Safe Antibiotics for Cats

By Betty Lewis

Whether your cat's suffering from a gastrointestinal disorder, a urinary tract infection or an infected wound, chances are the vet will prescribe an antibiotic to help her recover. There's a wide array of safe antibiotics for cats at your vet's disposal. The medicine he chooses will depend on what sort of infection she's fighting, as well as her current medical condition.

Different Infections, Different Antibiotics

When bacteria's working against your cat, an antibiotic can be successfully employed to fight back. If your cat has an infection, the vet will have to figure out what's at play to treat what's ailing her because not every antibiotic will work against every bacteria. The Merck Manual Pet Health Edition states that there's a wide array of classes of antibiotics for animal use, including penicillins, sulfonamides, cephamycins, quinolones, tetracyclines, cephalosporins, macrolides and aminoglycosides. Some antibiotics are effective against a host of bacteria, known as broad-spectrum, while others are very specific in their targets, known as narrow-spectrum.

Oral Antibiotics

Oral antibiotics are available in tablets, capsules, syrups or in oral suspension. Generally, oral suspensions tend to have a short shelf life, usually around two weeks, and often require refrigeration. Some broad-spectrum oral antibiotics commonly used in cats include amoxicillin, cephalexin, doxycycline and trimethoprim-sulfate and tetracycline. Other oral antibiotics your vet may consider for your cat, depending on her condition, include cefpodoxime, erythromycin, azithromycin, sulfadimethoxine, marbofloxacin, chloramphenicol, clindamycin, tylosin, metronidazole, enrofloxacin and orbifloxacin.

Topical Antibiotics

If your cat is suffering from a skin condition or a wound, the vet may prescribe a topical ointment containing antibiotics to heal an existing infection or keep infection at bay. Other ingredients may be in the ointments, including corticosteroids such as hydrocortisone acetate and prednisolone acetate, to provide relief from itching or inflammation. Topical antibiotics commonly prescribed for cats include penicillin G, bacitracin, gentamicin sulfate, neomycin sulfate, polymyxin B and thiostrepton.

Injectable Antibiotics

Sometimes oral antibiotics aren't practical, such as for a feral cat, or perhaps your cat simply doesn't take medicine well. Injectable antibiotics typically provide antibiotic therapy over a 14-day period, so there is no daily pilling involved. gentamicin, enrofloxacin, tylosin and cefovecin sodium are effective injectable antibiotics that are safe to use in cats.

Ophthalmological Antibiotics

A weepy eye isn't all that unusual in cats and the vet may prescribe an ointment to help clear up an eye infection. Neomycin, bacitracin and polymyxin B combine to make an often-used triple antibiotic ointment that's effective as an ophthalmic treatment. Other ophthalmic antibiotics include erythromycin, gentamicin and tobramycin.

Dosage and Side Effects

Antibiotics aren't one size fits all. When your vet settles on an antibiotic for your cat, it's based on several factors including what's causing her illness, how the drug will affect the infection, how the medication will be administered, other medication she's taking and the supportive treatment necessary for healing. When your vet prescribes an antibiotic for your cat, it's vital that you give her the medication as instructed. If she appears to feel better and act like her old self, don't discontinue her medication. Failure to give the entire course of treatment can result in a relapse, reinfection or resistance to the antibiotic. Side effects can vary widely, and may include diarrhea, vomiting and fever. Each medication carries its own potential side effects; your vet can fill you in on what's normal and what is not.