[The effect of the sedative and analgesic detomidine for laryngoscopy of adult horses and foals].

The study investigates the impact and effectiveness of the sedative and pain reliever detomidine in facilitating laryngoscopic exams in mature horses and foals. It concluded that detomidine is indeed effective, as it was well-tolerated in most of the animals, with the route and dose of administration, timing, and level of excitement of the animal influencing its effect.

Study Methodology

• The field trial involved a total of 193 foals and 806 mature Hanoverian horses, who underwent laryngoscopic examinations.
• The drug detomidine was administered either intravenously (i.v.) to foals aged 3 to 11 months (20 micrograms/kg) and to mature horses (15 micrograms/kg), or intramuscularly (i.m.) to foals below six months old (35 micrograms/kg).

Results of the Study

• Over 90% of all the animals which were given detomidine intravenously tolerated laryngoscopy without the need for additional usage of a twitch.
• In foals that were given the drug intramuscularly, more than 70% required a twitch to enable the procedure.
• The effectiveness of the drug was influenced by several factors like the dose, the administration route, the time between treatment and examination, and the degree of the animal’s excitement before treatment.
• All the treated animals displayed profound bradycardia, a condition featuring a slower than normal heart rate. However, arrhythmias were only observed in animals older than four months old and were more pronounced in those horses having a lower resting heart rate.
• Cardiovascular responses due to the drug never jeopardized any of the treated animals.
• Transitory dyspnea was seen in 13 foals (6.7%) and 10 horses (1.2%). Other side effects of the drug were rare.

Detomidine’s Impact on Pregnancies

• A total of 297 mares were treated with detomidine during their first eight months of pregnancy, and 66.7% of them gave birth.
• A comparison was drawn with 5499 untreated controls, who showed a 61% foaling rate. Therefore it was concluded that detomidine treatments did not have negative effects on horse pregnancies.