The British Appaloosa Society

  Welcome to The British Appaloosa Society


We thought that our members would be interested in various 'Health Matters' articles

As we discover new articles and write ups on various connected topics we will add them for you to read. If anyone has anything of interest to share or wants to see anything in particular then do let us know! So far, articles below include:-

  • Pssm
  • Foaling Facts   
  • Mites & Lice
  • Atypical Myoglobinuria
  • The Grey Gene
  • The LP Gene
  • Equine Colic
  • Osteoarthritis
  • Worming

Polysaccharide Storage Myopathy (pssm)

Courtesy of The University of Minnesota

Recent advances in PSSM genetic testing

The gene for PSSM has now been identified!

Polysaccharide Storage Myopathy (PSSM) is a common form of tying-up in many horse breeds and is characterized by excessive and abnormal storage of sugar (polysaccharide) in muscle cells. We have recently found a mutation in a gene that is highly associated with the presence of abnormal polysaccharide in muscle biopsies in several horse breeds. The genetic test for this mutation is now commercially available to horse owners and veterinarians through the University of Minnesota Veterinary Diagnostic Laboratory. We are calling this the classic or type 1 form of PSSM. This mutation is accounts for greater than 90% of PSSM cases in some horse breeds. For specifics about breeds see the flow chart below. This mutation appears to have its origins prior to the foundation of modern horse breeds, which is why it occurs in several horse breeds.

McCue ME, Valberg SJ, Miller MB, Wade C, DiMauro S, Akmand HO, Mickelson JR. Glycogen synthase (GYS1) mutation causes a novel skeletal muscle glycogenosis. Genomics (in press)

There appears to be a second genetic mutation (MH) that makes signs of PSSM more severe in Quarter Horses and related breeds. The PSSM and MH genetic tests are recommended in Quarter Horse-related breeds so we can make the best management and treatment recommendations.

Not all cases of tying up are caused by the PSSM mutation. If a horse is N/N but is showing signs of tying-up or muscle pain, it is possible that the horse has another muscle disorder which must be diagnosed by muscle biopsy.

Inheritance of PSSM: Each horse has two copies of every gene (genotype), one inherited from the dam and one from the sire. Every horse inherits either a normal or a mutant gene form each parent. We have designated the letter P to indicate the mutant PSSM gene and MH to indicate the mutant MH gene. A normal horse is designated as N/N. A horse with PSSM may be heterozygous P/N or rarely homozygous P/P for the mutation. Those horses that are P/P are often more severely affected and harder to manage.

The PSSM mutation we have discovered is inherited in a dominant fashion, meaning that one copy of the mutation can cause PSSM. This is different from diseases such as HERDA and GBED, which are inherited in a recessive fashion, where 2 copies of the mutant gene are required for disease. Because PSSM is inherited in a dominant fashion the chances of an affected foal being born are dependant on the genotype of the parents as follows:

• For example, breeding a P/N horse to an N/N horse gives a 50% chance that the offspring will have PSSM.

Thus any time a horse with PSSM is bred there is a minimum chance of 50% of an affected foal being born even if the selected mate is completely normal. The risk of producing an affected offspring when breeding a horse with PSSM is much higher because it is a dominant disease. Unlike the recessive diseases, where a horse with one copy of the gene is a “carrier” a horse with one copy of the PSSM mutation has PSSM.

We are currently in the process of publishing this information in scientific journals and more detailed information regarding the names of the abnormal genes and the specific breeds affected will be available after publication of these findings.

Current Recommendations for Submitting for Genetic Testing, Muscle Biopsy,  or Both

*Disclosure of financial interest: Drs. McCue, Mickelson and Valberg are the patent owners for the genetic testing for GYS1. A portion of the proceeds from this test will go towards their continued research as well as patent royalties.

Based on our current understanding of the two forms of PSSM and the genetic mutations we have identified, we are currently recommending the following approach in the diagnostic process for PSSM:

The British Appaloosa Society has now implemented compulsory PSSM testing for all colts/stallions presented for stallion licensing.

No colt/stallion will be eligible for stallion licensing if it is PSSM positive.

The Council would encourage and advise anyone wishing to breed their appaloosa mare to first make sure she is tested negative for PSSM and to ensure that the sire used is also tested likewise. That way you are guaranteed not to breed the condition forward. 

Please visit Animal Genetics UK for forms and pricing 

Foaling Facts:-

When is my mare likely to foal?

Mares can deliver healthy foals from 320 days pregnancy to 380 days. This means your mare may foal over 12 months from when she conceived! The average gestation length is 334 days. There are many factors which affect the length of pregnancy; For instance, ponies tend to have shorter pregnancies than thoroughbreds and colt foals are carried an average of two and a half days longer than fillies. Foals born before 320 days are considered premature. These foals are immature in development and are unlikely to survive.

Where should my mare foal?

Ideally mares should foal inside so if any complications occur around foaling she can be examined in a safe environment. A large straw box free from draughts where the mare has plenty of room to lie down is ideal. If your mare is going away from home to foal then it is best to move her 4-6 weeks before her expected date to ensure she has built up plenty of protection from infection at her new stable prior to foaling.

Signs and stages of foaling

Up to a few weeks prior to foaling the mare’s udder will develop (Known as ‘bagging up’). Within a few days of foaling drips of fluid may form as wax on the tips of the teats. This is called ‘waxing-up’. The ligaments of the hindquarters around the tail head tend to soften  closer to foaling. Many mares show no signs that foaling is imminent, so it is important to monitor them closely around their due date even if they do not look ready to foal.

Mares can foal at any time of the day but the most common time is between 11pm at night and 4 am in the morning. The foaling process is rapid. It is important to make regular checks on mares during the night when they are due to foal even if CCTV or foaling alarms are used. Foaling alarms can be rented per week. (See Observing the foaling with minimal disturbance to the mare is essential. There are 3 stages of labour:

Stage 1 labour lasts minutes to hours

The mare starts to feel warm (some sweat) and may turn to look at her flanks. She may become restless and start to paw at the ground. She will get up and down a few times before lying down to foal. She will then start to strain.

Stage 2 labour – Expulsion of the foal – lasts approximately 20 minutes

Stage 2 starts with the mare beginning to strain until the foal is expelled. It is important not to disturb the mare at this stage so that she remains on her side. The placenta starts to show at the vulva and then the foal’s feet (usually one foot in front of the other). The foal’s head then appears followed by the chest and belly. At this stage the foal’s hindlegs will remain inside the mare when a large quantity of essential blood will be transferred from the mare to the foal via the umbilical cord. The foal should s tart to paddle with its front feet and move its head to tear the bag of placenta covering its face. If there is no movement after 1-2 minutes then the bag should be torn. If the mare foals standing up then the foal should be held at the height of the vulva until the umbilical cord has stopped pulsating. Premature rupture of the placenta will prevent the foal receiving a major proportion of its blood volume.

Stage 3 labour – Expulsion of the placenta – within 6 hours of foaling

Once the foal has been born, it will usually stand up within 90 minutes. The mare will probably rise first and break the umbilical cord. Failure to expel all of the placenta and membranes within 6 hours of foaling can lead to toxic infection which may in turn lead to a sudden onset severe laminitis. If you are not certain that ALL of the placenta and membranes have been passed by three hours post foaling, you should ring us straight away so we can take steps to make sure they are all out within 6 hours of foaling. Naturally the mare will nuzzle, call and lick the foal. This is the start of a very firm bond. Your mare may be very good to handle usually but be aware that her foal is the most important thing to her. She may become anxious and protective of the foal so take care on entering the stable. Foals become very agile very quickly so do not take their cute looks for granted – they can still kick out and catch you unawares!

What should I look for in the first 24 hours?

The mare

• The afterbirth has been passed within 3 hours. (We recommend you save it in a bucket of water so it can be checked by the vet).

• The mare is allowing the foal to feed.

• The mare is eating and drinking, passing urine and faeces.

• There is no obvious bleeding from her back end or tears in her vulva.

The foal

• The foal has consumed plenty of colostrum within 6-12 hours of birth.

• The foal is feeding frequently and sleeping in between.

• The first droppings (meconium) have been passed (dark brown in colour). Some foals (especially colts) can become constipated and this may lead to serious infection.

• Urine has been passed.

• The umbilicus is not leaking fluid.

The importance of colostrum

Foals are born with an immature immune system as they have been protected from disease whilst in the mare’s uterus. It takes 6-8 weeks for their own immune system to develop to protect them from everyday ‘bugs’. Colostrum produced by the mare is the first milk. It is full of antibodies and energy. The foal can only absorb these antibodies across its intestine in the first 12-24 hours of life. Foals which fail to obtain at least 250ml of colostrum in the first 6-12 hours of life are likely to have unsatisfactory immunity leaving them wide open to infection. Many of these foals die in the first few weeks of life.

The foal may not receive its requirement of antibodies if:

1. the mare drips colostrum from the udder prior to foaling

2. the mare fails to produce enough colostrum – more likely in maiden mares

3. the foal fails to suck quickly or frequently after foaling.

If there is any doubt whatsoever that the foal has received enough colostrum, we recommend a blood sample at around 24 hours old which gives a rapid result to confirm that the foal’s level of immunity is satisfactory.

Checklist prior to foaling

• Ensure your mare has received a booster vaccination against tetanus 4-6 weeks before she is due to foal.

• Check what your insurance company will or will not cover in relation to foaling.

• If a Caslick’s operation (Stitching of the mare’s vulva) has been performed, contact the vet to reverse the procedure prior to foaling.

• Have your vet contact number ready

• Have the following ready for use if required:

Feeding bottle and teat – lambing teats are the most useful 

Umbilical dressing – 0.5% Hibitane or iodine 

If things aren’t going to plan… Phone the vet if:

• The mare has lost any colostrum/milk from the udder before foaling

• The foal is born prior to 320 days pregnancy

• The mare is in Stage 2 labour (Continuous straining) for more than 20 minutes without any sign of a foal

• Either the mare or the foal cannot stand after foaling

• There is excessive bleeding from the mare

• The mare fails to expel the afterbirth (placenta) within 3 hours

• The foal fails to suck within 90 minutes of birth

• You are not certain that the foal has received enough colostrum within 6 hours of birth (This is likely to be the case if you do not know what time the foal was born)

• If you are unsure about anything

It is recommended a check over of all foals within 24 hours of birth to check for any congenital defects such as heart murmur or cleft palate and an examination of the mare to ensure she is not damaged after foaling. 

Many thanks to Adlngton Vets for allowing these two factsheet to be printed.

Mites and Lice:-

Mites - Clinical Signs

By far the most common mite affecting horses is Chorioptes. These mites tend to affect the legs of horses with plenty of feather. They cause irritation which is commonly manifested by stamping of the hindlimbs, chewing of the forelimbs and rubbing the legs on each other or on the stable / fenceposts. Badly affected horses often have thickened skin and scabs, particularly around the pasterns. Some horses develop bleeding sores and secondary bacterial infection can cause lameness and swollen legs. Other species of mite can occasionally cause itchiness and skin lesions elsewhere on the body such as the face and neck.


The clinical signs of itchy legs in a horse with feathers is usually enough to make a diagnosis, but brushings of the hair can be taken for microscopic examination if required. Lesions elsewhere on the body may be subjected to a skin scrape to obtain samples for examination under the microscope.


There are no licensed treatments available. Many horses with feather will never be completely free from mites so it is more a case of keeping the condition to a level where it is not causing a significant problem. Our advice on treatment is as follows:

For mild cases:

Clip feather off once a month, wash legs in Hibiscrub or Seleen (to remove dirt and grease from the skin and keep secondary bacterial infection at bay), use shavings bedding and clear it all out monthly after clipping and washing the legs. Treat any scabs or lesions with antiseptic cream such as Dermisol. Adding an “anti-itch” supplement to the feed such as which may help to reduce irritation and self trauma. The old fashioned remedy of Flowers of Sulphur in Pig Oil applied every few days often helps, but can be very messy to use.

For severe cases:

There are a variety of treatments available which are prescription only medicines. We need to examine the horse to confirm the diagnosis and advise on the most appropriate treatment which could include injections, special washes or sprays. Antibiotic creams may be required to treat secondary bacterial infection.

Long term management of affected horses:

Turn out as much as possible (But look out for mud rash if the legs are clipped and the ground is wet and muddy). You may need to use and antiseptic barrier cream (such as Protocon or Protection Plus Cream) if there are any lesions or the skin is already damaged. Use a shavings bed or medicated bed and clear out the bedding regularly. Clip the feathers off all legs once monthly if you can do.

Lice - Clinical Signs

Lice infestations are very common in late winter and early spring, particularly in horses and ponies with plenty of hair. They are almost always associated with intense itchiness. Affected horses often rub off large patches of hair and can traumatise the skin to leave sores. The worst affected areas are usually the mane, forelock, lower neck and base of tail, although badly affected horses may have lice all over.


Any horses showing intense itchiness in winter and early spring are quite likely to have lice. The lice are just big enough to be seen with the naked eye and can often be seen moving around. Louse eggs may also be seen as small white eggs attached to the hair shafts. There are different types of lice which can be identified by taking brushings


We recommend using products containing permethrin which will kill the lice rather than just repel them. Most louse powders are merely repellents and are rarely enough to cure a chronic infestation. The easiest way to apply a permethrin product is in the form of Switch pour-on. This should be applied weekly for 4 weeks so any larvae hatching out of the eggs are killed as well. If there are several horses to treat, it may be easier using Barricade spray. Powders can be applied to in contact horses to reduce the risk of infestation transferring to them. Rugs should be washed or treated with powder or spray. Lice are contagious to other horses so try to keep affected horses isolated if possible and monitor other horses for signs of infestation. The louse species affecting horses cannot be passed on to humans but it is not impossible for them to give an occasional bite!

Atypical Myoglobinuria

Description of Atypical Myoglobinuria:

Atypical myoglobinuria is a serious equine muscle disorder. Atypical means it does not behave as expected. Myoglobinuria means that there is muscle damage, the end products of which are passed out in the urine. Atypical myoglobinuria can occur in little worked horses. It usually affects several horses or ponies in a group kept at grass with little or no supplementary feeding. Outbreaks of Atypical Myoglobinuria tend to appear after a period of heavy rain, when the animals may have become cold and wet. Their temperature, respiratory rates and pulse tend to remain normal. It is particularly upsetting as it often affects a group of horses often leading the owner to think the animals have been poisoned. Fortunately, the condition is fairly rare.
Symptoms of Atypical Myoglobinuria:
Mainly suffered in a Spring or Autumn associated with bad weather, the main symptoms are:
Sudden onset of stiffness unrelated to exercise
Horses appear very weak and tend to collapse easily, indicating muscle weakness, but affected muscle groups are not swollen or painful
The horses do not seem to be in severe pain and are usually able to eat and drink normally, even if they are too weak to stand up
The horse's urine is an abnormally dark red to chocolate brown colour
Causes of Atypical Myoglobinuria:
Associated with a sudden deterioration in weather conditions
Thought to be connected with a toxic fungal overgrowth that flourishes in foul weather.
Not protecting susceptible horses by providing shelter from bad weather
Not ensuring horses have supplementary feed, such as plenty of hay, while out at grass.
Not ensuring general good health and well-being
Not worming or taking care of infestation
Treatment of Atypical Myoglobinuria:
There is no miracle cure. A blood test should be obtained to ascertain the condition of muscle enzymes. If these are very high, it will confirm the existence of Atypical Myoglobinuria . The horse may be put on supportive treatment administered via a drip or painkillers.


HHo article adds:
In fact, atypical myoglobinuria is not due to poisoning, but may be linked to a toxic fungal overgrowth that flourishes in foul weather.
From Arabian lines forum:
Just a warning, probably directed more to the Northeners, we seem to be having an outbreak of Atypical myoglobinuria, we have seen two ponies on one farm and have contact with a neighbouring vet practice who are treating another.
It mainly affects grass kept horses, after a change to worse weather and can be fatal in 85% of affected horses.
The disease starts with fairly mild signs, which I think could easily be missed unless you had already seen a case, the horse appears a bit stiff, reluctant to move, may be standing or lying alone, or in some cases may be found completely flat out or dead in the field. I won't bore you with all the details but basically the muscles are badly damaged, the breakdown products are filtered through the kidneys, damaging them in the process, and excreted as dark coloured urine.
The clinical signs depend on the amount of damage incurred by the muscles and kidneys and the groups of muscles affected. Obviously if the heart muscle or diaphragm is affected then the prognosis is hopeless. Google it and familiarise yourselves with signs etc and spread the word to your yard mates and horse-owning friends.. Sorry to bring potential bad news, Haggis
A notification from the North of Scotland, but I think it is worth all horse owners and riders in the UK being aware of this disease......
Would you mind publicising this to BHS members in Highland South, please? We have unfortunately had three cases of atypical myoglobinuria, a fatal disease of young grazing horses, within our region and we would like to raise awareness of the disease.
Three horses have been destroyed after a diagnosis of atypical myoglobinuria was reached by Kessock Equine Vets this autumn and early winter. The signs include stiffness, depression with a low-head carriage, a high heart rate and a high breathing rate. Very dark brown urine is produced and the animals eventually collapse and can't get back up onto their feet. There has been an outbreak of this disease throughout Western Europe and over 200 horses have died. The disease mainly affects young stock, grazing permanent pasture with close proximity to water courses, such as lochs and rivers. A link has been suggested with pastures which have lots of deciduous trees and hence leaves on the ground. Prevention advice is limited to providing shelter and supplementary feeds when the weather is damp or wet. Providing stabling for part of the day, also helps reduce the risk. We have placed a notification on our web site at and more detailed information can be found at
Suffice to say, that this is a very serious disease and early treatment is essential for any hope of success. If owners notice stiffness in a horse or pony that looks under-the-weather, they should contact their vet immediately. 

The Grey gene !


 Grey is the dominant gene responsible for the gradual and progressive depigmentation  (fading) of the carrying horse. Grey cannot be considered a base-colour, or a dilution, rather a gene, which slowly removes pigment form the coat. Grey is considered to be the ‘strongest’ of all coat modifiers and acts upon any base-colour regardless of the carrying horse’s phenotype.

The fading process itself may last for several years, but once the hair is depigmented it will never re-develop with the horse’s original colouring. Since Grey is a dominant gene, where it is present it is expressed – however the final phenotype of the carrier will carry from horse to horse. Some Grey horses fade almost to full depigmentation (almost pure white) whereas others may be ‘fleabitten’ – whereby Grey has faded almost all of the horse’s coat but for a few tiny spots or  ‘fleabites’.  The grey carrying horse may also experience depigmentation of the skin itself, and before skin is fully faded may display ’mottling’.

DNA testing is available for the associated gene mutations responsible for Grey. The genetic test verifies the presence of the dominant Grey Gene (designated G) and presents results as one of the following:

Nn: Negative (non Grey horse)

Gg: Heterozygous. Positive for dominant Grey gene, carrying a single inherited copy. Carriers coat modified and eventually depigmented Heterozygous grey horses are statically likely to pass the gene to 50% of their progeny when bred.

GG: Homozygous. Positive for dominant Grey gene, carrying two inherited copies. Carrier’s coat modified and eventually depigmented. Homozygous grey horses are statistically bound to pass the gene to 100% f their progeny when bred; all foals will receive grey and fade-out.   

Why test for Grey

 Genetic testing of the grey gene may be beneficial for a number of reasons:

 Breeding purposes: For those interested in specifically breeding grey foals, Homozygous grey specimens are ideal, as they will always transmit the grey gene when bred, thus guaranteeing (eventual) grey progeny. Those looking to ‘breed out’ the Grey modifier to gain non-fading foals may hope for Heterozygous Grey horses. Some breed types have a large percentage of grey stock, which through historical lineage may harbour colours and dilutions ‘hidden’ by the masking effect of the grey.

The LP Gene has been 'spotted'

             Lp and PATN1 – what are they and what do they do?

March 2015 saw the arrival of a commercially available test for a gene called PATN1 (short for Pattern 1). It caused much excitement amongst breeders of spotted horses. So, what is PATN1? It’s the gene that is thought to be responsible for leopard and near leopard coat patterns. A horse needs another gene, called Lp (short for Leopard Complex), to work with PATN1 for it to look leopard or near leopard. Lp is the gene thought to be responsible for at least the basic appaloosa characteristics of mottled skin, white sclera and striped hooves. So how do the two genes work together? Sheila Archer, of the Appaloosa Project, used an analogy some years ago that helped to get heads around the complex subject of Appaloosa genetics. She likened Lp to a torch – when it was switched on you could see any other spotting genes that were present. She likened PATN1 to a cat.

The horse has no Lp (torch) and no PATN1 (cat). The horse is solid and cannot pass either gene to its offspring.

The horse has Lp (torch), but no PATN1 (cat). It has Appaloosa characteristics, mottled skin, white sclera and striped hooves. It can pass Lp on to its offspring.

The horse has no Lp (torch), but has PATN1 (cat). Because the horse has no Lp you cannot see the PATN1 gene by looking at it. The horse will look solid, but can pass PATN1 on to its offspring

The horse has Lp and PATN1. The horse will look leopard spot or near leopard, with spots covering a large part or all of its body. It can pass Lp and/or PATN1 to its offspring.

The horse has two copies of Lp (two torches). This reduces the amount of spots on the horse so it looks mostly white, with only a few spots, hence it’s a fewspot leopard, or near fewspot leopard. It will always pass Lp onto its offspring.

In the last three examples it is possible for the horse to have two copies of PATN1, which means it would always pass a copy of PATN1 to its offspring. This can be very useful if you want to maximize your chances of a loudly marked foal, as you could cross a horse that has two copies of Lp to a horse that doesn’t have Lp but has two copies of PATN1, to guarantee a foal that will have a copy of Lp and a copy of PATN1.

Since the discovery of LP, the main gene that controls appaloosa spotting patterns and associated traits, breeders have been anticipating DNA tests for the genes that work with LP to produce white appaloosa patterning.  

The Appaloosa Project are happy to announce that the white pattern modifier gene with the largest pattern causing effect, termed Pattern-1 for “first pattern gene” or PATN1 for short, can now be DNA tested for.  

A mutation in PATN1 was identified that is associated with increased amount of white in LP horses. This mutation (in combination with LP) behaves in a dominant fashion which means you only need one copy of the PATN1 mutation to observe large amounts of white as long as LP is present.

PATN1 in action

In terms of physical appearance, horses that are heterozygous for LP (LP/N) and that have inherited at least one copy of the PATN1 mutation tend to exhibit a leopard or a near–leopard pattern.  

In horses that are homozygous for LP (LP/LP), the PATN1 mutation (in one or two copies) most often results in a few spot or near-few spot pattern.

PATN1 with one copy of LP               PATN1 with 2 copies of LP

Benefits for breeders 

For breeders, the ability to test for PATN1 represents a huge advantage.  For example, if two leopards are mated (both heterozygous for LP and both carrying at least one copy of PATN1) they have a 25% chance of producing a horse without LP (a true solid) 

Without LP, the “on switch” for appaloosa patterning, there is no way to tell by looking at the horse if PATN1 is present and a valuable breeding animal maybe overlooked.

DNA testing will enable breeders to know if this horse has PATN1.  Animals without LP but with PATN1 can, when bred to horses that are homozygous for LP, produce loudly patterned spotted offspring. 

In addition, breeders can now test their leopard and fewspot horses to determine which ones are homozygous for PATN1 and thus could be more valuable to their breeding programs.

How to DNA test for PATN1 

To access the DNA test for PATN1, go to the UC-Davis Veterinary Genetics Laboratory

Listed under “Tests Offered” 

Appaloosa Spotting is the test for LP and 

Appaloosa Pattern-1 is the test for PATN1. 



Colic is one of the commonest equine emergencies. The word ‘Colic’ literally means ‘abdominal pains’ so is not very specific – there are many different types of colic and many different causes.

What are the signs of Colic

The presenting signs of colic can vary significantly in intensity. Getting up & down frequently. Rolling, kicking at the belly, flank watching and box walking are all typical signs. In some cases signs can be more subtle – the horse may just become dull and in-appetent, or slightly restless. It is important to note whether or not the horse has been passing normal droppings

Why? These occur for a number of reasons. If a horse has bad teeth and is not chewing food properly impactions can result, so having regular checks is a must. Worms (especially tapeworm) will most commonly cause impactions in the small intestine which sometimes require surgery to correct. Sudden changes in feed and routine or gorging on too much feed can also cause problems, and stress is thought to contribute to some cases. A rarer cause is sand impaction in horses grazing sandy pastures.

Where? The commonest site for impactions is at the ‘pelvic flexure’. This is a part of the large intestine where the diameter of the gut decreases dramatically as it turns a corner. This is designed to slow the movement of material in the gut, but can cause ingesta to become impacted. Impactions can occur anywhere including the stomach. Treatment and prognosis will vary greatly depending on the site.

 Displacements of large intestine: The large colon is arranged in a long U shape and is quite mobile. If there is some gas build up it is capable of becoming displaced. It can displace to the left and become trapped between the kidney and the spleen, or it can displace to the right and wrap around the caecum.

Tympany/gassy colic: Gas build up can cause distension of the intestine and pain without displacement arising.

Strangulation of the intestine: It is very serious when a part of the gut becomes strangulated or twisted and again there are many causes. In older horses fatty lumps called ‘lipomas’ can form within the abdomen. These are often on long stalks and can wrap around intestine strangulating it from the outside. The intestine is suspended in the abdomen by a sheet called the mesentery. There are areas where intestine can potentially become trapped in holes in this mesentery becoming strangulated. Both small and large intestine can also twist spontaneously. Usually horses with these conditions will show extreme pain.

Spasmodic colic: If the intestines have become overactive this can cause pain. Usually increased gut sounds will be heard. Medication to relax the muscle in the walls of the intestine can often resolve this.

Other causes of colic include peritonitis (infection of the abdomen), abscesses in the abdomen, foreign bodies, gastric ulcers and enteritis (infection and inflammation in the intestine).

What to do if your horse is colicking: You must contact your vet immediately if you suspect that your horse has colic. It is best to remove all feed and hay as eating will aggravate the problem. Some type of colic (especially gassy colic) will benefit from walking out, but if the horse is in a lot of pain it is better not to do this. If the horse wants to roll it is ok to allow this, as long as the horse is in a safe environment in order to avoid any injury during rolling.

The Veterinary Exam: The following are important clinical parameters that the vet will assess. Examination of a horse with colic requires the vet to use theses to look at the overall clinical picture rather than relying on any one sign alone.

 Degree of pain: Often the severity of colic signs can give a good indication as to how serious the type of colic is. However, some individuals will be more stoic or more sensitive than others so this sign alone cannot be relied on.

Mucous membrane colour and capillary refill time: The gums should be pink and moist. If they are pale this can indicate that the horse is becoming dehydrated. In severe cases the membranes may be ‘toxic’ – they appear to have blue/purple rings around the borders of the teeth.  Capillary refill time is measured by pressing a finger onto the gum, leaving a white print.  In a normal horse this white print should refill with the normal pink colour within 2 seconds as blood flows back to the area. If the time is prolonged this can indicate again that the hydration status is compromised.

Heart rate and pulse: In most horses the normal heart rate lies between 25 and 42 beats per minute. This may be higher in smaller ponies and youngsters. An increased heart rate can indicate dehydration or pain. Often, in cases of colic that require surgery, the heart rate will increase to 60-80 beats per minute. The quality of the pulse is also taken.

Gut sounds: Good put sounds should be heard on both left and right side of the abdomen/ If no gut sounds can be heard then it is more likely that eh colic is serious and may require serious, Sometimes specific areas of the gut are quieter that they should be, giving an indication of where the problem might lie. If increased gut noises are present it is likely that the horse has a spasmodic colic,

Temperature: This is taken in case the colic is being caused by the start of an infection in the gut. In the vast majority of colic cases this will be normal.

Internal (rectal) examination: This can be incredibly useful to try to diagnose the type of colic. Some of the things that can often be felt are impactions, displacements of the large intestine and distension of the large or small intestine. If distended loops of small intestine can be felt this almost suggests that the hors requires surgery.

Stomach tube: Sometimes the vet will think it is also necessary to pass a tube into the stomach to complete the exam. If a lot of fluid comes back up the tube this indicates that there is likely to be a blockage or twist in the intestines causing fluid to back up into the stomach (We call this reflux). If the stomach distends too much it can rupture which is then fatal to the horse’ If no reflux is obtained, fluids can be administered through the tube to maintain hydration.

Further tests: if a horse is referred to hospital there are a few further tests that will be done on arrival. These include blood tests, analysing a sample of fluid from the abdomen, and performing an ultrasound san of the abdomen.

Treatment: A decision will be made about whether the horse needs to be referred to the hospital for further investigation, fluid administration and possibly surgery. If the horse is treated at home, the main considerations will be pain relief and hydration status.

Analgesia: There are several different medications that can be given for pain relief which offer different degrees of strength. The vet will choose which one to use depending on the individual case. If a spasmodic colic is suspected, a mediation called ‘buscopan compositum’ is often used, which contains both a mild pain killer and a muscle relaxant.

Stomach tubing:  Administering fluids through the stomach tube can help to maintain hydration. In cases of impaction colic, salt water and possibly also liquid paraffin can be given to try to soften and move the impaction. This sometimes needs to be repeated several times before resolution.

Monitoring: It is always essential for the horse to be very closely monitored after medication is given. If further colic signs are seen the vet will need to re-examine the horse as soon as possible. If a horse does not respond to pain relief, the vet may decide that it is best to refer to hospital for treatment.



Osteoarthritis is a common cause of lameness in horses. It is a progressive degenerative condition and there is no cure, however it can often be managed. Osteoarthritis (also known as 'arthritis' and 'degenerative joint disease') is a degenerative condition of joints resulting in cartilage erosion and inflammation. Articular cartilage has very limited ability to repair so the condition is irreversible. Any joint injury or insult can result in osteoarthritis. Most cases are due to wear and tear. Horses are large animals and put huge forces on their joints. Injuries to ligaments or bone (chip fractures) and inflammations resulting from infection are also causes.

How do I recognise osteoarthritis?

Symptoms of osteoarthritis include:

• Lameness - this may be the only sign in many cases  

• Joint swelling

• Pain on flexion of the joint                                             

• Increased lameness after flexion

What should I do if I think my horse has these symptoms?

You should make an appointment to have your horse's problem investigated by your vet. Lameness examinations are often best performed at an equine hospital to allow a full examination and investigation with appropriate equipment. Lameness investigation is extremely challenging and can be very time consuming.

What will my vet do?

Your vet will perform a comprehensive lameness examination. Following the examination, nerve blocks are then used to localise the lameness or confirm that a swelling is significant. This can be very time consuming as each block takes at least 30 minutes to fully assess before progressing to the next block. Once lameness is localised, radiographs are taken to determine the severity and assist with determining a cause. Further imaging may be required, such as ultrasonography, scintigraphy or magnetic resonance imaging (MRI). Ultrasound is used to assess soft tissues and scintigraphy may be needed to assess bone if radiographs are not productive. MRI is available at some specialist clinics and gives very detailed images of soft tissue and bone.

Treatment for your horse will depend on the severity of the symptoms and may include:

• Rest and anti-inflammatories such as phenylbutazone.

• Anti-arthritic drugs, e.g. pentosan, hyaluronate.

• Feed supplements containing glucosamine and/or chondroitin sulphate.

• Intra-articular medications, these include corticosteroids, hyaluronate.

• Arthroscopic surgery - removal of chip fractures, trimming of cartilage and synovium, and flushing out of enzymes are all beneficial to the joint.

I have heard that intra-articular cortisone therapy damages the cartilage - is this true?

This statement is based on experiments where cortisone was used at extremely high dose rates in normal joints. More recent studies have shown that lower doses in arthritic joints actually prolongs the life of the cartilage. Used carefully, cortisone can increase the functional life of a joint significantly. There are risks, as with any treatment, so consult your vet about all the pros and cons before agreeing to intra-articular therapy.

What can I do to prevent my horse developing osteoarthritis?

It probably isn't possible to prevent osteoarthritis, especially in horses undergoing heavy athletic work. Measures you can take to help prevent your horse from developing the disease (especially at an early age) include:

• Keeping your horse well shod - well balanced feet will reduce the stress on lower limb joints.

• Avoid work on hard ground - this will reduce concussion to the lower limb joints

• Use cold therapy (icing) after hard work - this will help control inflammation.

• Regular use of anti-arthritic preparations - this may be helpful, but their cost effectiveness is questionable.

Views on Worming by Chris Dobson 

Hi everybody. I was talking to one of your  Society’s committee members last week saying that I have a pet soap box subject at the moment, worming. The reply would you like to write a little article about it for the Baps site? I thought for a while, and came to the conclusion that at this time of the year of long winter nights, I could spare a bit of time to put pen to paper, which may, hopefully, reveal some useful hints that new or even older society members/horse owners may find interesting. So here goes.

I have had horses all my life and I am now fast reaching the age when you are referred to as a wrinkly. I have had Hanoverians, cobs, thoroughbreds, coloured etc but whether you have owned a Shetland or a Shire they all have one thing in common, they have to be wormed. In September, which seems like the long and distant warm while ago now, my friend told me our local saddlery shop was holding one of their community evenings. We had both been to one the previous year when the topic was “feeding your horse” and learnt a few new useful things, so we thought why not. This time the topic was, yes, you guessed it WORMING!! They have a buffet, wine etc and a guest speaker and it is organised by one of the big animal drugs companies. Although we both have had horses all our lives we decided to attend as you are never too old to learn, things change all the time and we wanted to know if there were any new wormers on the market.

There was a good turnout of people about 50 in total of varying ages and gender. Our speaker was a very jolly, humorous chap, a practicing vet, and very knowledgeable. After starting by showing pictures on a large screen of all the different types of worms your horse’s stomach plays host to, anyone who was still eating any buffet items soon stopped. Yuck. Worms, they are the most disgusting things!! Pictures of similar height horses/ponies were shown and the audience were asked to guess their weight. Of course not many guessed accurately, because horses have different body shapes, and therefore weight. The vet asked well if you can’t guess their weight, how can you accurately give the right dose of wormer to your horse? Some of us older members shouted a ‘worming tape’ the one who shouted loudest got a tape as their prize. The Equimax worming tape is used, for those of you new to worming, to work out your horse/pony’s weight by measuring around their stomach in centimetres and converting this to how much wormer per 100Kg body weight should be given. Much more accurate than guessing. The only really accurate way of find out your horses weight is with a weighbridge and not many of us have one of those!! A family friend who has had horses all her life and runs riding school gave a 10 hand pony a whole tube of wormer. In the morning when she went to his stable he was laying on his back with his legs in the air, she had overdosed him. Fortunately he did recover with no lasting ill effects. It does however prove the worth of a worming tape which are about £4.99 or sometimes given free when you buy wormers. They are made of heavy duty plastic and should last a lifetime. 

It’s a known fact that most people underestimate their horse’s weight by 20%. Worms affect all horses whether kept at grass or stabled and unless treated they can cause weight loss, colic, diarrhoea and in severe cases even death. For wormers to be effective every horse must be dosed with the appropriate amount of wormer for their body weight. If horses are under dosed with the wormer, the internal parasites are exposed to a sub lethal amounts of the drug and this may leave a population of worms able to tolerate the wormer. In other words the worms can become resistant to the wormers, like some of us are to antibiotics. Increasing numbers of horses are kept on smaller areas and many paddocks are over grazed which can in itself lead to serious worm problems, more and more worm eggs are passed out in droppings on to the pasture, contaminating it, only to be eaten again.

The next point made was that since the eighties almost every 10 years a new worming chemical has come out, but due to the cost of research etc there would not be any this decade. However Equimax have brought out chewable worming tablets. eight in a pack original taste or apple, each tablet effective for 100kg bodyweight so making it quick and easy once your horse has been measured to determine how many tablets they require, rounding up to the nearest 50kg body weight never rounding down. My horses take these from my hand and eat them making worming much more easier and convenient. If you breed foals, remember,if possible to rotate their pasture every year as they contaminate grazing much more than older horses.

Worm your foal with the appropriate wormer from 10 weeks old this will give him a good start in life. All horses kept in groups should be wormed at the same time, if your horse is stabled keep it in for 24/48 hours and remove all dung and contaminated bedding etc afterwards. Change your wormer every time you worm, not only the Brand name but the effective chemical content i.e Invermectins, benzimdazoles, pyrantel embonates and Praziquantel.

In September I visited a livery yard it was a very hot day and as I stood by the gate to the mares field all I could smell was horse dung, on entering the field you could not take one step without treading on dung and this was a ten acre field with say 20 horses in it. So one of the most important messages I am trying to convey to you is poo picking is extremely important, as you may know it is a continuous cycle for the horse to pass out worms, graze next to his poo and re infect himself therefore wasting all the money you have spent on expensive wormers. Poo picking can be fun!! My grandchildren often play(in summer, when poo is dry) Poo golf and Poo tennis helping remove the dung from the field in a fun way. Apart from being a repetitive pain, I do find poo picking quite relaxing. So, after that heavy Christmas meal, when you go to visit your horse, do a bit of poo picking and exercise those stomach muscles you will feel better for it. In the long run so will your horse. If your local Saddlery has one of these community evening they are well worth attending, they normally have money off offers too!!

Brief general guide for what month specific types of worms appear.

Jan to March           Routine worming

April                      Tapeworm   

May September       Routine worming

October                 Tapeworm

November              Encysted Redworm

December              Bot worming


Thanks goes to Christine for taking time and trouble to put her experiences into words