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My cat is lethargic on Atopica for liver disease. Is this normal?

Updated On September 23rd, 2025

Pet's info: Cat | Mixed Breed | Male | neutered

My 10yo cat has been diagnosed with inflammatory liver disease. He's been on steroids and Ursodiol for a year. His liver enzymes went down then back up. After a laparoscopic biopsy they reaffirmed the diagnosis (no signs of infection or cancer cells) and put him on Atopica. He's normally an extremely active cat w/ a large personality. Right after the biopsy he went back to his normal self for 4-5 days. Since then he's shown a constant, rapid increase in lethargy. No eating or bathroom probs. ???

1 Answer

Most Helpful Answer

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Answered By Andrea M. Brodie, DVM

Veterinarian

Published on November 3rd, 2016

Lethargy is one of the side effects that can occur with Atopica for cats, about 13.6% of cats develop lethargy while on Atopica. While this in itself is not a problem, I would observe Thunder for other side effects such as vomiting, weight loss, diarrhea , decreased appetite,which are the most common side effects. If any of those occur in addition to the lethargy or if the lethargy gets worse, take Thunder back to the vet for a recheck and reassessment. There may be an infection (as his immune system is deliberately suppressed to combat the hepatitis), or your vet may want to change the medication.

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