According to the "West Australian Rabbit Council Yearbook 1996" and reports still being received by Rabbit Information Service, some rabbits have sufferred reactions after being vaccinated against RHD. All vaccinatons in Australia to date (12th July 1997) must be given by a veterinarian because the only vaccine we are allowed is still only available under emergency permit and is only administerable by veterinarians who record the users details.

A West Australian rabbit club member's report of some vaccine reactions and the ensuing tests to determine the cause states " A few days following vaccination of our first group of rabbits, we noticed our REW Cashmere Lop doe seemed to have eaten away a patch of hair over her shoulders, about 5 centimetres in diameter, and the skin had become severely blistered, although she was not in direct sunlight. We applied first aid, thinking she had been burnt, but our concern grew in leaps and bounds, a few days later, when several of the vaccinated group (and no others) had similar lesions with varying degrees of severity."

The report goes on to state "The obvious conclusions were drawn, and,on being invited with several other members to a seminar on the diseaseand the vaccine, brought it to the attention of the vaccine company representatives. They shared our concern and requested biopsies and scrapings to rule out infection, incorrect injection methods and parasites. We selected four of the eight affected rabbits for a scrape and one biopsy."

"Results of the scrapings were clear. To our dismay the biopsy results showed a definite reaction, not to the oil-base as hoped, but to the vaccine itself. The results were as follows:

HISTOPATHOLOGY. Lesions of extensive areas of severe acute superficial dermal necrosis (breakdown of skin layers) and epidermal loss, interspersed with severe dermal oedema (fluid build up) and mixed inflammatory cells throughout dermis, especially around vessels. The epidermis - moderately hyperplastic (thickened) with focal areas of subcorneal pustuals, serocellular exudation (serum production) and ulceration. No evidence of bacterial infection, not typical reaction of a bacterial pyoderma."

"MORPHOLOGICAL DIAGNOSIS: Superficial and deep perivascular dermatitis with multifocally coalescing areas of dermal necrosis and ulceration. Subcutaneous region also involved.

COMMENTS: Most likely an idiosyncratic ( a hypersensitive drug reaction) reaction to a component of the vaccine. The absence of large numbers of oil-containing macrophages ( a type of cell that appears at wounded areas to combat foreign matter) raises doubt that the reaction is to the oil component of the vaccine."

"As fanciers, we are predominantly dealing with show stock, and the nature and high proportion of reactions is not pleasing (40% of our original group). The hair loss and scarring areas of a black rex did grow back coloured rather than white, which is a good sign for exhibitors."

"As far as is currently known, the onset of reaction can vary from within 24 hours to a few weeks. In severity, reactions can range from slight hair loss (5 cent piece diameter) with no scabrous inflamation, to multiple reactions around injection site, bare, red and inflamed skin, pitted,bruised, and with a thick crusty scab developing. This appears itchy at a later stage and still causes problems as rabbits then strip them away. One report was of a Dwarf with approximately one third of its total body area reacting."

"First aid consists of anti-inflamatory creams such as Neotopic-H or Prednoderm,[consult your vet] the former being my choice."

"Antibiotics may be required in severe reactions [see your vet]. Unfortunately there is no way to prevent or predict whether a rabbit will react or not. We have been advised not to revaccinate the REW cashmere lop doe who reacted so immediately and so badly, as her body's response to the vaccine and virus is so acute."

This report also states "Although we can do little to prevent such responses in our present vaccine strategy, we can all do our part to help further research into the reaction. As many detailed records and/or photographs of as many reactions as possible have been requested, in order to accurately quantify and clarify the types of reactions."

Some of the above investigation was undertaken at Murdoch University, Western Australia.

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