Peer-reviewed veterinary case report
Dog died from severe liver damage after leflunomide treatment
By Aponte-Colon, Cristina et al.·Published in Frontiers in veterinary science·2025·Blue Pearl Veterinary Partners, United States·View original on PubMed →
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Original publication title: Case Report: Fatal presumptive idiosyncratic hepatic necrosis secondary to standard-dose leflunomide administration in a dog.
- Species:
- dog
Plain-English summary
An 8-year-old neutered male Greyhound was brought in for intermittent lameness and joint pain, which led to a diagnosis of immune-mediated polyarthritis. The dog was treated with prednisone and minocycline, and later prescribed leflunomide to help with his condition. Unfortunately, five weeks later, he became lethargic and weak, and blood tests showed extremely high liver enzyme levels. Despite receiving supportive care, the dog passed away, and a necropsy revealed severe liver damage linked to the medication. This case underscores the importance of monitoring liver function in dogs receiving leflunomide.
People also search for: Greyhound joint pain treatment · leflunomide side effects in dogs · dog liver problems symptoms
Abstract
An 8-year-old neutered male Greyhound was presented with intermittent lameness and joint pain, leading to a diagnosis of idiopathic immune-mediated polyarthritis. The initial treatment regimen involved prednisone and minocycline. Leflunomide (3 mg/kg PO q24h) was prescribed later for secondary immune modulation. Five weeks later, the dog exhibited signs of acute lethargy, weakness, and increased liver enzyme activities (alanine aminotransferase [ALT] 6,613 U/L and aspartate aminotransferase [AST] 3,718 U/L). Despitereceiving supportive care, the dog died. Necropsy revealed massive hepatic necrosis with effaced hepatic architecture and centrilobular pools of free blood, similar to findings noted in people with leflunomide-induced hepatic injury. This case highlights a previously unreported severe, idiosyncratic hepatotoxicity associated with standard doses of leflunomide in dogs, illustrating the need for vigilant monitoring and increased awareness of the potential need for dose adjustment if liver enzyme elevations occur.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/40400669/