Abstract
Canine angiostrongylosis was diagnosed in a whippet with typical signs of respiratory and circulatory distress. Subclinical Angiostrongylus vasorum infections were also demonstrated in two other whippets belonging to the same owner. All three dogs were given standard anthelmintic levamisole treatment combined with corticosteroids. Two days after initiation of treatment, one of the subclinically infected dogs developed severe hypovolaemic shock that required intravenous fluid therapy and corticosteriods to save its life. The shock is believed to have been caused by an anaphylactic reaction triggered by the rapid release of a large amount of worm antigen in the blood due to the rapid death of adult worms by levamisole. Thus, dog owners should be instructed to monitor dogs undergoing levamisole treatment against A vasorum. Alternatives to levamisole treatment of canine angiostrongylosis should be considered.