Pododermatitis with nodules and sinuses
Interdigital cyst syndrome
This usually occurs in short coated dogs e.g. Staffies, Bull Terriers, Great Danes and Rottweilers. In these breeds, the short bristle hair is easily pushed into the follicle by the dog's weight and toe movement.
These cases will have another folliculitis predisposing cause:
- Allergy i.e. atopy (commonly)
- Contact allergy (rare)
- Food allergy (rare)
Allergy signs may be mild, therefore look at the ears:
- Are they inflamed (erythematous)
- Is there licking of the forearm
- Is there body redness (erythema)
Look for signs of scratching, rolling or face rubbing.
If only one foot is involved, consider grass seed foreign body.
Single lesions can be tumours; however some tumours occur as multiple lesions. The common paw tumours are epitheliotrophic lymphoma, fibrosarcoma, metastatic adenocarcinoma, mast cell and squamous cell carcinomas.
Sterile nodular granulomas which are Langerhans histiocytic disorders
There are four categories of histiocytic disorders:
- Histiocytoma (button tumour) is a common benign and solitary fleshy tumour of young adults
- Cutaneous histiocytoses are multiple haired nodules on the feet and body that respond to steroids
- Systemic histiocytoses are similar to the cutaneous type but involve the skin and mucous membranes and respond to cortisone with Imuran
- Canine histiocytic sarcomas and canine malignant histiocytosis occur in Golden Retrievers, Labrador Retrievers, Bernese Mountain dogs and Rottweilers. These are difficult to treat, however some new anti cancer drugs are showing promise
This is a benign nodule that may ulcerate. They are usually single but can occur as inter-digital swelling in multiple feet.
Xanthoma in cats
This is a fat granuloma that can occur in cats associated with diabetes mellitus, lipid metabolic disorders and as a side effect of megestrol acetate.
A biopsy will give an accurate diagnosis.
Some cases will be simple to treat however in others a serious prognosis will be revealed, or the biopsy will lead to an investigation of a systemic disease.
|Interdigital cysts due to a
Staph obstructed furunculosis
|Focal adnexia dysplasia||