Managing Chronic Laminitis

   

Laminitis is a common, painful and ultimately potentially devastating condition affecting the feet and hooves of horses and ponies.

In the foot of the normal horse or pony, the hoof wall and the pedal bone (the lowest bone in the foot) are joined together by a finely structured tissue called the laminae. Despite the large weights being borne by the laminae, they are relatively delicate, and easily damaged. In the condition laminitis, the laminae become inflamed and extremely painful, making weight-bearing very difficult for affected horses.

Horses and ponies with laminitis will find it difficult to put their feet down, and will often adopt a “rocked back” stance to take weight away from the painful tissues. If the condition goes on for some time, or there are repeated occurrences in a horse, the damage can become irreversible leading to rotation of the pedal bone and permanent foot pain. In many cases of this severity, euthanasia becomes the only option.

Causes of Laminitis
 It is currently recognised that laminitis can fall into 4 broad categories:
1. Endocrine-related Laminitis - EMS and PPID

Over three quarters of horse owners believe that laminitis is caused by access to lush pasture, especially if the horse or pony is overweight. While grass is an important trigger factor, grazing alone does not tell the whole story. This is why some horses develop laminitis while others grazing the same pasture do not.It is proposed that when horses and ponies with an underlying hormonal disease graze and ingest soluble carbohydrates such as fructans, it causes an abnormally high levels of a hormone called insulin. The two conditions that are believed to be underlying in up to 90% of all laminitis cases are “Equine Metabolic Disease” (EMS) and “Equine Pituitary Pars Intermedia Dysfunction” (PPID/previously known as Cushing’s).Insulin is responsible for moving carbohydrates into tissues where it is stored as glycogen. There is very good evidence that high levels of circulating insulin results in laminitis in horses and ponies with PPID and/or EMS. In normal horses, without an underlying hormonal disease, grazing pasture is unlikely to cause laminitis.

Please find more information on endocrine-related laminitis at: www.talkaboutlaminitis.co.uk

2. SIRS - Systemic Inflammatory Response Syndrome

Laminitis can be secondary to a primary inflammatory/septic illness, such as colitis, septicaemia, peritonitis, retained placenta, carbohydrate/grain overload. The horse will be systemically unwell. They will usually have a raised temperature and abnormal white blood cell count and will often have diarrhoea/be depressed. In these cases it is imperative to treat the primary illness. Icing the feet has been found to be a very effective adjunct in delaying the progression of laminitis in horses with SIRS.

3. Supporting Limb

A severe protracted non-weightbearing lameness, e/g a fracture or septic joint condition,c an cause laminitis in another leg (usually the other leg in a pair).

4. Iatrogenic/Steroid-induced laminitis

The use of corticosteroids has also been implicated in causing or worsening laminitis, particularly in horses that are already prone to laminitis (such as those with undetected EMS/PPID).

Going from Acute to Chronic

We consider laminitis to be in the acute stage when it first developed. We consider the disease to be “chronic” when the pedal bone has rotated and/or sunk within the hoof capsule.How the horse developed chronic laminitis will affect how we treat is. If the horse has experienced laminitis due to carbohydrate overload or a septic issue, the laminae become considerable inflamed and swell and the hoof becomes hot to the touch. Initial treatment might include applying ice water to the affected feet during the first two to three days in those cases. However, in a horse that has laminitis due to an endocrine disease or supporting limb issues, there is often much less of an inflammatory response and the cold therapy will not be as effective, though it still can provide some pain relief.


Management:
The management below mostly applies to those with endocrine-related chronic laminitis.
1. Nutrition
• Obtaining and maintaining your horse or pony’s correct body weight is vitally important. We can show you how to use a weight tape correctly, and how to assess body condition score and cresty neck score – this will help you to monitor progress.
• Dietary management should reduce both energy intake and non-structural carbohydrates (NSC) but changes to your horse or pony’s diet slowly (over the course of at least 2 weeks).
• Restriction of grazing using a muzzle or starvation paddock can reduce grass intake while still maintaining exercise obtained during turnout. Simply limiting duration of turnout is unlikely to be successful as horses and ponies are able to consume a large portion of their daily grass intake in the first 2 – 3 hours of grazing.
• Soaking hay can be a very useful way of reducing the sugar and therefore the calorie content. The length of time you need to soak hay for varies considerably between different hays, so it may be worth having a forage analysis done to find out the energy content of your hay. Soaking time would normally be between 1 – 12 hours, depending on the type and quality of your hay. When giving soaked hay, it is also advisable to feed a broad spectrum multivitamin/mineral and amino-acid supplement (ask your vet for advice).
• Feeding hay in haylage nets or inside two hay nets (“double netting”) can help slow down your horse or pony to prolong feeding time.

2. Farriery and Foot Supports

It is often wise to take x-ray image of a horse or pony’s feet when chronic laminitis is suspected. This will help the farrier to trim the hoof correctly to attempt to counteract any rotation of the pedal bone. During acute stages confine your horse/pony to an area of deep supportive bedding (e.g sand/sawdust/pea gravel) or support the feet with e.g styrofoam, impression material, boots and pads.

3. Exercise

• Where laminitis is not a limiting factor, daily exercise aids weight loss and improves insulin sensitivity. Exercise intensity does not have to be high, but aim to build up to regular exercise of 30 minutes or more daily, once the hooves are stable if your horse or pony is recovering from an episode of laminitis.

4. Medication

During acute, painful stages of laminitis giving an NSAID (e.g Bute, Danilon, Equinoxx) will help reduce pain and inflammation. These should be used for as short a time as possible.If you suspect your horse may have PPID (Cushing’s) there is a treatment available called Pergolide - please ask us about this.

 **Regular check-ups from us will help monitor the response to management changes and any other treatment.**