Diet and management
changes to thwart obesity are the best weapons in the battle to prevent
laminitis according to veterinary experts at the 2019 British Equine Veterinary
Association congress.
David Rendle, Equine Internal Medicine Specialist at Rainbow
Equine Hospital explained that around 90% of laminitis cases have
endocrinopathic laminitis, “which is the same as pasture associated laminitis.”
This involves either equine metabolic syndrome (EMS) or pituitary pars
intermedia dysfunction (PPID – Cushing’s disease). Although 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
that if appropriate management changes are not implemented, the risk of
laminitis may persist.
On the management of endocrinopathic laminitis he concluded
that “central is clearly diet and management change, not pharmaceuticals.”
Andrew van Eps, from the University of Pennsylvania,
reiterated that the key to prevention of endocrinopathic laminitis is early
identification of horses at risk. “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,” he said.
Nicky Jarvis, of Redwings Horse Sanctuary, 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.
She went on to explain that if a horse has a body condition
score of 5 out of 5, about 40% of its bodyweight is fat, equating to 240kg of
fat for a 600kg horse.
She 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 on 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, Jarvis
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.
She advised that, rather than resorting to crash diets,
either in the summer, or once the horse has developed laminitis, it is better for
the owners to appreciate that it is natural 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.”
