A research project funded by The Horse Trust has found that various types of ocular tumours can be successfully treated with mitomycin C, a cytotoxic antibiotic isolated from a bacterium.
The research concludes that mitomycin C offers a safe and cost effective alternative to current treatment options such as surgery and radiation.
The research project was led by Fernando Malalana, while working as The Horse Trust's Clinical Scholar in Equine Internal Medicine at University of Liverpool. Fernando is now working as a Clinician Teacher in Equine Internal Medicine at the university.
Ocular tumours are more difficult to treat than tumours in other parts of the horse's body due to the risk of damaging the eye. In the study, Malalana investigated the use of mitomycin C in treating ocular squamous cell carcinoma, the most common ocular tumour in horses, and occular sarcoids, skin tumors that frequently affect the eyelids .
Mitomycin C is an antibiotic isolated from a bacterium, Streptomyces caespitosus. It is known to have cytotoxic effects and has been used to treat tumours in horses before, but only in combination with surgery.
Currently, the main method of treating ocular squamous cell carcinoma is by removing the tumour surgically or with radiation. Both treatments are costly and have a number of associated risks. There is also the risk of damage or scarring to the eye.
Fourteen horses with ocular squamous cell carcinoma, three of which were affected bilaterally, were included in the study. Mitomycin C was applied to the conjunctival sac of the affected eye; in some of the cases the treatment was combined with surgery. Malalana found that of the 8 eyes treated with mitomycin C alone, clinical resolution occurred in 6 cases. Of the 9 eyes treated with both surgery and mitomycin C, clinical resolution occurred in 7 cases.
Mitomycin C was also used to treat various types of sarcoids found in the eye. Currently, the most effective treatment for occular sarcoids is radioactive wire. However, radioactive wire treatment is not ideal as it is expensive, only offered in two locations in the UK, and has potential health risks to the vet applying the wire due to exposure to radioactivity.
Six horses and two donkeys with occular sarcoids, including one horse that was affected bilaterally, were treated with mitomycin C, which was injected directly into the tumour. Malalana found that of the nine nodular and fibroplastic occular sarcoids treated with the antibiotic, all were completely cleared. However, the vets did not have good results with verrucous sarcoids.
Malalana said: "The results of this research should offer hope to the owners of horses that have eye tumours. We have already been contacted by vets from across Europe to find out more information about this treatment and hope that it will be offered to more horses with occular tumours in the future".
Vets at the University of Liverpool are now testing the use of mitomycin C on other tumours that are difficult to treat surgically, including melanomas near the horse's anus. So far, two cases have been treated, but it is too early to tell whether treatment has been successful.
Malalana's research has been submitted to Veterinary Ophthalmology journal.
A research project funded by equine charity The Horse Trust has found that 40% of horses suffered a traumatic injury within the past year.
Only 13% of injuries occurred during ridden exercise, while 62% occurred while the horse was turned out in the field.
The research, which has been accepted for publication by the Equine Veterinary Journal, was carried out by Rosie Owen, who is currently working as The Horse Trust's Clinical Scholar in Equine Orthopaedics at the University of Liverpool.
Rosie said: "This Horse Trust-funded research shows that horses get injured relatively frequently - much more often than you would expect. Interestingly, most of the injuries happen during turnout, rather than during ridden exercise."
The results were obtained through analysing the responses from 652 randomly selected horse owners from north-west England, Midlands and North Wales, all of whom had a horse aged 15 years or younger. Owners sought veterinary treatment for 47% of the injuries reported, while the remainder were treated by the owner or a friend, or required no treatment.
Rosie identified a number of factors that were associated with an increased risk of injury. For example, horses that had been owned for a shorter period of time were found to be significantly more at risk of injury. She says the increased risk may be due to aggression from other horses when a new horse is introduced to a field, but owners can take various steps to reduce the likelihood of injury: "It's worth trying to avoid regular changes in group composition. A new horse should be introduced to the group gradually, preferably by providing adjacent stabling initially. Protective boots may help as the lower limbs are most at risk of injury. Also, if possible, the other horses in the field should have their shoes taken off during the period of adjustment, so they are less able to injure the new horse."
Rosie also found that horses turned out within larger groups were at an increased risk of injury. This is probably due to there being a larger hierarchy with multiple horses competing for dominance. However, she found that the risk of injury reduced when additional feeding areas were provided in the field: "If you provide hay or haylage to horses in the field, it's worth including an additional feeding area to reduce competition for food."
Other interesting findings included the lower incidence of injury in cob and pony breeds, compared to other breeds. Horses used competitively also had a higher risk of injury, which may be due to the additional athletic demands placed on these horses, or due to the way these horses are managed. Horses trained using Parelli methods were also found to be at an increased risk of injury, but as the numbers in this group were small, more research is needed to confirm this.
Although most of the injuries recorded in the survey occurred during turnout, 11% occurred in the stable, with most of the injuries affecting the head or eye. Rosie says owners can easily reduce the risk of stable injury: "There are various simple steps that owners can take to reduce the risk of injury in the stable. Try to provide hay from the floor, instead of in a hay rack, and make sure there are no protruding nails, hooks or sharp edges in the stable."
Rosie said that it would be useful to conduct further research to understand how injuries occur during turnout: "A lot of injuries are reported during turnout, but we're uncertain about what happened. It would be useful to observe the behaviour of horses in the field to see whether it's competition for food, or another factor, that is responsible for the high rate of injuries among horses."
Jeanette Allen, Chief Executive of The Horse Trust, said: "We are pleased that the research we've funded has provided such useful statistics on the risks of injury for horses. We hope that horse owners will follow some of the tips that Rosie has suggested to reduce the risk of their horse being injured."
A research project funded by The Horse Trust has discovered that a racehorse's performance does not markedly change after it has recovered from a tendon injury.
The research was led by Bryan O'Meara, who is in the final year of a three year clinical training scholarship funded by The Horse Trust.
Mr. O'Meara carried out the research at Donnington Grove Veterinary Surgery in Newbury, under the supervision of epidemiologist Dr Tim Parkin from University of Glasgow.
Tendonitis is one of the most common musculoskeletal injuries in racehorses, with a prevalence of 11-30%, according to earlier research.
Mr. O'Meara examined the clinical records and racing histories of 400 racehorses who had been treated for superficial digital flexor (SDF) tendonitis injuries over a five year period (2003-2008).
The race records of horses affected by tendon injury were compared with 400 matched control horses that had never suffered SDF tendon injuries.
The controls were horses training in the same establishment at the time of injury and of the same age and sex as the case horse.
The research looked at the performance of the racehorses in races before and after treatment for the injury, and at the performance of the control horses before and after the treatment date. The Racing Post Rating (RPR), which is published by the Racing Post after every race, was used as a measure of performance.
Mr. O'Meara found that there was no significant difference in RPR before and after the treatment date in case and control horses.
According to The Horse Trust, this result is unexpected as in vitro studies have found that healed tendon tissue has reduced elasticity due to the presence of scar tissue. This suggests that a horse with a healed SDF tendon would need to work its muscles harder to compensate and would therefore be expected to have lower performance.
Mr. O'Meara said more research is needed to back-up his finding that performance isn't significantly affected by tendon injury: "It could be that using Racing Post Rating to measure performance isn't sensitive enough to pick up a change in the horse's performance. However, it's encouraging that there's no marked change in performance after a horse has recovered from a tendon injury. These findings show that there's no need to give up on a horse that has a tendon injury - they can still come back and perform well, or can be used for other, less demanding riding activities."
The research also found that there was no significant difference between case and control horses when returning to racing and completing three races. Only after completing five races, or three years post treatment, was a significant difference found between case and control horses. This finding is a step towards developing a more accurate assessment of tendon treatment. Outcome after five races or three years post treatment is a better indicator of the outcome of treatment.
Mr. O'Meara said: "At the moment, some tendon treatments state their success as the percentage of horses that return to racing after treatment. However, we've shown that there's no significant difference between case and control horses at this time. At the moment, there are a myriad of treatments available to treat tendonitis. Hopefully this finding will be used in further research to learn which treatments are most effective."
Mr O'Meara's research also found a link between SDF tendon injury and the racehorse competing at its maximum performance level: the case horses were significantly nearer to their pre-injury maximum performance level in the race immediately before injury (compared to matched controls), suggesting that they were competing nearer their individual maximum performance level when the SDF tendon injury occured.
Equine charity The Horse Trust has reported an unprecendented number of enquiries from people wanting to rehome their horses and ponies.
In the three weeks since the financial crisis resulted in repossessions, job losses and cash shortages, more than 500 people made inquiries about having their horses rescued or rehomed.
Susan Lewis, The Horse Trust's marketing manager said: "There is a new generation of horses which is being affected in this way. Animals which have been cherished for 20 years and are now approaching retirement age are becoming too expensive for owners to maintain at livery - especially as the winter season is approaching with its inherent requirements for additional feed, housing and veterinary care."
She added: "Most people are saying: 'Help, what can I do? I adore my horse which has lived with me since I was a tiny child - but now I can barely feed myself let alone my horse. He has always come first - but having lost my home and the field in which I keep him, I just don't know where to turn'.
"It isn't a new story - and we have for many years warned horse owners that they face the issues of cost, care and commitment well into the old age of a horse, which can be up to 30 years. Now, however, it seems that we are facing a more widespread crisis."
Like most other horse charities, the Trust's Home of Rest for horses is full to capacity.
"We simply can't take on any other animals," said Susan. "The charity pound is now stretched to breaking point as people's purses dry up - and with rising feed prices and veterinary charges, it now costs more than £17 a day to keep a horse here.
The Horse Trust is funding a three-year project to develop a genetic diagnostic test for Fell Pony Syndrome (FPS) and thus enable control and possible elimination of the disease.
The work will be undertaken at the Animal Health Trust, Newmarket, and the University of Liverpool Veterinary School.
The Fell pony, an ancient British pony breed categorised as "at risk" by the Rare Breeds Survival Trust, has over the past decade or so been subject to a severe immune deficiency known as Fell Pony Syndrome (FPS), which results in the death of some of the newborn foals.
Foals affected with FPS appear normal at birth but within a few weeks begin to lose condition and suffer diarrhoea, coughing and weight loss. Severe anaemia and immune dysfunction follows, leading to wasting and finally death. The disease is always fatal.
As a large percentage of these ponies live and breed on the fell, the prevalence of FPS is unclear. Despite an improvement in foal registration numbers in recent years, Fell Pony Syndrome remains of concern to breeders.
Studbook analysis and knowledge of affected foals strongly suggests that this is an inherited disease caused by an autosomal recessive genetic mutation. A DNA based test for this mutation would enable carriers of FPS to be identified and the conception of affected foals prevented.
As well as identifying carriers in the Fell pony population, the project will be used to identify any carriers in other breeds which have been involved in the extensive outbreeding of Fell ponies over the years.
"The success of this project will prevent the suffering of newborn Fell pony foals affected with FPS," says project leader Dr June Swinburne, senior post- doctoral equine molecular geneticist at the Animal Health Trust Centre for Preventive Medicine. "Foals affected by the condition inherit an incurable genetic defect which results in severe wasting and a profound anaemia together with multiple infections. Veterinary intervention is in vain and once the condition is diagnosed foals are often euthanased. The gradual but relentless decline in these foals leaves both veterinary surgeons and breeders powerless.
"Breeders are supportive of our attempt to develop a diagnostic test which will help to prevent carrier-carrier matings, one in four of which results in an affected foal."
The Horse Trust's Chief Executive and resident veterinary surgeon Paul Jepson said: "This is an exciting and achievable project with significant benefits for equine health and welfare, as it will lead to the prevention and elimination of a fatal disease."