Medicine

Equine Medical Conditions

Laminitis

Laminitis is a cripplingly painful disease of the equine foot. It is caused by inflammation of the bond or ‘laminae’ between the pedal bone (P3) and the hoof wall.

It is still not fully understood what causes this to happen, although many risk factors have been identified. These include, obesity, hormone related diseases such as Cushing’s disease or equine metabolic syndrome. Overload laminitis (where the horse is originally lame on the opposite leg) and Endotoxaemia – often as a result of colic or retained foetal membranes after foaling.

The damage to the laminae can cause movement of the pedal bone, either sinking or rotation. This movement can cause long term problems with the function of the foot, and ongoing lameness.

Early signs of laminitis can be heat in the feet, increased digital pulses, stiffness or being ‘pottery’ at walk, with noticeable pain on turning or when walking on hard ground. Horses with severe signs of laminitis can breathe heavily, sweat profusely, refuse to walk or be unable to get up.

If you notice any of the above symptoms or are concerned that your horse or pony may have laminitis – please contact us immediately.


Vet visits

On examining your horse, the vet may use hoof testers to determine if laminitis is a likely diagnosis. The vet may want to remove your horse’s shoes, apply footpads for support and may recommend x-rays of the horse’s feet to check for any movement of the pedal bone. The vet will prescribe painkillers and anti-inflammatories for your horse and may give a mild sedative (ACP) to encourage your horse to rest.

Identifying any hormone related causes of laminitis, such as Cushing’s disease (PPID) or equine metabolic syndrome (EMS) at an early stage and managing these problems can significantly improve the outcome for laminitic horses and ponies. Initially blood samples are taken to check for these diseases, these can be taken at the initial visit.


Things you can do

Reducing the amount your horse needs to move is helpful both with pain management and reducing the likelihood of any movement of the pedal bone. Stable your horse if possible before the vet arrives. A deep shavings bed which covers the WHOLE floor of the stable will give your horses feet extra support. Keep your horse as calm and still as possible – sometimes providing your horse with an equine friend can be helpful.

The treatment and recovery of horses with laminitis can often involve prolonged periods of box rest. Our vets like to work in combination with yourselves as owners, and your farrier to provide the highest quality of treatment for your horse.


Donkeys are different!

A quick note for any donkey lovers out there. Laminitis is common in donkeys, however, donkeys are very stoical creatures and rarely show signs of pain or lameness. Often a ‘dull’ donkey or one who refuses to eat can be a donkey suffering from laminitis. If your donkey is just ‘not themselves’ please call us ASAP!

Cushing’s disease

Cushing’s disease or Pituitary Pars Intermedia Dysfunction (PPID) to give it it’s full and proper title, is a common disease of older horses and ponies, although can occur at any age. It is caused by a degeneration or breakdown of the nerve pathways in and around the pituitary gland, which sits at the base of the brain. This gland releases too much of a hormone called adrenocorticotrophic hormone (ACTH). This hormone can cause a number of changes in the body and can significantly increase the risk of your horse suffering with laminitis.


Signs of PPID

  • Laminitis
  • Hirsutism or being excessively hairy
  • Drinking a lot and urinating a lot
  • Abnormal fat distribution, being ‘cresty’ and insulin resistance
  • Sweating
  • Lethargy
  • Susceptible to other diseases – such as foot abscesses, ringworm, respiratory infections
  • In rare and advanced cases – seizures, weakness, blindness or collapse. These are thought to occur because the enlarged pituitary gland is putting pressure on the brain

Diagnosis

Often horses who are diagnosed with Cushing’s disease are already suffering from laminitis. However, early diagnosis and management can significantly decrease the risk of your horse suffering with laminitis.

Diagnosis is through a simple blood test, to check your horses level of ACTH. The ‘normal’ range is seasonally adjusted to take into account changes that may occur during spring and autumn.

Some horses can suffer from PPID and EQUINE METABOLIC SYNDROME at the same time. These horse may require further testing and dietary management.


Treatment

The only proven and effective treatment available for PPID is pergolide (prascend). After diagnosis of PPID the vet will recommend starting on this drug for 4-12 weeks, then re-checking your horses ACTH level. Often after a few months of treatment the clinical signs will start to resolve.

Side effects from taking pergolide are rare, but can include a short term loss of appetite.

Unfortunately, nothing can be done to prevent PPID developing, as it is a degenerative disease. However, with early diagnosis and good medical management there is no reason why your horse can’t continue to lead a full and long life. If you think your horse may be suffering from PPID, please get in touch!

Equine Metabolic Syndrome

Equine metabolic syndrome or EMS is a disease characterised by obesity and a predisposition to suffering with laminitis. Comparisons can be drawn between EMS and Type II diabetes in humans.

The cause of EMS is thought to be Insulin resistance, where there is a reduction in the body’s response to insulin, leading to high levels of glucose remaining in the blood. EMS can also result in altered fat composition, blood clotting disorders and damage to blood vessels. This can particularly affect the blood vessels within your horse’s feet – potentially leading to laminitis.

Any horse can develop EMS but some breeds are more prone to the disease. These include welsh breeds, Shetland ponies and warmbloods.


Clinical Signs

Obesity – signs such as a ‘cresty’ neck or fat above the ligament in the neck, fat around the eyes and tail head are common. However, a horse that is not obese can still suffer from EMS!

Lameness – often horses with EMS suffer from laminitis

EMS and Cushing’s disease are not the same thing. Although horses may suffer with both diseases at the same time and some features are similar, there are important differences to look out for.

Horses with Cushing’s will often be excessively hairy and sweat profusely – this is not the case with EMS

Horses with EMS are usually young or middle aged, horses with PPID are often older.


Diagnosis

EMS can be a difficult disease to diagnose.

Initially your vet may take a resting insulin and glucose level from your horse with a simple single blood tests. These tests can be helpful, but if they are normal it does not always rule out EMS. Your horse must be starved before testing.

Oral Glucose Challenge test – this test involves fasting your horse, then feeding your horse a sugary meal and testing insulin levels after 2 hours. This test is more accurate.

Adiponectin – This a newly available test. Studies have shown that high levels of adiponectin (a fat related hormone) mean it is less likely that your horse is suffering from EMS. Low levels of adiponectin in the blood means a diagnosis of EMS is much more likely.

The best way to gain an accurate diagnosis of EMS is through a thorough clinical exam and a combination of blood testing.


Treatment

The most important part of treating horses with EMS is dietary management and exercise.  Dietary restriction can often need to be quite severe so please contact us first to discuss your horses diet and requirements, before implementing any changes.

Essentially, your horse needs to be fed a high fibre, low-sugar forage at 1 – 1.5% of their bodyweight, alongside a vitamin and mineral balancer. Grazing often needs to be restricted or prevented altogether.

Remember! Grass can contain as much sugar as most varieties of pony nuts! Ad-lib grazing will not help with weight loss or managing EMS.

A drug called metformin can be used to aid the management of EMS in horses. This is still being studied to determine if it is effective and if horses can absorb the drug properly.