Convenia: Potential Side Effects for Cats

Convenia is a veterinary antibiotic that is used to treat a variety of infections in cats. However, there have been some reports of serious side effects associated with the use of Convenia in cats, including liver damage and bone marrow suppression.

cat deaths from convenia

Understanding the problem?

This medicine is a long-acting antibiotic given as injectable to cats under infectious conditions like skin conditions, UTIs, and others. However, reported cases with the injection site had shown inflammation, sarcoma, and tumor signs. At times, it is recommended as an oral route if tolerated well by the patient. Also, it is available in the form of patches but not free of local side effects.

The FDA has not issued any warnings about Convenia causing death in cats. However, the FDA has issued a warning about the risk of Convenia causing serious side effects in cats. These side effects can be life-threatening, and they can occur even when Convenia is used as directed.

If you are considering using Convenia for your cat, it is important to weigh the risks and benefits. You should also talk to your veterinarian about other treatment options that may be less risky.

Sometimes rescue is seen by presenting arguments in the failure of compliance of the drug schedule by the pet owners. The need to follow a plan and to medicate consistently fails in most cat owners. Thus, it can, in turn, causes drug resistance as one fails to receive antibiotics. Leaving the vets with the option of convenia to get through this issue. Thus, the easier way is always appealing, while other possibilities include more straightforward options like Clavamox and amoxicillin.

Is convenia the best choice?

The drug of such controversy is weighed in terms of award versus risk. The side overweighing wins the contest. But provided that safer and better options are available, one should go for them irrespective of convenience or price. Other antibiotics are generally are the safer options here for feline infections.

Convenia as medicine is selected, keeping the interest and condition of the patient in mind. The vet prescribing convenia never writes it on the prescription pad without discussing it with the cat parent. The vet prescribed it usually has an experience with its use and might not have any grave consequences.

Usually, the cat owner later sees the effect and is responsible for reporting any health concerns observed with medicine in the cat. Thus, a piece of advice here would be to discuss with the vet before using convenia as an option here. Usually, people get to see the name on the bill post damage done. It is administered to cat’s post-dental procedure. A thorough verbal communication firsthand will be good if you are convinced not to use convenia. In dire cases, you can get the vet to the right in a red box or with a red indicator saying no convenia.

Convenia treating UTIs

Cats complaining about urinary tract issues are usually catered for the inflammation and are prescribed antibiotics. The cat parent and the vet assume that it is an infection requiring no less than anti-bacterial treatment. The common symptoms they notice in this case include little or no urination, cat seen licking the genitals, sometimes urinating with blood in the urine, or urinating randomly at different locations.

These all symptoms are loosely attached to a bladder infection. Ignoring the fact that it could be mere inflammation, requiring comparatively lighter or simple treatment.

More than 90% of the chances are cat has sterile cystitis. Here sterile denotes the absence of infection or microbes, requiring no antibiotic but just anti-inflammatory medicine. The point of error here is recommending medication without any sensitivity test and going for the third-generation antibiotic bluntly. To save oneself from repetitive dosing, the vet also recommends convenia in this case. And dismissing the dire consequences that can come along here.

When one ends up recommending convenia or any other antibiotic, it results in causing resistance in the bacteria and greater chances of superinfection. The threat remains the same for both man and animal alike with the development of resistance species, requiring more potent antibiotics in the future to have a similar effect.

Alternative available for Convenia

  • Antibiotic Pills

Normally, the first line of treatment should include the use of oral medicine and the first generation of antibiotics. It is the simplest and easy to go route for treating both humans and animals. It presents a safe course of administration with sound absorption and excretion overstated half-life of medicine. However, one needs to be cautious with its use in the cat. The cat might take it conveniently, but it might get stuck at the throat.

Some medicines that are contraindicated for use here in the cat are inflammation and blockade or alteration in the esophagus structure.

  • Liquid Dosage Forms

Some antibiotics, for instance, Clavamox and clindamycin, are available as flavored liquids. They come in the form and are convenient to administer, plus it is a metered-dose. The good thing is there is no issue of getting medicine stuck in the esophagus. Plus, to make it more palatable, it is available in flavors of chicken and fish.

  • Transdermal

It is another route of presenting the medication to the pet. Here the drug finds its way into the body via an application on the skin. However, this is not an applicable route for giving antibiotics where higher levels are required in the body. Only the above three methods can provide sufficient levels necessary for producing a pharmacological effect.

The route of administration used with Convenia

  • Parenteral

This route is the one taken by injectables that bypass the small intestine. It includes various sites, common ones being intra-muscular and intra-dermal. In this case, the delivery should be proper with the correct technique. A little carelessness can cause local inflammation, muscle ache, or even septic fever.

However, it comes with superiority over any other dosage form as it presents a hundred percent bioavailability. But like its immediate effect and quick relief upon use, the side effect is also severe.

Since the cat leaves the hospital post-treatment, a single dose of convenia has an effect equaling to fourteen days of oral treatment. Cat deaths from convenia stay unreported and vague to be related to medicine or disease.

Emergency and caution with the use of Convenia

  • Convenia is referred for skin infection in cats and dogs. It produces an effect within a week with almost two months of residence in the body. The other antibiotics are cleared off rapidly from the body. Use in older pets should be done with caution.
  • In an emergency or adverse effects reported with convenia, one can check with the vet to have the condition checked.
  • For allergic reactions in pets, the medicine should be banned for any use in the future. However, the symptomatic treatment will be a long process since therapy has a long residence time. It will show the effects of necrosis, scabs over the skin, pruritus, erythema, etc. One can use anti-allergic and corticosteroids, depending on the severity of the reaction.
  • The vet can symptomatically treat ADR’s.
  • Before having the pet treated with convenia, there is no retrieval for the drug that has already entered the body.
  • Some other common ADR’s seen with it includes ataxia, seizures, anemia, lethargy in cat and anorexia.
  • Death may be caused in some cases too.
  • In case of death  or suspected to be caused by it, requires to have post mortem and reach conclusions.
  • Should follow a detailed microscopic examination of the autopsy. It will better bring on display the actual cause.
  • The drug gets withdrawn from the market following only with sufficient ADR reports. One should not be casual with reporting to let the medicine receive its fate.


How one describes Convenia as a medicine?

Convenia is a group of antibiotics, i.e., cephalosporin, known explicitly as cefovecin sodium manufactured and distributed by a company known as Zoetis. This is a medicine utilized for bacterial infections in animals like cats. Most of the time, the conditions are of skin, like those following a wound or abscess.

What medical conditions are treated with the use of convenia?

Convenia is an antibiotic that is from the third generation of the same. They are used in various kinds of infections like UTIs and skin infections. They also serve sound conditions with abscesses and wounds that cause many scratching and itching in the animal.

Does scratching or licking make skin condition any better?

The scratching that the cat does in response to the itching makes the skin condition worse. Sometimes it could be followed by licking or biting the body. This breaks or affects the body at that particular site causing the chances of infection to double. Otherwise, the bacteria or other microbes that were in the environment couldn’t enter the skin, which becomes more accessible in case of broken skin.

How different is the experience with convenia compared to that of another antibiotic?

The experience with convenia is different from any other counterpart. It could be explained with two prime reasons. One is its use as an injection and the fact that one particular dose of convenia is enough to fight down the infection under concern. Usually, this is preferred by the pet owner to save them from using the oral alternative. This will be as effective as oral medication taken in fourteen days. This is also why cat owners switch to convenia as they have to feed the oral medicine twice daily. And find convenia convenient instead.

What is a mode of action for convenia?

Convenia is anti-bacterial in action. It works by ripping off the cell wall of the bacteria by puncturing holes into it. This takes almost thirty minutes post-injection under the skin that it can be sensed in the body. Then within four hours of the injection, medicine starts [producing effect. By this time, sufficient drug levels have reached the blood to kill bacteria and retain the result.

What is the cost of convenia?

This is subject to the region of treatment, as prices vary from one place to another. Plus, the dose will be the deciding factor. A cat is usually treated by calculating the weight or body mass. While other factors like age and general health condition of the cat are also catered in deciding the dose.

The vet will be in the best position to reply to this query.

How can one buy convenia for its pet?

Convenia is not open for sale or an OTC product. This is strictly prescription medicine and shall require a vet to suggest for the cat if deemed necessary. It is also administered by the vet thus is catered altogether under professional supervision.

What is the usual dose of convenia?

No specific dose of convenia can be referred at this position. It is only the vet who looks into the condition of the pet. Followed by a calculation of its body mass. Convenia’s dose is thus calculated as per the cat’s need that will be sufficient to produce the pharmacological effect.

How quick is convenia in producing the effect in the cat’s body?

Convenia is used in different pets under various conditions. In every situation and pet, the amount is calculated as per the underlying disease and weight of the body. Thus the dose calculated is decided to be enough to reach peak blood levels in the infected animal. It can as much a 2 hours to make up to this level in the cat. In short, one dose of convenia is good enough to produce an immediate effect.

The vet best answers to this with the proper calculation following the severity of the condition and replying your concern with Convenia Side Effects.

How long it takes for convenia to leave the system of the animal?

The best answer to this finds its basis in the concept of half-life. This is the time it takes for a drug to turn half after being administered. Such is the elimination half-life, allowing the removal of the medicine from the body. In the case of convenia, the half-life is 6.9 days in cats and varies in other animals.

How many doses of convenia are required for a cat?

Usually, the reason for choosing the convenia is its convenient one-time dose. The convenia injected once to the infected cat is at par with oral antibiotics given twice daily for fourteen days. However, the vet also offers a second dose to completely put down the infection in some circumstances.

Are there any reported side effects of convenia?

Yes, there are ADR’s that are reported against the use of convenia. Some of the common ones include allergy at the injected sites and the common ones seen with the injection.

This accounts for others effects, including nausea, vomiting, diarrhea, muscle pain, dizziness, loss of appetite, and fever. The manufacturing company claims to have all ADR’s reported and to take responsibility for the same.

Why convenia is the medicine of choice?

The prescription that prescribes the medicine convenia states the following things.

  • Fast treatment with peak levels reaching within 6.2 hours
  • The dose is explicitly given by the pet.
  • Treatment spread on two weeks. This leaves you free of the daily delivery.
  • Saves you from keeping track of the dosage regimen.

Is there any place to get animals checked for convenia’s adversary?

Cats that tend to show allergic potential towards antibiotics. This includes allergy to cephalosporin and penicillin etc. One needs to check into the allergic profile or history of the pet. Necessitating one to get convenia under vet’s prescription and care to save oneself of any trouble.


Convenia is a group of cephalosporin used in skin infection and other infectious conditions in cats and dogs. Convenia is a powerful antibiotic that can be effective in treating infections in cats. However, it is important to be aware of the potential side effects of the medication. If you are considering using Convenia for your cat, it is important to talk to your veterinarian about the risks and benefits. It remains a controversial drug with some side effects, including nausea, vomiting, diarrhea, muscle pain, dizziness, loss of appetite, and fever. While many justify it with similar side effects in other medicines and the company openly taking responsibility for consequences.

Many cat parents do not risk the cat with use of convenia. On the contrary, many people do prefer convenia, with the convenience of having one drug administered. That is at par with the 14-day treatment of oral medication, twice daily.

Vets generally use it for skin conditions, urinary tract conditions, and post-dental procedures. But having gone for third generation, not only raises the chances of superinfection but also comes with a risk of life. Thus, a pre-discussion with vet can be made to see all treatment possibilities and saying no to convenia.


The information in this article is not intended to be a substitute for professional veterinary advice. If you are concerned about the safety of Convenia for your cat, you should talk to your veterinarian.

17 thoughts on “Convenia: Potential Side Effects for Cats”

  1. My cat was givin this covenia and passed in less than 30days also he did not have bacterial skin issue it was more a reaction from hartz flea shampoo the vet never told me the side affects nore anything really only that it was a antibiotic time release injection would last 14 days well im still grieving very bad as i had my cat for 19 yrs and was always very careful on what i would give him at home he was my only company and family now im all alone do to neglect on vets part its not right…
    Desiree McKee of valley center california

    • My cat of 9 years was given this injection without any teaching from the vet at all the vet treated her for a bladder infection without completing a urinalysis. She passed away 6 months later due to no appetite, lethargy, weight loss and many abnormal labs and Sarcoma. I brought her in three times in a three month period and medical exams were very incomplete until I had to tell the vet what to check . I believe the antibiotic caused her death due to side effects. She was a very healthy cat until she received this injection very poor care by the vet

    • I’m so sorry for your loss. I’m on this site for Covenia because just today I brought my 16 yr old cat to the emergency vet for what I believed to be a UTI. Although an ultrasound showed that her bladder appeared to be inflamed, it was very small (no urine), no stones or masses. Because there was no urine in her bladder, they couldn’t do a urinalysis but would prescribe an antibiotic anyway. Since she is very difficult to pill, I asked if they could just give her an injection instead. I wasn’t told what it was and didn’t know until I got home and looked at my bill. When I looked up Covenia I was horrified to see that it causes death in cats!! WTH! Why is it still being prescribed?! I am so scared now that I am going to lose my beloved cat that I’ve had for 16 years since she was kitten. How can we stop this from happening to someone else? What did you do? Again, my deepest sympathies to you. I know all to well the pain of losing a beloved pet. ❤️❤️

      • I have contacted the FDA as recommended by the web site “cat info” but have not heard anything yet also the manufacturer but again haven’t heard anything that’s seven months ago. I have read an necropsy would have to be completed for confirmation but wouldn’t do that to my dear beautiful Daisey. I am heartbroken as anyone would be with such a loss. I contacted the vet but he never responded again no information was given to me about the shot it was given and then I was informed. I wasn’t even asked if she was difficult to pill. She had never been sick and the only medication I gave her was pain med after her spay and she did just fine it was liquid. What I learned about this antibiotic and any injectable’s was to late for my sweet girl. Of course I blame myself for not being aware all of my prior cats never had problems put then never given this antibiotic Convenia.

      • I would also recommend if your cat stops eating or becomes less active have her seen and have blood work done to check kidney function, and complete blood work done. As I have posted I took my cat in three times and didn’t speak up until it was to late, antibiotics are hard on the kidneys especially a long acting injectable like Convenia can be very hard on the kidneys. Also give probiotics, antibiotics kills the good bacteria as well as bad in the gut. Also causes anemia my cats blood work was so abnormal after three trips to the vet and I had to request blood work the third time. Blood work will give you and idea how healthy your cat is

  2. Hi its me again,
    Im not sure why Ive only 1 reply to my post of my love Nellys death on August 24th,2021 from the injection of convenia, Im still a mess cause of his death I did fail to mention where this happenened, it was at Valley Center veterinary clinic & adminstered by Selena Savides also is .55 a recommended and safe dose for my cat had a weight of 11.58lbs also having CKD can someone let me know what they think the located at 14219 cool ranch rd in valley center ca i know nowit had not been shampoo as from covenia injection on july 30th,2021 to his death on 8/24/21 his lungs one was completely full of fluid and other lung was 3quarters full of fluid the vet adminstered emergency oxygen on the 23erd of August however he still died thr next morning do to negligence of such vet & treatment on my beloved Nelly kitty!! Also mention the apt was not to address the skin as much as it was made to see if his CKD should be or his cardiac issues which is out his heart and or kidney issues which i should be more, feel to email me at my own email af if not comfortable posting a reply !
    I’d hate to go through the pain I have been since his dealth…
    Sincerely ,
    Desiree McKee

    • I believe before the antibiotic Convenia or any antibiotics blood work should be completed to evaluate especially the kidneys before administering medications. This is what I learned to late for cat but put full trust in the vet. Loosing an animal to a medication that’s suppose to heal is very heart breaking.

    • Hi so sorry for the loss of your special companion your lovely cat. I had just been reading about convenia before I saw your post and it said it’s not recommended in cats with kidney disease. I don’t like any long acting drugs personally and prefer to administer daily it may not be as convenient but I feel if there is any reaction it can be stopped straight away.
      Hope you’re OK I know how hard it is to lose a beloved best friend x

      • When my cat was administered Convenia injection the Vet administered it then told me never questioned me whether I could administer medications by mouth or not. My cat had never received an antibiotic before the Convenia. It’s my understanding after research another antibiotic should be attempted first before the Convenia. At least one can stop an oral antibiotic but not an injectable. I have tried to contact the Vet never able to speak to him or get answers to my questions so many things were not done according to what I researched. I also believe where my cat received her injections were not the recommended sites to prevent possible Feline Injection Site Sarcoma.

  3. I’m really freaking out now as my cat just had a covenia injection on May 19, 2022. She has been sleeping mostly but not eating all that well. She also has ear drops twice daily which she hates. I’m just concerned now for her since she got that injection for possible skin infection and she’s never Been on meds before. I’m so sorry for everyone’s loss and will pray my cat don’t have problems with this antibiotic. If she does you will hear from me again. Guaranteed!! God bless you all for sharing.

  4. My cat just passed away from this drug! Stay away from it, look for different solutions, if vet offer this killing drug run!
    You don’t want to see you cat suffering, crying, not be able to move, eat or dring.
    This convinia drug should be baned!

  5. My poor cat was given covenia for a dental proceedure and is very lethargic and cannot stand for a few seconds. I called the vet and asked what they did to my cat and they said he has nerve problems. They also did not get my permission to do all of the work they did. He is 16 years old and he seems depressed and he won’t let me hold him. Well he was fine before I took him in and ate like a horse now he will hardly eat and can barely stand up. Can I file a lawsuit if anything happens to him? I have been so stressed over this and I don’t like seeing him like this. It really hurts me.

  6. My cat Glenn had developed discoloration and slight ascites in his belly in May 2022. I took him to our regular vet that we have used for 15 years and we had fluid analysis and a battery of tests done – every one of them was NEGATIVE – NO Pancreatitis, FIP, FIV, Nephric Syndrome, R-sided CHF, liver disease or hypoproteinemia. An Xray showed that he had a hernia. So, I scheduled surgery for the beginning of June.

    I asked the Vet what aftercare would be required and he informed me antibiotics to prevent any infection and pain medication. When I asked what kind of antibiotic, he said the Convenia shot. I told my Vet FIVE times that he knows that Glenn was an angel with taking liquid medication and I DID NOT WANT A CONVENIA INJECTION DUE TO MY OWN REASEARCH. FIVE TIMES!!! He assured me that he would not be given the injection. The morning of the surgery, I dropped him off, VERBALLY TOLD THEM AGAIN “NO CONVENIA” and had a note taped on his carrier “DO NOT GIVE CONVENIA SHOT – TAKES MEDICATION FINE”.

    When I picked him up in the afternoon after the surgery, I looked at his paperwork and it said “Convenia Injection”. I flipped out on the tech who brought Glenn out and said get my Vet out there right now. My Vet came out and said that he didn’t want Glenn to be moved around a lot after the surgery and the shot is better for him so that I didn’t have to force meds on him. I flipped my s*$# on him and asked who did he think he was to give Glenn a shot after I said no less than SEVEN times NOT to give him Convenia . . . and that he knew Glenn took liquid meds fine. He kept trying to calm me down and said that the shot WOULD NOT harm him and it was better for him. I asked him what Convenia is supposed to be used for, because anything I have read states skin infection and UTI, neither of which Glenn had, and he kept insisting it is broad spectrum and that Glenn would be fine. I told him that he had lost the right to care for our 6 cats, my Mother-In-Laws 3 dogs and my Mom and Dad’s cat. I said “How dare you do what I expressly told you not to do!” He kept trying to reassure me that everything would be fine as I walked out of the door carrying Glenn in his carrier.

    I took 3 days off of work to monitor him after the surgery and he was fine. I went back to work the Monday after, 6 days after the surgery. My Mom stopped over during the day and spent 3 hours with him. He was PERFECTLY FINE – 2 hours before I got home from work.

    When I got home at 5:30 pm, I sat down on the sofa. Glenn got up from his “spot” on the sofa, jumped down onto the floor, took a few steps over and sat down in front of me on the floor. He looked up at me, put a paw on my foot and started breathing extremely heavy. I picked him up and he started panting uncontrollably. I told my husband to get the carrier, we were taking him to the emergency Vet 15 mins. away. We never got the chance.

    In FIVE minutes, I held Glenn while he went from breathing heavily to gasping for air with his tongue hanging out, letting out howls. I got to stare him in the eyes, telling him how much I loved him and apologizing to him, while soaking him with my tears, as he died – suffocating – in my arms. I will NEVER get that image of fear in his eyes as he died out of my mind.

    After over an hour, when my Husband finally convinced me to let him lay Glenn down in the carrier until my Husband could dig a grave for him, I composed myself enough to call the Vet’s office. When I told the Tech who answered the phone what happened, she told me to stay on the phone and had another Tech get the Vet. He got on the phone after about 2 mins. and told me that he was coming to the house get Glenn, and that he would pay for a Necropsy to be done on Glenn. When he arrived at our house 20 mins. later, he, too, was in tears. He tried his best to comfort me and kept apologizing. I told him “just figure out if your stupid f-ing shot killed Glenn” and that I wanted him back to bury.

    The necropsy was done by the Senior Vet Pathologist at a local University. Glenn was returned to me after 2 days and I got to bury him next to his non-biological Brother.

    10 days later, my vet had me come to the office. He handed me Glenn’s written necropsy results.

    Glenn died from Acute Pulmonary Edema and Drug-Induced Secondary Immune-mediated Hemolytic Anemia. In other words, the Convenia shot killed Glenn by causing his immune system to attack his red blood cells . . . causing him to literally drown in my arms from his lungs filling with fluid.

    Second, he handed me the written copies of the report he filed with with Zoetis (Convenia’s manufacturer) . . . the report he filed with the FDA CVM . . .the report he filed with the AVMA and copied to the JAVMA.

    Third, he handed me the office’s new policy on Convenia – that it will only be administered as a last resort drug for non-responding bacterial skin infections and UTI’s”. He walked me around to each exam room in the office that had this new policy posted, IN FRAMES WITH GLASS and next to each frame was a literature rack with printed brochures regarding pet parents being informed and educated about medication and reactions/side-effects. In another Frame in each and every room was the practice’s policy that a pet parent has a right to decline any medication . . . and next to each of those frames was a separate sheet with each and every side-effect listed for Convenia. He asked me to pick up and turn over each and every brochure and on the back of every piece of printed literature, centered at the bottom, it stated “In Memoriam of Glenn”.

    Lastly he showed me the order form for the practice’s new written forms that each and every pet will have on file with any medication objections . . . and he called up multiple files in the computer system showing me that each pet now has, on their main screen, right below their name and breed, a section for “DO NOT PRESCRIBE OR UTILIZE FOLLOWING MEDICATIONS”.

    My Vet cannot apologize enough to me for Glenn’s loss and the literal hell that it must have put me through having Glenn die in my arms so horribly due to his and the other Vet’s at the practices’ ignorance regarding Convenia, and admitted that other pet parent’s had said they did not want Convenia for their pets, but that they always convinced them that it was a safe drug. He stated that unfortunately he had to see the results of Glenn’s necropsy in writing for him to realize that much of what is put online from pet parent’s regarding the death of their own pet’s was likely true. He said that he understood if our family did not use the practice anymore but that hopefully Glenn’s passing will save other parent’s the grief that I have had to endure . . . and that he can not and will never forgive himself for not listening to my wishes.

    I said to him I only hope that as I held Glenn in my arms as he died so horribly that he heard every word . . . how much I loved him . . . as he looked into my eyes, he saw that my soul, along with my heart, was breaking into a million pieces . . . AND THAT WHILE GLENN’S DEATH HAS CAUSED A POSITIVE CHANGE AT THE PRACTICE THAT LIKELY WILL PREVENT OTHER PET PARENTS FROM HAVING TO SEE AND FEEL WHAT I HAD TO WATCH, THAT I COULD NOT (and still have not) FORGIVE THE PRACTICE . . .

    and I don’t know if I ever will.

    I Love you Glenn and always will. I will see you again some day . . . and we can “stay for sleep”.

  7. Violeta and to all on here I am so sorry for your losses. I just lost my 13 year Hemi. He went to the vet on 7/16 and died 48 hours later after a shot of Depomedrol and Convenia. It was a traumatizing death…yowling in pain, unable to move, disoriented, gasping for air, drooling…etc. Everything happened within an hour. I wish I never let the vet give him the covenia…all other tests/bloodwork were fine for his geriatric workup on 7/16. He had itching and was chewing off his belly/hind leg fur from stress so that’s how he received the shots. He’s had Depo shot before but never with covenia. I am beside myself with grief. Comfort and love to you all and your fur babies who passed from this .

  8. My cat had this shot for an abscess from a cat bite. 2 weeks later my previously healthy 5 year old cat went into liver failure, septic shock and died a painful, horrific death.


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