Study suggests horses show distress after a companion’s death: full analysis

A newly highlighted study is giving scientific shape to something many equine veterinarians, barn managers, and pet parents have reported for years: horses often seem deeply affected when a close companion dies. In the Applied Animal Behaviour Science paper, researchers from the University of Lincoln and collaborators described “grief-like distress responses” in surviving horses, based on survey reports from people caring for 325 horses after the death of another equid companion. (sciencedirect.com)

The work arrives as equine end-of-life discussions are becoming more developed, especially around euthanasia planning, transport limitations, and welfare-centered decision-making. What has received less attention is what happens to the horses left behind. The researchers explicitly built on earlier work in dogs suggesting that the nature of the social bond shapes post-loss behavioral change, and they set out to test whether a similar pattern might be present in horses. The study was approved through the University of Lincoln ethics process and used an online survey to gather information on the deceased and surviving animals, their relationship, the circumstances of death, and behavior changes immediately after the loss and up to six months later. (sciencedirect.com)

The headline finding is that behavior changes were common, and often substantial. In the study discussion, the authors reported increased arousal in 58.53% of horses, increased alertness to stimuli in 45.83%, changes in vocalization in 68.63%, and increased movement in 67.68%. Decreased feeding and reduced contact-seeking with people were also common. Equus Magazine’s summary of the study emphasized especially high first-day reports of agitation or arousal, altered interactions around feeding time, heightened alertness, and calling out. Across sources, the pattern is consistent: after a companion dies, many horses appear restless, watchful, socially altered, and off their normal routines. (sciencedirect.com)

One of the more practical findings involved access to the body. According to the paper abstract, whether the surviving horse spent time with the body did not change behavior in the first 24 hours, but over the following six months it was associated with fewer persistent changes in vocalization and excitement around interaction or feeding. Horses that did not have that opportunity were more likely to show ongoing changes in arousal and vigilance. Claire Ricci-Bonot, a University of Lincoln researcher quoted in Stable Management, said the project suggests it can be beneficial to let companion horses see the body so they can register that the missing horse is not coming back. (sciencedirect.com)

That said, the study has important limitations, and clinicians should read it as an early welfare signal, not a final answer on equine grief. The data came from pet parent reports, which are vulnerable to recall bias, interpretation bias, and anthropomorphism. Equus noted that point directly, while also arguing that owner-reported patterns may still be valuable because these events are hard to capture prospectively in real-world settings. The authors themselves use careful language, referring to “grief-like” responses rather than claiming proof of human-equivalent grief. (sciencedirect.com)

Why it matters: For veterinary professionals, this study broadens the frame around equine loss. When one horse dies or is euthanized, the medical case may be over, but the welfare implications for herd mates may just be starting. That has practical consequences for discharge planning, euthanasia conversations, and follow-up advice to pet parents. Monitoring feed intake, sleep, social behavior, vocalization, arousal, and vigilance in the surviving horse may help identify animals that need extra management support. The findings also strengthen the case for discussing, when circumstances allow, whether companions should have controlled access to the body, because the aftermath may be shaped not only by loss itself but by whether the horse can process what happened. (sciencedirect.com)

What to watch: The field now needs prospective studies using direct behavioral observation, and ideally physiologic markers, to test whether these survey-based patterns hold up across different housing systems, bond types, and death scenarios. If that evidence builds, equine practice could eventually see more formal guidance on managing surviving companions after euthanasia or sudden death. (sciencedirect.com)