pain | Horse Racing Free Tips

Lots Of Older Horses Are Dealing With Chronic Pain, But Their Owners May Not Know It

Almost all older horses suffer from chronic pain, and one veterinarian believes many of their owners can't tell. Dr. Alex Bianco, clinical faculty in large animal internal medicine at the University of Minnesota told The Horse that chronic pain often factors into the decision to euthanize a horse but many horsemen fail to recognize it in its early stages.

Bianco cited a 2020 Swiss study that used 182 responses from experienced horse owners who considered their horses sound. When veterinarians examined the horses, they found that 100 of the horses in the study were considered a grade 2 or higher on the AAEP lameness scale, which is scored up to 5.

[Story Continues Below]

Adding to the challenge, older horses are often not given lameness exams, which leaves them at risk of suffering from unmanaged pain. Bianco also pointed out however that the same Swiss study acknowledged horse owners have a high level of trust in their veterinarians.

Bianco reported that options to address chronic pain include non-steroidal anti-inflammatory drugs (NSAIDs), opiates, gabapentin, acetaminophen (though liver toxicity may be a concern) and ketamine. Therapeutic options are also available and include corticosteroid injections into joints, topical diclofenac, therapeutic shoeing, transecting ligament, tendon or nerves to remove pain, or surgical fusing of joints.

Bianco said the key to improved welfare for older horses is making sure owners know they need to have their horses evaluated by their veterinarians regularly.

Sore Back? Skip The Bute

Horse owners have been known to take medications prescribed to the animals in their care, despite the possible dangers. While some anti-inflammatories, antibiotics, and dewormers may be the same in both human and equine medicine, but their formulations can be vastly different; because of this, human ingestion of equine drugs isn't recommended.

An American woman experiencing severe back pain attempted to take some phenylbutazone (Bute) that had been prescribed for one of the horses in her care. She took three doses of the non-steroidal anti-inflammatory drug (NSAID), each suitable for a 400-pound horse, reports the journal Clinics and Practice.

[Story Continues Below]

Three days later, the woman went to the hospital complaining of nausea, vomiting and weakness, which she said she had been experiencing for two weeks. She often had back pain that was controlled by use of over-the-counter naproxen, but reported that this episode was exceptionally painful, which is why she ingested the Bute.

She presented to the hospital with nearly low blood pressure, a high heart rate, and normal O2 levels, as well as dry mucous membranes. Blood work showed a low white blood count, low platelet levels, elevated liver enzymes, and acute kidney injury. Her urine blood screen showed use of amphetamines and marijuana.

Poison control and toxicology were engaged once it was discovered she had ingested the Bute, but no antidote was recommended. She was given an N-acetyl cysteine and sodium bicarbonate drip because of the suspected acute liver damage caused by the phenylbutazone.

After three days of in-hospital treatment, the woman was feeling better and checked herself out.

Though phenylbutazone was used in human medicine for the treatment of multiple forms of arthritis, it was removed from the human medicinal arsenal in 1970 because of an increased risk of agranulocytosis, a life-threatening blood disorder.

New Scale Makes It Easier To Track Progress In Endocrine-Related Laminitis Cases

Laminitis can be an insidious disease, sometimes coming on so subtly that indications are missed until horses are blatantly lame. The ability to grade lameness according to its severity can be helpful to determine if a treatment is working and to assess the efficacy of new treatments.

A scale had previously been developed to describe levels of lameness in horses that have laminitis from a specific episode, like starch overload or sepsis, but this scale wasn't necessarily applicable to horses that have laminitis caused by chronic endocrine disorders, which are common in overweight horses.

Dr. Alexandra Meier and a research team created a method for grading endocrine-induced laminitis. Called the Meier Scale, it uses five symptoms to determine severity of lameness: palpation of digital pulse, gait at the walk, weight shifting, response to lifting the foot and gait while turning in a circle.

To test the scale, the research team used 80 horses and ponies with endocrinopathic laminitis that were referred to 16 veterinary practices in Germany. Independent veterinarians assessed the severity of laminitis using the original scale and the new Meier scale. The vets assessed the horses on the day of diagnosis and again on days four, nine, 14, 25 and 42. Pain medication was withheld for 24 hours before the exams took place.

The scientists found that patient improvement was difficult to determine using the older method, but the Meier method was able to identify more subtle changes. The team also noted that there was significant variation in improvement of each clinical sign; for example, the horses remained lame when asked to turn in a circle for much longer than they shifted weight.

The researchers conclude that the Meier method provides a reliable and consistent method for monitoring endocrinopathic laminitis and its potential response to treatments.

Read the study here.

Questionnaire May Help Arthritic Equines Get Help Earlier

Osteoarthritis can be a painful condition in horses but, unlike people, horses can't talk with their veterinarians about where and how much it hurts. Now, a newly funded study from Morris Animal Foundation is testing to see if a simple questionnaire can help horse owners recognize and monitor signs of chronic osteoarthritis (OA) pain in their horses – helping their equine charges get earlier, more effective treatment and improving their quality of life.

Dr. Janny de Grauw, from Utrecht University in the Netherlands, and Diane Howard, PhD, MSc., Equine Science Master graduate from the University of Edinburgh, in the United Kingdom, are the recipients of the Donor-Inspired Study grant, funded by Dr. Wendy Koch, a veterinarian who has supported the Foundation for nearly 30 years. Dr. Koch has closely followed equine behavior and welfare research over the years and wanted to increase the amount of funding available for studies in these fields.

To effectively treat pain, caregivers and clinicians need a way of monitoring and quantifying the amount of discomfort felt. However, a survey of horse owners in the United Kingdom found that owners have limited ability to identify pain and disease in their horses, underlining the need for a simple way of helping people to recognize chronic pain in their equine companions.

“As veterinarians, we want to treat horses with painful and debilitating conditions like OA as effectively as possible,” said de Grauw. “How well we can manage their condition critically relies on recognition of subtle signs of (worsening) pain by owners and caregivers, who can then seek help.”

Under Dr. de Grauw's supervision, Howard developed the 15-item questionnaire based on changes in horse behavior through interviews with owners of horses diagnosed with osteoarthritis. The questions cover posture, facial expressions, movement and behavior.

She will validate the questionnaire by having 60 owners of horses with chronic OA pain and 20 owners of horses without OA complete it. The owners with OA horses will complete the questionnaire twice in two days while their horse's pain does not fluctuate, to evaluate how robust and reproducible the scoring instrument is.

The research team hopes the easy-to-use questionnaire will help horse owners recognize when their animals are in pain and contact a veterinarian for appropriate treatment. The instrument also may help owners monitor treatment effectiveness and pain progression over time, and guide owners and veterinarians in making quality-of-life decisions.

“Many horses may deal with pain that is not recognized, particularly in its early stages,” said Dr. Janet Patterson-Kane, Morris Animal Foundation Chief Scientific Officer. “Giving their caregivers effective tools for detection, monitoring and decision-making has the potential for significant animal welfare impact.”

Osteoarthritis is a major cause of chronic pain in horses but is an underrecognized and undertreated condition. Though often associated with advanced age, it can also occur in young horses. In addition to being painful, OA can severely curtail a horse's athletic career, and impact the bond between horse and owner if the condition limits a horse's ability to be ridden.

The Foundation's Donor-Inspired Study program allows individual donors and foundations to directly support research topics for which they have a passion and there is a pressing need. Applications for this grant were reviewed and rated, based on impact and scientific rigor, by a scientific advisory board, made up of equine behavior and welfare experts.

Morris Animal Foundation is one of the largest nonprofit organizations worldwide that funds health studies benefiting cats, dogs, horses, llamas, alpacas and wildlife. The Foundation currently is funding 150 studies encompassing a broad spectrum of species and diseases.