Common Antibiotics for Cats

A cat should not be treated with antibiotics unless its veterinarian has diagnosed an infection and determined which drug would be best. PetEducation.com warns that one of the "worst things a pet owner can do is stop treating an infection prematurely." Using insufficient doses of antibiotics, giving them too often or not for long enough may promote the development of resistance and make your cat sicker.

  1. Amoxicillin

    • The most commonly prescribed antibiotic for cats is amoxicillin. It is effective against bacteria that cause eye, ear and urinary tract infections, and, according to Vet Info, "it is beneficial over other antibiotics because it produces only minor side effects in most cats."

      Amoxicillin has a wide range of uses, fights many different bacteria and resists damage from stomach acid, resulting in a more effective and longer lasting drug.

    Cephalexin

    • Cephalexin, also known as Keflex, is a broad spectrum antibiotic useful in treating many common, uncomplicated bacterial infections. It is especially effective against staphylococcal skin infections, and Veterinary Partner's Wendy C. Brooks, D.V.M., explains that Cephalexin "is commonly used for long (six- to eight-week) courses against deep skin infections," called pyodermas.

      Side effects fo Cephalexin include allergies, allergic reactions with penicillins and gastrointestinal problems, such as diarrhea.

    Tetracycline

    • Tetracycline refers to a group of different antibiotics with a wide range of uses for infections in areas of the body such as eyes and the nervous system. It provides anti-bacterial protection by eliminating the bacteria's ability to produce proteins, thereby destroying the infection-causing bacteria.

      Tetracycline is also used for cats with an infectious tick-transmitted illness called ehrlichiosis.

      Doxycycline, a drug in the tetracycline antibiotic family, is a modification of the basic tetracycline structure. Doxycycline has an enhanced ability to fight difficult to treat infections by penetrating biological barriers and increasing the duration of action available to fight infections behind these barriers.

      Side effects of tetracycline drugs may include gastrointestinal upset, tooth discoloration, kidney or liver disease, hair loss and sensitivity to light.

    Sulfa Drugs

    • Sulfa drugs are used to treat intestinal and digestive tract bacterial infections, especially coccidia, intestinal parasites that cause intense diarrhea in cats and other animals. As Vet Info explains, "Bacterial infections of these types can cause painful inflammation, weight loss, diarrhea and vomiting, and a host of other symptoms." Sulfadimethoxine and Albon are effective at reducing the spread of these bacteria.

      Side effects of sulfa drugs may be "nausea, vomiting, fever, anemia, leukopenia and irritation of the liver or kidneys," according to ShelterMedicine.com.

    Erythromycin

    • Erythromycin has recently become popular again because of overuse of other more modern antibiotics that staphylococci developed resistance to over the years. Erythromycin inhibits protein synthesis of certain bacteria and is sometimes used to treat staphylococcal skin infections. Its main use in cats is for giardia, anaerobic bacteria and diarrhea.

      Possible side effects are neurological issues, lowered white blood cell, liver damage, blood in urine and gastrointestinal distress.