Week 3 Day 4 Flashcards
Large bladder stones in the presence of UTI and alkaline urine are usually struvite, particularly when accompanied by struvite (magnesium ammonium phosphate) crystalluria. In dogs, struvite stones are almost invariably infection-associated. The infecting organisms are usually urease-producers (Staphylococus, Proteus, Klebsiella, some E. coli) which alkalinize the urine and favor struvite formation. The single most important long-term management is prevention of infection.
Calcium oxalate stones are usually small (1 cm or less), are often present in the absence of UTI, and cannot be dissolved.
Cystine stones occur most often in Newfoundland dogs, dachshunds, and bulldogs. They are radiolucent and occur due to metabolic defects.
Urate stones are usually small and many. They are frequently radiolucent and can be related to underlying liver disease.
Topic: Canine Pulmonic Stenosis
The correct answer is balloon valvuloplasty. This procedure is performed by inserting a catheter into either a jugular vein or a femoral vein and advancing it into the region of stenosis at the pulmonic outflow tract. Once in place, a balloon surrounding the catheter is inflated to stretch the stenotic region open. Surgical valvulotomy or patch grafting is the treatment used for severe cases that cannot be balloon-dilated.
Topic: BOAS
This dog is likely suffering from heat stroke brought on by exercising in the warmer temperatures. His bulldog anatomy results in a
condition called brachycephalic airway syndrome. This can include a combination of anatomical abnormalities including stenotic nares,
elongated soft palate, everted laryngeal saccules, laryngeal collapse and hypoplastic trachea. Surgical correction of these defects at a
young age is the treatment of choice. Management includes avoiding exercise, excitement and overheating which may exacerbate the
patient’s condition. In the short term, anti-inflammatories may be given to help reduce edema of the pharynx and larynx. A tracheotomy
may be indicated if there is severe laryngeal collapse. Long-term antibiotics are not indicated, as there is no infectious component.
Castration is not a bad idea to prevent genetic transfer of this dog’s abnormalities.
Topic: Acid/Base Balance
The correct answer is metabolic acidosis. A low bicarbonate and total CO2 level is consistent with a metabolic acidosis. An elevated blood lactate of greater than 2.0 mmol/L implies that there is anaerobic metabolism occurring in this patient as a result of inadequate tissue perfusion, perhaps due to bleeding and trauma.
Nothing can be said about respiratory acidosis or alkalosis because no PaCO2 or pH is provided.
What is a common sequealae to physeal injury in a young dog?
The correct answer is angular limb deformity. Injury to an open physis in a young animal commonly leads to premature closure of the physis. Common sequela to premature physis closure includes angular limb deformities, shortened limb, malarticulation, ligamentous deformity, and osteoarthritis.
Topic:
PU/PD power page
Review central diabetes insipidius, fanconi syndrome
Pradofloxacin (Veraflox) is an orally administered, liquid fluoroquinolone antibiotic that was FDA approved in 2012 for use in cats to treat skin infections (wounds and abscesses) caused by Pasteurella multocida, Streptococcus canis, Staphylococcus aureus, Staphylococcus felis, and Staphylococcus pseudointermedius. The drug is not for use in dogs and it has been shown to cause bone marrow suppression resulting in severe thrombocytopenia and neutropenia.
Enrofloxacin has been associated with retinal degeneration in cats, particularly at high doses and is used with caution for this reason.
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.
Topic: CHF in Dogs
Oxygen, furosemide, and nitrates (nitroglycerin or nitroprusside); remembering that nitroprusside provides both venodilation and arteriodilation, while nitroglycerin principally causes venodilation, are the primary treatments for acute congestive heart failure.
The answer is chronic superficial keratitis, sometimes referred to as pannus. It is a condition seen mainly in German Shepherd and shepherd crosses and is due to UV light exposure. It is believed that the UV light alters corneal proteins leading to an immune reaction. It is treated with topical steroids and cyclosporine, and animals often require lifelong therapy. KCS is not the correct choice because of the normal tear test. Lymphoma in the eye should cause changes in the uvea or retina but rarely the cornea.
The presumed diagnosis based on the given signalment, physical findings, and diagnostics is splenic hemangiosarcoma, which is often associated with DIC.
Pleural fissure lines are typically diagnostic for pleural effusion. The fissures are the normal divides between the lung lobes and are not visualized on radiographs unless there is fluid in the chest or the pleura is very thickened. When there is a large amount of fluid, you may begin to appreciate a loss of detail, and it is possible lung lobes will collapse as a result of an inability to properly expand in the face of the pleural effusion.
A lobar sign is seen when there is a line of demarcation between a radiopaque (consolidated) lung lobe and a radiolucent (normal) lung lobe. There can be several causes for a lobar sign including hemorrhage, edema, or pus within the lobe.
An air bronchogram is seen when alveolar edema occurs as a result of fluid accumulating within the alveoli. Alveolar edema will result in a sharp contrast between the fluid in the alveoli and the air in the bronchi.
If you have 25% mannitol and you wish to give 500 mg per kg to a 15 kg dog, how much should you give?
25% corresponds to 250 mg/ml strength. At a dose of 500 mg/kg, the total dose for a 15 kg dog should be
7,500 mg which divided by 250 mg/ml equals 30 mls.
You should be suspicious for prostatitis in this patient. Your antibiotic choice should be based on culture and sensitivity results, but because your patient is sick you will want to start an antibiotic that has good penetration of the prostate until the culture results are back.
Chloramphenicol, erythromycin, trimethoprim and fluoroquinolones are able to pass the blood-prostate barrier. Cephalexin and cefpodoxime are cephalosporins and may be effective if the blood-prostate barrier is disrupted, but they would not be the first choice.
Although healing time varies with the size and cause of the ulcer, in general, an uncomplicated corneal ulcer will heal in less than 5 days. If an ulcer has been present for more than a week, it should be considered complicated and the source of complication should be looked for.
Corrective osteotomies of the radius and ulna are often performed to relieve pain and the functional abnormalities induced by angular limb deformities such as carpal valgus
Allopurinol is used in the treatment of urate stone forming Dalmatians. It acts by inhibiting the enzyme, xanthine oxidase, which metabolizes xanthine. The idea is that by stopping the purine metabolism pathway at this point, uric acid will not be formed in high quantities. However, if given at too high of a dose, xanthine will accumulate to levels where xanthine stones will form.
Topic: Pemphigus in Cats
In cats, the most commonly affected area is the head. Specifically, the pinnae, nasal planum, chin, or periocular region are involved. A smaller percentage of cats will also have lesions on their feet. Approximately 90% of cats with pemphigus foliaceus will have lesions in multiple sites, with over 75% having the head or face involved. Over 90% of cases will also have bilaterally symmetrical lesions. Although the condition is pustular in nature, these are usually not observed on clinical presentation; instead, crusts are seen as evidence of ruptured pustules. The condition is thought to be immune-mediated in nature with potentially a genetic component. Drug induced pemphigus foliaceus has been reported with the use of itraconazole. Interestingly, there is a case report of ampicillin inducing pemphigus foliaceus in a cat as well. All the other medications have been used for the treatment of this condition. A large retrospective study of 57 cats performed in 2003 documented that patients were more likely to respond with triamcinolone, as compared to prednisone or chlorambucil.
Topic: Feline Heartworm
An antigen test will be positive if there are female worms present. However, if there is an all male worm infection, you can have a false-
negative test result.
The heartworm antibody test is prone to false-positive results because a positive test can result from a cat that has been exposed, but cleared the infection. A negative antibody test cannot absolutely rule out infection as some animals with a low worm burden may not mount a sufficient antibody response to be measured.
The antibody test and the antigen test in cats each have their pitfalls. When used together, they can be useful in many cases.
The correct answer is the prognosis is very good with small ventricular septal defects and no treatment is needed. The prognosis of small VSDs is very good. Some will close by themselves within the first year of life. It is unlikely that a small VSD will cause any significant problems such as heart failure, though follow-up evaluation is warranted to monitor cardiac size and function. Large VSDs carry a guarded prognosis and require cardiac bypass for surgical correction or novel device closure via transcatheter techniques; neither of which are commonly employed in animals. Small VSDs cause a relatively more turbulent jet of blood through the small defect, causing a louder murmur than a large VSD.
Topic: HCM in Cats
The correct answer is improving diastolic filling by decreasing heart rate. The primary problem with HCM is thickening of the wall of the left ventricle, impairing diastolic filling. There is usually no problem with contractility and systolic function. Slowing the heart rate provides for longer diastolic filling, allowing the left ventricle to fill more effectively. Decreasing the heart rate also decreases the severity of systolic anterior motion of the mitral valve.
For this reason, the medications used most frequently to slow the heart rate are:
1) Beta- blockers (i.e. atenolol: 6.25-12.5 mg/cat orally qD-BID, or metoprolol: 0.5-1 mg/kg TID)
2) Calcium channel blockers: diltiazem: 1-2 mg/kg TID (PO) or 7.5 mg per cat TID
For cases with severe left atrial enlargement or cats in heart failure, also consider:
3) ACE inhibitors (i.e. enalapril or benazepril: 0.25-0.5 mg/kg once daily)
4) Diuretics: furosemide (Lasix): 1-2 mg/kg BID-TID
5) Preventing thromboembolic disease with aspirin or clopidogrel (Plavix).
Also, always keep in mind that you want to identify and treat possible underlying hypertension or hyperthyroidism that could be contributing to the disease.
There are several aspects to consider when determining the best treatment. The age of this cat provides an enormous advantage to bone
healing. This is a kitten and bone plating and dowel pinning will be exceptionally challenging in a patient this small. A cat this young will
likely achieve complete healing in approximately 2 weeks. Metacarpal bone fragments that have decent apposition and less than 50%
displacement will usually heal with conservative management and proper stabilization. Adult cats with fractures involving both weight
bearing metacarpals or severely displaced fractures are considered good candidates for surgery. Therefore, the best answer is to place a
spoon splint for 2 weeks. Note that the bandage is changed every 5 days to prevent any restriction of growth and development secondary
to the splint. In adult animals, bone healing typically will occur in 8-12 weeks.
Topic: Anesthetic Complications
A 2-kg kitten is being spayed at the humane society; she is intubated and is on isoflurane gas for maintenance. She is on IV fluids at 10 mL/hr.
Her blood pressure starts to drop during the procedure. You have already given her a bolus of fluids. Which of the following should you do first to try to increase her blood pressure?
Anesthetic gas is a potent vasodilator and causes profound hypotension, especially in small patients. Decreasing the vaporizer setting in
addition to crystalloids and colloids can help to facilitate getting the blood pressure up. If the pressure cannot be managed by these
simple measures, drugs such as dobutamine may be needed to help with blood pressure during the procedure. A dose of atropine will not
increase blood pressure directly; it will only increase heart rate. Good heat support actually helps to keep the blood pressure more stable
and is especially important in small patients to prevent hypothermia. A 90 ml/kg bolus would be a “shock dose” of fluids for a dog but is
too much for a cat, and this cat is hypotensive for other reasons.
The correct answer is CN Il. The presence of a palpebral indicates normal function of CN V and VII. The dazzle reflex examines CN II separate of the visual cortex (an animal with a cortical lesion will still have a dazzle reflex). Therefore the lesion is in CN II.
The causes of hypoxemia are low inspired oxygen, hypoventilation, V/ mismatch, shunt, or diffusion impairment.
Which chemotherapeutic drug cause fatal pulmonary edema in cats?
Cisplatin
The famed statement, “cis-plat splats cats” is quite appropriate. 5-fluorouracil is also contraindicated for use in cats, but it is neurotoxic.
Eosinophillic complex in cats
Typically, feline calicivirus is an upper respiratory pathogen that may cause oral ulcerations +/- conjunctival chemosis. However, outbreaks
of highly virulent and often lethal feline calicivirus infections have been seen. This is frequently referred to as “Virulent systemic feline
calicivirus (VS-FCV).” These infections are characterized by the signs described above; typically cats develop a severe acute upper
respiratory tract disease first, followed by characteristic signs of cutaneous edema and ulcerative lesions on the skin and paws. Edema is
located mainly on the head and limbs. Some cats may be jaundiced due to hepatic necrosis and/or pancreatitis. Thromboembolism and
coagulopathy caused by DIC may be observed including petechiae, ecchymoses, epistaxis or hematochezia.
Blastomycosis, caused by Blastomyces dermatitidis, is a systemic fungal disease that primarily affects dogs, humans, and cats. It is a dimorphic soil fungus that is found in the Mississippi, Missouri, and Ohio River valleys and also the mid-Atlantic states and the Canadian provinces of Quebec, Manitoba and Ontario.
Infection occurs primarily through inhalation. This is a systemic infection that can cause damage to any organ or system including the central nervous system but the most common clinical signs and physical exam findings include:
Depression, anorexia, weight loss, fever, lameness, lymphadenopathy, harsh lung sounds, draining skin lesions, chorioretinitis, uveitis, and cough.
Clinical signs may be suggestive of disease but definitive diagnosis depends on identification of the organism. As seen in the image, Blastomyces appears as a round to ovoid yeast measuring 8-25 um. It is pale pink when stained with H & E with a refractile, double-contoured wall. They have single broad-based buds.
Blastomyces is treated with systemic antifungal therapy, usually itraconazole.
INCLUDE CYTOLOGY IMAGE
Acid-fast staining is used to differentiate specific types of bacteria known as acid-fast organisms. Acid-fast stain is most commonly used to look for Mycobacteria, which are acid-fast. Nocardia and some bacterial spores and coccidian parasites are also acid-fast. In this case, an acid-fast stain would differentiate Nocardia (which is acid-fast) from Actinomyces (which is not acid-fast).
A KOH test is used to aid in the diagnosis of fungal infection, usually cutaneous infections from dermatophytes. Congo red stain is typically used to stain for amyloid fibrils and may sometimes be used to identify a specific type of Shigella. Trypan blue is a cellular viability stain. Silver staining is used to identify proteins, commonly type Ill collagen. It may also be used to identify certain fungal organisms.
The answer is central retinal degeneration. Cats with taurine deficiency can develop feline central retinal degeneration (FCRD) in addition to cardiomyopathy. This is because photoreceptors contain large amounts of taurine, and cats cannot synthesize it. The classic lesion is an elliptical area of tapetal hyperreflectivity starting in the area centralis dorsolateral to the optic disk that progresses to a horizontal band and eventually can involve the entire fundus.
This is a case of plasma cell pododermatitis which is a relatively uncommon idiopathic disorder of cats. While the history and description of the lesions is consistent with this uncommon disorder, other differentials could include pemphigus foliaceus, pemphigus vulgaris, or lupus erythematosus. A chemical or physical trauma could cause lesions such as these but do not fit well with the history. Neoplasia, infection, or sterile pyogranulomas are possible but would be unlikely to affect all paws simultaneously. Eosinophilic granuloma complex is also possible.
Biopsy is likely the only way to differentiate between most of these possibilities. Because plasma cell pododermatitis is rare, it is unlikely that you would be asked about details of this disorder. With plasma cell pododermatitis, you would expect to see intense plasmacytic infiltration of the dermal tissue, potentially with other inflammatory cell types present due to secondary infection. The disease is not thought to have an infectious cause at this time. Treatment usually involves long courses (10 weeks) of Doxycycline. Approximately, 80% of cats will respond to Doxycycline. If a good response is not seen then systemic glucocorticoids can be tried. Surgical excision of the foot pad may be necessary in cases that fail to respond to medical management.
Why is Toxoplasmosis of public health concern?
The correct answer is infants may be infected in utero and later show chorioretinitis along with mental retardation. Flu-like symptoms can
occur and lymphadenopathy may persist for months, but this is minor in comparison to the effects on in utero infants. Pregnant women
usually do not show any signs of infection. There are no cutaneous lesions in humans associated with Toxoplasma gondii infection.
Interestingly, greater than 95% of AIDS patients suffering from toxoplasmosis are a result of cyst reactivation in the brain and not due to a
recent infection. Their main signs are encephalitis, chorioretinitis, and sometimes pneumonia. To prevent exposure to pregnant women,
recommend that they do not change their cat’s litter box (avoid feces).
