Case Studies


Sterile pyogranulomatous dermatitis

Presentation: a six and half year old of Staffordshire bull terrier was presented with well demarcated ulcers underlying pustular crusts on the trunk and legs (figures 1 & 2).

History: The condition had started about 3 weeks after administration of a worming tablet and was not particularly pruritic.  Although the dog had previous history of allergies he had not had any signs for about 3 years. 

Diagnosis: After a clinical examination and some in-house cytology (figure 3) on matter collected from the ulcers, a tentative diagnosis of sterile pyogranulomatous dermatitis was made.

Sterile pyogranulomatous dermatitis is a condition where there is an aberrant immune response to an antigen (e.g. drugs, diet, infectious agents, etc).  It is a treatable condition, but diagnosis takes careful history taking and examination.  Confirmation is usually by histology, but in this case the client opted for trial treatment to limit the expense.

Outcome: The dog responded well and the lesions have now resolved (figure 4), so in this case the wormer was likely to have been the trigger.

Anita Patel (January 2012)


click on any image to enlarge

Figure 1 - Lesions on right foreleg

Figure 2 - Ulcers with crusts removed


Figure 3 - Cytology: neutrophils, macrophages, and few lymphocytes without any visible bacteria (x100 stained with DiffQuik)

Figure 4 - Lesions (resolved) after 4 weeks of treatment