Acetylcysteine is given by mouth, injection, or topically and is used on and off label to treat toxicities or to break up mucus. It is usually a prescription, but some forms may be found over the counter. Give as directed by your veterinarian. The most common side effect is an upset stomach. Do not use in pets that are allergic to it. If a negative reaction occurs, please call your veterinary office.

Acetic acid/boric acid otic (brand name Malacetic) is an antibacterial and antifungal medication used as an ear cleanser and drying agent in cats and dogs with ear infection. This medication may be part of a combination product. Acetic acid/boric acid otic comes as a liquid ear cleanser.

Acetic acid/boric acid topical (brand name Malacetic) is an antibacterial and antifungal medication used to treat skin infections caused by bacteria and/or yeast in cats and dogs. Some formulations may be used to treat ear infections. This medication may be part of a combination product. Acetic acid/boric acid topical comes in shampoo, liquid (spray and dropper), and wipe form.

Acetazolamide is a diuretic used off label and given by mouth to treat glaucoma or alkalosis. The most common side effect is stomach upset, but other side effects of the central nervous system, blood, kidneys, electrolytes, blood sugar levels, liver, or skin are possible. Do not use this medication in pets with liver or kidney disease, or low sodium or potassium blood levels. Use with caution in pets with acidosis, diabetes, pregnancy or lactation. If a negative reaction occurs, please call your veterinary office.

Acetaminophen with hydrocodone (brand name Vicodin®, Lortab®, Norco®, Nortab®) is a combination drug used for severe pain in humans. Acetaminophen is a pain reliever and fever reducer. It is not often used in animals and, when done so, must only be used in dogs. In this case, it is combined with hydrocodone, which is a potent, narcotic pain reliever. Acetaminophen/hydrocodone comes in a variety of different formulations.