Equine Health Update Issue 2 Volume 19 - Page 25

EQUINE | Equine Disease Update cases of salmonellosis in a number of states, all of which related to infection with serogroup C1 Salmonellae. A limited number of outbreaks of clostridial enteritis due to Clostridium perfringens Type A/β-2 toxin geno- type, were confirmed in Kentucky, USA. Several cases of proliferative enteropathy (Lawsonia intracellularis) were recorded in Kentucky and Michigan, USA. The fourth quarter of 2016 saw an additional 15 cases of Eastern equine encephalomyelitis confirmed in five states in the USA, nine of which were in Wisconsin. West Nile encephalitis was reported by Spain (nine cases) and the USA (20 cases involving six states of which 11 were in Oklahoma). The majority of cases in the USA were in unvaccinated horses. The USA continues to record outbreaks of rhodococcal disease in numerous states; a limited number were re- ported in the period under review. The fourth quarter of 2016 also saw recorded cases/outbreaks of several other diseases: ehrlichiosis in Switzerland (one outbreak), Ge- tah virus infection in Japan (single case), and equine en- cephalosis (single case in the Western Cape Province of South Africa). The University of Kentucky Veterinary Diagnostic Labo- ratory (UKVDL) plays an important role in its support of Kentucky’s horse industry. Between June 1, 2010, and June 30, 2012, onehundred and thirteen horses aged fifteen years and older were submitted for necropsy to UKVDL. Review of these necropsy cases revealed that the main organ system contributing to the death of this group of aged horses was the digestive system, followed rather closely by the cardiovascular system. Specific diagnoses of the digestive system that were noted in this group of geriatric horses included but were not limited to: strangulating lipoma; small intes- tinal entrapment, devitalization, and/or rupture; gastric rupture; large colon displacement, torsion, impaction and/or rupture; and necrotizing colitis of bacterial or un- known etiology. Causes of Mortality in Aged Horses in Ken- tucky Although prevention of these disorders is not generally possible, certain steps can be taken by owners to im- prove the digestive health of t heir horses. A consistent diet with sufficient roughage promotes a healthy diges- tive system for horses of all ages. However, as horses age, their teeth can wear unevenly and crack or break, pre- venting proper mastication and hindering the digestion of food. Therefore, proper dental care is crucial for older horses, along with appropriate nutritional substitutions for horses that can no longer chew forage adequately. Over the last century, the place of the horse in society has shifted from that of an absolute necessity, primarily used for transportation and labor, to more of a pleasure animal. Today, horses are most commonly companion animals, lesson horses, breeding stock, and sporting competitors, with more limited use for farm and ranch work. This change in usage has resulted in an increasing geriatric horse population, and accordingly, the need to better understand the complexities of geriatric horse health. Maintaining an appropriate deworming regimen for horses of all ages can also go a long way to preventing digestive dysfunction. For example, Causes of Mortality in Aged Horses in Kentucky poorly-managed parasitic infections can contribute to the formation of adhesions, leading to intestinal obstruction, and tapeworm infec- tion can lead to colic due to cecal impaction. Once an owner notices signs of colic and digestive distress, time- ly veterinary intervention can sometimes improve the outcome for a horse, particularly if corrective surgery is NATIONAL • Volume 19 no 2 • June 2017 • 25