Page 2051 - Cote clinical veterinary advisor dogs and cats 4th

1026 Vacuolar Hepatopathy

DIAGNOSIS ○ Rarely, masses are secondary to VH hyperadrenocorticism (pp. 485, 1426, and
(primary differential of a neoplasia) • If another underlying disorder is recognized,
1427) is appropriate.
VetBooks.ir Usually, increased liver enzymes activities ○ Can identify comorbid disease that might • Although benefits are not proved, hepato-
Diagnostic Overview
○ Can identify abnormalities of adrenal size,
it should be addressed.
symmetry
prompt hepatic ultrasound exam. Ultrasound
findings are suggestive, although not pathog-
been used (p. 452).
nomonic, of VH. The diagnosis is confirmed cause vacuolar hepatopathy (e.g., pancre- protective therapies such as antioxidants have
atitis, extrahepatic abdominal tumors)
by hepatic biopsy. For the majority of affected • Coagulation profile (p. 1325): rule out
dogs, the medical history, exam, and minimum coagulopathy if biopsy anticipated Nutrition/Diet
database are suggestive of endogenous or exog- • Serum bile acids: normal to mild increase Protein restriction, typical of liver-specific
enous hyperadrenocorticism. If not, a diagnostic typical of VH diets, is not required. Dietary therapy should
search for a primary disease process should be • If hyperadrenocorticism is suspected, screen be designed based on underlying conditions
undertaken. by low-dose dexamethasone suppression or and to achieve and maintain an ideal body
ACTH stimulation testing (pp. 485, 1300, weight (p. 1077).
Differential Diagnosis and 1360).
• Hepatotoxins (p. 1231) Drug Interactions
• Adverse drug reactions Advanced or Confirmatory Testing Any potentially hepatotoxic drug (e.g.,
• Infectious agents (p. 1230) • Hepatic cytology (p. 1112) nonsteroidal antiinflammatory drugs) should
• Inflammatory hepatopathies including ○ Small sample size limits diagnostic be avoided.
hepatitis and cholangiohepatitis accuracy.
• Copper storage hepatopathy (p. 458) ○ Specificity is poor for VH, limiting the Possible Complications
• Neoplasia (p. 1230) usefulness in confirming the diagnosis. Possible increased risk of thromboembolic
• Cholestatic disease, including mucocele ○ Most useful to rule out other hepa- disease and infections, considering the underly-
• Ischemia/hypoxic injury, including surgical topathies, including diffuse neoplasia, ing or associated conditions
hypotension and hypoxia, liver lobe torsion bacterial abscesses, parasite infestations,
or thromboembolic disease and suppurative hepatitis Recommended Monitoring
• Severe systemic or metabolic disorders • Hepatic histopathology (p. 1128) Protocols for monitoring patients with
○ Acute pancreatitis ○ VH is characterized by hepatocytes VH have not been established, other than
○ Sepsis, septicemia, endotoxemia, heat distended with cytosolic glycogen, with as required by underlying disease. Exam
stroke, trauma or without discrete membrane-bound and biochemical profile q 6 months seem
lipid inclusions. Severity is character- reasonable for most affected dogs. In Scot-
Initial Database ized as mild to severe and/or by the tish terriers, frequent ultrasonographic
Findings are typically associated with excess glu- acinar zonal distribution of hepatocyte surveillance is recommended to screen for
cocorticoids. Review history for any exogenous vacuolation. Acinar zonal distribution of the possible development of hepatocellular
steroid use, including topical preparations. In vacuolation is variable, although a diffuse carcinoma.
dogs with VH secondary to chronic stress or or predominantly zone 2 or 3 distribution
illness, the findings can be markedly different is most common. PROGNOSIS & OUTCOME
and are associated with the underlying disease ○ Because VH is confirmed only after
process. biopsy interpretation, samples should be • Most dogs with vacuolar hepatopathy
• CBC: often, components of a stress leuko- submitted for bacterial culture and copper associated with excess glucocorticoids
gram (lymphopenia, eosinopenia, neutro- quantification. or steroidogenic hormones have a good
philia, monocytosis) and thrombocytosis • Other diagnostic testing may be necessary prognosis.
• Serum biochemical profile to find an underlying cause for VH if • In dogs with vacuolar hepatopathy NOT
○ Very commonly, increased activities of endogenous or exogenous glucocorticoid associated with exogenous or excess
alkaline phosphatase (ALP) and gamma- excess is ruled out. endogenous glucocorticoids, the prognosis
glutamyl transferase (GGT) and outcome are based on the underlying
○ Lesser elevations of transaminases: aspar- TREATMENT condition.
tate aminotransferase (AST) and alanine
aminotransferase (ALT) Treatment Overview PEARLS & CONSIDERATIONS
○ Often, hypertriglyceridemia, hypercholes- For most dogs with VH, the focus of treatment
terolemia is detecting, managing and if possible, revers- Comments
○ Occasionally, decreased blood urea nitrogen ing the underlying disease process. This can If elevated serum ALP and GGT activities
(BUN) (noted with polyuria/polydipsia) include stopping exogenous glucocorticoids (if persist after removing the source of excessive
○ Mild hyperglycemia possible), treating hyperadrenocorticism, and steroid hormones, other causes should be
○ Normal bilirubin, albumin treating a condition resulting in stress-induced considered.
• Urinalysis: usually urine specific gravity hypercortisolemia.
< 1.020; moderate proteinuria (urine protein/ Prevention
creatinine ratio < 5) Acute General Treatment • Use the lowest effective dose of glucocorti-
• Abdominal radiography: evaluate hepatic size Acute treatment is not typically required coids necessary.
(subjective); hepatomegaly common with VH, other than appropriate treatment • For disorders requiring chronic glucocorticoid
• Abdominal ultrasound: sensitive tool for of underlying or associated conditions (e.g., use, consider steroid-sparing alternatives
evaluating hepatic parenchyma, the biliary treatment of neoplasia, cholecystectomy to (e.g., cyclosporine for immune-mediated
system, and vascular structures manage gallbladder mucoceles). disease).
○ Permits guided sampling of liver
○ Hepatomegaly with a diffuse hyperechoic Chronic Treatment Technician Tips
echogenicity typical of VH • There is no specific therapy for VH. Dogs with VH have a propensity for infec-
○ Hypoechoic nodules are common. • In most cases, reducing exogenous tions, delayed wound healing, and slow hair
○ Can reveal a coarse echotexture glucocorticoid administration or treating regrowth.

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