Scientists at the University of Montreal’s Quebec Research Group in Animal Pharmacology have found a way to recognize and treat osteoarthritis in cats – a condition that the owner might not notice and that can make even petting painful. “Osteoarthritis frequently affects cats’ elbows, backs and hips and joints in the hind limbs, and its prevalence increases dramatically with age. More than 80 % of cats older than 11 years old have it,” explained lead author Eric Troncy of the university’s Faculty of Veterinary Medicine. “Despite the fact that cats are the most popular pet in North America, nobody had found a way to easily diagnose and treat cat osteoarthritis. We used our knowledge of cat behaviour and worked with experts in human osteoarthritis to develop a diagnosis tool and test an effective medication: meloxicam.” Osteoarthritis induces chronic pain that results in a decrease in cat’s daily activity, a reluctance to jump and other behaviours that owners may notice.

The researchers examined 120 cats and found that 39 were suffering from osteoarthritis. They established an evaluation chart for measuring the cats’ pain by looking at their kinetic gait analysis, which reveals impairment in their limbs, their daily activity as recorded by an accelerometer, and how sensitive the cat is to touch by testing what level of force will cause the cat to withdraw its paw.

Once the researchers had standardized their evaluation tools, they proceeded to the treatment part of the study. For 74 days, a control group was fed a placebo while the others were fed different dosages of meloxicam. Meloxicam is an anti-inflammatory drug that is already used in the treatment of other animals. “Our study demonstrated that daily oral meloxicam administration over four weeks provided various levels of pain relief, depending on the amount of the drug the cat was given. Cats that were in treated with the high dosage continued to enjoy pain relief for five weeks after dosage stopped. None of the cats had any side-effects,” Professor Troncy said. “As expected, the drug unfortunately does not appear to reduce pain associated with touch, such as stroking – the same flawing occurs in hypersensitive osteoarthritic people treated with anti-inflammatory drugs.”

The study opens a range of possibilities for the application of the findings. “The touch hypersensitivity occurrence rate of 30% in our osteoarthritic cats sample is quite similar to what is reported in osteoarthritis-affected human beings. In pain research and development, we have so desperately looked for validated translational experimental models, when they could be here, in front of us, with natural diseases in pet animals,” Troncy said.

Nevertheless, the cats were able to regain the rest of their normal life. “Unalleviated chronic pain induces functional limitations, contributes to behaviour troubles and loss of the human-animal bond leading potentially to pet euthanasia or surrender,” Troncy explained. “The development of adapted therapy protocols to correctly treat arthritis associated chronic pain will provide a better quality of life particularly in older cats and will in turn have a direct impact on owners, as their cat will be more active and sociable.” The researchers will now start looking at how brain scans may further improve our understanding of pain in cats, particularly with regards to the neurophysiological hypersensitive process.

Meloxicam will be considered for use in cats by the Europe Medicines Agency on April, 2013.

About this study
This research was supported by funding from the Canada Foundation for Innovation, the Natural Sciences and Engineering Research Council of Canada, the Canadian Institutes of Health Research, the Morris Animal Foundation and by a partnership with the animal health pharmaceutical industry (Boehringer Ingelheim Vetmedica, Inc.). It results from a rich collaboration between the Quebec Research Group in Animal Pharmacology (GREPAQ) and the Centre hospitalier de l’Université de Montréal (CHUM) Research Centre – Musculoskeletal Diseases Axis. The studies were published in Research in Veterinary Science on February 13, 2013 (Moreau M, et al Kinetic peak vertical force measurement in cats afflicted by coxarthritis: Data management and acquisition protocols) and in theVeterinary Journal on February 14, 2013 (Guillot M, et al of osteoarthritis in cats and meloxicam efficacy using objective chronic pain evaluation tools). The University of Montreal is officially known as Université de Montréal.

Media contact:

William Raillant-Clark
International Press Attaché
University of Montreal (officially Université de Montréal)
Tel: 514-343-7593



Bijou is an 18-month old French bulldog that appears perfectly normal at first glance. She is healthy and her behavior is exemplary. However, her owner brought her to the Université de Montréal Faculty of Veterinary Medicine because he was intrigued by a particular feature: she has a disproportionately large clitoris!

The anatomical exam concluded that the vagina and uterus are normal. However, an ultrasound revealed the presence of a tissue that could be a non-developed prostate, and a subsequent x-ray identified a baculum (or penile bone) inside the clitoris, which is a trait of male dogs.

Analysis of the gonad tissues confirmed the presence of degenerated testicles containing seminiferous canals but no spermatocyte cells. And genetically, the dog’s chromosomes are XX, which is determinant of the female sex.

Absence of the SRY gene

The veterinarians conducting the medical examinations were about to be surprised yet again. Until now, these anomalies were rare but well documented. There are many cases of sexually female individuals with male characteristics. These individuals are usually carriers of the SRY gene, typically located on the Y chromosome, which triggers the genetic process of masculinization of the fetus.

However, it can occur in both humans and animals that translocation of the SRY gene during the spermatogenesis process makes it emerge on the X chromosome instead. The second sexual chromosome provided by the mother is naturally an X chromosome, which will result in double X individuals, hence females, but with masculine traits given the presence of the SRY gene. In humans, this anomaly occurs in one of 20,000 births.

However, this is not what happened to Bijou because the analyses show that the SRY gene is outright absent. “She is a female with two X chromosomes and testicles despite the absence of the SRY gene,” says baffled Professor David Silversides who diagnosed Bijou at the veterinary genetics laboratory in Saint-Hyacinthe.

Similar anomalies were reported in various farm animals such as pigs, horses, goats and twenty or so dog breeds. However, Bijou is the first French bulldog diagnosed with this unique condition in North America and the second in the world.

The SRY gene is absent in 20 percent of hermaphrodite cases, according to Professor Silversides. “In goats, we know the gene at the source of these malformations but we are completely ignorant about the process in other species including humans,” says Silversides. At least nine genes could be at play in dogs but every lead has been a dead end.

Searching for the recessive gene

These cases are troubling because based on current genetic knowledge the SRY gene is necessary to the development of masculine features. If an individual has a Y chromosome on which the SRY gene is either absent or inactive, that individual will genetically be male with sterile female genitalia. But the case of Bijou demonstrates that an unknown molecular environment can lead to the development of masculine tissues despite the absence of the triggering gene.

Professor Silversides puts forth the hypothesis of a recessive gene present in the genome of the species that both parents must have in order for the phenotype to be expressed. The case of Bijou could provide new leads while also providing insight into the process in humans.

To do so, however, it would be necessary to examine Bijou’s parents, brothers and sisters, which requires the collaboration of the breeders. “Unfortunately, the breeders aren’t very cooperative in such situations and our efforts have been unsuccessful,” says Silversides.

Given the now two diagnoses in French bulldogs, Professor Silversides believes that the genetic mutation can potentially reoccur and is determined to inform breeders of the risk of genital malformations with this breed.

This article translated from an original French text written by Daniel Baril

Cet article a été traduit du français