[Patricia A]

Hi..Diane has your vet ruled out what possibly is causing these high ALT”s from puppyhood? Glad to hear ultrasound is normal . Below are some common causes of the high ALT levels. ALT is an enzyme that may be released with any source of damage to the liver. Blunt trauma, anaphylactic reaction, systemic illness such as thyroid disorders, and other problems that have nothing to do with the liver can cause an elevation of ALT in the blood. Just because ALT is elevated doesn’t mean the liver is failing, however. This result is interpreted in conjunction with clinical signs and other bloodwork and imaging changes.
Increased ALT

Common Causes
• Inflammatory
o Infectious causes
 Bacterial cholangiohepatitis
 Leptospirosis
 Feline infectious peritonitis (FIP)  Histoplasmosis
 Infectious canine hepatitis
o Noninfectious causes

 Chronic hepatitis
 Cirrhosis
 Pancreatitis
• Toxic
o NSAIDS
o Phenobarbital
o Corticosteroids
o Methimazole/carbimazole
• Liver hypoxia or hypoperfusion o Anemia
o Congestive heart failure
o Shock
• Metabolic disorders
o Hyperthyroidism (cats)
o Hepatic lipidosis (cats)
o Cushing’s disease
o Diabetes mellitus/diabetic ketoacidosis
• Neoplasia
• Trauma
Generated by VetConnect® PLUS: Alanine Aminotransferase (ALT) Page 1 of 3

Uncommon Causes
• Portosystemic shunts (usually mild elevations if any)
• Toxic
o Mushroom
o Sago palm
o Aflatoxin
o Ragwort (horses) o Xylitol
o Tetracycyline
o Idiosyncratic drug reactions
• Inherited
o Copper storage disease (certain dog breeds, but particularly severe in Bedlington Terriers)
o Lysosomal storage disorders
• Severe skeletal myopathy, usually mild to moderate increases
• Nutritional hepatopathies
• Gastroenteritis
Related Findings
• Inflammatory
o Increased AST, ALP, GGT, total bilirubin
o Decreased albumin, cholesterol, glucose, BUN in severe cases
o Increased bile acids and ammonia
o Positive titers or PCR for leptospirosis, feline coronavirus (FIP), histoplasmosis o Positive bacterial or fungal culture of liver/bile
o Histopathology/cytology findings consistent with inflammatory hepatic diseases o Increased Spec cPL® or Spec fPL® with pancreatitis
• Metabolic
o Hyperthyroidism
 Increased T4, free T4, free T4 by equilibrium dialysis
o Hepatic Lipidosis
 Increased ALP
 GGT usually normal unless concurrent inflammatory disease is present  Enlarged liver on radiographs, hyperechoic liver on ultrasound
 Cytology/histopathology consistent with hepatic lipidosis
o Cushing’s Disease
 Increased ALP
 Decreased urine specific gravity
 Stress leukogram: increased neutrophils and monocytes, decreased lymphocytes and/or eosinophils  Adrenal function tests consistent with Cushing’s disease
o Diabetes Mellitus
 Increased serum glucose and glucosuria  Increased fructosamine
 Ketonuria (in severe cases)
• Neoplasia
o Enlarged/irregular liver on radiographs and/or ultrasound o Cytology/histopathology findings consistent with neoplasia

• This reply was modified 3 years, 8 months ago by Patricia A.
• This reply was modified 3 years, 8 months ago by Patricia A.