Illustrated Articles

Dogs + Medications & Supplements

  • Lactulose is used off label and is given by mouth to treat high blood ammonia levels and constipation in dogs, cats, birds, and reptiles. The most common side effects are diarrhea, bloating, gas, and abdominal cramping. Do not use in pets that are allergic to it or in pets with intestinal blockage/obstruction.

  • Latanoprost ophthalmic is applied in the eye and is used off label to treat elevated eye pressures and glaucoma. Give as directed by your veterinarian. Side effects include a burning or stinging sensation, mild eye redness, growth of eyelashes, or color change of the iris or around the eye. Do not use in pets that are allergic to it, or with eye inflammation (uveitis). If a negative reaction occurs, please call your veterinary office.

  • 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.

  • 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.