Saturday, April 30, 2011

Focusing on the next obstacle

Elite riders' eye movements may be key to show jumping success. Research from Nottingham Trent University found that an experienced show jump rider focused on the jump up to 3.05 seconds earlier before take off than did a less experienced non-competitive rider.

Thursday, April 21, 2011

Mares behaving badly

Plant oils might provide the answer to mares that are unruly when in season.

Some mares become unruly and difficult to manage when in season and perform poorly as a result. Various methods of controlling this behaviour have been suggested. Most are based on suppressing the oestrus cycle.

Sandra Wilsher and Professor Twink Allen at the Paul Mellon Laboratory of Equine Reproduction, Newmarket, England, were investigating the mechanisms of maternal recognition of pregnancy.

They found that intrauterine administration of oestrogen in fractionated coconut oil prevented mares returning to oestrus, However, they also found that the coconut oil alone (without oestrogen) had a similar effect, as did peanut oil.

Fractionated coconut oil was most effective when given 10 days after ovulation - luteolysis was delayed in 11/12 mares (92%). It was not as effective on days 8-12., although the difference was not statistically significant. When administered on the 6th day after ovulation, it inhibited luteolysis in only 25% of mares. 

Oestrogen in mineral oil, or mineral oil on its own did not block luteolysis when given 10 days after ovulation.

So it seems unlikely that embryonic oestrogens are important in the maternal recognition of pregnancy.

Fractionated coconut oil and peanut oil each contain various different fatty acids.  The researchers were unable to identify an individual component that was responsible for inhibiting luteolysis.  Instead, they suggested that it is likely that a range of fatty acids are capable of causing luteal persistence.

Further work is required to determine how the vegetable oils have this effect. However, it does seem that they may provide a practical way of preventing unruly behaviour in oestrus mares.


Thursday, April 07, 2011

Sublingual detomidine for needle-shy horses

How do you sedate a needle shy horse? Recent research suggests that detomidine, a sedative commonly used in horses, can be effective when administered under the tongue.
Detomidine is a popular choice for sedating horses, capable of producing profound sedation when administered intravenously.

Previous studies have shown that detomidine is not effective when administered by stomach tube, and is variably effective when mixed with food. However it seems to be absorbed through the gums and appears to be effective when given sublingually.

Recent research looked at the value of sublingual detomidine for sedating horses known to need sedation to permit routine management or veterinary tasks - such as farriery, routine dentistry, passage of a stomach tube or clipping.

The study by Dr Rachel B Gardner and colleagues was published in the Journal of the American Veterinary Medical Association.

Horses used in the study were all known to require sedation or strong additional restraint - such as a twitch - to allow the procedures to be carried out.

The treatment group comprised 129 horses treated with detomidine sublingually, at a dose of 0.04mg/kg (double the usual dose when given intravenously).

A further 42 horses were treated with a gel which appeared identical, but did not contain detomidine. The study personnel did not know whether they were administering the detomidine gel or the placebo.

The efficacy of the treatment was assessed according to whether it allowed the required procedure to be carried out. Treatment was only considered successful if the procedure could be completed without resort to further sedation or the use of a twitch.

The procedures were completed successfully in 98 of 129 (76%) of detomidine treated horses compared with only 3 of the 42 (7%) of control horses. Little or no ataxia was reported in 70% of detomidine treated horses

Sublingual detomidine was most successful for sedating horses for manual teeth floating and hoof trimming and shoeing. It gave a lower success rate for clipping with electric clippers - only half of the detomidine-treated horses could be clipped successfully.

For more details see:

Efficacy of sublingual administration of detomidine gel for sedation of horses undergoing veterinary and husbandry procedures under field conditions.
RB Gardner, GW White, DS Ramsey, JE Boucher, WR Kilgore, MK Huhtinen
J Am Vet Med Assoc (2010) 237, 1459 - 1464