Whenever it gets warm during the UK summer, we all need to be on the look out for myiasis in rabbits. May to September are the times they are most at risk, though in recent years the trend has been to see the season start earlier and end later. Flies are attracted to damp fur, urine and faeces where they lay eggs. These eggs then develop into larvae and maggots, which are attracted to skin and underlying tissues.
Posted: 26 June 2018
Green bottles (Lucilia sericata) are the most common cause of fly strike in the UK. Studies have shown that he incidence of fly strike is directly proportional to the numbers of green bottle flies, which are themselves influenced by patterns of higher temperature and rainfall.
Remember, this condition needs urgent attention, so don’t be tempted to leave it until the next day.
Potentially all animals are at risk from this condition, but we tend to find that it affects rabbits with one or more of the following problems.
Remove eggs, larvae and maggots - pick off as many of the external larvae as you can by washing in warm water. Remove the stubborn maggots using tweezers or forceps. Any maggots that have burrowed into the flesh can be encouraged to the surface of the skin by using a warm, damp towel.
Antibiotics and analgesia - the wounds will be extremely sore, and usually become infected. Failure to manage the pain will put the patient at risk from stress related complications such as gut stasis.
Investigate the cause - ultimately the underlying reason the animal has been affected needs to be found and treated to fully and effectively treat the condition. Often the cause is pain that prevents the animals from eating caecotrophs, grooming or moving about. We suggest X-rays to look for signs of arthritis or dental disease to try to identify and resolve the problem.
Don’t use Fipronil – it must be emphasised that you avoid the use of any preparations containing fipronil, as this is potentially lethal to rabbits.
Spot on or injectable treatments – these are used to kill the maggots (not all of them may be removed by washing and picking as they can burrow quite deep). Ivermectin or Imidacloprid are both effective.
Avoid hypothermia - try not to wet the rabbit’s coat excessively when removing the larvae, as you don’t want to cause hypothermia. Dry the area afterwards using clean soft dry towels.
Fluid therapy – this is essential if the rabbit is depressed or dehydrated. Give an initial bolus of 10ml – 15ml/ kg of crystalloids (Hartmann’s).
Myiasis is a distressing and potentially fatal condition. Whilst we can’t eliminate flies from the environment, you can encourage your clients to check their pet daily.
Rearguard contains Cyromazine, and is used for the prevention of blowfly strike (Lucilia sericata) in domestic rabbits for up to 10 weeks after dosing. Rabbits should be first treated in early summer before any flies are seen. Note: It won’t repel flies or kill adult maggots but works by preventing fly eggs from developing. Rabbits should be treated at 8-10 week intervals.