Penicillin G Injections

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Post   » Sun Apr 11, 2021 1:53 pm

Hi all.

Dealing with my sweet boy Smokey who has had eye crust and a cloudy eye.

I was prescribed eye medicine and shots of Penicillin G. They gave him one at the vet and I am supposed to give 13 more.

Than I went online and was scared.

His eating was going down but now is worse. Out comes the critical care and bene-bac.

The vet I went to is an exotic vet.

Just scared to give it to him but am desperate for him to get better.

Anybody ever given a cavy this shot? Should I demand something else?

I dont know what to do.

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Post   » Sun Apr 11, 2021 3:55 pm

Penicillin and related antibiotics are on the list of dangerous medications that should be avoided. Here is a link with a list:


Post   » Sun Apr 11, 2021 4:34 pm

Thanks ItsaZoo.

Orally obviously very bad as it will wipe out the good gut bacteria.

But a shot doesnt hit the gut. And I have seen many weird responses to what Penicillin G even is.

Was told this on another forum:

Welcome! When given orally it will usually kill guinea pigs, injections however do not go through the digestive system and cannot destroy the good bacteria, causing the fatal enterotoxemia and so are considered safe, albeit not the first port of call. I know of a few piggies who have been successfully treated with injections of penicillin, and have had them offered for one of my own should the treatment we initially tried not have worked.

But absolutely never, ever to be given orally and it should be injected carefully to ensure none is left on the coat after injecting as the piggy may groom it off and ingest it.

So super confused. Just want my little buddy better :-(

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Post   » Sun Apr 11, 2021 4:43 pm

That is confusing, and I’m not sure what the G means either. I hope your little one starts to improve!


Post   » Sun Apr 11, 2021 5:12 pm

I am going to call monday and see what they say. Seems we only know a little about our buddies medically. Visit was expensive and now feel bad he even had a shot but then I read what others have stated and am like UG.

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Post   » Sun Apr 11, 2021 11:12 pm

I can tell you it is not recommended in the Exotic Animal Formulary. The theory is that there are many medications that are much safer so why not use them instead of taking a risk?

Read over:

The only safe ways I have read about using dangerous medications is in an ophthalmic (eye) solution, very sparingly as a topical treatment for a bacterial skin infection (Triple antibiotic ointment, for example), or as a last resort in a specially formed antibiotic bead placed in a difficult to clear up tooth or jaw infection.

If you are seeing negative reactions right now, I would stop giving the antibiotic. Diarrhea would be a sign it absolutely must be stopped.

And got the T-shirt

Post   » Mon Apr 12, 2021 10:07 am

I'd be very hesitant about the shots. While it's true that the inject med doesn't go through the digestive tract directly, it still is spread all through the body and will eventually hit the digestive tract. An injection probably doesn't cause the massive gut bacteria die-off that an oral med would, but would still cause some, and that may be enough to cause fairly severe problems.

Penicillin G is just a naturally occurring penicillin:


Post   » Mon Apr 12, 2021 12:54 pm

Irie was given bactrim injections and he took it very bpattters said it does spread all over the body..
And Irie had problems pooping and had soft poops after injections...he was really poor andstopped eating by himself. And Bactrim is highly recommended, but even that it was too much for our boy who doesnt handle ABs well.

I would never ever ever risk penicillin injections..and the exotic vet that gave that topig-i dont know..where did he buy his diploma;)?


Post   » Mon Apr 12, 2021 3:50 pm

I hear you and thanks for the info. I have heard some things being done with it and Cavys but I found a formulary as well and said do not use
I was also thinking that it would eventually make it to the gut via blood.
Now if we had tried another thing 1st and the choice was this or death I would try it.
Also amazed at some on the contradictory info.
Found this -
"One advantage of the parenteral route in hind gut fermenters is that the antibiotics bypass the digestive tract and avoid potentially disturbing cecal microorganisms."
I cant say for sure but the last large poop he had was at the vets pre-shot.
No diarrhea but the poops are small. I have been doing the critical care and keeping up on the eye meds.
I have now called twice. If they dont give me something else Tuesday going to another vet unless they tell me something is "special" about this shot.
Sucks I did not know before the 1st shot was given.
Just wish I could actually talk to the dang vet. This is where I went and the only dedicated exotic vet in my area -

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Post   » Mon Apr 12, 2021 4:07 pm

Well, I don't blame you for choosing this clinic. They certainly have the credentials as exotic vets, and list pocket pets specifically, and have care information for guinea pigs. If my pig was ill, I would have chosen a clinic with these credentials, especially since they also have emergency care for exotics.


Post   » Mon Apr 12, 2021 5:15 pm

Thanks @itsazoo. That why to me this whole Penicillin G thing is so weird. Maybe they know something I do not?


Post   » Wed Apr 21, 2021 5:45 pm

I wonder if I should have just gave the darn shots. I have found some info that it is OK and the place I went seems very well credentialed for exotics.
This sucks. I went to a second vet and got Batril which has done nothing.
Going back to new vet and still have an appointment for old
Just want my little Smokey better ;-(

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Post   » Wed Apr 21, 2021 10:42 pm

How long have you been using the Baytril? My guinea pig had trouble with that and stopped eating after about 3 days. It's usually effective but can be hard on the digestive tract. Definitely get probiotics and give them about an hour after the Baytril.

This is a tough situation, and I think it comes down to which vet you feel more confident with. I hope you start seeing some improvement with Smokey.

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Post   » Mon May 10, 2021 1:13 pm

Penicillin G is SAFE and very good if given as injections for serious diffuse infections. Also my guinea pig has been prescribed with this medicine from one of the best and famous cavy savvy vets in Italy. My piggie has a bad issue, but just after the first shot he looked better than before. I also had great doubts, (as much as giving him Metacam in high doses) but the vet said that it can kill the piggie only if given orally. The problem in my case is only that my piggie is stubborn and refuses to open his mouth for eating CC... it is a fight all day long...
My piggie was also put under Baytril and had the best hunger and poo ever... Reactions are different, I see...
Have trust in your vet because he is probably updated.


Post   » Mon May 10, 2021 3:08 pm

This is very interesting to me,cause none of the vets we used over the years would ever do that...

And i am against using guinea pigs for experiements and everything-i think all should live like kings and queens:).
However-i found this..if anybody would like to read it.. ... &type=client

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Post   » Mon May 10, 2021 7:14 pm

It is a very old article. I do agree with you, Lisa12, I think you would not recommend Penicillin G.

I would NEVER say it was SAFE!

When there are other safer medications, there is no reason to choose one that can cause serious problems. I do agree the injections are a safer method but still would not advise it.

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