Ask the Vet
Rabbits - Preventing Flystrike
Question: I have just bought a Rabbit and friends have been warning me of the dangers of Flystrike especially during the summer months. Please could you tell me more about the condition and its prevention.
Answer: Anyone who has seen a flyblown rabbit has no wish to see another, and yet in summertime many vets see at least one or two every week. Flystrike occurs when flies lay their eggs on another animal, be it a sheep or a rabbit. The eggs hatch into maggots, which then eat away at the surrounding flesh. Certain species of fly (notably bluebottles) produce maggots capable of eating through intact skin. However, if the rabbit already has a break in the skin then any kind of maggot will be able to eat into the wound.
In warm conditions, the whole process from eggs being laid to maggots emerging can take just a few hours, so it is vitally important that rabbits are checked twice daily. In the worst cases, there may be severe tissue loss where maggots have literally eaten the rabbit alive: sometimes maggots eat down to the bone in the hind legs or even into the abdomen. Most cases of Flystrike are preventable, but occasionally even the best-kept bunny is afflicted. Prompt action is then vital to save the rabbit.
Flies aren't interested in clean, dry fur. They are attracted to damp or dirty fur, which is why mucky rabbit bottoms and flies can cause such terrible trouble. Most rabbits keep their bottoms very clean and dry, but it only takes one squashed faecal pellet to trigger problems! This is why even perfectly healthy rabbits need frequent bottom checks. Far and away the most common part of the body to be affected by Flystrike is the bottom, but it can occur on other parts of the body. There are even cases reported in healthy rabbits who have managed to soil the fur on their back or flanks.
The rabbits at greatest risk of Flystrike are those who can't attend to their personal hygiene, who produce loose droppings, or who have breaks in their skin. At particular risk are those suffering from
- Old, frail rabbits or those with poor balance
- Large dewlap or folds of loose skin or fat on abdomen
- Dental problems
- Long haired rabbits
- Previous fly strike
- Wounds or draining abscesses
If your rabbit falls into one of these high-risk groups, seek veterinary input as soon as possible. You need a strategy both for tackling the underlying problem (for example, pain killers for arthritic rabbits and weight loss for fat rabbits) and also to minimise the risk of Flystrike in the meantime.
The key to prevention is
- To recognise if your rabbit falls into a high risk category
- Don't allow your rabbit to get fat
- Be careful putting rabbits out on the lawn - scoffing unaccustomed grass may lead to loose droppings and soiled bottoms on high risk warm summer days! Any change of diet should take place over at least 1-2 weeks.
- High risk rabbits are safer indoors but daily bottom checks are still required
- Insect proof hutches and runs (e.g. by stapling net curtains over hutch fronts)
- Even house rabbits need to have their bottoms checked twice daily in warm weather
- If you find fly eggs on your rabbit, pick them off; check for concealed maggots; and step up your prevention programme.
- Since 2002, a prescription-only product has been licensed for use in rabbits to prevent Flystrike and is available from your local veterinary surgeon. This is a liquid preparation that is applied to the rabbit, lasting for up to 10 weeks. It prevents Flystrike by blocking the maturation of blow-fly eggs into the harmful maggot stage.
If you find maggots on your rabbit this is an emergency, day or night - seek immediate veterinary attention. Once at the vets, the severity of the situation can be assessed. Very bad cases (where large amounts of tissue has been eaten away) are best put to sleep immediately to prevent further suffering. Less severe cases may survive, but there are many problems to be overcome and intensive treatment will be required. Flyblown rabbits are usually very unwell and shocked. They are at high risk of severe infection and will be in pain. Add to this any underlying problem (as we've already said, most flystruck rabbits have underlying medical problems) and the situation can be complex and treatment extremely challenging.
Treatment consists of clipping away the fur, removing obvious maggots with tweezers and looking closely for concealed maggots that may have already eaten their way under the skin. The affected area may well require bathing in an appropriate solution. This whole process often requires a sedative or general anaesthetic, which carries a much higher risk than normal because flyblown rabbits are so sick. Most fly-struck rabbits need intravenous or subcutaneous fluids, antibiotics to treat infection, and anti-inflammatory drugs which double up as painkillers. If the rabbit survives, there may be a large area of skin loss, which will take weeks to heal. During this time the rabbit will remain at high risk of infections and further bouts of Flystrike. Careful nursing will be required as well as a full assessment of any underlying problems and an obsessive prevention strategy.