Horse Health - Vet On Call

By: Horse Deals

Horse Health - Vet On Call
Don’t just cut the rations for obese ponies

‘Condition scoring may not work for ponies’, say researchers

Researchers at the department of clinical science at the University of Liverpool, supported by World Horse Welfare, have presented new research questioning the accuracy of conventional equine body condition scoring in ponies.
The study, "Managed weight loss in obese ponies: evaluating weight change, health and welfare", involved five mature, overweight or obese ponies and aimed to restrict their feed intake to 1% of body weight of a chaff-based complete diet for 12 weeks.

During this time their weight change, health parameters and behaviour were monitored. All ponies remained healthy throughout the trial and an appropriate and safe rate of weight loss was achieved.
Clare Barfoot, registered nutritionist and the research and development manager for SPILLERS®, explained: "Bodyweight decreased at a steady rate. However, despite significant weight loss, the body condition scores of the ponies didn’t change. This highlights the concern that body condition scoring may not be the most effective way to monitor early weight loss in ponies."

Also noticeable was that the feeding activity of the dieting ponies was decreased by 74% compared to ad lib intake, highlighting the need for a feeding system sensitive to behavioural needs.
In response to the study, the research group is in the process of developing a new condition scoring system designed specifically for ponies.

Donation will help Bransby horses

Robinson Animal Healthcare has donated more than 250 rolls of Equiwrap to Bransby Home of Rest for Horses in time for the winter season.
The Lincolnshire charity is currently caring for 270 horses, ponies, donkeys and mules and education officer Verity Chappell explained: "The Equiwrap will be extremely useful when foot infections and skin ailments such as mud fever are more common."
Equiwrap is a powerful self-adhesive bandage made from elasticated crepe and comes in single rolls. It shapes to the contours of the legs, providing support, protection and holding dressings in place.

More funding for strangles test

The Animal Health Trust (AHT) has secured an award of £580,000 from the Wellcome Trust to fund the development of a new diagnostic test for strangles that takes only 30 minutes.
This has been achieved in part by a two-year fund-raising campaign run by the AHT and British Horse Society. Money donated by the general public, along with funding from the Horse Trust, has already allowed scientists at the AHT to develop a diagnostic blood test that gives results in 24 hours.

Changes afoot at RVC

A new equine surgery and intensive care unit is being built at the Royal Veterinary College Equine Referral Hospital in North Mymms, Hertfordshire.
The single-storey surgery will accommodate two treatment theatres, recovery boxes, offices and equipment stores. A monorail hoist will allow staff to move horses from the surgery to the recovery areas.
The new building will be connected to the existing Large Animal Clinical Care Centre, which is getting a mezzanine floor, plus extra examination and consulting rooms. The project is due to be completed in January next year.

Q: Our 12-year old part-
warmblood show jumper appears to have developed windgalls above one of her fetlocks and the swelling seems affected by the weather. As a youngster, she also had a spavin on the opposite leg but this hasn’t been a problem since it settled down. She doesn’t appear to be lame or unlevel, but we are preparing to sell her in the next couple of months and are concerned about how this may affect prospective buyers. We’ve been told that magnotherapy boots may help, so would you agree? On the same note, please could you advise us about any treatment for both conditions and let us know if the mare might fail a full vetting?

Ed Lyall BVetMed CertEM (StudMed) MRCVS replies:

A windgall is regarded as a swelling associated with the flexor tendon sheath that protects the superficial and deep digital flexor tendons as they run down the back of the fore or hind fetlock joints. The swelling is due to a build up of synovial fluid within the sheath, a proportion of which may be due to thickening of the actual soft tissue structures that make up the tendon sheath or fibrous material accumulating within a chronically inflamed sheath.

In many cases, a swelling associated with a windgall isn’t a problem and they are seen commonly on the hind limbs of older, larger horses. These windgalls aren’t associated with lameness and can fluctuate in size. They are often fairly soft when felt and idiopathic (they appear spontaneously and the cause is unknown).
A more sinister situation is where the tendon sheath is swollen and hard and there is intermittent lameness associated with the affected limb. Often, there is pain when the limb is flexed tightly resulting in lameness when the horse is trotted off after a flexion test. Visually, the sheath is swollen and there is a notch in the swelling running around the back of the fetlock where the annular ligament is constricting the tendon sheath. Also, it may be possible to feel a soft fluid swelling at the back of the pastern under the skin, running down to just above the level of the heel bulbs.

In these cases, there is some soft tissue problem associated with the structures of the tendon sheath. An ultrasound examination will give an indication as to what has been damaged and the treatment required. It may also be appropriate to inject the tendon sheath with local anaesthetic to prove that it is indeed causing the lameness.

Treating tendons

The structures that might be damaged in the sheath could include the superficial and deep digital flexor tendons, the annular ligament and the sheath itself. Annular ligament syndrome is a common condition where an inflammatory process occurs within the sheath. The release of inflammatory mediators causes a swelling of the annular ligament which then constricts the structures within the sheath, resulting in further inflammation, an increased swelling of the sheath and so on.

This condition is relatively simply treated through a small operation to cut the annular ligament at the back of the fetlock, thus releasing the pressure off the sheath. The important thing to try to identify what was the initial cause of the inflammation using ultrasound.

The ultrasound examination may identify tendonitis within one of the tendons, which may require rest. There may be a longitudinal tear in one of the tendons that may need to be repaired by keyhole surgery. In some instances, a simple cortisone injection into the sheath to settle early onset inflammation is appropriate.
For the windgalls that appear to be idiopathic magnetic boots can be useful, as can leg cooling machines or ice bandages, in conjunction with stable bandaging at night.

It’s important not to confuse swellings above the fetlock with swelling of the fetlock itself, as in the picture of joint effusion. Here, the swelling is indeed above what most people think is the fetlock but it is actually in a pouch of the fetlock that extends up between the back of the canon bone and the suspensory ligament. This is swollen with excess fluid and is called a joint effusion.
Once again, this may be idiopathic in origin and may not result in lameness or pain on flexion test. It may, however, indicate pathology associated with the fetlock joint.

Spavins and swellings

Also mentioned in the question was the development of a spavin that subsequently disappeared. This most likely was a swelling of the large articulating joint of the hock, the tarsocrural joint, and is correctly known as a bog spavin.

A true spavin is a hard swelling overlying the lower flat joints of the hock due to osteoarthritis, as shown by the main image of the chestnut leg. Again, bog spavins are joint effusions; in
young horses, they may be associated with joint pathology such as osteochondrosis desicans (OCD), as in image of the X-ray. However, in a lot of cases the joint swelling is idiopathic and disappears with time.

Other swellings that occur in the hock region include fluid accumulations in the flexor tendon sheaths at the back of the hock, resulting in a thoroughpin. Again, these should be examined by X-ray and ultrasound to evaluate their significance.
When it comes to the sale of a horse with swellings such as windgalls, some purchasers would be put off due to the cosmetic appearance, particularly if the intended use is showing.

From a vet’s pre-purchase examination point of view, lots of factors will be taken into consideration, such as the age of the horse and its intended use. Most importantly, the clinical findings such as the presence of lameness or a positive response to flexion test, as well as the turgidity (amount of swelling) of the sheath on palpation, will assist the
vet in the decision-making. If there is any doubt, an ultrasound scan can be performed.

About Ed Lyall

Ed Lyall grew up at his parents’ North Yorkshire equestrian centre. He graduated from the Royal Veterinary College in 1994 and was awarded a scholarship to continue his studies there. He is now a partner at Arundel Veterinary Hospital in West Sussex. He is an examiner in equine stud medicine and a treating vet at Hickstead and the South of England Show. His interests include competing his grade B horse in affiliated show jumping.