Equine Health Update EHU Vol 20 Issue 02 - Page 35

International News | EQUINE Cutaneous lymphangitis can become chronic if left untreated or if treatment is ineffective. Chronic expansion of the subcutis by edematous fluid due to faulty lymphatic vessels can result in the deposition of fibrous tissue and permanent limb disfigurement. This emphasizes the importance of rapid diagnosis and treatment of cutaneous lymphangitis. Sporadic lymphangitis, also known as “Monday morning leg,” can also result in swollen distal hindlimbs. This condition can develop in horses that are stabled or immobile for extended lengths of time, typically days or more. The cause of sporadic lymphangitis is not well understood, but luckily the condition typically resolves after exercise. Cutaneous lymphangitis is occasionally diagnosed at the University of Kentucky Veterinary Diagnostic Laboratory. However, the exact frequency of the condition cannot be easily estimated through typical diagnostic submissions, because diagnoses are frequently made by veterinarians in the field and don’t require extensive diagnostic evaluations. CONTACT: Dr. Alan Loynachan, alan.loynachan@uky.edu, (859) 257-8283, Veterinary Diagnostic Laboratory, University of Kentucky, Lexington, Kentucky Eye Neoplasia Neoplasia is the abnormal growth of tissue which, if it forms a mass, is commonly known as a tumor. Neoplasia may be benign (tends to be less destructive) or malignant (tends to be invasive and may spread to other tissues). The spread of a tumor is known as metastasis. Tumors of the eye itself are very rare in horses, but tumors of the structures around the eye are surprisingly common. The most commonly diagnosed types of neoplasia in this area are sarcoids, melanomas, and squamous cell carcinomas. Other tumors such as lymphoma and mast cell tumors may also be found. Most tumors around the eye of the horse do not metastasize, but they can be locally aggressive and have serious effects on the welfare and use of the horse. Early treatment of eye neoplasia is therefore strongly recommended. Sarcoids are believed to be the most common skin tumor of the horse and can be seen in various forms. Sarcoids that occur around the eye are frequently more aggressive in nature, invading into the eyelid musculature, especially those located on the upper eyelid. Horses will usually have additional sarcoids in other locations, so a thorough examination of the horse is recommended to identify any other lesions that need to be treated. Traditionally, sarcoids were often left without treatment, but as they almost invariably become larger and more difficult to treat, early intervention is strongly recommended to avoid long-term sequelae. Treatment may involve topical or intralesional chemotherapy, surgical procedures (most successfully by laser surgical removal), or radiotherapy. No single treatment is 100% successful for these difficult lesions. Radiation has the highest reported • Volume 20 Issue 2 | July 2018 • 35