Emergency: Vet wants to give penicillin!!


Post   » Thu Dec 25, 2014 6:16 pm

Hello, everyone

(I will apologize beforehand for the long post. I am trying to be as detailed as I can. For those of you who do not want go through all of my post I have written a short version bellow)

I have Freya, a 5 year old female guinea pig. More than 3 weeks ago I took her to the vet because she started being incontinent and she was leaking urine. The vet did a physical examination, took a urine sample which was bloody (through pressure in the abdomen) and an ultrasound which showed sediment but no bladder stones and started her on Baytril 1ml twice a day orally because he suspected a UTI. Her appetite and poop were normal but she was feeling a bit down.

A few days later there was no improvement as she was still leaking urine. I called the vet who told me to continue the Baytril for 2-3 weeks and that it was too early to notice an improvement as the infection seemed serious. Also, he told me that the culture from Freya's urine got back negative but I should continue with Baytril anyway.

By the way the vet doesn't have a specialty in exotics or guinea pigs in general but he is very good with a lot of experience and has been my vet for 2 and a half years (I live in Greece and the vets here do not specialise in anything so this vet was the best I thought I could find).

Anyway, I called the vet again on the 11th day of the treatment and he told me that it seems the Baytril is not working and that she probably has some infection that is resistant to Baytril. His plan was to stop Baytril for 5 days then go to the vet's office and get another urine sample which I did.

The results came out after 4 days and the culture showed that she had an infection caused by two organisms: E. Coli and Proteus Mirabilis which are both susceptible to Baytril!! My vet told me to start the Baytril again.

At this point Freya was eating very little and she deteriorated really quickly over a few hours to not eating at all on her own. Also she lost weight, she was leaking blood and got really bloated. I was trying to force feed her Cavia Nature Rebalance pellets with a syringe unsuccessfully since the pellets are hard to pass through a syringe even if you soak them. I couldn't find Critical Care anywhere because it is not imported in Greece.

Out of pure luck, I found an animal clinic that has Critical Care and I wrote them an email to which they answered in an hour. I talked to the vet from the animal clinic (who is by the way American and has an exotic animal specialty - the only one with such specialty currently in Greece) and she was kind enough to provided me with Critical Care and metacam the same night. Her opinion was that it is not a UTI and it must be her uterus. The vet was really nice and seemed concerned about Freya.

She examined Freya the next day through physical examination and took two X-rays which showed that her stomach was extremely big and full of air and that her bowels were all pushed up. Apparently something was pushing her intestines up (according to the vet it was her uterus). I asked for an ultrasound but she said it is unreliable and that she will not be able to clearly see the urerus. She suggested putting a catheter in her bladder to clean her up and if that wasn't the problem an operation (hysterectomy). She also told me that the previous urine cultures where useless because you can not get a clean sample with pressure.

The following day she went under anaesthesia and the vet inserted a catheter to her bladder. She told me that her bladder was in a really bad shape and that there was blood coming out together with sand and epithelium. She decided not to open her up yet to see if the infection cleared after she cleaned Freya's urinary tract and if she doesn't improve dramatically in 2-3 days then we operate on her. She switch to Marbofloxacin 0.25ml daily instead of Baytril. We were also giving her injections of Metoclopramide, a motility drug to help with the bloat, metacam and Butarphanol to ease her discomfort. I kept feeding her the Critical care (30g a day). She also gave me some digestive enzymes and instructed me to give Freya megadoses of it C (over 100mg) and keep the Critical care going together with the Metoclopramide, the metacam and the Butarhpanol.

Freya started to get constipated (I suspect because of the Butarphanol which is an opiod drug) and was eating very little on her own although I was offering her food all the time. It looked as if some times she had appetite but she was too uncomfortable to move. After I stopped the Butarphanol she started pooping again and the bloat was getting better. There was little improvement however because she wasn't eating enough.

Today it's been 3 days after the catheterization with little improvement. For the record I am feeding her 50g of dry Critical Care a day with it C supplements (over 100mg), digestive enzymes and I am still giving her metacam. She is uncomfortable, unable to move and unwilling to eat on her own except a few times when she has appetite and eats a few vegetables or some hay. She is still bleeding but on the bright side, the bloat got better and she poops a lot.

The most alarming thing of all is that she is really thin! I can completely feel her spine and ribs and she looks extremely skinny and weak. Her weight however hasn't dropped at all since I started force feeding her. But compared to her previous normal weight of 1250g (before she got sick) she is now 1080. According to the vet that is normal and she is not critically underweight. Also, she told me that as long as she is not eating on her own she will never gain the weight back and the important thing is to maintain her in that weight.

So, getting to the point now, the vet doesn't think the big problem is her bladder but still thinks it's her uterus (she told me that the most probable cause is cancer in the uterus or bladder). She thinks that surgery is inevitable but she wants to make sure it is not a really bad case of infection by giving her AMOXICILLIN tomorrow. If Freya doesn't start eating by the day after tomorrow then she will operate on her. I objected to the use of penicillin based drugs and she told me that they are dangerous when ingested orally and not when given through injections. She also told me that vets DO give penicillin to guinea pigs to clear up infections and that I shouldn't worry. I told her I was uncomfortable with injecting her with penicillin and that we should try something else instead but she said that penicillin is our best choice now.

I am researching for quite some time about guinea pigs and penicillin and I really do not want to inject her with that kind of antibiotic. I have 10 hours to decide and I really do not know what to do. Freya is very sick and I do not want to do anything that will make her worse.

Has any of you a similar experience? Did any of you inject a pig with amoxicillin and what was the outcome?

PS: What is your opinion on giving her poop of a healthy pig through a syringe? I asked the vet about probiotics and she said they are not needed because Freya is taking digestive enzymes instead. Should I go on and do it anyway?


HERE is the short version for those who do not want to go through my post: I have Freya, a 5 year old female guinea pig who, according to the vet, has either a really bad case of bladder infection or some other malignant condition in her bladder or uterus. The vet wants to give Freya an injection of Amoxicillin and says it is safe when injected. What should I do?

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Contributor in 2020

Post   » Thu Dec 25, 2014 6:38 pm

I'm sorry, I couldn't take the time to read your post (people coming over), I will come back to it later... Whatever you do , do NOT let the vet give her penicillin.


Post   » Thu Dec 25, 2014 6:41 pm

Even as an injection??

Btw thanks for your reply. I would really appreciate it if you found the time to read my post because I have 10 hours until I call the vet.

That is my guess also that Amoxicillin would be toxic no matter what. Maybe through an injection it would be safer but the mortality rate just still be really high, right?

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Supporting my GL Habit

Post   » Thu Dec 25, 2014 7:04 pm

What's his weight? What was the dose of Baytril? I've had better luck with bactrim for bladder infections, although that doesn't sound like it would combat all your pig is infected with.

Extra fluids could help. I've often done subcue fluids when dealing with pigs' bladder issues.

I've heard of injecting penicillin, but I don't think I'd let my vet do that.

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Post   » Thu Dec 25, 2014 7:08 pm

As an injection such antibiotics can be given, in certain cases, where other drugs will not work. Penicillin, amoxicillin and other dangerous antibiotics are not toxic to guinea pigs per se. They have too broad spectrum effect against gut bacteria and if given orally, can result in fatal increase of Clostridium bacteria amount (the bad ones) and diarrhea. Injected antibiotic doesn't have immediate contact with intestinal bacterial flora, thus the side effects are minimalized.
I have read in our forum about injecting guinea pigs with penicillin in cases of bad tooth abscesses, and the results were positive.

And got the T-shirt

Post   » Thu Dec 25, 2014 7:12 pm

NO penicillin, including amoxicillin.

Not even as an injection. Most antibiotics are given to guinea pigs orally, as injection sites can develop painful sterile abscesses.

I haven't had a pig that has needed such an antibiotic, but I can't find anything, anywhere, that suggests that penicilin or its analogs are safe for guinea pigs.

It may be difficult for her to take a blood sample from your pig, but that would tell her whether or not the pig has an infection without the risks of giving amoxicillin.


Post   » Thu Dec 25, 2014 7:32 pm

Her weight is 1080g and the Baytril dosage as 1 ml orally every 12 hours as I stated above. But now she is taking Marbocyl 0.25 ml through injection for the last 4 days. I did give subcutaneous fluids twice.

I have also heard of injecting penicillin with mostly negative outcomes.
I know about penicillin and this is why I thought it was odd that an vet who specialised in exotic animals would give it to a guinea pig.
I am not willing to gamble with the pig especially when the vet thinks an infection is not her main issue. I would like to know HOW safe is injected amoxicillin? What percentage of pigs develop enterotoxemia or other fatal conditions?

I inject her myself for days, the injection is not the problem for me but the drug is. I also thought about a blood test. I asked her to take a sample through her bladder with paracentesis but she told me that she won't do that because she might pierce her uterus or intestine in the process given how upset her abdominal area is.

Btw thanks a lot for your answers

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Post   » Thu Dec 25, 2014 7:56 pm

See gl/stones.html
Is there any reason why your guinea pig is not getting sulfamethoxazole trimethoprim ? Bactrim here? gl/antibiotics.html#bactrim
Last edited by Lynx on Thu Dec 25, 2014 7:57 pm, edited 1 time in total.

You can quote me

Post   » Thu Dec 25, 2014 7:56 pm

"I would like to know HOW safe is injected amoxicillin?"

Simple. NOT AT ALL.

You have found a good vet, but I'm going to take a guess she's going by what UC Davis has done.


Some pigs have survived penicillin injections. I suspect that was pure luck and an extremely strong GI system. Injected antibiotics still work systemically, and therefore they still reach the GI even if not directly or as quickly.

If it were me I'd ask about using another AB first. As PooksiedAnimals and Lynx mention, Bactrim (trimethoprim sulfa; it goes by a number of names -- Septrin, Ditrim, TMP-SMZ, Tribrissen, and others) is usually the first AB of choice for a UTI.

I would NOT LET MY PIG BE INJECTED with penicillin or any penicillin analogue. No, it is not oral but it is still fatal in many if not most cases.

The only "nonstandard" AB I'd consider for a pig belonging to me if needed is Zithromax (azithromycin). It is in a toxic class of AB but has been used successfully in cavies.

Try Bactrim first.

"I am not willing to gamble with the pig especially when the vet thinks an infection is not her main issue."

You are wise. Go with your instincts; they are good ones.


Post   » Thu Dec 25, 2014 8:14 pm

I asked the vet about bactrim and she said that you cannot find it in Greece any more in the syrup form but she can prepare the syrup herself from the tablets. But she still thinks that amoxicillin is the best choice. Besides, Freya's GI doesn't work properly (she is bloated and doesn't eat by herself very much) so I guess injecting her with penicillin would completely destroy what's left of her GI function.

I guess I will push for Bactrim.

What do you think about probiotics or poop from a healthy pig? I asked the vet for probiotics and she said there's no need because she is taking digestive enzymes (oxbow papaya tablets). Should I give them anyway? Or should I give pig poop?

You can quote me

Post   » Thu Dec 25, 2014 8:22 pm

Either would be fine.

Digestive enzymes and probiotics are not quite the same thing. If you have a healthy pig you can give her "poop soup" from, that might be best and safest at this point. The papaya tablets are designed more for rabbits, which are similar to guinea pigs in many ways but NOT in all and again, digestive enzymes and beneficial bacteria are not the same thing.

Commercially available probiotics don't have the exact beneficial bacteria in them that normally reside in a guinea pig's gut. They're helpful nonetheless, but as badly messed up as Freya's GI is right now, I think droppings from a healthy pig are your safest bet right now IF you have a healthy pig you can get them from.

" ... so I guess injecting her with penicillin would completely destroy what's left of her GI function."

I tend to agree, and further to believe she would not recover.

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Post   » Thu Dec 25, 2014 11:39 pm

I am so glad you are aware of the risks of using penicillin. We've had several people post here that did not know and lost their guinea pigs.

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Post   » Thu Dec 25, 2014 11:53 pm

"I asked the vet about bactrim and she said that you cannot find it in Greece any more in the syrup form but she can prepare the syrup herself from the tablets."

This is a common pediatric drug here, so it is also possible that the syrup can be found at a human pharmacy. I agree that Bactrim is the better choice for UTI. I have had pigs on Baytril for UTI with no improvement whatsoever. Bactrim is usually easier on the GI system than Baytril, in my experience.


Post   » Fri Dec 26, 2014 4:38 am

Thank you for your answers!

Unfortunately, the vet was correct, I googled it and the Bactrim syrup was discontinued a year ago for commercial reasons. I can still call the pharmacies to double check but today it's a holiday and most of them are closed. In any way I will ask the vet if she can prepare it herself using the tablets.

I knew that penicillin is lethal, not only from guinea pig sites but also historically from medical experiments that have used guinea pigs and rabbits. The thing is that I really trust the vet and she has been very helpful to us until now. She is also the only exotics vet here and seems really knowledgable. This is why I was so surprised to learn that some vets do use penicillin injections while knowing the risks.

In any case, Freya GI is not working properly because she is not eating by herself so I guess amoxicillin is out of the question. I will talk to the vet soon and see if we can use Bactrim or something less dangerous.

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Post   » Fri Dec 26, 2014 7:48 am

I saw the 1ml of Baytril - but that doesn't tell me what the concentration was (mg/ml). I was just trying to understand how strong of a dose of Baytril your pig was getting.

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Post   » Fri Dec 26, 2014 9:25 am

Find out what the smallest concentration of trimethoprim sulfamethoxizole pill is and work with that. Can be crushed, quartered, put in a suspension and properly measured.


Post   » Fri Dec 26, 2014 9:48 am

The Baytril was the standard syrup 0.5%. The concentration was 5mg of enrofloxacin in 1 ml. So she was getting 5mg every 12 hours. According to the second vet the dosage was too low and should have been 2ml every 12 hours.

I managed to find Bactrim under different brand name. The concentration is 480mg/5ml (400mg sulfamethoxazol and 80 mg trimethoprim) and her weight is 1080g. The vet instructed me to give her 0.6 ml every 12 hours. Is this correct?

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Supporting my GL Habit

Post   » Fri Dec 26, 2014 5:54 pm

480mg/5ml is 96mg/ml. Bactrim is dosage is 30mg/kg, which works out to be about 32mg for your pig. That's 0.34 ml for this strength of bactrim. Or at least that's what my math is getting me.

The 1ml of Baytril for your pig is on the low side or the normal Baytril range. Hopefully she'll improve on the higher dose?


Post   » Sat Dec 27, 2014 2:35 am

That's what my math is also getting to, 0.3 ml but the vet says 0.6 is the correct dosage. I gave her 0.6 in the end.

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Post   » Sat Dec 27, 2014 9:52 am

Ditto on both of your calculations.

The higher dose will likely not hurt but do watch for diarrhea.


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