Scientific Results: Lifetime prevalence of malignant and benign tumors in companion dogs

Who worked on this research?

Where was it published?

Veterinary and Comparative Oncology

What is this paper about?

Cancer is a cause of dog illness and death just as it is for humans. We are interested in understanding more about the causes and outcomes of cancer in companion dogs. To begin that work, we decided to look at data from the Health and Life Experiences Survey data for the first ~27,000 dogs who were enrolled in the Dog Aging Project Pack.

We had two goals. The first was to estimate the lifetime prevalence of cancer in the Dog Aging Project Pack. In other words, we wanted to know what proportion of the Pack had a history of malignant tumors. The second was to determine what dog characteristics were associated with lifetime prevalence of malignant tumors.

We determined that the lifetime prevalence of malignant tumors was approximately 30 per 1000 dogs. The lifetime prevalence increased with increasing dog age and dog size. For example, the smallest dogs (toy size and small dogs) had a lifetime prevalence of about 18 per 1000 dogs while standard size and large dogs had a lifetime prevalence of about 35 and 42 per 1000 dogs respectively. Interestingly, there was no difference in the lifetime prevalence of malignant tumors between purebred and mixed breed dogs.

What do these results mean for me and my dog?

The results of this particular study are descriptive, meaning that these results shed light on patterns of cancer occurrence, but these results don’t have any direct meaning for individual dogs or their humans at this time.
However, this research is an important first step because we have to understand when and how cancer occurs before we can understand why, and we have to understand why before we can find new treatments.
Cancer is a disease that affects both humans and our dogs. Many cancers share similar features in both species and the etiology (set of causes) and the treatment can be similar in our furry companions. The DAP Pack presents a unique opportunity for researchers to explore the reasons why cancers occur in order to help both species live longer, healthier lives together.

Where can I learn more?

Schwartz, SM, Urfer, SR, White, M, et al. Lifetime prevalence of malignant and benign tumours in companion dogs: Cross-sectional analysis of Dog Aging Project baseline survey. Vet Comp Oncol. 2022: 1- 8. DOI:10.1111/vco.12839.

Abstract:

Although cancer is widely regarded as a major contributor to canine morbidity and mortality, its frequency in companion dogs has only infrequently been characterised. We analysed cross-sectional data from the baseline survey of owners of 27 541 living companion dogs enrolled in the Dog Aging Project as of 31 December 2020 to estimate the lifetime prevalence of malignant and benign tumours and several potentially-associated characteristics. Survey questions elicited information on history of ‘cancer or tumors’ including organ site and histologic type. Owners reported 819 malignant tumours (56% sited in the skin, muscle or other soft tissue) and 404 benign tumours (69% sited in the skin, muscle or other soft tissue). The lifetime prevalence of malignant tumours (29.7/1000 dogs) was approximately double the lifetime prevalence of benign tumours (14.7/1000 dogs). Lifetime prevalence of both malignant and benign tumours increased with dog age at survey completion. There were no statistically discernable differences in age-adjusted lifetime prevalence of malignant (prevalence ratio (PR) = 0.93 [95% confidence interval (CI) 0.82, 1.07] or benign tumours (PR = 1.10, 95% CI 0.91, 1.34) in mixed vs. purebred dogs. The lifetime prevalence of malignant tumours increased with increasing dog size class; compared to toy and small dogs, the age-adjusted PRs (95% CIs) for medium, standard, large, and giant dogs were 1.65 (1.28, 2.11), 2.92 (2.35, 3.64), 3.67 (2.92, 4.62) and 2.99 (1.23, 4.02), respectively. Similar though less pronounced patterns in relation to dog size class were observed for benign tumours. Ongoing prospective data collection will permit future studies on risk factors for canine tumour incidence.