Page 735 - Clinical Small Animal Internal Medicine

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64 Canine Inflammatory Liver Disease 703

affected dogs was 7.8 +/− 4.1 years, with a range of 2.4– parenchyma was found to be normal in seven dogs,
VetBooks.ir 14.5 years. No comprehensive study has been performed irregular in 11, and to have increased echogenicity in
three. Interestingly, three dogs with AH had evidence of
to determine the breed predispositions to AH, although
in this same study, Jack Russell terriers may have been at
It is not possible to make a definitive diagnosis of AH
increased risk. ascites on ultrasonographic examination.
based on results of clinical pathology or diagnostic
imaging. Definitive diagnosis ultimately relies on histo-
History and Clinical Signs logic examination of liver tissue. However, as animals
with AH may be systemically unwell, liver biopsy is
Clinical signs in dogs with AH are usually nonspecific and often not performed in the acute setting, with patient
similar to those described for CH. Interestingly, in one treatment based on a tentative diagnosis. Fine needle
study of dogs with AH, clinical signs had been present for aspiration cytology is not reliable for the diagnosis of
10.0 weeks (range, 0.5–52 weeks) before diagnosis. Again, AH, and is not recommended.
the clinician should pay particular attention to subtle wax-
ing and waning GI signs, depression, lethargy, anorexia,
weight loss, and polyuria and polydipsia. Clinical signs of Therapy
HE may also occur in the patient with AH. Physical exami- Therapy for AH is aimed at the underlying cause, if
nation findings are generally unremarkable, although the known. However, as the etiology of most cases is cur-
liver is occasionally palpably enlarged in the dog with AH. rently not understood, treatment is generally sympto-
Dogs with an infectious etiology may also be pyrexic and matic and supportive. In one retrospective study, dogs
show other signs of systemic disease.
with AH were treated with antibiotics (5/16), hepatic
support diet and ursodeoxycholic acid (7/16), and 5/16
dogs were not treated. Due to the potential for an under-
Diagnosis
lying infectious cause, corticosteroids are usually avoided
As discussed earlier, clinical pathology is usually the in dogs with AH . The use of antiviral drugs in dogs with
next step in the investigation of a dog with suspected CAV‐1 infection has not been studied. Fluid therapy is
AH. Clinical pathology findings include elevations of required if the dog is anorexic, and short‐term nutri-
liver enzymes, including ALT, AST, ALP, and GGT. In tional support by methods of assisted enteral nutrition is
one study, there was no significant difference in any rou- sometimes also required.
tine biochemical or hematologic variable between dogs
with AH and CH. However, if liver function is assessed, Prognosis
it is more likely to be within the reference range in dogs
with AH. The prognosis for AH is variable, and likely dependent
Diagnostic imaging is often performed after clinical on multiple factors, such as the etiology, severity of dis-
pathology in the assessment of the dog with suspected ease, and how early treatment is instigated. In a previous
AH. Abdominal radiography can be used to assess liver study, the median survival time of dogs with AH was 34.9
size, although as detailed earlier, ultrasonography is months. It is also possible that AH progresses to CH in
the preferred imaging modality for the investigation of some dogs. For instance, in a study of 12 dogs with AH
liver disease. In one study of 21 dogs with a histologic that had a repeat liver biopsy performed after approxi-
diagnosis of AH, all apart from two had abnormalities mately six weeks, histopathology revealed complete
detected on ultrasonographic examination of the liver. remission of inflammatory and degenerative changes in
Hepatic size was assessed as normal in seven six dogs, no changes in one dog, and progression from
dogs, enlarged in eight, and small in six. The hepatic AH to CH in five dogs.