Mitogen-induced lymphocyte and cutaneous reactions in dogs.

The lymphocyte response of dogs to mitogens was determined using separated lymphocyte and whole blood lymphocyte proliferation techniques. Reactivity to optimal doses of the following mitogens was demonstrated in decreasing order of intensity: phytohemagglutinin, Pokeweed mitogen, conconavalin A and sodium periodate. The canine cutaneous reactivity to these mitogens was also determined. Grossly, erythema and induration with all mitogens was maximal at 24 h. Microscopically, lesions using all mitogens consisted of edema, hyperemia and diffuse dermal infiltration with polymorphonuclear leukocytes and mononuclear cells. These mitogen-induced lesions may represent a specific lymphocyte-mediated inflammatory response, although a nonspecific reaction cannot be excluded.