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Educational Articles

Cats + Medications & Supplements

  • Hydralazine is given by mouth and is used off label to treat high blood pressure and some causes of heart failure. Side effects include decreased appetite, vomiting, and/or diarrhea. Do not use in pets that are allergic to it or in pets with heart vessel disease, low blood pressure, severe dehydration, or severe blood loss. If a negative reaction occurs, please call your veterinary office.

  • Hydrocodone is an opiate agonist given by mouth as a tablet or liquid and used off label to treat pain and dry cough in dogs. The most common side effects include sedation and constipation. Do not use this medication in pets that are allergic to opiates or that have ingested a toxin. Use with caution in debilitated or geriatric pets, pets with a head injury, or pets that have thyroid, heart, lung, liver, kidney, or adrenal disease. If a negative reaction occurs, call your veterinary office.

  • Hydrocortisone ophthalmic is a topical steroid medication used to treat surface inflammation in the conjunctiva of the eye. It is used to treat inflammatory eye conditions in cats and dogs. It may be used “off label” or “extra label” to treat eye conditions in animals other than cats or dogs. Hydrocortisone ophthalmic comes in ointment and liquid drop form. Avoid use in animals with viral or fungal infections, corneal ulceration, and birds.

  • Hydrocortisone topical is a medication applied to the skin that comes in many forms such as creams, ointments, shampoos and sprays, and is used to treat itchiness and inflammation. Side effects may include irritation at the application site, and with long-term use can include thin skin, skin bumps, and blackheads. Use this medication with caution in pregnant pets or in pets with skin tuberculosis. If a negative reaction occurs, call your veterinary office.

  • Hydroxyurea is given by mouth and is used off label to treat certain cancers in cats and dogs. Common side effects include bone marrow suppression, lack of appetite, vomiting, diarrhea, mouth and stomach ulcers, loss of toenails and/or hair coat. Do not use in pets that are allergic to it, or in pregnant pets unless absolutely necessary. If a negative reaction occurs, please call your veterinary office.

  • Hydroxyzine is given by mouth or injection and is used off label to treat allergic or itchy conditions. Give as directed. The most common side effect is sedation. Do not use in pets that are allergic to it or cetirizine, or pets that have heart failure, urinary obstruction, or stomach obstruction. If a negative reaction occurs, please call your veterinary office.

  • Idoxuridine is an antiviral topical medication used to treat viral infections of the eye, such as feline herpesvirus-1 in cats. Idoxuridine comes as eye drops or can be compounded by your veterinarian into an eye ointment. Give as directed. Side effects of idoxuridine include eye irritation. Pregnant women should NOT handle this medication.

  • Imatinib is given by mouth and is used off label to treat certain types of cancers in dogs and cats. Give as directed. Side effects may include nausea, vomiting, muscle pain, diarrhea, skin rash, or lack of energy. Do not use in pets that are pregnant or nursing. If a negative reaction occurs, call the veterinary office.

  • Imidacloprid is used on and off label and is applied topically to the skin to treat flea infestations. It is frequently used in combination with other medications to treat a variety of parasites. Side effects are uncommon but may include irritation at the application site, or, if the medication is accidentally ingested, drooling, shaking, vomiting, and decreased appetite. Do not use combination products in young pets. Certain combination products should be used in cats. If a negative reaction occurs, please call your veterinary office.

  • Imidocarb dipropionate is an injectable medication that is administered by a veterinarian to treat babesiosis in dogs. It is also used off-label to treat other protozoal infections in dogs, cats, and horses. Most common side effects include mild drooling, tearing, vomiting, or nasal drip. Do not use in pets with exposure to cholinesterase-inhibiting drugs, pesticides, or chemicals. If a negative reaction occurs, please call your veterinary office.