Nearly a quarter of the mature Icelandic horses assessed in a study in Denmark were either overweight or obese, researchers report.
The University of Copenhagen study team also found that owners tended to underestimate the body condition score of their horses.
Rasmus Jensen, Signe Danielsen and Anne-Helene Tauson, writing in the journal Acta Veterinaria Scandinavica, set out to find the prevalence of obesity among the breed in Denmark, and to compare body condition scores assessed by the owners against those of an experienced person.
They also correlated the body condition score against body measurements.
A total of 254 Icelandic horses, all aged four or older, were used in the study. The group comprised 140 geldings, 105 mares and 9 stallions. The animals lived on 46 farms across Denmark.
The owners and the experienced individual scored the horses on the nine-point Henneke scale, with 1 being in poor condition and 9 being extremely fat.
Two weight tapes were used to assess body weight. Girth circumference, neck circumference and height at the withers were also measured.
The researchers found 70.1% of the horses were assessed as being in optimal condition, with a body condition score of 5–6. It was found that 5.9% of the horses were underweight, with body scores of 3–4; 13.8 % were overweight (with a score of 7); and 10.2 % were obese (with scores of 8–9).
The body condition scores of the 254 horses varied from 3 to 9.
Owners body-scored 216 of the horses used in the study. Owners underestimated the scores in 90 of the 216 cases, while there were 41 over-estimations.
The ratio of girth circumference to height at the withers increased with the body condition score, as did the ratio of neck circumference to height at the withers. The body weight estimated with the weight tapes also rose with the body condition scores.
“This study is the first to document that overweight and obesity is a common problem among Icelandic horses in Denmark,” the study team reported.
“The results … show that 24% of mature Icelandic horses in Denmark are overweight or obese, and that owners tend to underestimate the body condition score.”
Discussing their findings, the researchers noted that equine obesity was considered the most important welfare issue affecting equines in the western world, carrying with it an increased risk of insulin resistance and laminitis.
Icelandic horse were considered to be “easy keepers” – that is, easy to keep in a good body condition.
One reason for horses being overweight or obese might be that owners tended to underestimate the body condition score, they suggested.
The evidence suggested that a girth circumference to height-at-the-withers ratio if 1.21 might indicate overweight or obesity in Icelandic horses. This ratio was different to that reported for horses and ponies of other breeds.
The researchers were all affiliated with the Department of Large Animal Sciences, within the Faculty of Health and Medical Sciences at the University of Copenhagen.
Body condition score, morphometric measurements and estimation of body weight in mature Icelandic horses in Denmark
Rasmus B. Jensen, Signe H. Danielsen and Anne-Helene Tauson
Acta Veterinaria Scandinavica 2016 58(Suppl 1):59 DOI: 10.1186/s13028-016-0240-5