Page 1142 - Small Animal Clinical Nutrition 5th Edition

1188 Small Animal Clinical Nutrition

VetBooks.ir CASE 68-4

Polydipsia/Polyuria in a Doberman Pinscher a
Philip Roudebush, DVM, Dipl. ACVIM (Small Animal Internal Medicine)
Hill’s Scientific Affairs
Topeka, Kansas, USA

Patient Assessment
A five-year-old neutered female Doberman pinscher was examined for polydipsia and polyuria. The dog’s history was uneventful
except for treatment of a recurrent interdigital cyst. Physical examination was normal. Body weight was 28.6 kg with a body con-
dition score (BCS) of 3/5. The dog had weighed 32 kg during an examination five months earlier. Blood was obtained for a com-
plete blood count and serum biochemistry profile. Urine was obtained for a urinalysis.
Results of the complete blood count were normal. Serum biochemistry profile abnormalities included elevated liver enzyme activ-
ity (Table 1, Day 1). Results of the urinalysis were normal except for dilute urine (specific gravity = 1.005). Radiographs of the
abdomen were normal except for a small liver silhouette.
Liver specimens were obtained using an ultrasound-guided biopsy needle. Histopathologic changes were consistent with mod-
erate, diffuse, subacute hepatitis. Most of the inflammatory cells were neutrophils and macrophages. Macrophages and some hepa-
tocytes contained focal accumulation of granular pigment. Special stains were positive for accumulating copper, but the quantity of
copper was not determined. Bacterial culture of one of the biopsy specimens recovered a coagulase-negative Staphylococcus spp.This
organism was considered normal flora or an opportunistic pathogen; it was sensitive to most commonly available antibiotics except
ampicillin.

Assess the Food and Feeding Method
b
The dog was normally fed four cups of a dry specialty brand dog food (Iams Minichunks ) once daily in the evening.
Questions
1. What is the most likely diagnosis for this patient?
2. Outline an appropriate feeding plan for this dog.
3. In addition to the feeding plan, what other medical therapy is appropriate for this patient?
4. How should the response to therapy be monitored?

Answers and Discussion
1. Middle-aged female Doberman pinscher dogs may develop an aggressive form of chronic hepatitis. Affected dogs may present
in fulminant hepatic failure, or the disorder may be detected early based on elevated serum enzyme activity found on routine
screening biochemistry profiles. Dogs with advanced liver disease present with weight loss, anorexia, polydipsia/polyuria, icterus,
ascites, bleeding tendencies, severe depression and/or signs of hepatic encephalopathy. Dogs presenting in reasonable condition
when first examined survive longer. These dogs are typically bright and responsive, have minimal weight loss and do not have
ascites or hepatic encephalopathy. Typical laboratory findings include hypoalbuminemia, elevated liver enzyme activity, hyper-
bilirubinemia, elevated fasting bile acid concentrations and prolonged coagulation studies.
Histopathologic features of chronic hepatitis in Doberman pinschers include variable degrees of degeneration and necrosis of
periportal hepatocytes and mixed inflammatory cell infiltrates. Portal fibrosis may be mild to severe; hepatic cirrhosis occurs in
severely affected dogs. The livers of affected dogs have moderately increased copper and increased iron concentrations. The role
of copper is not understood but may be associated with cholestasis. Iron accumulation may be associated with hepatic necrosis,
hemorrhage and inflammation. Excessive copper and iron accumulation may aggravate ongoing hepatic inflammation.
2. General recommendations for the nutritional management of patients with chronic hepatitis include feeding foods that are ener-
gy dense, contain adequate levels of potassium, avoid excess levels of protein, copper, iron, sodium and chloride and contain some
fermentable fiber. These goals can be met with either commercial veterinary therapeutic or homemade foods. Highly palatable,
energy-dense foods offered in multiple small meals throughout the day may help overcome the nausea and gastrointestinal (GI)
complications often associated with liver disease.
3. Definitive medical management of dogs affected with chronic hepatitis is not well established. Medical therapy often includes
antibiotics, antiinflammatory and immunosuppressive drugs (e.g., prednisone, azathioprine), choleretic or bile “altering” agents
(e.g., ursodeoxycholic acid), vitamin E and other antioxidants, zinc supplementation and copper chelating agents (i.e., D-peni-
cillamine, tetramine). Diuretics may be needed for patients with severe ascites. Hepatic encephalopathy should be treated with
reduced protein intake, oral antibiotics, lactulose and retention enemas (Table 68-10).