Research Report: Antibiotic Resistance Increases in Hospitalized Horses Even When No Antibiotics Are Administered

by Fran Jurga | 22 September 2009 | The Jurga Report at Equisearch.com

A team of researchers working at Philip Leverhulme Equine Hospital at the University of Liverpool have discovered that Escherichia coli (E. coli) bacteria in a horse's intestine appear to acquire antibiotic resistance while a horse is hospitalized.

E. coli is a bacterium that is commonly found in the lower intestine of animals. Most E. coli strains are harmless and are part of the normal flora of the gut.

The researchers found a significant increase in multiple drug resistance in E. coli samples isolated from horses' feces after a period of hospitalization.

Research team leader Adele Williams (shown in photo) received funding from British equine charity The Horse Trust and presented her research earlier this year at the European College of Equine Internal Medicine Congress.

Williams and fellow researchers collected fecal samples from randomly selected horses over an 18 month period between 2006 and 2008 when the horse was admitted, and again after the horse had been hospitalized for seven days. The selected horses included horses treated and not treated with antibiotics before and during hospitalization.

E. coli bacteria cultured from the samples were tested for their sensitivity to eight antibiotics (neomycin, ampicillin, ceftiofur, gentamicin, chloramphenicol, ciprofloxacin, tetracycline and trimethoprim) using the Kirby-Bauer disk diffusion method. The antibiotics chloramphenicol and tetracycline are not used at the hospital.

The researchers found a significant increase in resistance during the week's hospitalization for seven of the eight antibiotics; no significant difference was found for neomycin. Antibiotic resistance increased even in horses not treated with antibiotics and to antibiotics that are not used in the hospital.

This increase may be due to the transfer of antibiotic resistant genes as a result of selection pressure for antibiotic resistance in the hospital environment, or it may be because the number of resistant E. coli is greatly increased due to selective pressure so that they are much easier to detect, or that resistant isolates have been acquired from the environment. Further research is needed to understand the source of antibiotic resistance in the environment.

"Pathogenic bacteria are likely to be exposed to the same selection pressures or could receive the same resistant genes, so it is vital we improve hygiene in equine hospitals and reduce the overuse of antibiotics," said Williams. "People who work in equine hospitals need to pay strict attention to hygiene and should reserve antibiotics for essential cases only."

Examination of Horse Teeth Surfaces Can Identify Root Disease in Many Cases

by Fran Jurga | 5 August 2009 | The Jurga Report

One of the most interesting and rapidly growing sectors of veterinary medicine is the study of oral medicine and surgery. Equine dentistry is especially fascinating both because of the size and variety of the dental system of the horse and the massive jaw.

The fact that the teeth are always growing often confounds horse owners and is a basic reason why routine dental inspections and care are so important to horses: The mouth your horse had last year is simply not the same mouth he has today.

The new interest in all things dental has meant that universities are interested in doing research and that funding and senior researchers are now available, and academic journals are open to publishing scientific and practical information on the horse's mouth.

While veterinarians may be excited about their new power tools for doing dentistry work on your horses' mouth, they won't be using it on most horses unless there is a problem. The most important part of dental care is regular and thorough examination of the teeth.

A problem in horses is pulpitis, an inflammation in the tooth's root that can lead to serious tooth decay at the root. This is different from periodontitis, which is inflammation in the tissue surround the tooth. British research Miriam Casey conducted a study of teeth affected by pulpitits that has been accepted for publication. Her work provides veterinarian with another good reason to have a look inside your horse's mouth.

She found that it may be possible to intervene when a horse has pulpitis in the early stages, rather than to allow it to progress to the point of damaging the tooth to the point of needing extraction or causing the horse a lot of pain, even though the root of the tooth is not visible to the naked eye.

By examining the chewing surface of the extracted teeth diagnosed with pulpitis, Casey observed lesions in the dentine that a veterinarian would be able to see when examining the mouth with a light and mirror. The lesions were visible in 57 percent of both the lower and upper jaw teeth; no lesions were visible in the chewing surface of any control (normal) teeth.

Currently, radiography of the jaw is the only way to diagnose pulpitis if an infected tooth is suspected. This visual analysis guideline may be helpful for veterinarians. Casey is not prepared to speculate on the relationship between the defects in the dentine at the chewing surface and the inflammation within the tooth.

Click here to read more about Miriam Casey and her research project. The research was conducted at Bristol University and her funding is provided by The Horse Trust. The photo shown is courtesy of The Horse Trust.

I think we will be seeing lots more interesting research about horse teeth and oral health coming to the forefront in the next few years, and no doubt, eventually, a wave of new commercial products to improve oral hygiene in horses. If you think about it, the horse is perhaps the only animal that uses its mouth in its work and the loriner's art is surely the next to surge forward with the aid of technology and modern materials. But the horse needs a healthy mouth to begin, and the interesting research about how the horse uses its mouth and head for balance and breathing/eating/senses is still an area where new discoveries are being made. The horse's mouth may be one of its last frontiers!

What's Killing England's Fell Ponies? Charity Funding for Research Intends to Find Out

Fell ponies look like miniature Freisian horses, but look again: this is a unique breed with a long and glorious history. With long feathers and arched necks, they make the loveliest children's ponies, and the sight of them wandering their native Cumbrian countryside is the stuff that wild horse legends are made of.

But their numbers have dropped since World War II, and the gene pool has shrunken to a bottlenecked puddle. Can this breed be saved? The Horse Trust, a UK charity, has given a donation of more than US$200,000 to the Animal Health Trust, a research center known for its work on strangles and orthopedic problems in horses, and the University of Liverpool. The charity has charged them with the task of finding out how to stop Fells Pony Syndrome (FPS).

FPS is a severe immune system disorder that results in the death of some of the newborn foals, further shrinking the breeding stock available to help the breed survive. The breed is listed as "at risk" by the Rare Breeds Survival Trust.

Foals affected with FPS appear normal at birth but within a few weeks begin to lose condition and suffer diarrhea, coughing and weight loss. Severe anemia and immune dysfunction follows, leading to wasting and finally death. The disease is always fatal.

Studbook analysis and knowledge of affected foals strongly suggests that this is an inherited disease caused by an autosomal recessive genetic mutation. The problem may trace to a single stallion who was a dominant force in the breed. 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.

“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,” 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 euthanized. The gradual but relentless decline in these foals leaves both veterinary surgeons and breeders powerless."

According to the Horse Trust, FPS at the moment is restricted to the Fell pony population but could spread to other breeds at any time. Indeed it may be possible that carriers of the condition already exist in other breeds which have interbred with the Fell pony over many years.

Another rare breed, the Dales pony, and other native British breeds will be randomly tested to detect any further penetration of the defect into the equine population.

To learn more: The Horse Trust has one of the best horse charity web sites anywhere on the web. This remarkably generous and insightful organization funds research and welfare projects that benefit horses all over the world, not just in Britain. The Horse Trust was formerly known as the Home of Rest for Horses and has a long tradition of recognizing the welfare and health needs of horses.

The Fell Pony Society is trying to cope with the devastation of their breeding stock and preserve this lovely breed of pony, which dates all the way to the Roman occupation of Britain.

Photo from the Fell Pony Society.