Parasitic worms of the digestive tract
Esther van Praag, Ph.D.
Warning: this file contains pictures that may be distressing for some persons.
Dozens of different parasites can be found in the digestive tracts of rabbits, hares, and cottontails. Some are very rare, some are pathogenic only under exceptional circumstances; others have barely been studied. We will describe those most commonly found in house rabbits.
Wild rabbits as well as healthy house/pet rabbits living in clean conditions can be infested by gastrointestinal parasites. With domestic rabbits, the life cycle of the parasites is often disrupted when the appropriate conditions for development of the larval stages (L1, L2 and sometimes L3) are not met indoors.
Many parasites are heteroxenous (multihost): in order to reproduce, they must live in several host intermediates before infesting the final host. For instance, the different juvenile forms of the liver flake (Fasciola hepatica) are found in certain snails in the grass of marshy areas before entering the rabbit digestive tract. The little fluke larvae (Dicrocoelium lanceolatum) need to live in snails and ants before becoming infective in rabbits. Those worm parasites are rarely found in rabbits living indoors as their life cycle is broken due to the absence of intermediate hosts in the house environment. Other parasites are monoxenous (single-host). Their larval stages are generally found in wet grassland, stagnant water, or hay before being ingested by the unique and final host, the rabbit. Such worms are more commonly found in house rabbits.
In order to prevent worm invasion in a house rabbit, it is essential that:
· forage not be gathered in areas where there are numerous dogs, cats, rodents,
· fresh greens and vegetables be washed carefully with running water,
· hay and straw used as litter be changed regularly (this avoids attracting flies too),
· hay that cannot be changed daily be given on a feed rack, where it cannot be soiled with feces or urine,
· the litter boxes themselves be cleaned daily with hot running water, acetic acid, or chlorine.
Nematode parasitic worms
Nematode parasitic worms of the domestic rabbit
Clinical features and diagnosis
Thanks are due to thank Simone van der Meij, and her rabbit Jasper, for the pictures or worm-infested droppings, and to Arie van Praag, for the picture of Flora.
3. J.E. Harkness, J.E. Wagner (1995) The Biology and Medicine of Rabbits and Rodents, Williams and Wilkins. p. 372.
4. S. Boucher, L. Nouaille (2002) Maladies des Lapins. Editions France Agricole, p. 122-135