Lost Appetite in Penicillin G Procaine/Benzathine "Bicillin" Treatment for Abscesses

[hhumphrey13]

Hi everyone,

TL;DR: Rabbit diagnosed with either jaw cancer or jaw bone infection. Currently treating with Bicillin. She gradually stopped eating. Why?

My 7 year old rabbit, Leila, has almost completely lost her appetite, and I don't really know why. The vet thinks she either has jaw cancer or a jaw bone infection, and it all started in February.

February 2016 - Started grinding her jaws/teeth and starting drooling. Vet thought it had to do with an impact of hair in her stomach, so she was put on gut motility drugs and hairball gel.

February through July 2016 - Symptoms continued and she gradually started eating less and less hay and became anorexic. Vet still thought it had to do with her gut, so he continued to prescribe hairball gel.

July 2016 - Symptoms and weight loss continued. After having a strong feeling that something was wrong with her teeth due to her grinding them and drooling, I strongly suggested a dental x-ray from the vet. He agreed to do this and also wanted to perform blood tests, so he anesthetized her with gas in order to draw blood and took the dental x-rays while she was out. He immediately noticed that something was off with her right lower jaw and said it was either cancer or an infection but needed to wait on the blood work to make sure. A few days later, he called with the blood test results: Because she didn't have a high white count, he did not think it was infection. Additionally, because she was anemic, he said that was a sign of something chronic--like cancer. Cancer was his final diagnosis, but said since there was still a possibility that it was infection and the cancer was not treatable, he prescribed entrofloxin (Baytril) as a last ditch effort. He told us to keep her as comfy as possible until the end.

August 2016 - She stopped eating hay completely, so we began making "Angel's mush" for her, which she would gobble up quickly. Continued Baytril.

September 2016 - She gained weight since she was eating again. She started getting abscesses on the right side of her face (same side her bad jaw is on) both above and below the eye. They ballooned quickly. Our vet couldn't really help us or didn't know what to do. He said surgery would be too much on her since she's older and in poor condition.

September 21, 2016 - I took matters into my own hands and researched "abscess treatment without surgery" and came up with the Bicillin treatment. With the our vet's approval we started injections on September 21st, 2016--0.25 ml every other day of Dura-Pen (she weighs 2 kg). The huge abscess on her face bursted two days later; we squeezed out as much pus as possible and let it scab over on its own.

October 13, 2016 (today) - The former huge abscess looks worlds better as it is just a small scab, but she still has a small abscess above her eye that you can't notice until you actually touch it. We're still giving the Bicillin (Dura-Pen) every other day, but two days ago, we reduced the dosage to 0.2 ml instead of 0.25 ml.

Problem: She's not eating. This happened gradually over about two weeks and got to the point where she won't eat at all. What's strange is that most of the time, she acts hungry, and she'll run in circles around our feet when we bring out her mush, but then sniffs at it and won't eat. She's never had any problems with eating unless it's a GI issue, in which case she would exhibit obvious signs like laying on her tummy and being in pain, but she's never been outright finicky. This has been going on for over a week. We've been force feeding her with Oxbow Critical Care. We've also given her Metacam for pain, and she was on Prednisone for a while--nothing seemed to help with her appetite.

We're really at a loss here. Could the Bicillin treatment be causing her loss in appetite? I read some where that since we're giving the shot subcutaneously, it bypasses the stomach, and therefore could not upset it. Is this true? I must say, the gradual loss of appetite happened close to the same time we started giving the Bicillin, but I suppose it could be a coincidence. If it is the possibility of the Bicillin, can we and should we lower her dosage even more?

Thanks in advance for any advise or insight you may have.

 

[JBun]

Any antibiotic has the potential to cause nausea/digestive upset in rabbits regardless of the dose given. Pen g has to be given to rabbits by injection, and yes it usually means it won't upset their digestion, but there are always the rare cases where a rabbit is sensitive to it regardless. I've had an injected antibiotic cause nausea/lack of appetite in a rabbit before. If you feel it's the antibiotic causing the lack of appetite you could always ask your vet about switching to a different antibiotic, making sure that it's one that penetrates bone if the infection is verified to be in the jaw bone. Also make sure that the method of administration is safe for rabbits, as some antibiotics are deadly to rabbits if given orally.

If you decide to stick with the durapen and want to try a lower dose, that is something you should discuss with your vet as lowering the dose too much will also affect the antibiotics ability to fight the infection. Your rabbit seems to already be getting a pretty low dose for her weight and personally I wouldn't want to lower it anymore. Normal dose is 40,000-80,000IU/kg and you're giving 30,000IU/kg(?), so that's even less than the lower recommended dose. Whatever antibiotic you end up giving, always keep a close eye on your rabbits poop. This will give you an indication of any problems it might be causing. Small poop means a decrease in appetite, sticky poop means irritation to the digestive tract, runny poop means the gut flora has been disrupted and caused enterotoxaemia, which is an emergency.
http://www.medirabbit.com/Safe_medication/Safe_drugs_main.htm

Another possibility for the lack of appetite is that it is causing her jaw pain when she eats. You don't mention the meloxicam/metacam dose, so it's possible it's either being under dosed by your vet(common mistake with non rabbit savvy vets) or it just needs to be raised to the higher dosage range. Or your rabbit may need to be on a stronger pain med like tramadol.

One other possibility could be your rabbit has developed other dental issues: like molar spurs that cut into their cheek or tongue when they eat, rotten teeth that need removing, elongated tooth roots that cause pain when chewing, and these all can cause a lack of appetite due to pain when chewing, while the rabbit may still act interested initially at wanting to eat. It's also a common thing to occur when a rabbit has been on critical care feedings for a while, for them to develop molar spurs as they haven't been eating hay which would normally keep their teeth worn down.

Just making a guess here by some of what you've said, but your vet doesn't sound like he's terribly knowledgeable about rabbits to me. So if possible at all, first thing I would do is find a rabbit savvy vet or specialist. Next I would make sure the vet does a thorough dental exam to rule out molar spurs or other dental issues as a cause for the lack of appetite. If the initial dental exam doesn't show any problems, I would want new head xrays taken to see if there are any other underlying dental problems that show up, and also where the infection is at this point. If the dental exam and xrays don't give a cause for the lack of appetite, I would want to switch to a different antibiotic to see if that causes an increase in appetite, and consider increasing pain meds as well.
http://rabbit.org/vet-listings/

Just know that if it is in the jaw bone, that clearing it up completely is very unlikely and it's just more a matter of managing the infection with antibiotics and pain meds, which includes switching antibiotics when needed, such as when the current one isn't having any effect on the infection. Antibiotic treatment will likely have to be long term as well. I know of rabbits that had to remain on them for over a year. There will come a point too, when you will need to decide whether continued treatment is helpful for your bun or not as the ongoing infection will eventually cause weakening of the jaw bone, and at some point the pain and infection will no longer be manageable with medication. And only you and your vet can determine when this time comes.

Just one more thing, I don't know if the prednisone was a recent thing, but if it was please do not let it be given to your rabbit again, unless in the direst of circumstances. Steroids cause depression of a rabbits immune system, which is the last thing you want when your rabbit has a bacterial infection. Generally they are only used as a last ditch effort because of their negative side effects in rabbits.
http://www.medirabbit.com/Safe_medication/Corticost/Cortico.htm

http://www.medirabbit.com/EN/Dental_diseases/Treatment/Facial/abs_dental.htm
http://www.medirabbit.com/EN/Skin_diseases/Bacterial/Absc_treat/abscess_treat.htm
http://wildpro.twycrosszoo.org/S/00dis/Bacterial/Osteomyelitis_Lagomorphs.htm

 

[Aki]

Loss in appetite is a possible side-effect for most medication. I haven't done specific researches on this, but vaccination can cause a loss in appetite in rabbits and it's an injection so, I'm not really convinced by the 'bypasses the stomach so causes no upset' argument. Your rabbit problem is probably the consequence of several things : the medication may play a part (Bicillin is considered to be pretty safe, but loss in appetite is listed as a possible side effect as you probably know), a rabbit who had stasis before is more prone to get it again, the stress from the treatment might play a part, she might have felt unwell and once the process has begun, it's hard to stop it, maybe she's got another tooth problem...

Considering you are giving her pain meds, the absence of signs of pain doesn't mean much. Moreover, my rabbit, Aki, had GI stasis for several weeks this year and showed no signs of pain, mainly because there was no gaz (it was the 'silent' kind of stasis, when the gut is like 'dead' and I thought it was even scarier than the gurgling form). Is your rabbit pooping at all? Have you tried giving her different kind of food (like baby food, fresh vegetables...)? Can you hear her guts, is it 'moving' when you put your hand on it?
If your rabbit is not eliminating correctly, it might be a good idea of go to your vet to take an x-ray of her stomach. Maybe Reglan / Emeprid might help making her want to eat? Rabbits don't stop eating for no reason so either she's in pain, either the drug is upsetting her stomach or she has stasis for some reason. It's sometimes really hard to pinpoint the problem (it took me almost a month of absolute hell to discover why Aki wasn't eating when there seemed to be nothing wrong and the vet couldn't find anything either - of course, there was a reason and once I found it it was obvious...).
If your rabbit is almost healed, slowly lowering the dosage of Bicillin might be a good idea. In any case, meds and a regular handling is never ideal for rabbits who have trouble eating. Have you called your vet to ask about this?

 

[hhumphrey13]

Here's an update for you guys. We're happy to hear any insights anyone is willing to give us.

We took Leila to a different vet to have her teeth examined and find out if that's possibly why she isn't eating. The vet said she couldn't find any problems with her teeth. We sent that vet Leila's x-rays, which show a deformation in her right mandible. The vet sent them to a specialist surgeon, who looked at them and said he thinks it looks more like a tumor than an abscess.

The vet recommended we make an appointment with the surgeon, who would biopsy the tumor, debulk the area, and then send it out to have a vaccine developed. So we're waiting on that.

In the meantime, we asked the vet about whether or not we should take Leila off the Bicillin because she's not eating. The vet said to stay on. But after careful consideration, we decided to cease the treatment. This is because Leila has been eating so little and has become so emaciated, and because it's just not possible for us to force-feed her enough times during the day to sustain her, and also because we didn't think she would have lasted until this appointment with the surgeon. She's already started eating on her own, so we're reasonably certain that was the cause of her lack of appetite.

The challenge now is dealing with any abscesses that emerge or re-emerge, and hoping she is eating and comfortable for long enough to get her to the surgeon.

Her poops were very small when she wasn't eating. They're normal-sized now and of normal-consistency.

Regarding metacam: we actually abstained from giving it to her out of fear that it was hurting her stomach. So she actually wasn't on pain meds for most of the time that she wasn't eating, and she also didn't exhibit any clear signs of pain. The typical dosage we use when we do give her metacam is hard to define. We use the syringe that came with the medicine because the medicine has to be drawn from the tip of the container. The syringe is marked in terms of the animal's weight, rather than the amount of medicine. I believe it was our vet who said to give her an "8-pound dose". The concentration is 0.5mg/mL. Does this dose sound consistent with what you guys give for chronic pain?

Thanks to both of you for your responses.