Effect of temperature on race times

A few years ago, the major racetracks in California introduced synthetic tracks. It was hoped that this would give a more consistent surface and lead to fewer casualties than either turf or dirt tracks. In general, this has proved to be the case.

However, horses often run more slowly on the synthetic surface than on dirt. Furthermore, it has also been noticed that race times vary with temperature.

A study conducted at the Del Mar Racetrack in California monitored the change in temperature during the day and compared it with the speed of horses running on the track. Lead researcher was Dr Mick  Peterson of the Mechanical Engineering Department of the University of Maine.

The research team measured air temperature, the temperature on the track surface and at four depths within the track. These measurements were recorded throughout the day over a 42-day period

They also recorded the fastest times for 6-furlong (1.2km) races, which took place in the afternoons, and the times taken for fast training 'work', which happened in the mornings.

Inspection of the data showed that horses ran more slowly in the afternoons. This correlated with changes in air temperature and the temperature of the track surface and subsurface.

Higher afternoon temperatures were associated with slower racing times. The fastest times recorded during the afternoon races were slower than during the morning work sessions.

Why should this be?  A possible explanation could be found in the characteristics of the wax used to coat the fibres. Within the range of temperatures experienced during the day was the temperature at which the wax started to undergo thermal transformation - i.e. melt.

The scientists suggest that the physical properties of the wax may underlie the effect of temperature on track characteristics.

They suggest that further work in the future should include a study of the various components of the racing surface, to identify the component responsible for the change and to assess any influence it might have on the risk of injury.

New strangles test developed

Scientists at the University of Maine have developed a novel rapid test for strangles.

Current culture techniques require several days to confirm a diagnosis of strangles. The new test, which detects a specific protein on the Streptococcus equi bacterium, can produce a result in a matter of hours.

A grant of nearly $500,000 from the Maine Technology Asset Fund has made the development possible. The project also involves renovations at the UMaine JF Witter Teaching and Research Center to create an animal handling area for disease diagnosis, an equine isolation area, and a technology transfer center classroom with video-endoscopy equipment.  This will be used for training veterinarians as well as being involved in research into infectious diseases.

The grant will also fund the purchase of portable endoscopes for use by Maine veterinarians at farms and stables around the state.

The test has already proved successful in early trials. Now the new funding will allow the scientists to carry out a large scale trial to check its reliability and efficacy before making it commercially available.

Principal investigator is Dr Robert Causey, a veterinarian and associate professor in the University of Maine Department of Animal and Veterinary Sciences.

"There's no doubt that the market for this is potentially global" says Causey. "Wherever there are horses there is this disease. No one has ever tried to do this before. This puts Maine right in the front of strangles research."

"The economic impact of an outbreak can be devastating to a commercial equine facility."

The kits, which are being developed by Maine Biotechnology Services (MBS) in Portland, have an antibody on a membrane that changes colour when exposed to a strangles protein.

The strangles test kit is the first to be developed using this technology. As additional new antibodies are developed by MBS, the test kits could be adapted to more quickly detect and diagnose other equine infections.

Do feral horses have ideal foot conformation?

A natural lifestyle - freedom to roam, and the ability to choose what to eat - does not necessarily result in ideal foot conformation.

The feet of feral horses, such as the North American mustang and the Australian brumby, have been held up as examples of ideal conformation. However, not all feral horses are the same, as work carried out in New Zealand demonstrates.

A report published in the Australian Veterinary Journal documents the shape and abnormalities of the feet of Kaimanawa feral horse population.

Kaimanawa horses are small (133-151cm at the withers), being descended from Welsh and Exmoor-type ponies that have been feral since the 1880's. Other bloodlines were added as the result of escapes from farms and cavalry units so that present day horses are more closely related to the Thoroughbred.

About 1500 animals live in a land of upland plateaux, with steep hills, river basins and valleys, covering an area of about 700sqkm.

The research team took standardised photographs of all four feet and lateromedial radiographs of the left fore foot of 20 adult horses from the Kaimanawa horse population.

They found a wide variation between horses. There was no consistent foot type. Foot abnormalities were surprisingly common. For example, 35% had long toe conformation, 15% had medio-lateral imbalance, and 85% of horses had lateral wall flares.

Other common abnormalities included large hoof wall defects, frog abnormalities and contracted and under-run heels.

The most surprising finding was the radiographic and visual evidence of chronic laminitis. Laminar rings were present on 80% of horses.

Lead researcher was Brian Hampson of the Australian Brumby Research Unit, at the University of Queensland’s School of Veterinary Science. 

"The large range in the morphometric variables and the high incidence of abnormalities in the feet of Kaimanawa feral horses may be related to dietary or environmental influences, or a combination of both" Hampson explains.

"There may be insufficient environmental pressure driving natural selection of foot type. Perhaps their environment, consisting of a soft substrate and with easy access to pasture and water, tolerates a broad range of foot conformation in Kaimanawa horses."

"Clearly this group of feral horses should not be used to guide the direction of foot care practice."

Read more at Equine Science Update.

Challenge of Chorioptes infestation

Infestation with the mite Chorioptes bovis can prove difficult to eradicate. A Swiss study found that two doses of moxidectin oral paste, combined with environmental treatment, failed to eliminate the parasite from heavily feathered draft horses.

The study, led by Silvia Rüfenacht of the Dermatology Unit of the Department of Clinical Veterinary Medicine at the University of Berne, was reported recently in Veterinary Dermatology.

Chorioptes bovis is a particular problem of draft-type horses with hairy legs. The mites live on the skin surface, feeding on skin scales, but may survive for three weeks or more in the environment. They tend to be more of a problem in the winter when horses spend more time housed.

Not only do the mites cause irritation, they may contribute to the development of chronic pastern dermatitis - thickened swollen skin with warty ("verrucose") lumps.

The study was designed to use licenced products and be practical for owners to carry out.

Horses were treated twice, three weeks apart, with 0.4mg/kg moxidectin oral paste. Environmental treatment, carried out on days 0 and 14, consisted of removing all bedding, brushing out the stable, grooming area, and horse transporter. All surfaces, tack, and grooming equipment were treated with anti-parasitic disinfectants.

Horses were examined just before the first treatment (day 0) and 14 days, 6 weeks and 6 months later. The clinician, who did not know which horses were in the treatment  or placebo group, took skin scrapings and assessed the degree amount extent of crusting and skin folds

Initially, all horses showed pruritus (itching) manifest as rubbing, biting or stamping, and this continued throughout the study. Treatment had no significant effect on the number of mites found in skin scrapings, nor on the severity of skin folds.

The only significant finding was that the treated horses showed a decrease in skin crusting over the 6 month follow up period. But that was the only difference between the treatment and placebo groups. There was no other difference in clinical signs or in the number of mites found between the two groups.