Convenia vs. Traditional Oral Antibiotics for Pets

Unlike traditional oral antibiotics, Convenia is injectable and lasts up to 2-3 weeks

In recent years, many veterinarians are now reaching for the injectable antibiotic Convenia for many common infections presented to the veterinary clinic, including those of the skin, urinary tract and respiratory tract. Convenia is given typically as a single injection, which can last up to 2-3 weeks in pets. This convenient injection is a welcome relief to many animal guardians who don’t have to struggle and fight with their pets once to three times daily, which is the typical frequency that other oral antibiotics are given.

Many times, veterinarians will recheck the pet in 2 weeks for a second injection if needed, which often will resolve many common infectious diseases. There are very few negatives when using Convenia, except if the pet is allergic to the injected medication.  Allergic reactions that may be seen are most commonly digestive upset, especially diarrhea and/or vomiting. While this reaction is not common, if it does occur, it may last up to a few weeks, necessitating the need for medical management of these symptoms during this time. The only other negative reaction would be if the infection being treated is resistant to the antibiotic, in which case alternative antibiotic therapies will be needed in the following weeks.

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  1. My 14 year old cat had an upper respiratory and sinus infection. Without doing a culture, the local vet insisted the infection was caused by the Herpes virus and gave Buster 6 injections of Convenia in a 2 month timeframe. Instead of getting better, Buster became progressively worse. I took Buster to another clinic where Buster was given blood tests and a culture. The test results showed that Buster never had Herpes, but now he was dying of kidney failure. The tests further indicated that the infection was resilient to Convenia. Buster stayed in the clinic for 3 days where he was subjected to daily massive subcutaneous fluids. Despite these efforts, Buster’s kidney functions never improved, and he died a week later.

    Regardless of the claims Pfizer makes regarding Convenia, I now know that massive amounts of any antibiotic that remains in the system damages internal organs. And in the hands of incompetent and ignorant professionals, it becomes a lethal weapon.

  2. Dr. Michael Dym, VMD veterinarianMarch 12, 2013 at 12:38 am

    Hi Barbara….Sorry to hear about your cat and unfortunate experience using convenia like that. if herpes was the cause, then no antibiotic should have been given so frequently as antibiotics dont cure viral infections anyway. At some point blood work should have been done in a cat this age before all of the injections.

  3. Hi Dr. Dym,
    Thank you for your update. At every visit, I did ask the vet why he gave Buster antibiotic injections if he suspected Herpes caused his respiratory problems. The vet said it was to prevent secondary infections. I also asked him to do a culture to ensure Buster really had Herpes, but he said there was no need for a culture because he saw the same symptoms hundreds of times, and it was always Herpes. Later, I was told by one of his assistants that a culture was never done because the vet did not know how to do a culture.
    I feel terrible guilt over what happened to Buster. Granted he was not a young cat, but he was strong, vital, and active, and he loved life. I made the mistake of trusting a so-called professional whose only interest was money instead of ethically treating my beloved pet.

  4. Dr. Michael Dym, VMD veterinarianMarch 13, 2013 at 9:06 am

    Hi Barbara…..You clearly loved your feline companion very well. Sounds like your vet was just following typical standard of practice in traditional vet practice. Unfortunately not much traditional veterinary practice helps with feline herpes anyway, which is why vets reach for antibiotics. I have found long term holistic and/or homeopathic medicine much more effective.

  5. My rat terrier, Dixie has some form of antibotic given since 12-01-12, for her lung infection. The infection has never cleared up, so yesterday April 30, 2013 my Vet. gave her Convenia, her breathing seems worse! She has had acid reflux from 12-01-12 and I have gave her Pepto Bismol for that . My question is can I give this to her will it react with the Convenia?

  6. Dr. Michael Dym, VMD veterinarianMay 1, 2013 at 9:22 pm

    I would not give peptobismol for acid reflux. Famotidine or pepcid AC may be a better choice at dose of one half mg per pound once to twice daily. If signs persist, see vet for recheck and possibly chest x rays to make sure no other disease processes going on.

  7. I have had an Upper Respiratory Infection infect all 5 of my cats since Dec. 25th, 2015. Barely 2 weeks. All of my cats have been given Convenia for possible secondary infections but no culture was taken. The cat suffering the most cleared up just a few days after the treatment and 2 of the cats have remained very congested and sneezing with no noticeable change.
    I don’t know if Dr. Dym is still answering but what sort of treatment do you recommend with this type of infection affecting one cat after another in my house?
    I am keeping the 2 worst case cats in isolation but don’t have the facility to isolate them all. I’ve never dealt with URI’s in the 40 years I’ve raised cats. I am constantly cleaning and disinfecting food and water bowls and every area I see them hang out for more than 5 minutes.
    Any objective suggestions for treatments would be very welcome.

  8. My generally healthy cat was treated twice with Convenia for once for a mouth abscess, once for a bladder infection. Both times had severe lethargy and complete loss of appetite to the point I though I was going to lose her. She was a generally healthy cat but after the first treatment with Convenia for the abscess, suddenly developed kidney disease. I spoke to my vet about this and he actually got a little perturbed and told me that he has never known this medicine to cause any side effects. We have very few good vets in my area but now I’m at wits end. I don’t know how to deal with a vet that won’t admit that it is at least possible that my cat did react negatively to a drug. These side effects are listed as possible on the actual drug website. I love my little girl as if she is my child. It is killing me to think that I allowed her to be administered a drug that may have harmed her.

  9. I love convenia. My cat would not be alive today without it. I am grateful for the time it has given us.

  10. My cat’s teeth get abscessed every couple of months. My vet and I don’t really want to pull all her teeth. She is only 6 years old. The first time she was given a shot of Convenia and also a shot of depomedrol. About 2 days and she was back to her normal self. This was back in August. Since then every month in a half she has been getting just the convenia. But she has not gotten back to her old self like the first shot. Could it be because of the other shot of medicine?

  11. Stacy, I am sorry to hear about your cats abcessed mouth. It sounds a lot like stomatitis which is incredibly painful for your cat. I have had 2 that had bad gums and one had sores in her mouth. Convenia and depo does help but eventually it stops working. Both of my cats have had full mouth extractions and were immediately better. They usually don’t pull the fangs and now I have one who needs to have those removed. Please get a second opinion and do consider having the teeth removed.

  12. I am a desperate mother worried about my daughter who loves her cat more than anything we all love Kovu, he got a shot of convenia a few days ago because of just a physical exam without any UTI test just a exam she said it was more than likely uti. Kovu has been acting tired than normal but personally I think he is just getting older and maybe in heat. But my daughter is worried to death I try insuring her he is ok and will be ok but I can’t say anything she is worrying us all please email her some kind of comforting word pleaseeee and thankyou

  13. Hi Tonya, and thank you for your inquiry. We hope Kovu is feeling better! For any medical concerns, we always recommend you consult your veterinarian. However, for non-emergency questions, you can contact Dr. Dym directly using our Ask the Vet form.
    ~ Abby, PetMeds Pro

  14. My older dog had a shot of convemia & ear infection.loss of appetite..did not know it was a bad I’m so worried !!

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