EQUINE | Equine Disease Update
EQUINE | Equine Disease Update
echocardiography with the potential to provide information on aspects of cardiac function that have largely been ignored previously .
Clinical highlights : Smartphone apps and echocardiography devices have become a viable option for monitoring exercise associated dysrhythmias and may provide access to echocardiography technology to more equine clinicians .
Nutrition
Dr Joe Pagan addressed the influence of nutrition in the equine athlete . Recent developments include the use of feeds with moderate to high fat content . The horse , though lacking a gall bladder , has a surprising ability to utilise fat . As fat has high energy density and slowly releases of that energy , these feeds provide for an ideal alternative for nervous horses . An adaption period of 5 weeks is required for the muscles to adapt to the utilisation of the new energy source . Diets low in nonstructural carbohydrate ( NSC ; 15 – 30 % digestible energy [ DE ]) are ideal for patients with recurrent exertional rhabdomyolysis and polysaccharide storage myopathy . However , these diets are not suited to every horse , particularly not those doing high intensity work that require fast readily available digestible energy . The primary substrate for energy production in the horse is muscle glycogen and its use is closely related to the intensity and length of exercise . During high intensity work muscle glycogen is depleted and needs to be replaced quickly for the muscle to work optimally . Diets low in NSC (< 20 % DE ) take longer than 3 days to replenish muscle glycogen stores fully , unlike diets with medium ( 20 – 30 % DE ) to high ( 30 % DE ) NSC content .
Another topic of interest was the effects of furosemide on the horse ’ s electrolyte balance and total body water . Although not legal to race on in South Africa , it is used during training . Furosemide results in a total body weight loss of approximately 40 kg in the form of isotonic urine .
Loss of isotonic urine does not activate thirst receptors and thus dehydration can easily result . Administration of a hypertonic electrolyte paste post-exercise may encourage drinking and to replace the sodium and chloride lost in association with furosemide .
Clinical highlights : Future equine nutritional research is focusing on nutrigenomics and nutrigenetics . Nutrigenetics is the study of the effects of nutrients on gene expression while nutrigenomics is the study of how individual differences in genes influence the body ’ s response to diet and nutrition .
Medicine
Prof Derek Knottenbelt focussed on the diagnosis and treatment of sarcoids and melanomas . Sarcoids are progressive tumours and should be dealt with as early in as possible and treatment should be aggressive . Smart surgery , where the tumour is isolated before it is removed , may be useful . Alternatively , laser resection , cryosurgery , ligation and a variety of chemical agents [ 39 ] can be used , all with the aim of removing all cancer cells . Prof Knottenbelt commented that clinicians continue to ignore melanomas on the whole when they should be taking action sooner . Most , but not all , early melanomas are benign but over time will show malignant transformation and micro metastasis . Prof Knottenbelt is a proponent of the idea that melanomas should be removed as early as they are identified . Other topical treatments have proved ineffective [ 40 ] or logistically very challenging .
Clinical highlights : Avoid biopsy of suspect sarcoids unless appropriate treatment is initiated immediately . Melanomas should not be ignored .
Podiatry
Dr Stephen O ’ Grady advocated a scientific approach to farriery . Much of what is thought , practiced and even taught about equine podiatry is based on tradition and
• Volume 19 no 3 • September 2017 • 11