Lice infestation

Rabbits can host a variety of parasites on their fur and skin. These are termed as ectoparasites, since they live on the outside of the rabbit. Lice fall into this classification and can be a problem for pet rabbits.

Clinical signs of a lice infestation may include pruritus (intense scratching), bald patches within the fur or thinning of the fur.

With advanced infestations, the rabbit may appear very agitated, restless and may also lose weight and eat less because they spend so much time scratching. Anaemia may also be present, especially in very young rabbits, as lice feed by sucking the rabbit’s blood. This is especially noticeable in albino rabbits which will appear very pale. Severe anaemia can cause weakness and even death.

The rabbit louse is Haemodipsus ventricosus, and is a sucking louse, but is thought to be rare in pet rabbits. They are normally found along the back and on the sides of the rabbit as well as around the rump area. Adult lice are visible with the naked eye and can be seen moving. The eggs (nits) are oval in shape and are laid and firmly attach to the shafts of the hair, these can also be seen with the naked eye. The entire lifecycle from egg to louse takes 2-5 weeks where environmental conditions are at an optimum.

Ivermectin injections at 7-10 days apart for 3-4 treatments are normally effective. Treatment needs to last long enough to eradicate the eggs as they hatch.

Imidacloprid (Advantage®) is effective in dogs and could also be used in rabbits.

Do not use fipronil (Frontline®) in rabbits as it has been associated with toxicity.

There has been some discussion as to whether or not the rabbit louse can act as a vector for myxomatosis. In theory, if a louse from a myxomatosis infected rabbit found its way onto a domestic rabbit this is potentially possible, although in reality an extremely unlikely possibility.

However, it is recommended that all rabbits are vaccinated against myxomatosis, which now, with the new combined myxomatosis and viral haemorrhagic disease vaccine (Nobivac Myxo-RHD), only requires an annual booster.

This has not been documented, since the lice are species specific, but it is wise to get your rabbit treated as soon as you notice any symptoms, and to clean the environment after every treatment.