My cat is itchy. How quickly does Zyrtec start working for relief?

You should see an improvement of symptoms within a few hours of administration. If not, you can discuss a different antihistamine, OTC or prescription, with your veterinarian. Just as in people, different antihistamines may be more effective in different dogs. Allergies can be frustrating to diagnose, so discuss allergy testing, hydrolyzed diets and food elimination trials with your veterinarian in addition to antihistamine use.

Antihistamines, like cetirizine, don't often work well in dogs. It is worth a try to use them but dogs metabolize them so quickly they just don't have the effect you would expect in most cases. Also, remember, if his scratching is not due to an allergy then that may be why it is not working. After 4 hours you should have noticed it working already.

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.

Hello and welcome to Petco Pet Education Center, formerly Petcoach. A safe dose of Cetirizine is 2.5 - 5 mg per cat, so this is likely half a tablet. Please make sure that Cetirizine is the only medical ingredient in the tablet, and there are no other additives. Pseudoephedrine is very toxic for cats, if this is present in the tablet, go to your vet right away. If you have given 10mg, that is ok, she might just be sleepy. Best of luck with Panda.

Dogs around 10 pounds in weight should only get a half tab once per day. If the Zyrtec doesn't seem to be working, or seems to wear off too quickly, I would contact Hope's vet. It may be time to switch to a stronger medication, or try a different OTC such as Claritin to see if it is better for longer-term control of Hope's allergies.

Hello, sorry to hear about Eli. Unfortunately, anti-histamines don't work well with that time of allergy reaction. Typically, we can use a short course of steroids or a steroid injection to break the itch cycle. These may be obtain from your veterinarian through a prescription. Know that steroids in cats can cause increased anxiety and muscle loss. Hope this helps and best of luck.

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.