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Educational Articles

  • 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.

  • 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.

  • Crate training is most used with dogs, but it can be useful for kittens and cats too. Crate training is useful in many situations, such as providing a safe place when home alone or unsupervised. Cats that are calm in their crates experience less distress when they need to travel, visit the veterinary hospital, or stay at a boarding facility. Starting while your cat is young makes training easier, but even adult cats can be trained to relax in a crate. If your cat shows signs of distress (e.g., prolonged vocalization, trying to escape, salivation, rapid continuous movement) while using the training methods provided in this handout, consult your veterinarian.

  • 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.

  • One particularly dangerous type of foreign body in cats is a linear foreign body: a long, thin object such as string, yarn, or tinsel. If one end of the linear foreign body becomes lodged in the gastrointestinal tract, intestinal perforation may occur due to bunching up of the intestines. The most common signs of a linear foreign body include vomiting, anorexia (refusal to eat), dehydration, and lethargy. If your veterinarian suspects a linear foreign body, your cat will need an exploratory laparotomy (abdominal surgery).

  • The liver is an important organ necessary for controlling many different body functions. Signs of liver disease include increased drinking and urination, abdominal swelling, jaundice, digestive upset, and weight loss. Because of the varied actions of the liver there are several blood and urinary tests that can reveal liver disease. Imaging can be used to determine if there is a change in liver size or irregularity in liver tissue. Ultimately, a liver biopsy is often needed to definitively diagnose liver disease. A biopsy may be obtained by fine needle aspiration through the body wall or a surgical biopsy may be necessary. Anesthesia in a cat with liver disease will carry increased risk but often is relatively low. Treatment of liver disease depends on the diagnosis, but sometimes specific diets are recommended to help manage or slow the disease.

  • Primary liver tumors in dogs and cats are rare. There are 4 types: hepatocellular tumors, bile duct tumors, neuroendocrine tumors, and sarcomas. These cancers can be massive, nodular, or diffuse in form. In dogs, most liver tumors are malignant, while in cats, most are benign. The signs of liver tumors range from being asymptomatic to having inappetence, fever, lethargy, and weight loss; and less commonly, nausea, vomiting and diarrhea; increased drinking and urination; and jaundice. Occasionally there are neurological signs, such as seizures. With tumor rupture and intrabdominal bleeding there may be weakness, collapse, and difficulty breathing. The diagnosis is based on history, clinical signs, exam findings, diagnostic imaging, and FNA or liver biopsy. A biopsy is best for a definitive diagnosis. Surgery is the treatment of choice for most primary liver tumors followed by chemotherapy. Chemoembolization is a newer treatment.