Is your vet a health risk?

Vets that work with horses are more likely than other vets to carry methicillin-resistant Staphylococcus aureus (MRSA), according to an Australian study.

The researchers, led by Dr David Jordan, collected nasal swabs from 771 individuals, who were also asked for details of the type of work they did and with which species.

Analysis of the data showed that veterinarians that worked mainly or exclusively with horses were more likely the carry MRSA in their nostrils.

MRSA was present in 5.8% of those taking part in the study. However, the data revealed differences depending on the type of work the individuals performed.

Positive swabs were obtained from 11.9% of veterinarians who spent a lot of their time on horse work. (This was 13 times that of the vets involved in industry or government work. Less than 1% of them had positive swabs).

The figures were even higher among people who worked only with horses.  The results showed that 21.35% of them had nasal swabs positive for MRSA. (They were 23 times more likely to have their nostrils colonised by MRSA than were vets working for government or industry.)

Considering the extent of carriage of MRSA and the seriousness of the disease it can cause in humans and animals, Dr Jordan recommended that vets should take more precautions to prevent the spread of MRSA

"The higher than normal prevalence of MRSA carriage among veterinary clinicians in Australia is a cause for concern in the profession and warrants further investigation for specific risk factors, particularly for vets who work with horses"

He suggests that guidelines specific for equine work are needed. These should include: "enhanced personal hygiene during handling of animals; better sanitary management of premises, equipment and waste; greater awareness of biosecurity during handling and surgical procedures; and reform of use of antibiotics - especially those of importance in human medicine such as the fluoroquinolones, third generation cephalosporins and gentamicin."

Read more at www.equinescienceupdate.com

Hendra virus vaccine progress

Australian scientists have succeeded in developing an experimental vaccine to protect horses against Hendra virus.

Hendra virus (HeV) was first isolated in September 1994 from an outbreak at a training complex in Hendra (a suburb of Brisbane, Queensland, Australia) after which the virus was named.

During that initial outbreak 14 horses died. Seven other horses were found to have been infected and were humanely destroyed. Two humans were affected, one of whom died.

In five of the 14 known outbreaks, the infection has spread to people. The virus has killed four of the seven people infected.

Fruit bats (Pteropus spp), commonly known as flying foxes, have been identified as the natural host for the Hendra virus.

“Our trials so far have shown that the vaccine prevents the infection of horses with Hendra virus,” said Dr Deborah Middleton from the Australian Animal Health Laboratory (AAHL).

Stopping the disease in horses could also help protect people from the disease.

"All the human infections have come from contact with infected horses," Dr Middleton explains. So if you can control the disease in horses, you break the transmission cycle to people as well as protecting the health of horses.

Studies so far have shown that the vaccine will prevent horses becoming infected. It also protects them from developing the disease and shedding the virus.

Further work, including field trials and product registration, is still required. However, if all goes well, the vaccine may be available as soon as 2012.

Dr Barry Smyth, President of the Australian Veterinary Association, said that both vets and horse owners would welcome the news on the vaccine.

“It’s important that veterinarians and horse owners continue with precautions that reduce the risk of spreading the virus and that they report suspected cases immediately,” Dr Smyth said.

Read more at: www.equinescienceupdate.com

Saddle research uncovers new theory in asymmetry

The Saddle Research Trust (SRT), believe they have discovered a new theory in rider asymmetry, which they feel will have implications for equine performance and welfare.

Following a series of pilot studies carried out in conjunction with educational establishments throughout 2010, the charity claims to have evidence that highlights previously unidentified areas and measurable characteristics of saddle performance.

Anne Bondi BHSI, Director for the trust explains: “The initial objective of our early pilot studies was to measure the effect of the rider asymmetry using a variety of scientific measuring systems open to the trust. It soon became apparent that a more complex pattern of interaction was occurring, one that could not just be explained by a rider sitting crookedly.”

Humans are not perfectly symmetrical, and most riders are aware of being right or left handed. This ‘handing’ often creates a loss of symmetry in the rider in the vertical plane.

“After observing this common occurrence we began to examine further the effect the saddle has on the rider and their posture” she continues.

A similar lack of symmetry also exists in the horse in the horizontal plane. The movement of a horse’s back and limbs creates movement in the saddle, generating an unstable platform for the rider. This forces riders to adopt a compensatory action - accentuating the already asymmetrical posture. The horse also compensates for carrying the asymmetrical rider by counterbalancing.

According to the SRT, this is far more complex than a ‘chicken and egg’ situation. It involves a mixture of symptoms involving asymmetries in the horse, rider and saddle, but more significantly the interaction between them.

"Our studies to date have shown a clear lack of synchronisation in this three-way interaction, and it is our understanding that the degree to which this occurs is greatly affected by saddle design and fit."

“We have raised many new questions about the effect of saddles on asynchrony, as well as identifying measurable characteristics in saddle performance. Although our work is in its infancy we believe it will have far-reaching effects on all levels of equestrianism.”

Read more at www.equinescienceupdate.com

Bedding dope test risk

Flunixin excreted in the urine may be ingested with bedding, risking prolonging the time taken to clear the drug from the body.

Owners and trainers should be aware that horses may recycle anti-inflammatory drugs such as flunixin in the stable environment. This may prolong the time the drug is detected in the urine - thus increasing the risk of positive dope test.

Flunixin is a non-steroidal anti-inflammatory drug commonly used in horses. The rules of many disciplines prohibit its presence in the blood or urine of horses on the day of competition.

Detection times have been established for some medications to help veterinarians advise owners and trainers on how long before a competition treatment should be withdrawn to minimise the risk of the drug being found in the urine. However, research in France shows that the problem can be complicated by horses absorbing flunixin from bedding that has been contaminated by urine containing the excreted drug.

Work at the Laboratoire des Course Hippiques, found that, even if bedding is removed completely and the floor brushed out, there is still a risk of a "rebound" increase in urine flunixin levels.

Dr Marie Agnès Popot and colleagues looked at the excretion profiles of flunixin in urine collected from horses under various systems of stable management. They gave flunixin as either a single intravenous dose (1mg/kg) or as an oral paste (0.5mg/kg twice daily for 3 days).

Horses were housed in stables from which the bedding was either completely removed on a daily basis, or only "skipped out" (removing only soiled bedding on a daily basis, and cleaned completely once a week.)

The largest rebound in urine flunixin concentration was seen in those horses kept in stables that were not cleaned completely on a daily basis. However, removing all the bedding and sweeping the floor could not totally prevent rebound in flunixin levels. The only circumstance in which a rebound in urine flunixin levels did not occur was when the drug was given intravenously and the horse was moved to a clean stable after 24 hours.

"Flunixin is mainly eliminated by renal clearance and a large amount of flunixin is eliminated in urine within the first 24 hours following administration" the researchers explain in a report in the Journal of Veterinary Pharmacology and Therapeutics. "Then, for horses housed in unclean boxes, the conditions  exist for the possibility of prolonged recycling; the only way to break recycling is to move the horse in  another separate box after the first 24 hour of treatment, rendering unavailable the flunixin excreted in the urine for the first 24 hour."

They conclude that attention to stable hygiene can drastically reduce the risk of spurious drug excretion profiles for drugs such as flunixin that are mainly eliminated in the urine.

Read more at www.equinescienceupdate.com