Genetic basis - Footpad hyperkeratosis in Rottweilers is a hereditary skin disorder caused by a frameshift mutation (c.2541_2545delGGGCT) in the DSG1 gene, which encodes desmoglein 1—a key protein for cell adhesion in the skin. The disorder is inherited in an autosomal recessive fashion, meaning affected dogs have two copies of the mutant gene. Dogs with only one copy are carriers and do not exhibit symptoms. This mutation leads to a lack of functional desmoglein 1, compromising skin barrier integrity and predisposing affected dogs to additional skin and ear infections, as well as allergies
Pathophysiology - The disease manifests as abnormal thickening and hardening of the footpads due to excessive proliferation and keratinization of the epidermal cells. Histologically, the pads show villous projections of dense keratin in the stratum corneum. The skin barrier dysfunction also facilitates recurrent bacterial infections and allergic dermatitis, similar to syndromic forms seen in humans with biallelic DSG1 mutations
Complications - Severe pain and discomfort, often requiring regular trimming under anesthesia. Breakdown and cracking of pads, leading to secondary bacterial infections. Allergic skin disease and recurrent ear infections. Reduced mobility due to pain
Why This Matters to Breeders and Vets - For breeders, improving breed health and minimizing the occurrence of painful, lifelong conditions is a priority—responsible breeding can eliminate this disorder. For veterinarians, early recognition means instituting supportive care (keratolytic treatments, moisturizing, pain management, infection control) and advising breeders to test at-risk dogs. Coordinated efforts benefit animal welfare, breed reputation, and client satisfaction