What does it mean if AST analysis is elevated in a dog? - briefly
An elevated AST (aspartate aminotransferase) level in a dog typically indicates liver damage or disease. This can be due to various causes such as infection, inflammation, or toxicity, and prompt veterinary attention is advised.
What does it mean if AST analysis is elevated in a dog? - in detail
Elevated levels of aspartate aminotransferase (AST) in a dog can indicate several underlying health conditions, primarily affecting the liver and heart muscles. AST is an enzyme found in various tissues throughout the body, with significant concentrations in the liver, heart, skeletal muscle, and kidneys. When these tissues are damaged or stressed, AST levels in the blood can increase.
In dogs, elevated AST levels often suggest hepatic (liver) damage or disease. Common causes include:
- Hepatitis: Inflammation of the liver due to viral infections, toxic exposures (such as ingestion of certain plants, medications, or chemicals), or immune-mediated conditions.
- Liver Tumors: Benign or malignant growths within the liver can lead to cell damage and subsequent release of AST into the bloodstream.
- Portosystemic Shunts (PSS): Abnormal blood vessels that bypass the liver, allowing blood to flow directly from the intestines to the heart, leading to liver dysfunction and elevated enzyme levels.
- Liver Cirrhosis: Chronic liver disease characterized by fibrosis and scarring, which impairs liver function and can result in increased AST levels.
Additionally, cardiac (heart) issues may contribute to elevated AST levels:
- Myocarditis: Inflammation of the heart muscle often due to viral infections or immune-mediated processes.
- Cardiomyopathy: Diseases of the heart muscle that can affect its structure and function, leading to increased enzyme release.
- Heartworm Disease: A parasitic infection caused by Dirofilaria immitis, which can damage heart tissues and elevate AST levels.
Other potential causes include skeletal muscle damage from trauma or exertional rhabdomyolysis, as well as kidney disease, though these are less common in dogs compared to liver and heart conditions.
Diagnosing the cause of elevated AST levels involves a thorough clinical examination, reviewing the dog's medical history, and performing additional diagnostic tests such as blood work (including other liver enzymes like ALT), urinalysis, imaging studies (X-rays, ultrasound), and possibly a liver or heart biopsy.
Prompt veterinary care is essential for determining the underlying cause of elevated AST levels in dogs, as early intervention can significantly improve outcomes for many hepatic and cardiac conditions.