Prevalence and Characteristics of Squamous Cell Carcinoma in Canine Oral Tumors

Squamous cell carcinoma (SCC) is one of the most common malignant oral tumors in dogs, accounting for approximately 20% to 30% of all cases, making it the second most prevalent oral malignancy after malignant melanoma. This type of cancer primarily affects middle-aged to senior dogs, with an average age of onset between 8 and 10 years. Interestingly, large breed dogs may be at a slightly higher risk of developing SCC compared to smaller breeds.

Understanding Squamous Cell Carcinoma in Dogs

Squamous cell carcinoma in dogs typically presents as irregular, cauliflower-like masses within the oral cavity. These tumors are most commonly found in areas such as the incisors, the premolars of the lower jaw, and the molars of the upper jaw. Additionally, SCC can develop on the tongue and tonsils, making early detection challenging without regular oral examinations.

One of the alarming characteristics of SCC is its potential for bone invasion. At the time of diagnosis, around 77% of cases exhibit bone involvement, which can significantly complicate treatment and prognosis. However, despite this aggressive behavior, only a small percentage of cases show metastasis to the lungs, with less than 10% displaying symptoms in the regional lymph nodes. It’s important to note that enlarged lymph nodes in affected dogs may not always indicate metastasis but could be a result of inflammatory cytokines produced by the tumor.

Higher Metastatic Potential in Specific Locations

SCC tumors located at the base of the tongue and the tonsils are particularly worrisome due to their higher propensity for local lymph node involvement and distant lung metastasis. This makes early intervention and aggressive treatment strategies crucial in managing these cases effectively.

Interestingly, a variant of SCC known as papillary squamous cell carcinoma, which tends to occur in younger dogs, shows a different clinical behavior. While it may locally invade surrounding tissues, it does not typically metastasize, offering a more favorable prognosis compared to the more common forms of SCC.

The prevalence and characteristics of squamous cell carcinoma in canine oral tumors highlight the importance of early detection and intervention. Regular veterinary check-ups, particularly in older and large-breed dogs, can be instrumental in catching these tumors before they progress to a more advanced and challenging stage. Understanding the distinct behaviors of SCC based on its location and variant type can help guide treatment decisions and improve outcomes for affected dogs.