Squamous cell carcinoma (SCC) stands as the second most prevalent skin cancer in dogs, primarily attributed to UV radiation exposure. Affected areas typically include regions with sparse hair and pale or depigmented skin. The significance of spontaneous canine cutaneous SCC as a model for its human counterpart is underscored by its resemblance. This study assesses the expression of key markers—Epidermal Growth Factor Receptor (EGFR), Cyclooxygenase-2 (Cox-2), and Ki-67—in canine cutaneous SCC. Our objective is to investigate the association between their expression levels and classical clinicopathological parameters, unraveling the intricate relationships among these molecular markers. In our retrospective analysis of 37 cases, EGFR overexpression manifested in 43.2% of cases, while Cox-2 exhibited overexpression in 97.3%. The EGFR, Cox-2 overexpression, and Ki-67 proliferation indices, estimated through immunohistochemistry, displayed a significant association with the histological grade, but only EGFR labeling is associated with the presence of lymphovascular emboli. The Ki-67 labeling index expression exhibited an association with EGFR and Cox-2. These findings propose that EGFR, Cox-2, and Ki-67 hold promise as valuable markers in canine SCC. EGFR, Cox-2, and Ki-67 may serve as indicators of disease progression, offering insights into the malignancy of a lesion. The implications extend to the potential therapeutic targeting of EGFR and Cox-2 in managing canine SCC. Further exploration of these insights is warranted due to their translational relevance and the development of targeted interventions in the context of canine SCC.

Oral squamous cell carcinoma (OSCC) is a common and highly aggressive dog tumor known for its local invasiveness and metastatic potential. Understanding the molecular mechanisms driving the development and progression of OSCC is crucial for improving diagnostic and therapeutic strategies. Additionally, spontaneous oral squamous cell carcinomas in dogs are an excellent model for studying human counterparts. In this study, we aimed to investigate the significance of two key molecular components, Cox-2 and EGFR, in canine OSCC. We examined 34 tumor sections from various dog breeds to assess the immunoexpression of Cox-2 and EGFR. Our findings revealed that Cox-2 was highly expressed in 70.6% of cases, while EGFR overexpression was observed in 44.1%. Cox-2 overexpression showed association with histological grade of malignancy (HGM) (p = 0.006) and EGFR with vascular invasion (p = 0.006). COX-2 and EGFR concurrent expression was associated with HGM (p = 0.002), as well as with the presence of vascular invasion (p = 0.002). These data suggest that Cox-2 and EGFR could be promising biomarkers and potential therapeutic targets, opening avenues for developing novel treatment strategies for dogs affected by OSCC. Further studies are warranted to delve deeper into these findings and translate them into clinical practice.

Transitional cell carcinoma of the urinary bladder is a significant neoplasm in dogs, characterized by a poor prognosis and a high metastatic potential. These canine spontaneous tumors share many characteristics with human transitional cell carcinoma, making them an excellent comparative model. The role of inflammatory infiltration in tumor development and progression is frequently contradictory, especially concerning tumor-associated tissue eosinophils (TATE) and tumor-associated macrophages (TAMs). This study aims to analyze TATE and TAMs in canine transitional cell carcinoma of the urinary bladder. Congo Red staining was used to identify TATE, and immunohistochemistry was performed to detect TAMs in 34 cases of canine transitional cell carcinoma of the bladder carcinomas, categorized into low and high grades. Statistically significant differences were observed between the number of eosinophils and macrophages in the two groups of tumors. The number of TATE was higher in low-grade malignant tumors, but the number of TAMs was higher in high-grade tumors. Our findings suggest the importance of TATEs and TAMs in the aggressiveness of canine transitional cell carcinoma and propose their potential use as therapeutic targets.

Cutaneous squamous cell carcinoma (CSCC) in dogs is a locally invasive tumor that typically occurs in areas of poorly pigmented skin due to sun exposure. Identifying new biomarkers, such as syndecan-1 (CD138) and E-cadherin, is fundamental for tumor diagnosis and prognosis. Dysregulation of syndecan-1, expressed in epithelial tissue, fibroblasts, and plasma cells, is associated with poor prognosis in several types of cancer. Similarly, E-cadherin, which plays a crucial role in cell adhesion and epithelial functionality, is also linked to adverse outcomes. This study evaluated the expression of syndecan-1 and E-cadherin in 47 cases of canine cutaneous squamous cell carcinoma. The results showed that the intensity of syndecan-1 decreased with increasing tumor aggressiveness, and its presence in the stroma was significantly associated with tumor grade. E-cadherin also demonstrated a decrease in intensity with increasing malignancy. However, the association between syndecan-1 and E-cadherin was not statistically significant. E-cadherin reduction and stromal syndecan-1 positivity seem to be associated with tumor aggressiveness in canine cutaneous squamous cell carcinoma. Further studies are needed to explore their roles in tumor progression.

Squamous cell carcinoma (SCC) is a type of epithelial cancer that originates in the squamous epithelium and can develop in any area of the body covered by this tissue. Cutaneous SCC is characterized by a locally aggressive tumor, highlighting the importance of identifying new therapeutic targets to combat this disease effectively. Syndecan-1, a molecule often deregulated in cutaneous SCC, is a type 1 transmembrane proteoglycan primarily expressed in epithelial and plasma cells. The ectodomain of Syndecan-1 is frequently shed, rendering the molecule soluble and capable of interacting with various other molecules. This review aims to comprehensively analyze Syndecan-1 expression in cutaneous squamous cell carcinoma (CSCC), elucidate its role in tumorigenesis, and assess promising therapeutic strategies that target Syndecan-1 and its associated pathways. Therapeutic approaches often focus on molecules that facilitate the shedding of the Syndecan-1 ectodomain, such as matrix metalloproteinases (MMPs) and heparanase. Inhibition of heparanase and MMPs has shown potential in preventing the degradation of Syndecan-1 and reducing tumor invasiveness. Additional strategies include using synthetic proteoglycans, peptide mimetics such as syntenin, and overexpression of the C-terminal fragment of Syndecan-1 to suppress tumor growth and migration. Moreover, targeting microRNAs that regulate Syndecan-1 expression presents another promising therapeutic tool. These therapies are designed to modulate the function of Syndecan-1, potentially affecting the progression of CSCC and improving clinical outcomes.

Background/Objectives: Dog tethering remains a common containment practice in several regions despite increasing concerns about its implications for animal welfare. This study aimed to assess veterinary professionals’ perceptions in Portugal about the impact of dog tethering on canine health, behavior, and welfare, as well as their views on its regulation. Methods: An anonymous, structured questionnaire was distributed online to veterinary professionals to collect data on clinical exposure to chained dogs, observed health and behavioral outcomes, and attitudes toward criminalizing the practice. Results: A total of 331 veterinarians participated, of whom 71.9% reported encountering chained dogs during their professional activities, particularly in rural areas. Most respondents perceived the tethering conditions as inadequate, particularly regarding freedom of movement and the fulfillment of behavioral needs. Frequently reported consequences included alopecia at the restraint site, poor muscle condition, physical injuries, fear-related behaviors, reduced socialization, and increased aggression. Preventing escape was identified as the primary perceived motivation for tethering. The majority of veterinarians supported some degree of criminalization, particularly when welfare impairment was evident. Conclusions: These findings reflect veterinary professionals’ perceptions of the welfare risks associated with prolonged tethering and underscore the need for integrated strategies combining regulation, education, and accessible, humane containment alternatives.