Fly strike

Veterinarians know that with the arrival of the warmer months, comes the common problem of rabbits affected by flystrike being presented to them. This is a deeply distressing condition for owners, the veterinary team and especially the rabbit, which is literally being eaten alive. However, with some simple preventative measures, hopefully your bunny will never have to endure this condition, or if they are unlucky enough to be affected, you will be able to act quickly enough so they are one of the lucky ones who can be saved.

Certain species of flies (eg bluebottles), use other animals as a host to lay their eggs on, which hatch into maggots, and then proceed to eat into the flesh of the animal, causing immense suffering to the animal, which in essence is eaten alive.

Flies are attracted by soiled or wet fur, usually around the tail area of the rabbit, but any area can be affected, or any open wound, cut or scratch. Once laid, the eggs will hatch into maggots within 12-36 hours, burrowing into the rabbit’s flesh, causing vast tissue damage and pain, which can prove to be fatal even with prompt veterinary treatment.

The months of April to October are quoted as being the months when animals are more susceptible to flystrike, but it has been reported to have occurred in rabbits as early as January or as late as November, so owners need to be vigilant throughout the whole year, but extra vigilant during the flystrike season of April to October.

Any rabbit, even those kept as houserabbits who keep themselves beautifully clean, can be affected by flystrike; it only takes one area of soiled fur/skin or scratch, and one fly. However, not surprisingly those most at risk are rabbits who have frequent dirty bottoms, so ensuring that your rabbit is clean and dry is the best prevention against this awful condition. If your rabbit is often affected by a dirty bottom then, along with your veterinarian, you need to ascertain the cause of the problem in order to treat the underlying condition, whilst also being extra vigilant in spotting the first signs of flystrike.

Possible causes of dirty bottoms include:

• Dental disease making cleaning too painful.
• Spinal problems making cleaning difficult or painful or causing difficulty in adopting the correct position to eat the cecotrophs (normal soft droppings produced by rabbits which are eaten direct from the anus as they are produced).
• Balance problems unable to adopt the correct position to clean themselves.
• Obesity too fat to reach their bottoms to keep clean or retrieve the cecotrophs.
• Incorrect diet leading to too many cecotrophs being produced.
• Too much dried food filling up on this and so not hungry enough to eat the cecotrophs, which then get left and stuck to the tail area.
• Old age not able to keep themselves clean.
• Urinary tract diseases, causing incontinence or abnormally smelly urine.
• Disease of the uterus of female rabbits, because of the abnormal odour associated with discharges, and also because disease of the uterus is painful and can stop the rabbit grooming itself.

Longhaired rabbits are more susceptible to flystrike, because of the amount of fur they have, and feces are more likely to get caught up in the fur. Any bloodied area (cuts or wounds, etc) will also attract flies.

As far as flystrike goes, prevention really is better than cure and cannot be stressed enough, and even if your rabbit isn’t classed as being at high risk of developing flystrike, it is still imperative you still do as much as you can in preventing them from contracting it low risk, doesnt mean no risk.

Ways on trying to prevent flystrike include:

• If possible, treat any condition which places the rabbit in a high-risk category.
• Consider spaying does which are not used for breeding (there are many other benefits to this procedure too).
• Ensure that your rabbit isnt overweight and is fed a correct diet.
• Check the whole rabbit, paying special attention to the back end and tail area, at least twice a day, going through the fur to check for soiled/wet fur or maggots.
• If the rabbit has a dirty bottom, clean it for them immediately.
• High risk rabbits may be safer inside the house but must still have their bottom checked twice daily.
• Clean litter trays daily and remove all soiled bedding from hutches daily.
• Staple net curtains over the hutch/run to insect proof them.
• Consider using Rearguard (Elanco):
  • This is a liquid that is applied to the tail area of the rabbit using a sponge; if any eggs are laid on the area it will prevent them from hatching into damage-causing maggots.
  • Rearguard is available from your veterinarian.
  • Even if you are using Rearguard, you must still check your rabbits bottom area regularly.

You may not be able to see any actual maggots as they may be concealed under matted or soiled fur (especially in long-haired rabbits), so if your rabbit is displaying symptoms such as restlessness, irritation, ‘wetness’ or abnormal odour around a certain area (usually the tail area), lack of appetite, sudden aggression, etc, you should take them to your veterinarian immediately. If you suspect flystrike and your veterinary surgery is closed, then you must phone an emergency on-call veterinarian.

If you can see any obvious maggots remove them with tweezers as quickly as possible, but do not put the rabbit into water in an attempt to wash off some of the maggots. Clippers don’t work very well on wet fur and your veterinarian may be delayed in treating your rabbit if they have to dry the fur first. The longer a rabbit is left the more damage the maggots will cause, which may be impossible to treat, with the only option of putting the rabbit to sleep, to stop it suffering any longer, so time really is of the essence.

Cases of flystrike can be successfully treated if caught early, but this is dependent upon the amount of damage caused by the maggots and if your veterinarian feels that the rabbit has a reasonable chance of recovery.  It is also necessary to take account of any underlying diseases such as dental disease which may also affect the likely outcome.

If your veterinarian feels that the rabbit has a reasonable chance of recovery, treatment will usually consist of:

• Clipping the fur from the affected area to assess the damage.
• Washing and removing all visible maggots.
• Surgery to remove any concealed maggots, necrotic (dead/infected) tissue and repair tissue damage.
• Antibiotics to prevent a secondary infection or treat infection if one is already present, fluid therapy and other treatments to counteract the effects of toxins that may have entered your rabbit’s bloodstream, and painkillers to make your rabbit more comfortable.
• Identifying the cause as to why the rabbit was affected with flystrike and treatment to correct any underlying problem.

Rabbits will need to be anesthetized for surgery and often rabbits affected with flystrike are suffering to some degree with shock, and so will carry a higher anesthetic risk.

If the rabbit does survive, the wounds can take weeks to heal and during this time the rabbit will be at an increased risk of further bouts of flystrike and also infections, so careful nursing by the owner will be required and preventative treatment measures must be stepped-up.