcium channel blockers, and diuretics. Beta blockers may improve blood flow and reduce arrhythmias. They may also decrease dynamic obstruction of the left ventricular outflow tract.
Atenolol treats HCM
Feline Vaccine Recommendations
The correct answer is rabies vaccine given in distal right rear leg, FeLV vaccine given in distal left rear leg, no vaccines should be given in intrascapular space. These recommendations were made to facilitate earlier diagnosis and easier treatment of vaccine-associated fibrosarcomas in cats. They also were made to allow findings to be correlated with which vaccine(s) was (were) causing the tumors. It was recommended that other vaccines be given in the distal right front leg.
The biopsy results show cholangiohepatitis which is inflammation of the biliary system and liver parenchyma. It can be autoimmune in nature, or may be triggered by underlying infection or neoplasia. Concurrent diseases often include pancreatitis and inflammatory bowel disease.
The main treatment of non-suppurative cholangiohepatitis is prednisolone since it is most often immune in origin. Ursodiol is often used for its immunomodulatory, hepatoprotectant, and antifibrotic effects. It helps with the flow of bile through the liver. Other helpful therapies include S-adenosylmethionine (SAMe) and Vitamin E.
Pancreazyme powder and vitamin B12 injections (cyanocobalamin) can be useful in chronic pancreatitis but would not be the best treatment for cholangiohepatitis.
Budesonide is a steroid that may be beneficial for inflammatory bowel disease but would likely not provide enough systemic anti-inflammatory effects for the liver disease.
Metronidazole or Clavamox are often used in conjunction with prednisolone if infection is suspected but is not the primary treatment for this disease. Antibiotics are more important in suppurative cases.
Chlorambucil is used as an immunosuppressant in refractory cases of cholangiohepatitis when the prednisolone is not enough to control the disease.
L-carnitine may be beneficial if hepatic lipidosis is a concurrent problem from the anorexia but is not a treatment for cholangiohepatitis Vitamin E is a good antioxidant for the liver. Vitamin K may be used in cases of liver failure especially prior to surgery for liver biopsies.
Acetaminophen toxicity in cats usually occurs when owners administer the drug, unaware of its significant potential toxicity in cats. In this case, the cat’s clinical signs are most consistent with acetaminophen toxicity based on the Heinz body anemia that is present. Cats can die from oxidative damage and methemoglobinemia within 1-2 days of ingestion. It may also be associated with hepatotoxicity in cats, although this is seen more frequently in dogs.
Recall that cats are particularly sensitive to acetaminophen because they have decreased glucuronyl transferase activity which conjugates acetaminophen to glucuronic acid for excretion. As a result, 50-60 mg (a single tablet) may be fatal for a 4-5 kg cat.
Treatment should consist of toxin removal if possible by inducing emesis in some cases. As the cat in this case is already vomiting, this may not be necessary. Activated charcoal is controversial and should only be given if ingestion occurred within hours and should be administered very carefully in cats due to the risk of aspiration.
The specific antidote is acetylcysteine which binds to some of the reactive metabolites of acetaminophen and increases the availability and synthesis of glutathione. Other treatments may include S-Adenosylmethionine (SAMe) which has hepatoprotective and antioxidant properties. Cimetidine can be given to inhibit the p450 oxidase in the liver and limit formation of toxic metabolites. Ascorbic acid can also be used as an adjunct treatment to bind toxic metabolites. In cats with signs of hypoxemia from severe hemolytic anemia (PCV <20%), a transfusion and further supportive care may be warranted.
The image shows polycystic kidneys. This is an inherited disease that most commonly affects Persian cats. Other breeds such as Himalayans and British shorthairs are occasionally affected as well. The responsible gene is autosomal dominant. The homozygous form is lethal in utero and all affected living cats are heterozygotes.
The disease is diagnosed most reliably by ultrasound and treatment is similar to that of other causes of chronic renal disease with fluids, a low protein diet, gastric protectants (such as famotidine), maropitant, and appetite stimulants.
Cyclophosphamide, doxorubicin, vincristine, and prednisone are treatments for lymphoma, which can also affect kidneys bilaterally, but generally the lesions would not be cystic in appearance such as those in the picture.
Typically, the cysts are diffuse throughout both kidneys so surgical excision is not an option.
Antibiotics such as ampicillin and enrofloxacin are not usually necessary unless a concurrent infection is found.
Lithotripsy is a form of treatment used to break up urinary calculi which is not commonly employed in animals.
Dedxmedetomidine is an alpha 2 agonist with some action on alpha 1s so it leads to peripheral vasoconstriction –> reflex bradycardia (cardiac output decreases when blood pressure increases).
Why do our patients become cyanotic on dexmed?
Peripheral vasoconstriction makes it harder for tissue to perfuse adequately despite the lungs oxygenating appropriately.
Normotension:
Systolic > 90 no more than 160
MAP > 60 no more than 90
Diastolic > 30 no more than 60
for comorbidity patients, add 10 mmHg to these values
for dexmed sedation patients, add 20-30 mmHg to these values
