Working donkeys might deal with much more pain than their owners realize. Hardy animals, donkeys don’t appear to suffer from laborious work, hard conditions, and lameness issues the way a horse might. But according to a study by British scientists, that could be because donkeys have far more subtle ways of expressing pain.
“They’re much harder to read in terms of pain behavior than horses; they have a different set of behaviors that relate to their pain experience,” said Rebecca Whay, PhD, of the University of Bristol School of Veterinary Sciences, in the U.K. “They’re speaking their language through behavior. (They’re) working equids who … have an awful lot of problems but seem so calm. But when you learn to watch their behavior it’s like watching them shouting.”
Whay and her fellow researchers studied 40 male cart-pulling donkeys in Pakistan that had been identified by a charitable organization as having health issues, including poor body condition, poor hoof condition, wounds, and lameness. They treated half the donkeys with a pain-killer (meloxicam) and the other half with a placebo as a control group. Then they observed the donkeys’ behavior at rest for the next four hours.
They found that the treatment group was more alert and interested in the environment and exhibited more investigative behavior than the control group, Whay said. They also yawned and licked more and lay down less often than controls. Meanwhile, donkeys in the control group shifted their weight and kept their eyes closed more often.
The results are likely to be specific to male as opposed to female donkeys, she added. Essentially, the pain relief allows them to feel freer to express their own natural behaviors. “The male donkeys are disposed to be more vigilant, to be seekers,” she said. By contrast, female donkeys might finally allow themselves to rest once they feel relief from pain.
The donkeys’ owners had variable levels of recognition of their animals’ signs of pain, Whay added. “Some were very aware and very conscious with how their animals communicate with them and often used terms like, ‘love’ when referring to their donkeys,” she said. “But others were not really ready to recognize that animals experience pain.”
The next step is to develop an ethogram—a list of recognizable behaviors—to describe signs of donkey pain, said Whay.
“There’s a whole array of behaviors, not limited to just the behaviors we saw in this study,” she said. “We’re not good at recognizing stillness and inactivity as a sign of pain. We’re used to recognizing people saying they’re pain and exhibiting pain behaviors and eliciting a response from others, sympathy or doing something about it. And we need to understand that that’s just not what donkeys do.”
Treating working donkeys with analgesics is an “interim” goal, with a longer-term goal to “try to reduce the welfare challenges that these animals face,” Whay said.
The study, “Identifying behavioural differences in working donkeys in response to analgesic administration,” was published in the Equine Veterinary Journal.