Anaphylactic reaction in a cow due to parenteral administration of penicillin-streptomycin.

Anaphylactic reaction rarely occurs after the 1st injection of penicillin-streptomycin in cattle. Immediately following intramuscular injection of a Holstein-Friesian cow with penicillin-streptomycin, the cow showed abnormal clinical signs that included respiratory distress, urticaria, and lacrimation. Recovery took approximately 2 h after intramuscular injection of dexamethasone. This report presents clinical findings recorded 20 and 40 h later.