AT the recent British Equine Veterinary Association [BEVA] Congress, veterinary experts expressed the importance of weight control in order to manage the risk of laminitis.

They stressed that obesity in horses needed to be tackled through correct management of weight loss, diet and general stable management.

Laminitis is one of the most common conditions treated by equine veterinary surgeons. However, there remains a lot about the disease which is unclear, including the exact links with endocrinopathic (glandular) disease.

The congress involved expert speakers from around the world sharing the latest knowledge on laminitis including causes, diagnosis, management and prevention. Speakers included David Rendle of Rainbow Equine Hospital, Andrew Van Eps from the University of Pennsylvania and Nicky Jarvis of Redwings Horse Sanctuary.

Approximately 90% of laminitis cases have endocrinopathic laminitis. “This is the same as pasture associated laminitis,” according to Rendle. This involves either equine metabolic syndrome (EMS) or pituitary pars intermedia dysfunction (PPID). While greater understanding of EMS and PPID has helped in preventing laminitis, there is still much that remains unknown.

Rendle pointed out that insulin dysregulation is often disregarded in the assessment of laminitis when PPID is suspected. He warned: “If insulin dysregulation and metabolic dysfunction are overlooked in horses that are diagnosed (often incorrectly) with PPID and appropriate management changes are not implemented, the risk of laminitis may persist.”

On the management of endocrinopathic laminitis, he commented: “Central is clearly diet and management change, not pharmaceuticals.”

Andrew van Eps reiterated that the key to prevention of endocrinopathic laminitis is early identification of horses who are at risk of developing the condition.

He said: “Management to reduce the laminitis risk in these cases can then include a combination of dietary control, pasture access management, weight loss and exercise which can dramatically reduce the risk of laminitis development or progression.”

Change in mindset is needed

Nicky Jarvis explained the grave negative impact obesity has on horse health. “The horse isn’t just a little bit chunky. It actually has ‘ill health’ because of that amount of fat,” she said.

Jarvis added that, when a horse is classified with a body condition score of five out of five, approximately 40% of its bodyweight is fat, equating to 240kg of fat for a 600kg. “Owners love to say ‘but he’s always been like this and he’s never had laminitis before’ so it can be incredibly hard work to change the mindsets.”

Jarvis explained her approach to weight loss, which aims at dropping 0.5% to 1% of the horse’s current bodyweight per week by feeding a daily ration (dry matter) equivalent to 1.5% of bodyweight. Appreciating that weight loss in the field can be difficult as intake can’t be quantified, she outlined practical management tactics such as strip grazing, grazing muzzles, track systems, shared grazing with sheep, or pre-grazing with horses who are in healthy condition.

She emphasised the advantages of forage analysis to ensure hay is of a low water soluble carbohydrate content (10%-12%) and the benefits of soaking it. For animals resistant to weight loss, despite a controlled diet, she suggested the careful introduction of good quality barley straw as a partial forage alternative for horses with good teeth, at up to 40% of the ration.

For long-term approach, she advised: “Rather than crash diets, either in the summer or once they have got laminitis, it is better to encourage people to realise that it’s a natural thing for horses to lose weight over winter. And, if we can get them to keep those rugs off and persuade them not to go to their local shop and buy supplementary feeds and grains just because they feel cold, we wouldn’t have so many problems during the summer months.”

Web: beva.org.uk