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Educational Articles

Cats + Medications & Supplements

  • Ephedra is prescribed most often treat breathing problems and is given by mouth. Give as directed by your veterinarian. Side effects include increased heart rate, body temperature, and blood pressure, agitation, restlessness, sleeplessness, nausea, tremors, and vomiting. Do not use in pets that are allergic, pregnant, nursing, are debilitated, elderly or young, or have glaucoma, heart disease, high blood pressure, seizures, diabetes, anxiety, enlarged prostate, liver disease, kidney disease or thyroid disease. If a negative reaction occurs, please call your veterinary office.

  • Ephedrine is most commonly given by injection (and rarely by mouth) and is used off label to treat low blood pressure and certain types of urinary incontinence. Give as directed by your veterinarian. Common side effects include restlessness, fast heartbeat, and high blood pressure. Do not use in pets that are allergic to it or in pets with severe heart disease or abnormal heart rhythms. If a negative reaction occurs, please call your veterinary office.

  • Erythromycin is given by mouth or injection and is used off label to treat bacterial infections and gastrointestinal motility problems in many animal species. Common side effects include diarrhea, lack of appetite, and vomiting. Do not use in pets that are allergic to it, have liver disease or dysfunction, or in pets such as rabbits, gerbils, guinea pigs, or hamsters. If a negative reaction occurs, please call your veterinary office.

  • Erythromycin ophthalmic is an antimicrobial medication used to treat certain types of eye infections. It may be used “off label” or “extra label” to treat other eye conditions. Erythromycin ophthalmic comes in ointment form. Caution when using this medication in pocket pets as fatal diarrhea may occur if ingested orally.

  • Esafoxolaner + eprinomectin + praziquantel is given topically on the skin to treat and protect against various internal and external parasites and prevent heartworm in cats. Side effects are rare but may include hair loss at the application site, gastrointestinal upset, skin reactions, or neurologic signs. Use caution in sick or underweight cats. If a negative reaction occurs, please call your veterinary office.

  • Eyebright is an over the counter supplement, given by mouth or used topically as an adjunctive treatment for infection and inflammation of the eyes, skin, or mucous membranes. Give as directed by your veterinarian. The most common side effect is a sensitivity reaction that may include redness, itching, or irritation. Do not use in pets that are allergic to it or that are pregnant, nursing, have had eye surgery, or have diabetes. If a negative reaction occurs, please call your veterinary office.

  • Famciclovir is given by mouth and is used off-label to control feline herpesvirus. Give as directed. Side effects may include vomiting, diarrhea, decreased appetite, and increased drinking and urination. Do not use it in pets that are allergic to it or penciclovir. If a negative reaction occurs, call your veterinary office.

  • Famotidine is an antacid given by mouth or into the vein, and is commonly used off label to treat gastrointestinal ulcers and acid reflux. Side effects are uncommon but may include a slow heart rate, stomach upset, or dry mouth and skin. Use cautiously in pets that are geriatric or have liver, kidney, or heart disease. If a negative reaction occurs, please call your veterinary office.

  • Fenbendazole (brand names Panacur®, Safe-Guard®) is a medication used to treat a variety of parasites in dogs. Its use in cats for the treatment of parasites is off label or extra label. Fenbendazole comes as oral granules or as a liquid suspension and is given by mouth. At regular doses, fenbendazole does not usually cause any side effects. Fenbendazole should not be used in puppies younger than six weeks of age or in sick animals.

  • Fentanyl is an opioid medication used off-label to treat pain in cats and dogs. It is often given as an injection in hospital, but patches may be prescribed to deliver fentanyl transdermally (through the skin) for pets at home. This handout describes common side effects, risk factors, and drug interactions. If a negative reaction occurs, please call your veterinary office.