Equine Health Update EHU Vol 20 Issue 02 - Page 34

EQUINE | International News One case of equine neorickettsiosis was recorded in Washington State, USA. Rotaviral enteritis was confirmed in Argentina (two outbreaks in 2-month-old Thoroughbred foals on separate premises) and France (a single case). The USA reported cases of proliferative enteropathy caused by Lawsonia intracellularis in Kentucky (10 cases) and Pennsylvania (one case). Clostridial enteritis/enterocolitis due to Clostridium perfringens Type C toxin was linked to six cases of disease in Kentucky. The USA confirmed 30 cases of Eastern equine encephalomyelitis in the fourth quarter of 2017, 12 of which were diagnosed in Wisconsin. 103 cases of West Nile encephalitis were reported across numerous states in the USA, with New York and Utah each responsible for 26 cases. Rhodococcal- related disease is endemic in the USA, with eight cases confirmed during the review period. Infection with Corynebacterium pseudotuberculosis, the cause of Pigeon Fever is endemic in the USA; a single case was diagnosed in Washington State. Cutaneous Lymphangitis The lymphatic system is an important component of the cardiovascular system and consists of lymphatic vessels, lymph nodes, tonsils, spleen, and thymus. Lymph, which is a clear colorless fluid, is formed from fluid loss that occurs during normal nutrient exchange in capillary beds. Lymph is transported by lymphatic vessels to regional lymph nodes for filtration to aid in immunologic detection of microorganisms, toxins, and foreign material. Once filtered, the lymph is again transported by lymphatic vessels to large veins, which ultimately return it back into the circulatory system to replenish the fluid lost from the capillaries. 34 Lymphatic disease can occur when lymph vessels become inflamed, leaky, and/or blocked. Cutaneous lymphangitis—inflammation of lymphatic vessels of the skin—is fairly uncommon in horses, does not exhibit age, sex, or breed predilections, and can develop from both infectious and non-infectious causes. Clinically, cutaneous lymphangitis can manifest as a swollen limb, skin abnormalities characterized as multiple skin nodules that can abscess or develop draining tracts, and/or lameness. Cutaneous lymphangitis typically affects the distal portion of a single hind limb, between the hock and hoof. Due to the characteristic appearance of affected limbs, the disease is commonly referred to as “big leg” or “fat leg.” Infectious cutane \[\[]\\Y][ۘ[BY[\X]Y]܈YY[H[[X[Z\[ۈوZXܛܙ[\\ˈ]\ܘYX[BXYۛY[ܜ\]Y][Y\\œ[][[[\H[][\Hܜ\ۈH[YH\K[X[ۈوH[\]X\[H][[˜۝[Z[][ۈو[[H\[\X\XK[[[ۛHܞ[XX\][H]YX\[\ŠH]\]]HY[و[\]]H[\[]\Y[ۂ]\K]\\H܈Z^Y[X[ۜ]\X\XKX\\[\ \\œ Y\\[H[[\\\]ZK\]\[HY[[]XK]Y[ۘ\Y\Y[K\ؘX\][HXܛܝ[KX[ؘX[\\]][K[\\XHX[ZH H]\Hو[\H[[\[[][[\[\[]\ˈY][ۘ[K][HX\ܛ^ H]\BوܛX\H܈\\XH\[Z[[H B]\Hو\^X[\[]\H[]HY[\X]Y][\]X\[H[X[ۋBTH\\[HYHH[\[\^X›[\[]\ˈX]Y[و[X[\][[\›[\[]\[Y\\X]H[[ZXܛؚX[ۋB\Y[[KZ[[[X]ܞHYY\\K[\X[ZYZ[YK(\]Z[HX[\]H8(