Ancylostoma tubaeforme

The nematode Ancylostoma tubaeforme is a hookworm of cats that occurs around the world.  Infection with A. tubaeforme is rare in cats in Canada.   The pre-adult and adult parasites in the small intestine can suck blood, but many cats infected with A. tubaeforme will rarely, if ever, show clinical signs.  Heavy infections or infections in animals that are otherwise stressed, however, can cause loss of condition and anaemia.

Phylum: Nematoda
Class: Secernentea
Order: Strongylida
Superfamily: Ancylostomatoidea                                                                                                        Family: Ancylostomatidae

Ancylostoma tubaeforme is one of the hookworms of cats. It is related to the hookworm of dogs and cats (A. ceylanicum), and also to the hookworms of dogs (Ancylostoma caninum, and A. braziliense), and of people (A. duodenale and Necator americanus). The adult parasites and the eggs of these various hookworm species are morphologically similar, and the life cycles and pathology share many features. Some species of hookworm are able to infect several species of host, including people.

Adult A. tubaeforme are basically similar in structure to A. caninum in dogs, with three pairs of pointed teeth arising from the dorsal margin of the buccal capsule. The eggs of the two species are also similar but those of A. tubaeforme are slightly longer - up to approximately 75 μm.

Ancylostoma tubaeforme occurs in cats, primarily in warmer areas of the world. It is very rarely diagnosed in Canada, where most cases are in animals imported from endemic areas. In a recent national study, it was detected in shelter cats in Ontario and Quebec, but not western Canada (overall prevalence 2%) (Villeneuve et al., 2015).

The life cycle of A. tubaeforme is direct. Cats may become infected through ingestion or skin penetration of third stage larvae in the environment (subsequently following mucosal or semi-tracheal migration routes, respectively), or ingestion of third stage larvae in paratenic hosts (subsequently following a mucosal migration).  The relative importance of these transmission routes is not known.  The pre-patent period is 2-4 weeks.  There is no evidence of prenatal or transmammary transmission.
essentially similar to A. caninum in dogs. There is no evidence of prenatal or transmammary transmission.

Ancylostoma tubaeforme does best in warm, moist environmental conditions that support the development and survival of the infective larvae. Sub-optimal hygiene also favours the parasite by exposing susceptible cats to these larvae. For animals in shelters or breeding facilities, where host density enhances opportunities for transmission, effective treatments are a key element of all control programs.

These are essentially similar to A. caninum in dogs, including anaemia. Many cats infected with A. tubaeforme do not develop severe clinical disease.

Diagnosis is as for A. caninum on dogs, using fecal flotation to recover eggs. History and clinical signs may also be helpful. The strongyle-type eggs of A. tubaeforme are readily distinguishable from those of other nematodes of cats in Canada.

Ancylostoma tubaeforme is rare in cats in Canada, and therefore treatment is rarely indicated.  Several products are, however, approved in Canada for this parasite. Resistance is not yet documented for hookworm in cats, in contrast with dogs.

Control of A. tubaeforme depends upon dealing with the sources of infection. This means treating any “carrier” animals, especially the mothers of young kittens, and aggressively treating the kittens if they show any evidence of hookworm disease. The free-living stages of A. tubaeforme (eggs and larvae) are susceptible to thorough cleaning with a disinfectant. Limiting the animals’ access to areas potentially contaminated with infective larvae and to parantetic hosts is also helpful.

Ancylostoma tubaeforme is not considered a significant zoonosis. In theory it would be possible for infective larvae of A. tubaeforme to invade human skin, but the burying of feces by cats and the use of litter boxes probably minimize this risk.

Epe C (2009) Intestinal nematodes: biology and control. Veterinary Clinics of North America Small Animal Practice 39: 1091-1107.