Cats in Hats Pain Study

Aliénor Delsart, Aude Castel, Guillaume Dumas, Colombe Otis, Mathieu Lachance, Maude Barbeau-Grégoire, Bertrand Lussier, Franck Péron, Marc Hébert, Nicolas Lapointe, Maxim Moreau, Johanne Martel-Pelletier, Jean-Pierre Pelletier, Eric Troncy, Non-invasive electroencephalography in awake cats: Feasibility and application to sensory processing in chronic pain, Journal of Neuroscience Methods, Volume 411, 2024, 110254, ISSN 0165-0270, https://doi.org/10.1016/j.jneumeth.2024.110254.

The following was excerpted from the article cited above and the press release.

When being tested for chronic pain from common conditions like osteoarthritis, awake cats tend to shake off and chew the wired electrodes placed on their heads to produce electroencephalograms (EEGs). Scientists at the Veterinary School of the Université de Montréal have found a way to scan the brains of cats while they’re awake, using electrodes attached under specially knitted wool caps (and apparently a sweater).

Feline osteoarthritis leads to chronic pain. In humans, sensory exposure can modulate chronic pain. The scientists were interested in determining if that might work in cats.  In recent studies of human pain using electroencephalography (EEG) revealed a specific brain signature for human osteoarthritis. However, EEG pain characterization or its modulation did not exist in cats, because all EEG were conducted in sedated cats, using intradermal electrodes, which could alter sensory (pain) perception.

 To overcome cat rejection of the electrodes, a wool hat was specially made for the study. The hat is described as knitted in the press release, but looks like it may be crocheted in a couple of the pictures.  The little cap held the electrodes in place even during cat movements. One of the graduate students was able to make the caps. For anyone who is interested in this there are several YouTube videos, and the “Cats in Hats” pattern book can be found on amazon patterns are also available on Etsy. Yes, I once actually knitted little kitty hats as part of Halloween outfits for my cats. Only one of my cats was happy to wear it, but she was perfectly content to do so.  

EEG evaluations of lights and scents impact on pain were performed in conscious cats, in a quiet and dim-lighted). Ten gold-plated surface electrodes were placed without shaving the hair under the caps. After assessing their stress and pain through stimuli passed through the electrodes, the scientists then went about exposing the cats to soothing stimuli such as colored lights and comforting smells, to ease their suffering.

This is the first successful use of EEGs in conscious cats with surface electrodes recording brain activity while exposing them to sensory stimulations. Though they seemingly did not find lights or scents that would ease pain, the scientists felt this work opens new avenues for investigating feline chronic pain and its potential modulation through sensory interventions. No doubt, further work will discover that a heating pad reduces the pain. I am just guessing that based on the five cats that have been part of our family over the years. Though I poke gentle fun at the research, I welcome this work because there have been several times over the decades that I wanted to know if a cat was in pain, and what they were feeling.

The study was approved by the Institutional Animal Care and Use Committee. The care and handling of all cats adhered to the Canadian Council on Animal Care’s guidelines. Adult neutered cats (n=11 (6 females); [3–16] years) with naturally occurring OA were enrolled in the study. Cats were selected based on their behavioral compliance- willingness to wear hats and lie still in while staying awake. 

 This study was partially funded by the Morris Animal Foundation (A.CA. & E.TR.). This work was sponsored, in part, by Discovery grants, a Collaborative Research and Development grant, as well as by an ongoing New Opportunities Fund grant , a Leader Opportunity Fund grant and a series of research groups.