Equine Injury Database statistics released

The Jockey Club recently released an updated North American fatality rate for Thoroughbreds based on two years’ worth of data in the Equine Injury Database (EID), the North American database for racing injuries.

The results are from data collected from 87 North American race tracks between November 1, 2008 and October 31, 2010, in Thoroughbred flat racing. Included in the data are horses that suffered a fatal injury during a race and immediately after a race, and those that succumbed to a race-related injury subsequent to race day.

Based on an analysis of 754,932 starts recorded during the two-year period November 1, 2008 - October 31, 2010, the prevalence of fatal injury declined to 2.00 per 1,000 starts, as compared to the 2.04 per 1,000 starts for the one-year period November 1, 2008, - October 31 2009.

Dr. Tim Parkin,  a veterinarian and epidemiologist from the University of Glasgow, who serves as a consultant on the Equine Injury Database, performed the analysis.

He noted that the change in the overall fatality rate stemmed from cumulative two-year data that revealed a statistically significant difference in the prevalence of fatality on both turf and synthetic surfaces versus dirt. The difference in the prevalence of fatality between synthetic and turf surfaces was not statistically significant.

“The addition of 376,000 starts to the database in year two enabled us to statistically validate certain trends seen in the data,” said Parkin. “Trends will continue to emerge and evolve as additional data becomes available for study and as more complex statistical analyses are performed. This will allow us to understand how different variables, alone and in concert, may impact the risk of fatality.”

Other trends gleaned from Parkin’s analysis of the cumulative two-year data, included:

• The prevalence of fatality in 2-year-olds continued to be significantly lower than older horses racing on dirt surfaces. However, on synthetic or turf surfaces, there was no statistically significant difference in the prevalence of fatality between 2-year-olds and older horses.
• The prevalence of fatality continued to be unaffected by distance, weight carried and movement of races off the turf.
• Fillies and mares competing in races that were open to horses of all sexes were not at an increased risk of fatality compared to those competing in races restricted to fillies and mares.                               
  

                   
"These calculations are considered estimates of prevalence because they represent a two-year sample of data and not a complete census" Parkin explains. "The statistics included here do not imply anything about the relative safety of a racing surface or a horse’s age. As the data contained in the EID continues to grow, some of the current statistical conclusions may change as a reflection of increased certainty associated with a larger data set."

“We will continue to publish these national benchmarks on an annual basis to provide the necessary statistical foundation participating racetracks need for monitoring and comparing their individual results,” said Matt Iuliano, The Jockey Club’s executive vice president and executive director.

 “As the database continues to grow, we look forward to the additional information and statistical power it will yield to improve the health and safety of the racehorse."

Read more at www.equinescienceupdate.com/articles/eid10.html

Are pinworms becoming resistant to anthelmintics?

Barely a month goes by without another report of anthelmintic resistance. The usual culprits are the cyathostomins - the small red worms.

Now it seems that the pinworm, Oxyuris equi, might also be developing resistance. Or at least, doubts are being raised about whether anthelmintics are beginning to lose their effectiveness against the parasite.

Compared with the cyathostomins, Oxyuris equi is less important as a cause of disease. Generally, the parasite is not considered pathogenic. However, the female worms cause irritation by depositing their eggs on the skin around the anus of the host. This leads to tail rubbing - and may be mistaken for "sweet itch" (insect bite hypersensitivity.)

Thus far, it has not been necessary to formulate specific control measures against Oxyuris, as it has always been assumed that routine treatment with modern anthelmintics would be sufficient to control it.

However, in a letter to the Veterinary Record, Andy Durham of the Liphook Equine Hospital and Gerald Coles of Bristol Veterinary School mention several anecdotal reports of Oxyuris infection despite recent anthelmintic treatment.

In contrast, earlier studies have shown Oxyuris to be susceptible to commonly used anthelmintics.

Durham and Coles have received enquiries from clients about horses rubbing their tails - despite having been recently dewormed with macrocyclic lactones.

They would like to hear from veterinary surgeons who have encountered similar cases, to assess if this is a widespread problem.

They offer to examine, free of charge, sticky tape preparations from suspected cases.  Veterinary surgeons wishing to submit a sample are asked to contact Dr Gerald Coles, at the Bristol Vet School.

Shivering horses required

University of Minnesota researchers are looking for help to investigate the perplexing condition known as "Shivers"
 
"Shivers" or "Shivering" has been recognised since the heyday of working draft horses.

Even so, little is known about it. Now researchers, led by Dr Stephanie Valberg, at the University of Minnesota, want to put that right.  "We are trying to establish the cause of Shivers, if this condition is inherited, and if dietary therapy is effective."

A research project has been set up at University of Minnesota and the Neuromuscular Diagnostic Laboratory in conjunction with Dr John Baird of the Ontario Veterinary College.

The researchers are looking to collect data on as many Shivers cases as possible. Initially they hope to identify risk factors, and investigate the influence of factors such as gender, breed, diet, exercise, and infection on the development and progression of the disease.

If you want to be involved, and have a horse you know, or suspect, has shivers, the first step is to complete a survey and submit it, together with a video of the horse.

The researchers specify the format the video should follow to ensure that all relevant information is included.

Within three weeks of receipt, the researchers promise to send you a report which will tell you whether or not the horse is affected with the condition.

Confirmed "Shiverers" may then be invited to take part in further research. The plan is for a controlled trial in which the effect of diet on the condition can be examined. If you are chosen to take part in the further study, you will probably be asked to feed an experimental diet for the duration of the study.

Dr Valberg explains: "In our previous studies on conditions such as Polysaccharide Storage Myopathy (PSSM) and Recurrent Exertional Rhabdomyolysis (RER), we have determined that certain dietary changes can be highly effective in alleviating symptoms of disease."   

It is hoped that dietary modifications may have a similar beneficial effect in Shivers.

Dr Valberg continues: "In the case of a diet trial, it would be necessary to have an additional, non-Shivers, horse participate in the trial who is approximately the same age and living in the same environment as the horse with Shivers. This is essential in conducting a controlled, viable study."   

For more details on how to take part in the research go to the shivers research website

For a comprehensive explanation of what is currently known about shivering visit the My Horse University webcast.

Equine genetic research progress

Knowledge of the horse’s genetic blueprint has opened many avenues of research according to a recent report.

The “genome” is the term used to refer to an individual’s full set of DNA.  In the horse, it consists of about 2.7 billion base pairs. DNA carries the genes that code for thousands of different kinds of proteins. The precise characteristics of each gene are determined by the sequence in which four bases  - adenine (A), thymine (T), cytosine (C) and guanine (G) - are laid out along the DNA's double-helix structure.

A special supplement to the scientific journal Animal Genetics has been published to emphasise the importance of the genome to equine research.

The Dorothy R Havemeyer Foundation, a private foundation that conducts scientific research to improve the general health and welfare of horses, funded publication of the supplement. Its founder and sole benefactor was Dorothy Havemeyer McConville, also known as Dorothy Russell Havemeyer.

The Foundation appoints principal investigators to work on specific projects. Currently the focus of research is on equine reproduction, behaviour, and infectious diseases and on the creation of an equine genetic map.

Genetic research has long been a topic of interest to the Foundation, a workshop on the subject having been convened first in 1995,

Dr Ernest Bailey, of the University of Kentucky's Gluck Equine Research Center, wrote in the foreword to the supplement: "In this issue, scientists report research and discoveries made possible using the new genomic information."

"Indeed, the work includes gene discoveries and genetic characterization of horse breeds and sheds light on hereditary conditions that affect performance of horses. But the genome information is also useful to understand non-hereditary diseases and traits as well. Several reports in this issue address gene expression in connection with exercise and laminitis."

Bailey emphasises that using the genome sequence in research will bring many benefits both to the horse and to the economy as a whole.

"As scientists become more familiar with using genomic information for equine studies, we can anticipate more discoveries and the development of new diagnostic tests, therapeutic products and management approaches to improve the health and well-being of the horse."

"This should be remembered as a legacy from the Dorothy Russell Havemeyer Foundation."

The full report is available for download (free).