What is Laminitis?
Laminitis is a common, extremely painful and frequently recurrent condition in horses, ponies and donkeys affecting he tissues (laminae) bonding the hoof wall to pedal bone in the hoof. This can result in the pedal bone sinking or rotating within the hoof under the weight of the horse. In extreme cases this the pedal bone can penetrate the sole of the foot. More than 7% of equine deaths are linked to laminitis.
Causes of Equine Laminitis?
- Diseases associated with inflammation
e.g. certain types of colic, diarrhoea, retained placenta, severe pneumonia.The precise sequence of events leading to laminitis is unclear, however in diseases associated with inflammation, the inflammation of the lamellar results in failure of the adhesion between the laminae and laminitis
- Endocrine (hormone) disease
e.g. Equine Cushing’s disease (pituitary pars intermedia dysfunction; PPID) and equine metabolic syndrome (EMS). The hormone insulin is responsible for the series of events leading to laminitis.
- Mechanical overload – supporting limb laminitis (SLL)
e.g. associated with a fracture or infected joint in the other leg so that the leg which is bearing all of the weight is at risk of laminitis. In mechanical overload laminitis, it is thought that there is inadequate blood supply to the lamellar tissue associated with excessive and continuous weight-bearing.
Clinical signs:
- Lameness* affecting most commonly at least two limbs. * Some horses get very mild laminitis that is not severe enough to cause any visible lameness but does result in divergent hoof growth rings.
- Lean back posture from horse as it directs its weight onto its heels and away from the painful toe area
- Lameness is more obvious on hard ground or when horse turns
- Shifting weight between feet when resting
- Increased digital pulses
Pain with use of hoof testers at the point of frog on the foot.
Treatment:
- Pain relief – NSAID’s such as phenylbutazone or flunixin.
- Icing hooves (3 days)- in cases associated with inflammation.
- Foot support e.g Lilypads and deep bedding to the door – limits movement of the pedal bone.
- Box rest along with dietary changes are if endocrinopathic – soaked hay at 1.5% of the horses body weight only. o
- .If the laminitis is the result of an underlying condition, such as an endocrine disorder, the disease should be treated accordingly e.g. pergolide (Prascend) for pituitary pars intermedia dysfunction aka Cushings.
