This report concerns of 37 cases of allergenicity to domestic animals, dogs and cats. Clinical observations and skin tests confirm diagnosis showing dog and cat danders as etiologic factors. Sixteen cases were positive only to cat and dog danders and twenty one cases were associated with house dust, mould spores, feathers, etc. Bronchial asthma, rhinitis and contact dermatitis in face and lips were observed. Symptomatic treatment, elimination or avoidance when possible of contact with these animals and specific hyposensitization was carried out. Allergic symptomatology disappeared in twenty three cases, five abandoned treatment and in the others the allergic episodes showed less incidence and frequency. Shorter treatment time necessary for cases positive to dog and cat danders (a year to year and a half). In the others two or three years were required.