our 17 year old cairn terrier has been on Apoquel for 4 mos. the itching, decreased but never stopped. He has been lethargic, urinating more then usual. He has urinated in front of me, also not wanting to stay outside, or even go outside. which is causing more messes to clean up. He has had two seizures which he has never had his whole life. I believe it is the medication that has caused them. He takes mg. tablets, we decreased it to 1/2, he is still having all the symptoms I have described but the seizures started at 1/2 the dose. I am very much convinced Apoquel has caused the seizures.
Animals are often treated with antibiotics for infections they have developed. There are side effects of penicillin when it is used in animals. MRSA may develop in pets as a consequence of treatment.   Nutritional deficiencies can develop in pets as a side effect.  Destruction of the normal protective flora of beneficial bacteria can occur in dogs and horses.   Dogs may have side effects that include: pain in their joints, loss of appetite, vomiting, flatulence (instestinal gas), fungal infections and digestive problems.   Like humans, dogs can have a similar side effect related to developing a serioys allergy. A serious and possibly fatal anaphylactic can occur. Side effects that are concurrent with anaphylaxis include: breathing problems and shock. 
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