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Educational Articles

Medications & Supplements

  • Leflunomide is an immunomodulating agent used to treat certain immune-mediated conditions in cats and dogs. It is used off label (extra label) in veterinary medicine. Leflunomide comes in a tablet form that may be specially compounded into a liquid. Wear gloves when handling and do not handle if pregnant or nursing.

  • Leuprolide is given by injection and is used off label in ferrets and birds to treat reproductive and adrenal problems. Give as directed. Side effects in ferrets may include pain at the injection site, breathing difficulties, and sleepiness. Do not use in pets that are allergic to it or other gonadotropin-releasing hormones, and do not use in pregnant or nursing pets. If a negative reaction occurs, please call the veterinary office.

  • Levetiracetam is given by mouth or injection and is used off label to treat seizures and epilepsy. Give as directed by your veterinarian. Common side effects include sleepiness and incoordination in dogs and decreased appetite, incoordination, drooling, and sleepiness in cats. Do not use levetiracetam in pets that are allergic to it. If a negative reaction occurs, please call your veterinary office.

  • Levothyroxine is thyroid hormone replacement given by mouth in the form of a tablet or capsule. It is used to treat hypothyroidism and its use in cats and certain exotic animals is off label. This medication should not be used in pets with certain heart conditions, untreated Addison's disease, or hyperthyroidism.

  • Lidocaine/lidocaine combinations topical are local anesthetics that provide anesthesia (a numbing effect) to the skin in cats, dogs, and other animals. Combination products may contain other local anesthetics, antibiotics or antimicrobials, steroids, antihistamines, and/or cleansing agents.

  • Lincomycin is given by mouth or injection and is used on and off label to treat certain bacterial infections. Give as directed by your veterinarian. Common side effects include vomiting, diarrhea, or drooling. Do not use in pets that are allergic to it or similar drugs, in pets with a candida fungal infection, very young pets, or in rabbits, hamsters, guinea pigs, or horses. If a negative reaction occurs, please call the veterinary office.

  • Lokivetmab is given by injection and is used on and off label to treat itchiness in dogs. Give as directed. Side effects are uncommon but may include vomiting, diarrhea, sleepiness, lack of appetite, or pain at the injection site. Do not use in pets that are allergic to it. If a negative reaction occurs, please call the veterinary office.

  • Lomustine is given by mouth and is used off label to treat certain cancers such as mast cell tumors and brain tumors. Give this medication as directed by your veterinarian. Common side effects include vomiting, diarrhea, lack of appetite, and hair loss. Do not use in pets that are severely allergic to it. If a negative reaction occurs, please call your veterinary office.

  • Loperamide is given by mouth and is used off label to treat signs of diarrhea. Give as directed by your veterinarian. Common side effects include constipation, bloat, and sleepiness. Do not use in pets that are allergic to it, that have diarrhea due to an infection or a toxin, or that are positive for the MDR1 gene. If a negative reaction occurs, please call your veterinary office.

  • Lorazepam (brand names Ativan®, Lorazepam Intensol®) is a benzodiazepine medication used off label to treat behavior problems such as anxiety, fears, and phobias in cats and dogs. It can also be used to treat seizures or to stimulate appetite in cats. It is given by mouth or injection. Do not use in pets that are allergic to it or other benzodiazepines, or that have severe breathing problems, or liver disease. If a negative reaction occurs, please call your veterinary office.