Free app teaches how to identify pain in dogs and cats

Dog and cat owners now have a tool to assess the pain felt by their pets. Created by a group of researchers from Unesp (Paulista State University), the application –available online, free of charge and in Portuguese– aims to reduce the suffering of animals.

The tool can help decide whether it is necessary to take the pet to the veterinarian, provide a basis for lawsuits about mistreatment and help identify whether animals used in research are in pain. It can also help veterinarians in their assessments.

The researchers also hope that the pain assessments, accessible both on the animalpain.org website and on the Vetpain app, will contribute to changing the view of cattle, pig, horse, donkey and sheep breeders – other animals included in the tool.

According to Stelio Pacca Loureiro Luna, professor of the veterinary course at Unesp Botucatu and coordinator of the studies, many producers ignore the animals’ pain and still see analgesia as an extra expense.

“They think that using analgesics and anti-inflammatories leads to an increase in cost. It actually increases, but pigs that are anesthetized before castration, for example, have greater weight gain. Analgesia is not an enemy of the producer, it is an ally” , defends Luna.

The scenario of attention to the pain of animals has already improved a lot in relation to 1984, the year in which the professor graduated. At that time, says Luna, stray animals were used in teaching, there were no committees to guarantee care during research, much less concern for their suffering.

“Only 10% of pets received painkillers before the 90s”, he recalls. Dissatisfied, he began researching how to identify pain in animals in order to help change this mindset based on data.

The first big question was how to design scales for beings who, unlike humans, do not have the ability to verbally express their level of discomfort. “We detect pain in animals through the expression of behavior. Behavior is the animal’s language”, replies the professor.

But then another question arose: how specific does the animal’s manifestation need to be? After all, the fact that a dog refuses to eat does not mean that it is in pain.

The answer to this question came from a method that includes the detailed analysis of images. The researchers record videos of the animals before surgery, in the postoperative period and after administering analgesics. Thus, it is possible to compare how they behave naturally, in suffering and through relief.

“We score the behaviors in relation to occurrence and duration. Does the animal look at the affected area? Does it have an arched back? Does it spend more time lying down? The scale is defined based on these behaviors and those that are habitual and the animal stops expressing, how to stop playing”, clarifies Luna. The result varies between species. While a cat in pain wags its tail a lot, a dog puts it between its legs, for example.

In the application, the researchers make available both the evaluations they created –the scale for cats Unesp-Botucatu, from 2013, is recognized worldwide– and scales from other research groups, which allowed to increase the number of incorporated species.

“Our group started with cats because, until then, they were considered to have less pain than dogs. The percentage of cats in which veterinarians used analgesia was lower, pain intensity was assigned lower. We saw that it was a species that demanded attention”.

The years of study allowed us to understand the peculiarities of each species. Horses change their behavior a lot in the presence of an observer, which makes analysis difficult; rabbits hide pain; dogs are usually scandalous and give more signals, while cats suffer in silence, expressing discomfort in a subtle way.

There are also differences when comparing manifestations of acute pain and chronic pain. “In an acute pain, the animals express the response intensely. You try to touch the area and he bites, kicks. In chronic pain, the reaction is milder because he already recognizes it as something present”, compares Luna.

“Acute pain is evaluated by veterinarians, but chronic pain is evaluated by the guardian because he lives with the animal and the alterations are very subtle, they are only noticed in day-to-day life”, adds the researcher.

When opening the tool, the user is asked about the species he wants to evaluate. By clicking on the picture of the corresponding animal, a page with available pain assessment scales is opened. The characteristics of each scale are presented, how to evaluate each characteristic and a preview of the aspects that should be considered, with videos that exemplify the different behaviors of the animal.

Afterwards, the score at which the use of analgesics may be necessary is informed and there is a link to the evaluation, which requires filling out a registration form with some personal data. The video below features a complete tutorial.

According to Luna, the information provided by users will help to draw an overview of the interest in pain. “It will be possible to know if they are tutors or veterinarians, for example. And if they are men or women, since historically men underestimate pain and give less painkillers”, she comments.

The teacher’s expectation is to offer the tool in ten languages ​​and also provide assessments with the help of artificial intelligence.

“For the time being, we still place it point by point, animal by animal. Each point identifies a facial action unit and, when the animal is in pain and changes its expression, the angles and distances between the points change. The system calculates which ones. of these changes are more important for pain assessment and it points out the ones with greater weight”, says Luna.

According to the researcher, the program hits 80% of the cases, a rate even lower than the more than 90% achieved with some scales, and the goal in the coming years is to increase accuracy by increasing the database.