Thousands of doses of antibiotics are dispensed each year for ferrets and rabbits. Importantly, not one single dose of any of these antibiotics is approved for the animals that are receiving the medication. Presently, there are no antibiotics approved by the FDA in the United States for the small mammal pets classified as minor species. It is likely owners of these animals do not realize the antibiotics they are giving to their small mammal pets are not approved for their pets. Although, this does not change the fact that antibiotics are important medications for ferrets and rabbits, it is best that owners be informed of this information.
An important consequence of the lack studies to gain approval is that there are few pharmacokinetic investigations of antibiotics in ferrets and rabbits. Veterinarians do not have studies directing them to either dose or length of treatment or frequency of administration of antibiotics in ferrets and rabbits. There are no drug company brochures guiding veterinarians as to the indications of certain antibiotics in ferrets and rabbits. Veterinarians who treat ferrets and rabbits must rely largely on empirical data and anecdotal information when using antibiotics in these animals. It is therefore not surprising if antibiotic treatment failure occurs in these patients when the very basics of antibiotic administration are unknown.
The best antibiotic to use is based not only on the spectrum of activity of the antibiotic but also on the safety of that antibiotic in rabbits. It is always preferred to use an antibiotic that has the least likelihood of inciting gastrointestinal disease. Some of the safer drugs include trimethoprin sulfas, Quinolones, chloramphenicol, aminoglycosides, and metronidazole. Antibiotics that are intermediate in their ability to incite gastrointestinal disease include parenteral penicillin, oral or injectable cephalosporins, tetracycline, and erythromycin.
Antibiotics that are highly likely to cause gastrointestinal dysbiosis include amoxicillin, ampicillin, clindamycin, and lincomycin. They suppress the normal gastrointestinal flora allowing other flora to proliferate leading to deleterious changes. The abnormal flora changes the pH which increases volatile fatty acid production, thereby further suppressing the growth of normal bacteria. Eventually, enteritis develops and ultimately the production of toxins from Clostridium, specifically Clostridium spiroforme (iota toxins) leads to enterotoxemia.
Administering oral medicines to a rabbit
Even the tiniest rabbit can put up quite an effective fight if it doesn’t want to take its medicine. It’s important to be calm and in control when giving your rabbit medicine so that neither you nor your rabbit gets hurt (even our most experienced volunteers have been bitten by rabbits trying to avoid their med.
To give oral medications to your rabbit:
Wrap your rabbit in a towel: Place the towel over your rabbit’s back and ‘tuck in’ the edges to confine your rabbit’s movements.
Carefully kneel over your rabbit, so that your knees are on either side of your rabbit’s head, and your weight is on your feet or butt (and not on your rabbit’s body in any way!) Bring your legs and knees in close to your rabbit’s body to immobilize him or her during the procedure.
Keep the medicine syringe in your dominant hand.
Use your non-dominant hand and place your thumb and fingers over either side of your bunny’s face, so that you are touching the upper sides of his or her mouth on both sides.
Gently pull your rabbit’s cheeks/lips upward, being VERY careful to keep your fingers away from the front of your rabbit’s face. That’s where his or her very sharp teeth are!
Place the syringe into the side of your bunny’s mouth. There’s a gap between the front and back teeth that allows for a syringe.
Gently empty the syringe into the back of your rabbit’s mouth. Allow him or her time to swallow–don’t dump the whole syringe fast if it’s a full syringe (if you are administering more than .3 of a cc, slow down a bit to give your rabbit time to handle the fluid).
Apologize profusely and give your rabbit one too many treats to try to buy back his or her love and affection.
Injectable antibiotics for rabbits
Some infections require injectable antibiotics that your vet must prescribe. “Pen-G” or “Combi-Pen” are injectable antibiotics sometimes used in bunnies.
Skin irritation or formation of sterile abscesses after subcutaneous injection of antibiotics like penicillin or enrofloxacin (Baytril) is possible. When the antibiotic is dissolved in a water-based solution, e.g., enrofloxacin, the formation of sterile abscesses can be avoided by diluting the amount to be given by the same amount of a sterile saline solution. Beside sterile abscesses, the use of Baytril over longer periods of time may lead to muscle necrosis Fluoroquinilone antibiotics can moreover lead to cartilage damage of the cartilage and damage of joints (arthropathy) when used over a longer period in young rabbits.
Risk of Antibiotic-Associated Diarrhea
Yes, with caution: nephrotoxic
No oral form available
Yes, impregnated in antibiotic beadsYes, in nebulization protocols