Is off-brand Zyrtec safe for cats? What ingredients to avoid?

She should be fine but you may notice some side-effects. The most common adverse effects of zyrtec are sedation, lethargy, vomiting, drooling (hypersalivation), and lack of appetite. If the side effects last more than 8 hours you should have her examined b your vet. I do not recommend you give her any more for at least another 24 hours.

Benadryl (diphenhydramine) can be used for cats. Other over the counter antihistamines for use in cats include Chlor-Trimeton® (chlorpheneramine), Claritin® (loratadine) and Zyrtec® (cetirizine). You can get doses for any of the above from your veterinarian. Legally, we are prohibited from supplying doses for medications, even OTC meds, in the absence of a physical exam and a VPCR (Veterinarian-Patient-Client Relationship).

Unfortunately, by law it is illegal for the experts at Petco Pet Education Center, formerly Petcoach to give the dose information for any drug, including OTC drugs, without seeing the animal in person first. That's because doing so requires a veterinary client patient relationship which cannot be achieved via an internet forum. In addition, the experts cannot say for certain if a specific drug is safe for your cat. I would give your vet a call to see if you can safely give Kitty an antihistamine, or take him into an ER vet.

I suggest you talk to your vet about the possibility of switching to a different medication. Zyrtec works great for cats and it is dosed only once per day. The other option is switching to liquid Benadryl however, cats don't like that much either and she will learn to not interact with you if you are shoving a nasty tasting liquid down her throat twice a day. Have you tried mixing the medication with a very stinky food like canned tuna. Also, warming up the food in the microwave (before adding the medication) will make the smell stronger to help mask the medication smell. If she won't eat the medication no matter what then you may have to resort to putting the pill down her throat yourself. There are some good YouTube videos online you can watch or you can take her to your vet so they can show you how to do it. https://www.youtube.com/watch?v=sRcsgpJ0GSE Hope this helps. Best wishes.

No, I wouldn't recommend doing this without speaking to your vet about it. That's because recommending to do this requires a veterinary client patient relationship which cannot be achieved via an internet forum. In addition, I cannot say for certain if a specific drug is safe for Zoey. Give your vet a call, and they can let you know if Levocetirizine 5mg is safe to give her.

It should begin to work within a couple hours of administration. The half life allows for once daily dosing in cats. That said, not all antihistamines are effective in every cat. You must find the one that is most effective for your cat.

Although uncommon, cetirizine can cause sedation, lethargy, and lack of appetition animals. Please call your vet and discuss the clinical signs that he is experiencing. Your vet may want to switch medications or might want to see your cat to make sure there isn't something else causing the problem.