Convenia for Cats: Sacrificing Safety for Convenience?

cat injection vaccination veterinarian

Most cat owners know that medicating a cat can be challenging. That’s probably why many veterinarians as well as cat owners celebrated when Convenia, a long-acting, injectable antibiotic, came on the market in 2008. Convenia is manufactured by Zoetis, formerly Pfizer Animal Health.

The idea of a one-time injection, instead of giving regular anitibiotics in pill or liquid form once or twice a day for two weeks or more, seemed like a great solution to the problem.

However, contrary to regular antibiotics, which are rapidly cleared from the body, Convenia stays in the body for two months or longer following injection, even though the antibacterial effects only last for two weeks. All drugs have some side effects. While some cats may do just fine with Convenia, others may have side effects ranging from mild to life threatening. And with a long acting drug like Convenia, there is no way to simply stop giving the medication – it’s already in your cat’s system.

Amber was one of those hard-to-pill cats. After careful discussion with my vet, I agreed to use Convenia following a dental procedure, which I’ve now come to learn is an inappropriate use for this drug. At the time, I only had misgivings about it because of its long-acting properties. Thankfully, she had no side effects other than some mild diarrhea, which is a common side effect of most antibiotics.

I recently came across a comprehensive article about Convenia by Dr. Lisa Pierson, the founder of, one of the best and most comprehensive websites about feline nutrition. In her article, Dr. Pierson weighs the pros and cons about administering this drug to cats:

Convenia: Worth the Risk?

Dr. Pierson’s article is a must read for all cat owners.

Editors’s note: comments about your  experience with Convenia are welcomed and encouraged. Comments that are disrespectful of others or malign the veterinary profession or individual veterinarians will be deleted. Please read our comment guidelines for more information.

References to other resources and/or websites or Facebook pages about Convenia which may be provided in the comments section are not endorsed by the site owners.

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752 Comments on Convenia for Cats: Sacrificing Safety for Convenience?

  1. Whitney
    February 6, 2020 at 9:41 pm (2 weeks ago)

    Hi everyone, I’m hoping I can find some reassurance. Last Friday (1/31) I rushed my 15-year-old kitty, Jonas, to a new vet because ours was out for his mother-in-law’s funeral. The night before, Jonas had started throwing up violently and that morning he had facial tremors. The vets were great and did bloodwork on him, everything came back perfect except his WBC count was elevated. They chose to treat him for nausea and an unidentified infection, and he was given injections of Cerenia and Convenia. I wasn’t spoken to about either of them, I just noted the names and decided to google them later to see if I should be aware of any side effects.

    Well, you’re all familiar with what comes up for Convenia. I have been a wreck and terrified I have sentenced my best friend to a horrible fate. I have had panic attacks and haven’t slept well in days. He has showed no negative reactions so far – he eats well, drinks well, is active, his bowel movements have produced some soft stool but nothing that seems super concerning. He hasn’t hidden or acted differently at all. But I can’t stop worrying. After reading through comments here I began giving him some of his brother’s probiotics (he takes them for IBS) to helpfully keep him on the right track.

    Do I just keep closely monitoring him and rush him in if there are any bad signs? I am praying that since it has almost been a week and he’s been his normal self that nothing bad will happen. I’ll never let it be given to him or any of my kitties again. I called my regular vet for reassurance and the nurse acted a bit annoyed with my worry, she said that his normal vet would have given him the same treatment and that they use Convenia all the time and have never had adverse reactions. He was apparently given a dose of it back in 2017 for a different illness and never reacted to it then, either, I just didn’t google it the last time.

    He did spit up a tiny amount today, but he had eaten some treats quickly. It was enough to make me freak out all over again but he hasn’t done it since.

    Any advice or reassurance would be great. I’m a very anxious person, especially with health anxiety, but for my babies it is at a completely different level. I am an absolute mess with worry and don’t know how to make it through the next 60ish days until it’s totally out of his system. Thank you all for sharing, I feel like I’ve let him down.

    • Ingrid
      February 7, 2020 at 5:39 am (2 weeks ago)

      I can understand how worried you are, Whitney. Since it’s been a week and you’re not seeing any signs of an adverse reaction, it’s probably unlikely that he will have any problems.

      • Whitney
        February 7, 2020 at 10:01 pm (1 week ago)

        Thank you, Ingrid. I appreciate it deeply. He’s done great still today but I’ll continue watching him vigilantly. I’ve also shared this space and other resources with my friends who are also cat parents so they know to avoid Convenia whenever possible. It’s just not worth the risk.


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