Lameness can be seen in the faces of horses, study shows
A veterinarian familiarised with a catalogue of equine facial expressions was able to identify ridden horses with lameness issues through studying pictures that included only the head and neck.
The findings of the British study have been reported in the Journal of Veterinary Behavior: Clinical Applications and Research. The researchers expressed the hope that horse owners could be taught to use a simpler version in order to potentially detect lameness issues earlier.
Poor horse performances were often explained away by rider issues, training problems or behavioural abnormalities. However, riders often failed to recognise lameness, the study team noted.
For their study, they used an ethogram – a catalogue of observed behaviours – based around equine facial expressions which they had described in a previous paper.
In that study, the ethogram was tested by 13 individuals, from horse-owning amateurs to veterinarians, with their level of agreement being assessed at 87 percent. Their level of horse experience had little influence on the accuracy of their assessments.
It was concluded that the ethogram could reliably be used by people from different professional backgrounds to describe equine facial expressions, but further work was needed to determine if non-lame and lame horses could be differentiated through its use.
The study team, led by equine orthopaedics specialist Sue Dyson, set out to determine if the ethogram could be adapted to a pain scoring system for ridden horses.
For this second phase, an equine veterinarian was trained in the use of the ethogram and was provided with a customised instruction catalogue.
She was asked to assess a total of 519 head and neck photographs of 101 horses under saddle at both the trot and canter. Seventy-six of the horses had previously been assessed as lame and 25 were considered free of gait abnormalities. The pictures included 30 photographs of seven lame horses, together with 22 photographs of the same horses after local analgesia had temporarily abolished their lameness issues.
The number of pictures for each horse ranged from 3 to 13.
The vet analysed the images without any prior knowledge of the soundness of the horses involved.
She applied a pain score – where 0 was normal and 1-3 were abnormal – for each feature identified in the ethogram. In effect, she was applying a facial pain score.
In the end, the vet identified a total of 27,407 facial markers across all the photographs.
Dyson and her colleagues reported that the pain scores were significantly higher for lame horses than non-lame horses. The lame horses returned lower scores after the local anaesthetic drugs had kicked in, which the study team had hypothesised would happen.
The facial markers showing the greatest difference between lame and sound horses included ears back, a twisted nose, being above the bit, eyes partially or fully closed, signs of tension around the eyes, intense staring, and an open mouth with teeth showing.
The study team concluded that the facial expression ethogram in combination with a pain score can be used to differentiate sound and lame horses.
“It is likely,” they said, “that the ethogram can be simplified to enable its use by owners, trainers, paraprofessionals and veterinarians to enable pain to be detected without recognition of changes in gait, or in association with lameness.
“This is a significant development towards the assessment of welfare in ridden horses.”
The study team comprised Dyson, Jeannine Berger, Andrea Ellis and Jessica Mullard, who was the veterinarian who assessed the images.
The study was supported by World Horse Welfare and the Saddle Research Trust.
Can the presence of musculoskeletal pain be determined from the facial expressions of ridden horses (FEReq)?
Sue Dyson, Jeannine M. Berger, Andrea D. Ellis, Jessica Mullard
DOI: http://dx.doi.org/10.1016/j.jveb.2017.03.005
The abstract can be read here.
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This is true. I rescued a mare who was 300 pounds underweight. Couldn’t put any weight on her right front foot, hopped on three legs in the blistering heat without shade of any kind. Later learned it was an abscess. Got that fixed, she started gaining weight with an excellent low starch feed, good quality hay, and grass. Got x-rays since she was still lame on the front. She had laminitis in both front feet. With her former owner, it got worse when she was not cared for for so long. She was left on a 100-acre pasture, stuck and unable to walk to the water or to get hay. Out with other horses that would badger her; it was awful and she was over 20. During the time I had her she got more care and love than ever. She gained the weight back all of it and was doing well. She even trotted once. She could never be ridden of course, but that didn’t matter. Then one day, her face changed. I could see the pain in her eyes. It is a scene like no other. She never had this look even when walking on three legs. I knew it was time. She was laid to rest under a giant oak tree by the vet. That girl had more heart than I have ever seen. She was only with us 10 months, but during that time she blossomed into a different horse. She was happy and loved to be scratched. The face of a horse can tell you a lot. It isn’t something that needs to be studied it is an obvious fact. When a human or animal is in grave pain it will show throughout their body. She showed me that she couldn’t go on anymore. I kissed her and told her she would be running soon, pain-free, across the rainbow bridge. I had to walk away. I was unable to witness the vet putting the needle in her neck. I broke down in tears, screaming in pain. Once she was gone I went out and sat by her hugging her neck and kissing her muzzle for at least an hour. Then she was placed into the deep hole and covered up. She was an angel and I am so happy to have had her in my life. Even if it was for a short time. She died knowing she was loved and cared for. Her name was Precious, the most fitting name for such a wonderful girl. Watch your horses face and the horses of others. Look for changes and take action immediately.
Thank you for sharing Robin. Your mare was very lucky to live her last months with you!!