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Educational Articles

  • The lacrimal duct is part of the nasolacrimal system, a series of narrow tubes that allow tears to drain from the eye into the nose and mouth. This duct can sometimes become blocked or fail to develop properly, resulting in tears overflowing and potentially staining the face below the eye. The clinical signs, diagnosis, and treatment options for the condition are explained in this handout.

  • Lactated Ringer’s solution (also known as LRS, Ringer’s Lactate) is a fluid and electrolyte (salts) replacement solution used to correct fluid and electrolyte imbalances in cats, dogs, birds, pocket pets (small mammals), and other animals. Lactated Ringer’s solution comes in injectable form, usually given subcutaneously for at home administration.

  • 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.

  • Laser surgery is a procedure that generates a beam of light energy at a specific wavelength, resulting in the cutting of tissues. There are three major advantages of laser surgery when compared to traditional stainless steel surgical scalpels, which are decreased pain, decreased inflammation, and improved tissue healing. Routine procedures such as ovariohysterectomy and castration are commonly done with laser.

  • 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.

  • Leaky gut syndrome refers to an increase in the permeability of the intestines. This condition may be caused by any significant insult to the intestines. Acute cases of leaky gut may be caused by infection, trauma, toxins, or medication overdoses. Chronic cases, in contrast, may be caused by food allergies, long-term NSAID use, or other causes. Your veterinarian will perform diagnostic tests to determine the underlying cause of your cat’s intestinal disease and treatments will be targeted at the specific underlying disease that is causing your cat’s leaky gut.

  • 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.

  • Lenticular sclerosis is the term for a bluish, transparent haze that develops in the lens of the eye in middle-aged to senior cats. Vision does not appear to be significantly affected. While the exact mechanism is poorly understood, it appears that the lens gradually becomes denser or harder with age. There is no specific treatment for lenticular sclerosis, nor is treatment necessary.

  • 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.