april 2006

Dog Skin: Pemphigus foliaceous

Pemphigus foliaceous is an uncommon autoimmune disease directed at intercellular adhesion molecules. Triggering factors are unknown and most cases are considered idiopathic. However, occasionally it does represent a manifestation of a drug reaction or can appear as a paraneoplastic syndrome. Lesions generally arise on, but not confined to, the face, ears and digits in ititial stages but then often become generalised

may 2006

Dog: Demodicosis

Canine demodicosis results from an unexplained proliferation of Demodex canis mites within hair follicles. It occurs as a localised disease (onset in young dogs, resolves spontaneously within 6-8 weeks) or as a generalised disease (CGD), which carries a more guarded prognosis, although there are reports of spontaneous resolution in dogs less than 1.5 years of age. CGD is also usually juvenile in onset but adult onset disease also occurs which may reflect an underlying immunosuppressive disease.

june 2006

Ostrich: Conjunctival Mycobacteriosis

Atypical sites of mycobaterial infection in birds (primarily recorded in the Emu) include the conjunctiva. Caseonecrotic cores are surrounded by a broad ring of palisading epithelioid macrophages and multinucleate giant cells with a moderate admixture of heterophils, lymphocytes, and plasma cells. At necropsy, granulomas can also be found in visceral organs. Acid-fast bacilli are demonstrated in lesions using Ziehl-Neelsen or Fite's stains (see inset). Cultures usually isolate Mycobacterium avium (complex).