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 catinfo.org, 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 welcome. Comments that are disrespectful of others or malign the veterinary profession or individual veterinarians will be deleted.

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.

Photo: istockphoto

Dr. Goodpet

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

  1. Lyn
    February 20, 2015 at 10:29 pm (5 days ago)

    I’m now deeply concerned about this drug. My Sunderi has CKD and has a slight discharge from her stoma site. This gets cleaned every day but I thought I’d take her to the vet to get it checked and perhaps get an antibiotic cream for the .area. The vet said she’d give her an antibiotic injection. I specifically asked her if it would be ok given her kidney issues and she said it would be fine. Wasn’t until I got home and checked the name of the drug that I found so much negative info on it. Has anyone heard of a cat with CKD being given this drug? I am now worried about her as she has had anaemia which is now under control, and has been doing fine with all of our TLC. I will be devestated if a simple antibiotic causes her to crash again after all our, and her, hard work and determination.

    Reply
    • Ingrid
      February 21, 2015 at 7:31 am (5 days ago)

      I know you’re keeping a close eye on Sunderi, Lyn – if you notice anything out of the ordinary, contact your vet immediately. If she’s going to have a reaction to the drug, it would most likely happen within the first 24-48 hours, but since the drug stays in the system for up to two months, you want to remain vigilant even if she seems in the clear.

      Reply
    • Catlady
      February 21, 2015 at 2:46 pm (5 days ago)

      Hi Lyn, I’m very sorry to hear this has happened. I am one of the admins for the Convenia Adverse reactions Facebook page and I also work for a veterinarian who does not and will never use Convenia. Anemia is a common adverse reaction among many and this is very concerning. It is clearly listed in the insert that comes with the drug under Foreign Market Experience:
      death, tremors/ataxia, seizures, anaphylaxis, acute pulmonary edema, facial edema, injection site reactions (alopecia, scabs, necrosis, and erythema), hemolytic anemia, salivation, pruritus, lethargy, vomiting, diarrhea, and inappetance.
      Unfortunately, Convenia follows no rules and reactions do not necessarily happen right away. This is the main reason why vets are clueless about the dangers of this drug and assume that what are in fact true reactions are chalked up to being just another illness that happened to manifest after. Reactions can happen anywhere from hours to weeks to a month or more. The only thing you can do is watch your kitty closely and get her seen immediately if there is even a hint of a reaction. You also should get your kitty on probiotics asap. Benebac powder, which is available in 1 lb jars online, is what most people have had success with, and what my clinic has used successfully on a few patients that were injected with Convenia during ER visits and we were left to clean up the mess. Convenia pretty much kills all the good bacteria in the body, and the good bacteria is necessary for good health, so you need to supplement for a few months until after the Convenia is completely out of the system. The protocol for this is a http:/noconvenia.com I would also have a serious one on one discussion with your vet about this and make sure they put NO CONVENIA on your chart.

      Reply
  2. Ada
    February 9, 2015 at 10:45 pm (2 weeks ago)

    Both my cats have had covenia in the last few years and we have thankfully had absolutely no problems with it.

    Reply
    • Jon
      February 16, 2015 at 7:45 am (1 week ago)

      My little Peanut just got his shot a few days ago and is doing wonderfully. His leg infection is clearing up very fast and he’s doing much better. ALL drugs have rare unwanted effects but this one is great plus you don’t have to stick a pill down your cats throat every day and we know they appreciate that a lot!

      Reply
      • Ingrid
        February 16, 2015 at 7:56 am (1 week ago)

        I’m glad Peanut is not having any adverse reaction to Convenia, Jon. You are correct, all drugs have side effects. The problem with long acting drugs like Convenia is that when an animal has severe side effects, there’s very little that can be done since the drug stays in the system for up to 60 days. As long as cat guardians are informed of the potentially serious side effects of this drug prior to administration, and why a drug reaction to a long acting drug is different than a drug reaction to a drug that only stays in the system for a few hours, it’s up to each individual to determine whether they’re willing to accept that level of risk. Sadly, far too many vets fail to make cat guardians aware of these risks and/or give it without the owner’s consent.

        Reply
        • Jon
          February 18, 2015 at 6:39 pm (1 week ago)

          Peanuts doctor explained everything very well to me but I had to factor in that he will not let anyone put a pill down his throat and the last time I tried he puked it up in his litter box and buried it so I wouldn’t find it. He has very healthy liver and kidneys so I wasn’t worried about it plus his infection was so bad I did have much of a choice. I’m not a vet or scientist so I can’t really say with 100% certainty this drug is perfectly safe and for all animals but Peanut has an amazing doctor and if he recommended it I have full faith in it. I’m really sorry about all the kitties that were lost but there are tons of things it could have been instead of an antibiotic. Infection can cause the body to do strange things including causing organs to shut down.

          Reply
          • Ingrid
            February 19, 2015 at 7:11 am (7 days ago)

            I’m glad to hear that Peanut’s doctor explained the risks, Jon. Far too many vets either don’t, or don’t seem to be concerned that potential risks with a long acting drug are different than risks with drugs with a shorter half life. It will always be an individual decision for each pet guardian, and there may be some situations where the benefit is worth the potential risk.

            FWIW, the vet I’ve used for many years just changed clinics, and I followed her. She doesn’t use Convenia, but the other vet at the clinic does (and believe me, she’s doing her best to educate that vet about why it shouldn’t used in cats.) When my records were set up at the new clinic, I insisted that my records were labeled “NO CONVENIA UNDER ANY CIRCUMSTANCES.” I would be far more comfortable if the clinic didn’t use it at all, though.

    • Sango
      February 18, 2015 at 11:41 pm (1 week ago)

      I am happy that Convenia worked out for you and your cat. It has helped many of my cats and it is convenient. But after one of my young cats, Yani, who had a minor skin infection died within a couple hours of the convenient injection, and in hindsight was a contributing factor to three my other cats deaths, I will never allow the use of Convenia on my cats again. The convenience of convenia is not worth the risk. I am sure now that deaths happen more often than we know, and even if it is 1 in 10,000, when it is your cat that dies it, telling me that death is a rare side effect is of absolutely no consolation.

      Reply
      • Jon
        February 19, 2015 at 7:11 am (7 days ago)

        I’m sorry about your babies. Losing a cat is not easy. In the future if you ever have to have an injection for anything for any of your kitties have them stay at the vet for a few hours to make sure they’ll be ok just in case. I couldn’t imagine my home without Peanut in it. He’s what makes it a home.

        Reply
  3. Penny Williams
    February 9, 2015 at 5:38 pm (2 weeks ago)

    I lost my sweet cat Piper to a Convenia shot 2 years ago Thanksgiving weekend. I had my landlord take her to a vet who was not her regular one because she was walking as though she were in pain, and as our vet had earlier ruled out an infection, I was not thinking in those terms and did not tell him to warn the vet not to give her Convenia. They found and abcess in her elbow and gave her a shot. She did not display immediate symptoms, but a couple of weeks later, she went into respiratory distress and X-rays showed pulmonary edema in an advanced stage. The vet said she’d been building it up for a while (like two weeks). Several hundred dollars and a stay at the emergency vet in the next state got her dried out, but it went too far and she became severely dehydrated. By the time I got her back to a local vet, her blood was so thick they couldn’t get any. Her heart failed when they started giving her fluids, and she died. Yes, pulmonary edema is one of the known side effects of Convenia.

    Reply
    • Ingrid
      February 9, 2015 at 5:51 pm (2 weeks ago)

      I’m so sorry, Penny.

      Reply
    • EvaServal
      February 9, 2015 at 6:38 pm (2 weeks ago)

      So very sorry Penny…

      Reply
  4. Connie West
    February 9, 2015 at 4:49 pm (2 weeks ago)

    i believe Convenia killed one of my strays. i was not told about side effects. he went downhill right after the shot. my new vet is AAHA accredited and when i asked to please put “no Convenia” on all of my cats charts he told me not to worry, that that drug was not even in the building

    Reply
    • Ingrid
      February 9, 2015 at 5:27 pm (2 weeks ago)

      I’m sorry about your stray, Connie. I like that your new vet isn’t even carrying Convenia.

      Reply
      • EvaServal
        February 9, 2015 at 6:38 pm (2 weeks ago)

        I’m so sorry about your stray Connie… I fear we are going to see more and more on this thread…

        Reply
  5. EvaServal
    February 3, 2015 at 1:58 pm (3 weeks ago)

    So very sorry about Yani, Dave. I don’t believe at all that this is rare. My dog and several others (cats) reported here can’t be the only ones. I’d love to know what you find out. It’s heart breaking and I’m so very sorry for your loss.
    Eva

    Reply
    • Dave
      February 5, 2015 at 1:29 pm (3 weeks ago)

      Thank you, EvaServal, for your sentiments. Since Yani’s death, my vets have been warning their clients about Convenia, and they are saying that no one that gets the warning wants the injection for their pets now. I have asked my vets to please spread the word at DVM conferences and conventions and they are already letting all their DVM friends know, at least word is out in Ohio now, where I live. I have decided that I will request the info under the freedom of information act from the FDA. I won’t get around to it until next week. Dave

      Reply
      • Ingrid
        February 5, 2015 at 2:13 pm (3 weeks ago)

        I’m so glad to hear that your vets are taking this seriously, and that they are spreading the word, Dave. I know it won’t bring Yani back, but perhaps there’ll be some comfort in knowing that other cat guardians will now be warned about Convenia.

        Reply
      • EvaServal
        February 5, 2015 at 4:44 pm (3 weeks ago)

        Oh that is such good news! It’s baby steps and I pray this killer Covenia is off the market soon!

        Reply
  6. Dave Cornett
    February 2, 2015 at 8:22 pm (3 weeks ago)

    ps .The ’41’ at the end of my comment was typed by one of my other cats just was I went to post it.

    Reply
  7. Dave Cornett
    February 2, 2015 at 8:18 pm (3 weeks ago)

    I have a cat rescue and have had several cats treated with Convenia, but the other day (1/29/2015) I took my cat, Yani, to the vet because he had an abscess from a cat bite. Yani was five years old and very healthy. The vet cleaned the wound and gave him a Convenia shot.

    She sent me home with Yani telling me he would be just fine. When we got home I let him out of the carrier and left him alone. I figured he needed some rest. When I checked on him a few hours later, he was dead and already well into rigor mortis. I was beside myself with grief!

    I went straight away to my Vet. She checked the paper that comes with Convenia and showed me that death was listed as a possible reaction! She was shocked. She had not done her due diligence and not realized herself the danger and had certainly not informed me. Yani was easy to handle and I could have easily given him an oral antibiotic.

    This experience has made me wonder if a couple of my cats who were quite ill might not have died also because of the Convenia, whereas I thought it was because of the illness. My vet and I both reported to Zoetis. Their Vet said that death does happen, but it is rare. I think it is happening a lot more often than they are letting onto. I felt I was given the run around. I suspect they are not forwarding the ADEs to the FDA. They wouldn’t tell me how many reports have been made. I have also filed a report with the FDA and will encourage my Vet to do the same.

    To find out how many reports have been made, I would have to make a request under the Freedom of Information Act, which has a cost. I don’t know how much, but am considering it. 41

    Reply
    • Ingrid
      February 3, 2015 at 7:00 am (3 weeks ago)

      I’m so sorry about Yani, Dave. Your story, and the stories of so many others who have left comments on this post, make me think that reactions to Convenia are not all that rare. If you decide to pursue getting the information about the number of cases that have been reported, please keep us posted on what you find.

      Reply
    • Michelle
      February 17, 2015 at 6:45 pm (1 week ago)

      Our cat was given Convenia for a suspected urinary tract infection before culture results and was deathly ill within 48 hrs and died of liver failure on day 8.
      My vet says Zoetis says that not one single cat has ever been reported to have died from Convenia. Really?!?

      Reply
      • Ingrid
        February 18, 2015 at 7:17 am (1 week ago)

        I’m so sorry about your cat, Michelle. I find Zoetis’ response to your vet extremely disturbing.

        Reply
  8. EvaServal
    January 5, 2015 at 12:40 am (2 months ago)

    Frank,
    My sincere condolences… I wish they’d take this product off the market.
    I wish you comfort and peace in these times.
    Sincerely
    Eva

    Reply
  9. Debi
    January 3, 2015 at 2:30 pm (2 months ago)

    So sad and frustrating that this keeps happening and the drug is still being given. It’s been almost 2 years now that I lost my precious Cholla to this horrible drug. Both my vet and I reported it to the FDA and Zoetis. Still not even a warning is given to cat guardians of the danger. It must be extremely profitable. How anyone is comfortable profiting from the terrible death these sweet fur babies must endure after a Convenia shot is beyond my comprehension.

    Reply
  10. Frank
    January 2, 2015 at 9:35 pm (2 months ago)

    I took our cat Zeus in the day after Christmas because he was having intermittent episodes of vomiting and although he was eating normally it looked as though he was still losing weight. We thought he may have some kind of intestinal parasite but all in all he was in good health. The vet said they wanted to do a blood test and give him some intravenous fluids as they felt he was a bit dehydrated. They also made a passing comment that they wanted to give him an antibiotic as a precautionary step in case he had an infection. The antibiotic they gave him was Convenia. As soon as we got him in the truck to take him home, he immediately started to vomit. We didn’t think much of it as that is why we took him to the vet in the first place. Later that evening he was very antisocial which is unusual for Zeus, but thought he was mad because we took him to the vet, you know how cats are! Over the weekend we notice he was very lethargic and didn’t want anything to do with anyone in the house, even our son who he absolutely adored couldn’t hold him as he wanted to just get away from everyone. To make a long story short, he soon stopped eating and looked like a person who was on drugs and didn’t know where he was. The following Monday, 3 days after his vet visit, I noticed he kept getting up and laying down in different positions as if he was uncomfortable. The following morning we found him hiding under the Christmas tree and meowing in a very pathetic way. He would not eat and just laid in the same place for hours at a time. Later that afternoon I took him back to the vet and told them that whatever they did to him, he was definitely not himself. I was told that he was having kidney failure and they would need to give him an IV overnight. Well, he didn’t even make it through the night! They called early the next morning and said that he had passed away. The only thing I could attribute this sudden death to was the antibiotic shot he received and within 5 minutes of doing a search on the internet I found several posts such as this from Ingrid and quickly realized that our cat suffered the same fate as other cats that had received injections of Convenia. Please, if your vet says they want to give your cat or dog an antibiotic, make sure it is NOT Convenia! I am convinced that this is what killed our cat.

    Reply
    • Ingrid
      January 3, 2015 at 7:15 am (2 months ago)

      I am so sorry, Frank. Please make sure that you and/or your vet report what happened to Zeus to the FDA and to Zoetis, the maker of Convenia.

      Reply
  11. R A Sullivan
    December 12, 2014 at 7:38 pm (3 months ago)

    We have a 14 y.o. Tuxedo cat who has epilepsy. She has been successfully treated with phenobarbital for several years, with NO breakthrough seizures. we have routine blood analysis to check kidney and liver function.
    Recently she had a large abscess on her chin. The vet suggested Convenia to my husband because of the convenience of its dosing. Never were we told that it remains in the tissue for more than 60 days. Our cat has had two seizures in one week, one a massive event over 3 minutes long. Neither vet had any information regarding the concurrent use of anti-convulsants with Convenia. I have provided them that information copying it directly from a professional website. Seizure are a serious side effect. I am not a blame placer , but a problem solver. I suggest anyone who has had this happen to them to report it immediately to the Convenia website. We will never allow the use of Convenia with out cats.

    Reply
    • Ingrid
      December 13, 2014 at 7:03 am (2 months ago)

      I’m sorry this happened to you. Please report this to the FDA as well. All my best to your kitty for a complete recovery.

      Reply
      • EvaServal
        January 5, 2015 at 12:32 am (2 months ago)

        R.A. Sullivan, I’m so ver sorry about your sweet cat… my condolences.
        Hugs

        Reply
      • EvaServal
        January 5, 2015 at 12:35 am (2 months ago)

        Frank,
        My sincere condolences. All these incidents are horrible and unnecessary. I don’t understand why this product is still on the market. (money is why)
        Again, I’m so very sorry for your loss… I pray you get comfort in these times.
        Sincerely,
        Eva

        Reply
  12. EvaServal
    December 8, 2014 at 1:08 pm (3 months ago)

    Terry, I’m so very sorry… heart breaking… :(

    Reply
  13. terry parolini
    December 8, 2014 at 8:15 am (3 months ago)

    we adopted a kitten Lili, from a humane society, she came with the normal humane society issues, upper respiratory, weeping eye. I brought her home on Sept 11, 2014. She had been spayed. Lili was so tiny 1.5lb, I thought she was 6-7 weeks old. We returned home and I was reviewing her paperwork and discovered she was close to 12 weeks old. She was very active fit right in with our other cat and 110lb dog. She acted like a typical “crazy” kitten, she loved being cuddled and would curl up under my neck to nap. I wanted her checked out by our own vet. I brought her in the next day Sept 12th, he agreed she had an upper respiratory infection and that she was very small for her age but healthy. He suggested the convenia shot, I agreed. I did ask about side effects and what to watch for, he did say she could be tired for a day or 2, she was. A month plus, Lili started to sneeze, green “snot” started to appear around her nose so we brought her in again. On November 3rd they gave her a second shot of convenia. She started to go down hill immediately. She would just sleep, no more playing she didn’t even care to cuddle. We brought her in on November 26th and they placed her on a second oral antibiotic after conducting testing for Feline Lukkemia and other feline issues. I told the vet that I think it was the shot, because she went downhill right after that second shot. Lili could hardly walk, when she did she would stagger and fall over. She began to pee and poop where she was sleeping. I purchased a baby animal milk formula thinking it would be like “ensure” I would give her water with a syring to make sure she was getting some water. She would stagger to the water and food bowls but ate very little. We brought her to the vets to board her as my husband was going to Mayo for cancer surgery and we couldn’t leave her home with the person watching our other pets, we realized Lili needed extra attention. This was on Dec 2nd, 6 days after her last visit……they recommended that we put her down, her temp was 10 deg below norm, her kidneys were failing. I was sick. I told the vet that I read up on the shot convenia and believe this is was the start of her failings, I said I am not blaming anyone but feel I should have been told the side effects not just that it is an antibiotic and is used all of the time without problems…..they don’t know that…..people may not make the connection with their sick pet getting sicker after the shot and just think it’s the illness. I know in my heart that shot was what started Lili’s downslide and eventually forced me to make that heartbreaking decision, euthanizing her. In less than 3 months I spent over $500.oo to kill my poor little kitten.

    Reply
    • Ingrid
      December 8, 2014 at 8:45 am (3 months ago)

      Oh Terry, I’m so sorry about Lili. My heart goes out to you.

      Reply
    • Lesley Le Page
      December 9, 2014 at 4:58 am (3 months ago)

      Terry, I absolutely feel for you and your poor little kitty. Convenia successfully killed two of my cats. The first one was ill with breathing difficulties, took her to the vet, Convenia was administered and immediately she began staggering when I tried to put her back in the cat carrier. She improved after about a week, but then suddenly disappeared. We found her later – she had died alone, in the wet and cold. I insisted that our vet put a report into the manufacturers, Pfizer. I left instructions with the vet to put on their system that Convenia should never be used on any of our cats or dogs in the future. When another of our cats became poorly, my daughter took her to the vet. They gave her Convenia! She died the next day in my arms. THIS DRUG SHOULD BE TAKEN OFF THE MARKET AND PFIZER SHOULD BE SUED!

      Reply
    • Vicki
      December 9, 2014 at 12:12 pm (3 months ago)

      Terry please file a report with Zoetis (the manufacturer) and FDA – see Dr. Pierson’s article for contact info).

      My Leo died back in July from Convenia. We had a necropsy performed and I spoke with both of these organizations. The FDA said that only about 1% of people actually follow through with a report and they must have significant amount of data before anything can be done. She thanked me for calling. Please ask your vet to send in a report as well.

      I’m so sorry about Lili…it is heartbreaking.

      Reply
      • Michelle
        February 17, 2015 at 6:49 pm (1 week ago)

        Dear Vicki-
        Could you share the results of your necropsy?
        My Vet informed me today that Zoetis told him that not one single cat has ever died from Convenia use.
        Also, that the drug is processed through the kidneys, not the liver, so sudden and accute liver failure after Convenia is not related to the drug.
        Appreciate your advice.
        Michelle

        Reply
        • Vicki
          February 18, 2015 at 5:54 pm (1 week ago)

          I can email you his report…what they are saying is that science never recognizes anything as absolute; so there is no way that they can prove that Convenia was the reason for his death.
          I will say that when my vet called and told Zoetis what happened they offered immediately to pay for the necropsy that we had had done. She didn’t ask them too (I had already paid the vet) they offered.
          FDA will do something only when there is enough data to “suggest” that there is an issue. That is why more people need to have the necropsy performed and sent in. It’s a horrific experience but I had hoped that it would help. I was disheartened when FDA told me that there isn’t enough data for them to act.
          Zoetis will never admit that their drug caused a death…I would hope that your vet would know that. Have him/her read the caution label for adverse effects and check the European warnings…they apparently have enough data for them to believe that there is an issue.
          if you want to contact me please do so via info@halfthewayhome.org

          Reply
          • EvaServal
            February 18, 2015 at 6:39 pm (1 week ago)

            I wished there was a “like” button for your comment, Vicki

  14. EvaServal
    September 15, 2014 at 12:45 am (5 months ago)

    Hi Saguil,
    Keeping you and your kitty in my prayers. Please do get your kitty on the probiotics that Catlady is recommending…
    All the best.
    Eva

    Reply

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