After I relayed this information on our FB page someone commented that their vet was told to stop giving this shot but she couldn't remember why so I did some research on google.
This shot, as I understood it from my vets info years ago is mainly for deep tissue injuries and dental infections. Several of my cats have had this shot and we've had no problems or reactions from the ones who have received it. So needless to say I was not really that concerned about the shot until she told me this.
The first cat we had that got this shot was for a deep tissue wound. The second had diarrhea. Others that received the shot were feral and sick and I could not medicate them so they gave them the convenia shot for various colds/URI infections. The vet told us that even though it was mainly for deep tissue wounds that we could give it a try and it might help which it did. So the scope in which we have used the shot for was for more than just deep tissue or dental problems and it did seem to work.
One such instance was when our Wendycat had horrible watery diarrhea and stopped eating. After the shot she didn't eat for 4 days straight and then suddenly started eating whether it was the shot or something else we don't know but she survived and I was thankful the shot helped at least I think it did. I have noticed that my vet seems more willing to give this shot for a more wide variety of ailments that at first and I believe its because it seems to have helped. There are many drugs that are used for more things than they are intended for at first and vets have found other uses for them.
So back to my research online. I found this information that I did not know which is the down side of this shot. I think its good to know all you can about a medicine so you can make a decision as to what you would like your vet to prescribe for you cat as its usually the owners preference that determines this.
This shot is an extended slow release antibiotic. As with any medicines it can have reactions and sometimes they can be severe depending on the animal. The problem with this shot is that it is not like other antibiotics that are usually out of the system quicker. Convenia exerts its antibacterial effects for approximately 1-2 weeks but stays in the body for over 2 months.So if your cat has a severe reaction to this there is no way to clear its body of it. Death has occurred in some cases.
Convenia shots seem nice to those who don't want to go through the trouble of medicating once or twice a day as most antibiotics require but you must decide if it is worth the risk especially when there are safer means of medicating available. I believe, after much reading, that it is a good alternative for say ferals or for what it was intended for but in the future we will use this more sparingly than we have in the past in light of what I have learned about . Most people don't understand that the drug lasts in the system for up to 65 days. I know I didn't and so I thought I would pass this information along to all of you.
Here is a very helpful link where I got most of my information.