Four species of helminths, two Trematoda and two Cestoda, were collected post-mortem from an otter (Lutra lutra) killed in the suburbs of Edinburgh.

Plagiorchis (Multiglandularis) lutrae n. sp. was recovered from the small intestine. This is the first record of Plagiorchis sp. from an otter.

Cryptocotyle lingua (Creplin, 1825), 38 specimens, was recovered from the anterior and middle thirds of the small intestine. This is the first record of C. lingua from an otter.

Dibothriocephalus medius n. sp., a single specimen, was recovered from the small intestine. This is the first record of Dibothriocephalus sp. from an otter.

Schistocephalus solidus (Muller, 1776), four specimens, was recovered from the small intestine. This is the second record of Schistocephalus sp. from an otter and the first record of its occurrence in this host in Britain.

Worm egg counts have shown that after the end of June infestations of pathogenic significance occur in a considerable percentage of Scottish hill lambs. On the West Coast, however, heavy infestations do not occur until August, when the egg counts in other areas are rising again after falling for a few weeks in July.

Identification of larvae from faeces cultures confirm that Ostertagia spp. are the first cause of high worm egg counts, followed in August by Trichostrongylus spp., then by H. contortus and C. ovina, and finally by B. trigonocephalum. Nematodirus spp. may be sufficiently numerous in a few districts to be of pathogenic importance in June and July.