The seal louse, Echinophthirius horridus: an intermediate host of the seal heartworm, Dipetalonema spirocauda (Nematoda)

Heartworms, Dipetalonema spirocauda, are common in harbour seals, Phoca vitulina, that strand along the New England coast. Lice, Echinophthirius horridus, taken from a stranded harbour seal infected with seal heartworm carried three developmental stages of D. spirocauda. This is the first report of an intermediate host of the seal heartworm.