Mankind domesticated wild wolves thousands of years ago until they became their most loyal allies, evolving from pets to practically family members. About 30,000 years of coevolution, one of the most famous cases of artificial selection in animal history. The material improvement of the dog’s living conditions has led to the expansion of academic disciplines and the emergence of specialties such as veterinary medicine and its clinical aspect, as well as the industry focused on their care. A success that has also changed the way they die: cancer is the leading cause of death in these pets.
In large dogs weighing more than 50-60 kg, the diagnosis of bone cancer is made after an average of 5 years, compared to 11 detections in canids weighing less than 5 kg. Breed also has an impact, as purebred dogs are diagnosed at 8.2 years of age, while mixed varieties do not develop the disease until 9.2 years of age. That data will be collected in the new study to be published this Wednesday in the journal Plos ONE.
The sample of 3,452 dogs analyzed cancer diagnoses and the association with their size, sex and breed, and found an average age of 7 years
Jill Rafalko, geneticist at PetDx Pharmaceuticals
Among the breeds well represented in the study, the researchers were able to find that Mastiffs, Saint Bernards, Great Danes and Bulldogs had the youngest median age of diagnosis, around six years, with English Mastiffs having the youngest median age of 6 years at cancer diagnosis (five years). Boxers, Vizslas and Bernese Mountain Dogs had a mean age of diagnosis of 6.1 to 7 years.
Breeds more prone to tumors later, around age 10, include dachshunds, cocker spaniels, Australian Shepherds, beagles, and terriers. At 11.5 years, the Bichon Frize has the oldest median age at diagnosis. Other details indicate that bitches usually develop cancer at an older age than males, and that tumors were found later in spayed dogs than in non-spayed dogs.
A veterinarian sterilizes a dog in the resort of Cancun, Quintana Roo (Mexico), Lourdes Cruz (EFE)
The work, led by geneticist Jill Rafalko, analyzes the mean age at cancer diagnosis in dogs and how it relates to their size, sex and breed, using a sample of 3,452 American dogs with cancer. Rafalko, of pharmaceutical company PetDx in La Jolla, Calif., explains how his work aims to help “raise awareness of the importance of early care and public screening in dogs,” he says, because it’s less harmful than it is in humans treatment for the animal in the long term.
New prevention model
Rafalko’s pharmaceutical team is focused on animal liquid biopsy, a novel method of non-invasive blood testing that detects tumor samples before they metastasize to any organ. In the paper, they indicate that it would be desirable “to begin testing on dogs two years before the average at which, by virtue of their type or weight, they begin to suffer from the symptoms of the disease,” which tests would be in dogs at the age of seven, depending on characteristics even at four. Animal oncologist Andi Flory, the center’s chief medical officer, explains that the development of this cancer treatment technique and its statistical animal model is “a path toward standardizing prevention.”
There is a brutal generational change, I see it mostly in owners under 40 years old. Animal care is a very expensive specialty, so there must be a very large emotional factor involved
Noemí del Castillo Magán, Surbatán Veterinary Clinic
Professor Elena Martínez de Merlo, from the Faculty of Veterinary Medicine at the Complutense University of Madrid, who is not related to this study, explains that “currently, oncology in small animals is absolutely topical because the incidence of cancer is very high.” . The specialist points out that this is due to two complementary reasons: the importance of these animals in the lives of their owners has meant that the field of study of oncology has changed radically in the last 30 years. invasive preventive therapy “the future, the way forward,” but it raises questions about how “liquid biopsy will measure cancer severity and types of malignancies in the same disease.”
“The oncology study in animals is always lagging behind that in humans, but is changing very quickly; In addition, our goals are different: quality over quantity of life,” explains Martínez. The researcher believes that the epidemiological sample from the US cannot be extrapolated directly, but it is consistent with other analyzes of canine cancer conducted in Europe.
Noemí del Castillo Magán, at her Surbatán veterinary clinic in Madrid, also recognizes the importance of dog welfare in people’s daily lives, also unrelated to the recent study. “A brutal generation change is taking place, which I see after years of experience, especially among owners under 40 years of age. Animal care is a very expensive subject, so there must be a very big emotional factor,” argues Castillo. Both experts point out how important it is in veterinary medicine to preserve the dog’s quality of life, which is why they affirm that prevention will be the way forward for the industry.
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