Ancylostoma caninum

Description

Ancylostoma caninum is found rarely in the UK but it is a major pathogen of dogs in many warmer and tropical regions of the world and it may be encountered in dogs that have travelled under the Pet Travel Scheme. A. caninum may be recognised on examination under a microscope by its large buccal cavity which contain three pairs of teeth along its anterior and ventral edges. Two smaller teeth are also present at the base of the cavity. The life-cycle of A. caninum is detailed elsewhere but it should be noted that L3 larvae of this species mainly enter by the transcutaneous route so that intestinal disease and blood loss are mainly seen in younger animals.

Pathogenesis

A. caninum may cause disease in the following ways:

• The adult A. caninum is an avid blood-sucker, removing up to 0.1 ml of blood from the small intestinal wall every day. Heavy infections may occur when puppies ingest large numbers of L3 larvae from the milk of an infected dam or if they are exposed to a heavily contaminated environment and affected animals may show severe clinical signs, including:
  • Severe acute anaemia which may occur in the prepatent period (before eggs are present in the faeces).
  • Chronic anaemia that results in depletion of iron reserves.
• All hookworms may cause dermatitis, particularly in older animals which have developed some local cutaneous immunity and are able to kill invading larvae in the skin.