Abstract: Background – Cancer screening is used to identify malignant tumors prior to development of clinical signs, with the aim that early cancer detection may lead to improved outcomes. To understand the potential benefits of cancer screening in dogs, a greater understanding of the prevalence of cancer in higher-risk populations of dogs as well as which cancers are frequently identified are needed.
Hypothesis/Objectives – Determine the prevalence of undiagnosed malignant neoplasms in a cohort of healthy middle-aged to older dogs.
Animals – 913 healthy, client-owned dogs screened for eligibility to participate in the Vaccination Against Canine Cancer Study.
Methods – Dogs between ages of 5.5 to 11.5 years and mixed breed or breeds at higher risk for cancer development were evaluated at three study sites. Physical examination with aspiration of dermal and subcutaneous masses, CBC, biochemical profile, urinalysis, 3-view thoracic radiographs, and abdominal ultrasound were performed to identify occult cancer in all patients prior to study enrollment.
Results – Twenty-three dogs were diagnosed with cancer, with another 11 dogs highly suspicious for cancer but not definitively confirmed, resulting in a 3.7% prevalence of undiagnosed cancer in this population of dogs. Twenty-two (65%) were diagnosed by physical examination through aspiration of cutaneous or subcutaneous masses, with mast cell tumors diagnosed most commonly (n = 10).
Conclusions and clinical importance – The frequency of cancer diagnosis in this population of middle-aged to older higher risk breeds is low, however routine physical examination was able to detect the majority of these malignant tumors.
Learning Objectives:
Summarize the principles of cancer screening.
List methods of cancer screening currently available to veterinarians.
Describe the benefits and limitations of various cancer screening methods in veterinary medicine.
