Lameness is most common reason for euthanasia in older horses, according to horse owner survey

A research project funded by The Horse Trust has found that lameness is the most common reason for euthanasing a geriatric horse.

This research is the first in the UK to provide data on the causes of death in geriatric horses. Although post-mortem studies have provided some data regarding causes of death, “old age” was previously reported as the most common reason for euthanasia of adult horses.

The research was carried out by Joanne Ireland at the University of Liverpool and led by Dr Gina Pinchbeck. Ireland surveyed horse owners living in the North-West and Midlands areas of England and North Wales who have a horse aged 15 years or older. 918 owners of geriatric horses were followed in a cohort study and 118 mortalities were reported during the 18 month follow-up period, of which 111 were euthanased.

The researchers found that 24% of horses were euthanased due to lameness; an additional 12% were euthanased due to laminitis – a common cause of lameness. After lameness, colic was the next most common cause of euthanasia, with 21% of owners citing this as the main reason.

In an earlier stage of the project, the researchers had found that half the geriatric horses surveyed suffered from lameness, but only 24% of owners reported the problem.

“Although, anecdotally lameness is common in the older horse this is the first study to quantify its contribution to mortality in the older horse,” said Dr Pinchbeck. “Owners are often missing the early signs of lameness in their horse, which means the condition isn’t being managed and may deteriorate faster. I would recommend that owners of geriatric horses ensure their horse has an annual health-check from the vet so these problems can be picked up earlier.”

Dr Pinchbeck said it would be useful to carry out further research into lameness in geriatric horses to find out the main causes of lameness and how these may be prevented or treated. There are many potential causes of lameness in horses, including arthritis, laminitis and foot problems.

The research team also found that half of the horses euthanased were suffering from concurrent health problems and these influenced the owner’s decision to euthanase in 43% of cases. The most frequently reported additional health problems were musculoskeletal problems, with the majority of these reported as arthritis.

The mortality rate among the horses surveyed was 11 per 100 horse-years at risk, meaning that if  100 geriatric horses were followed for a year, an average of 11 would die. The mortality rate for horses over 30 years of age was over five times the rate than in horses aged 15 – 19 years.

Jeanette Allen, Chief Executive of The Horse Trust, said the data provided by this research is likely to provide useful information for both horse owners and vets to enable them to improve the welfare of older horses.

“As there are a significant number of geriatric horses in the UK, it is vital that we understand more about the health problems that affect them,” said Allen. “We hope that more owners of older horses will give their horse an annual health-check to enable the horse to have a longer, healthier life.”

The research was published in the September 2011 issue of Preventive Veterinary Medicine.