Northdale Veterinary Practice
1 - How do pet rabbits get myxi?
The most likely source of infection for pet rabbits is via biting insects and other arthropods, mainly fleas, but also flying biting insects such as mosquitoes, transmitting the virus via their mouthparts, from local wild or domestic infected rabbits. Also possible, if wild rabbits have access to the garden, or can get close, eg through a mesh fence or run, is direct infection from rabbit to rabbit via respiratory tract secretions. Of course, once one rabbit in a group is infected, this route is also a worry with regard to the infection of the other rabbits (see later)
2 - What is the incubation period? (How long from one going down with it to keep fingers crossed until the rest are clear?)
The incubation is variable, depending on the route of infection and thus the site of disease. Skin lesions (from biting insects) may be seen from as early as 4 days, becoming very definitely noticeable by 10-14 days. One can expect by that point, that the eyelids will be noticeably swollen, and if biting insects are the route of infection, one is probably out of danger of infection at that point, as long as no infection been introduced after the suspected date of the initial case.
Lung infection can be seen in group housed rabbits, where aerosol spread into the environment, leading to inhalation, and subsequent pneumonia, may not be noted until up to 20 days after infection. This is much less common than the typical skin, face and eyelid swellings that are so familiar.
3 - If one rabbit in a pair or group gets it, will the rest?
Not necessarily, especially if they are rapidly separated, or steps are taken to reduce insect spread. Individual immunity obviously varies, otherwise all wild rabbits would have succumbed to it and died by now. Previous infection or vaccination will help afford immunity, but immunity is not long-lived, and not absolute. Different rabbits will have different health statuses, and be more or less susceptible. However, given the highly infectious nature of the disease, and the generally poor level of immunity present, the likelihood of infection of all in contacts is highly likely.
4 - Should infected rabbits be pts?
This depends on the virulence of the strain, the form of the disease, and the immunity of the rabbit. If the lesions are dry and nodular, and quite discrete, this cutaneous myxomatosis carries a good prognosis, and I would definitely not put such rabbits to sleep. If there is generalised disease, with swelling of the head, including ears and eyelids, and genitals, with or without lung involvement, then the outlook is far worse. If these rabbits have been vaccinated, they have a better chance of survival. Treatment with antibiotics (for secondary pasteurellosis and other bacteria), anti-inflammatories, nebulisation and drugs to improve respiratory function (to help breathing), nutrition, fluid therapy, and raised environmental temperatures (to 85 F / 29.5C), may effect a cure in a small number of cases, but this has to be weighed against the distressing and uncomfortable nature of the disease, and the welfare problems if a decision is made to treat. It is a horrible way to die, and extremely unpleasant for anyone watching it.