Older dogs, lightly coloured coats and several breeds were associated with a higher risk of cutaneous squamous cell carcinoma (cSCC) in a new Australian study.
Researchers used VetCompass Australia records from 2014 to 2023 to identify 295 dogs with histologically confirmed cSCC, matching each case with four controls from the same practice and time period to give a comparison group of 1,180 dogs. They found that dogs who were older, pale in colour, or who were a certain breed had increased risk.
Risk factors
Age was one of the strongest risk factors. Compared with dogs aged 2-6, those aged 7-11 had 7.4 times the odds of cSCC, while dogs aged 12 or over had 4.8 times the odds.
Coat colour also appeared important. Dogs with entirely white coats had 2.8 times the odds of cSCC compared with those with dark solid coats, while white mixed-colour dogs had 2.5 times the odds.
Dalmatians, bulldogs, Staffordshire terriers and schnauzers all had significantly higher odds of cSCC than mixed-breed dogs.
The effect was particularly marked in Dalmatians and bulldogs, although the relatively small numbers within individual breed groups resulted in wide confidence intervals and mean the exact size of the increased risk should be interpreted cautiously.
The authors suggest that some breed associations may be partly explained by physical characteristics such as short coats, sparsely haired ventral skin and lighter pigmentation, which provide less protection from ultraviolet radiation.
More than half of the tumours were found on areas of the body caudal to the thorax, while 17% involved the digit or nailbed. Cases were also more frequently recorded in Queensland and New South Wales, particularly along coastal areas, which is consistent with a possible role of UV exposure in cSCC.
Findings may help identify higher-risk dogs
The study provides further evidence that age, pigmentation and breed can help identify dogs at greater risk of cSCC, although the Australian population and its high levels of UV exposure need to be considered when applying the findings elsewhere.
The researchers also note that the overall number of cases was relatively small once dogs were divided into breed and other subgroups, and that demographic differences between cases and controls may have introduced some confounding.
For vets, the findings support paying particular attention to persistent or changing skin lesions in older, lightly pigmented dogs, especially on areas with limited hair coverage or greater exposure to sunlight.
Source paper:
Zhang JJ, Dejene H, Granados-Soler JL, et al. Demographic and environmental factors associated with canine cutaneous squamous cell carcinoma development in Australia: a retrospective matched case-control analysis. Veterinary Research Communications. Published 24 October 2026.
