Convenia, a long-acting injectable antibiotic, is very convenient. As is apparent, the drug’s name is based on its convenience. It works for up to 2 weeks. But is it worth the risk? Are you sacrificing safety for convenience? Will your cat pay a heavy price for a medicine which is convenient to you? I think this is quite an interesting philosophical question.
Having read up about this drug, my personal opinion is that it is probably not worth the risk to use it. As a result, if my veterinarian asked me if he could give my cat a long-acting antibiotic, I would first ask the name of the antibiotic and about the possible side-effects. Even then I would probably say no for the following reasons.
Stays in the Body for 2 months
The first word of warning about this drug is that it stays in the cat’s body for over 2 months. As a consequence, if there is a bad reaction the body will not clear the drug in the usual short space of time which occurs with other antibiotics and therefore the cat’s owner will have to request that her cat is urgently hospitalized and given long-term treatment, which, with respect to one case (see below), cost $6,000 (USD). It is worth mentioning, that there is no way to nullify the effects of the drug once it is in the body so if there is a negative reaction all you can do is treat the cat intensively and hope for the best.
All drugs are to a lesser or greater extent poisons for a cat but there are, of course, substantial benefits and the benefits outweigh the negatives. There is always a risk of side-effects, so if the drug remains in the body for such a long time those side-effects will continue to be generated with possible grave consequences, even death.
There is still some misinformation (or out of date information) on the Internet about Convenia. For example, the European Medicines Agency website has a document dated 2006 which states that “no side effects have been reported with Convenia to date”. Clearly that is out of date. The information should have been updated. It may have been incorrect at the time it was written because the company which makes the drug, Zoetis, state that there have been reported side-effects in foreign market usage.
The side-effects include anaphylaxis (an allergic reaction leading to shock), tremors, ataxia, seizures, acute pulmonary oedema, facial oedema, injection site reactions, haemolytic anaemia, salivation, lethargy, vomiting, diarrhoea, loss of appetite and pruritus.
Based upon my research, the most common adverse events are anaemia, tremors/ataxia, seizures, diarrhoea, lethargy, anorexia and death.
It may also be the case that Convenia is being administered too often when there are safer choices. This may be because it is highly convenient.
Personal Experience of Long-acting antibiotic
I have been asked by my vet whether I wanted my late cat, Charlie, to be injected with a long acting antibiotic and I said yes because I knew that Charlie was one of those cats who hated to be given a pill and at the time I was unaware of the risks. It was almost impossible to get a pill into his mouth and down his throat. This makes Convenia highly attractive to many cat caretakers/guardians. This sort of drug is probably becoming increasingly popular.
Humans and Antibiotics
I’ve always thought that some veterinarians can be a little bit too eager to administer antibiotics almost as a preventative measure. This goes against modern thinking with respect to administering antibiotics to humans. There is currently a lot of thought being given to the problems that we are creating for ourselves if we dispense antibiotics too freely because bacteria becomes resistant and there may come a time when antibiotics don’t work which would be a catastrophe for humankind unless there are alternatives. Indeed, a lot of research is currently taking place to find alternatives (by this I mean different ways to kill bacteria).
Dr Lisa Pierson refers to the case of Eddie. Eddie’s veterinarian gave him a shot of Convenia even though, according to Dr Pierson, the shot was unnecessary. Convenia should not be a first choice antibiotic in dental issues according to Dr Pierson. It was given after routine dental cleaning presumably to prevent a possible bacterial infection.
Eddie stopped eating and had severe diarrhoea within two days of being injected with Convenia. At this point there was a possibility that he could have died because there have been some cases of cats dying shortly after being injected.
As this was an emergency, Eddie was hospitalised having developed severe anaemia which is a known reaction to drugs which Convenia belongs to. Eddie received blood transfusions and specialist care. He recovered completely but it took a long time and as mentioned it was extremely expensive – hardly convenient for Eddie’s guardian.
On the Internet, you will discover other stories about this drug of a similar nature but there aren’t many. I think the potential dangers are somewhat underplayed on the Internet, which, incidentally, may indicate that the drug is relatively safe.
However, this is about risk and benefit. As mentioned, with a long acting drug the chemicals stay in the body for a long-time and are not flushed out relatively quickly which is usual for conventional antibiotics. It is this, as I see it, is which raises the risk to an unacceptable level and which is why I would not agree to its use on my cat.
Sources: Dr Pierson (catinfo.com) – ema.europa.eu – medhelp.org – zoetis.com – ifdogscouldtalkasvh.blogspot.co.uk