How to Detect Flystrike in Rabbits (and how to prevent it)

One of the reasons that rabbits are such difficult pets to take care of is that they can develop some unusual health conditions that are actually quite serious. Flystrike is one of these conditions. It is a scary and deadly illness caused by a measly housefly.

Flystrike happens when a housefly lays eggs on a rabbit. As the eggs hatch, the maggots burrow into the rabbit’s skin and begin to eat them alive from the inside. It is a highly fatal condition that can result in death within a 24-48 hour period.

Because flystrike can become serious very quickly, if you ever notice signs of this condition (especially any visible maggots), it’s important to seek professional medical help immediately. If you need help finding a rabbit veterinarian, try using the House Rabbit Society’s list of vets.

What is flystrike?

Flystrike is when rabbits get infested with fly larvae. If a rabbit’s fur around their behind is damp or dirty with urine or poop, a fly might decide it’s a good place to lay eggs. About 48 hours later the eggs will hatch into maggots. These maggots will instinctively eat whatever is available to them, burrowing into the rabbit and eating their flesh.

How long can rabbits live with flystrike? It’s gross to think about, but flystrike can be a real danger to rabbits. Once the larvae hatch, they can kill a rabbit within a single day. You will need to take immediate action to get rid of the maggots and save your rabbit’s life. Flystrike is a highly fatal disease, but if you get your rabbit help quickly and get the maggots removed, they can still make a full recovery.

What types of flies cause flystrike in rabbits?

The type of fly that you want to look out for most is the blowfly (also known as the green bottle fly). These flies are a little bigger than the typical housefly and are highly attracted to wet fur, especially if there is urine or feces present. Flesh flies and screw-worm flies, found in tropical areas, are also a major danger to rabbits. 

The common housefly (Musca domestica) and other similar species are not quite as dangerous, but they can also cause flystrike. It’s best to take measures against any kind of fly infestation to avoid the possibility of flystrike as much as possible.

What do fly eggs look like?

The best way to catch a flystrike infection early is to find the eggs before they hatch. Fly eggs look like tiny, white grains of rice. You will typically find them clustered together near your rabbit’s bottom or just above their tail. However, it is possible to find these eggs on other areas of your rabbit, or in their litter box and bedding. Fly eggs are very difficult to see on white rabbits or rabbits with a white underbelly, but try to be diligent in your search for the small rice-like eggs.

If your rabbit has been outside, it’s a good idea to pick them up and check for any eggs when it’s time to come back in. This is especially important in warmer months when flies are more active. 

The symptoms of flystrike

The most obvious sign of flystrike is when you can see the maggots or eggs on your rabbit. Sometimes you can see a few of the larvae on the surface of your rabbit, but they will also burrow into the skin. If that’s the case, you might not see any maggots on your rabbit and you will have to rely on other indications.

• Lethargy or listlessness
• Seizures 
• Lack of appetite
• A bald spot near the tail 
• Abnormal odor
• Shock (Learn more about shock in rabbits)

If you notice any unusual behavior in your rabbit, especially if they are not eating or moving around much, it’s vital to get them to a veterinarian right away regardless of if you think they have flystrike or not. Rabbits tend to hide signs of sickness, so they won’t show abnormal behavior until they feel very sick and require medical attention.

• Read more: Subtle signs of sickness in rabbits that you should take seriously

How flystrike is treated

The only way to really treat flystrike is to remove all of the maggots from your rabbit. The vet will usually have to anesthetize the rabbit, trim the fur, and flush the wound to get all of the maggots out. Since the maggots can burrow deep into the rabbit’s skin, it may also require a surgical procedure for extreme cases. 

If the infestation is serious, the vet may also recommend euthanizing the rabbit because it can be a painful condition. The sooner you can get your rabbit to the vet, the better chance they will have of surviving.

Aftercare will include antibiotic treatment and any other medications that might be necessary (such as a gut mobilization medication). You will also need to be very diligent about keeping your rabbit and their environment clean since a sick rabbit recovering from surgery could attract more flies.

Can you treat flystrike at home?

I do not recommend trying to treat your rabbit at home. Some sources will recommend washing the rabbit’s bottom in water to flush out the maggots, but if you don’t know what you’re doing, you can make the situation worse instead of better. You can also make it more difficult for the vet to help later on if your rabbit has wet or matted fur.

How to prevent flystrike

Since flystrike is not easy to detect early, the best thing you can do to help your rabbit is by taking steps to prevent flystrike in the first place. No method is going to give your rabbit 100% protection, but by taking these steps you can significantly reduce the risk. The hope is that if you take these measures, you will never have to deal with a flystrike emergency.

• Keep pet rabbits indoors. Keeping rabbits indoors, especially those that are at-risk, is one of the best actions you can take for preventing flystrike. Since flies are not present in most homes, this tends to be one of the safest preventative measures.
• Use fly screens, fly traps and fly repellant plants. For rabbits who are kept outside, and even for indoor rabbits, you can use flyscreens, non-toxic fly traps, and plants that naturally repel flies to help keep them away from your rabbits. Some plants that are safe for rabbits and repel flies include basil and lavender.
• Clean your rabbit’s enclosure regularly. It’s best to get into the habit of cleaning out your rabbit’s litter box every day since this is the area that will attract flies the most. Other bedding should be cleaned out on a weekly or bi-weekly basis to keep your rabbit’s area from attracting flies.
• Give your rabbit a healthy diet. A healthy diet that is high in fiber (lots of timothy hay) will help to prevent soft or unformed poops and subsequently decrease the chance that poop will smear onto the rabbit’s fur. A healthy diet also helps to prevent obesity, which is another risk factor for flystrike. (learn more about how to give your rabbit a healthy diet)
• Give your rabbit a large enclosure. A large enclosure gives your rabbit more space to sprawl out away from their litter box or soiled bedding. It will also help your rabbit stay more active and healthy. I recommend using a pet playpen instead of a traditional rabbit cage. It’s usually cheaper and gives your rabbit more space (learn why a pet playpen is the best enclosure for indoor rabbits)
• Check your rabbit for signs of eggs. Whenever your rabbit comes back from playing outside, pick them up and check for the presence of any eggs. If your rabbit lives outside or has a more permanent outdoor play area, make it a habit of checking them once a day, or even twice a day in the summer.
• Keep a fly swatter at hand. If I ever even hear the sound of a fly in my home, I immediately grab a fly swatter and hunt them down. It’s best to have a no-fly policy so that you reduce the risk of flystrike even more.
• Help your rabbit stay clean and dry. If your rabbit is elderly or disabled, reduce the risk of flystrike by cleaning their bum to prevent urine stains or a poop buildup.
• Trim long fur. Long-haired rabbits, like lionheads and angoras, are more likely to get poop stuck or matted in their fur. You can help them out by trimming the ends of their fur, especially around their butt and belly.

Related Reading: How to effectively clean your rabbit’s habitat

Flystrike in the summer vs. winter

Flystrike is much more common in warm weather months because that’s when flies are more active. In the northern hemisphere, rabbits are most at-risk from around April to October, with the highest risk months being June through August. For every degree (ºC) warmer the weather gets, rabbits are 33% more likely to get flystrike. However, it’s still possible for a rabbit to get flystrike in winter if there happen to be flies present.

What rabbits are more at-risk for flystrike

Rabbits who are healthy and able to keep themselves clean are at a much lesser risk of developing flystrike. If a fly lays eggs on a healthy rabbit, they will usually be able to groom themselves and remove the eggs before they hatch. However, even healthy rabbits are at risk if the fly happens to lay the eggs in a hard-to-reach spot.

Risk factors for flystrike include:

• Outdoor rabbits. Outdoor rabbits are at risk simply because there are more flies outdoors than indoors. 
• Obese rabbits. Obese rabbits often have more difficulty keeping themselves clean. They may not be able to reach to clean off their bottom, leading to matted fur, urine stains, and feces clumping on the fur. This is more likely to attract flies.
• Elderly rabbits. Elderly rabbits also have a more difficult time keeping themselves clean. As they age, rabbits lose flexibility and might start to develop arthritis. A study in 2018 concluded that rabbits over 5 years old are 3.8 times more likely to get flystrike. 
• Disabled rabbits. Rabbits who are disabled may lack the mobility to keep themselves clean. If you aren’t diligent to help them maintain cleanliness every day, they have a higher risk of flystrike.
• Injured rabbits. Flies are also attracted to open wounds and the smell of blood. If your rabbit has any injuries, always be diligent to keep them clean and check for any fly eggs.
• Sick or stressed rabbits. Sick and anxious rabbits are less likely to take the time to groom themselves properly. While healthy rabbits can clean fly eggs off of themselves, sick and stressed rabbits often do not.
• Rabbits with wet fur. In addition to blood and feces, flies are also attracted to moist places. It’s best to make sure your rabbit’s fur stays dry.
• Intact female rabbits. Studies have shown that female rabbits who have not been spayed are 3.3 times more likely to get flystrike.
• Rabbits with dental problems. Dental problems can also prevent a rabbit from cleaning themselves properly. It’s always best to bring your rabbit in for an annual wellness exam so that their teeth can be checked.
• Rabbits kept in an unclean habitat. A dirty habitat is a major risk factor for flystrike. A buildup of urine, poop, fur, hay, and food can easily attract flies, even in an indoor environment. Get into the habit of cleaning your rabbit’s enclosure regularly.

Related Reading: Why it’s safest to keep rabbits as indoor pets

Can indoor rabbits get flystrike?

Even though indoor rabbits are much less likely to be affected than outdoor bunnies, you always want to be careful. As someone with indoor rabbits, flystrike isn’t something that I spend a lot of time worrying about, but if I find even one fly in the house, I’m on the alert checking for signs of flystrike in my rabbits.

Over the summer of last year, I had a minor infestation of the common house flies inside of my rabbit’s room. Fortunately, I knew the risk that flies could bring to my rabbits and took immediate action to get rid of the flies before they could do any damage. It only takes one fly getting inside and laying eggs in the wrong place for your rabbit to get flystrike. 

Is it okay to use topical fly-repellant medications or sprays?

Some people have heard of F10 Germicidal Wound Spray with Insecticide and Rearguard (available in the UK) as topical medications that act as fly repellents for rabbits. However, some rabbits are known to have adverse reactions to these sprays, so I recommend talking to your rabbit veterinarian before using either of these products. 

Sources:

1. Axelson, Rick DVM. “Rabbits – Fly Strike.” VCA Hospitals. https://vcahospitals.com/know-your-pet/rabbits—fly-strike
2. “Flystrike in Rabbits.” Rabbit Welfare Association. https://rabbitwelfare.co.uk/rabbit-health/illness/flystrike/
3. Harriman, Marinell. “Fly Strike.” House Rabbit Society. https://rabbit.org/health/fly-strike/
4. Rachel Turner, Elena Arsevska, Beth Brant, David A. Singleton, Jenny Newman, PJ-M Noble, Philip H. Jones, Alan D. Radford. “Risk factors for cutaneous myiasis (blowfly strike) in pet rabbits in Great Britain based on text-mining veterinary electronic health records.” Preventative Veterinary Medicine. Science Direct. May 2018. Accessed: https://www.sciencedirect.com/science/article/pii/S0167587717307729
5. “What’s flystrike in rabbits? Symptoms, treatment & prevention.” VetsNow. November 2020. https://www.vets-now.com/pet-care-advice/flystrike-in-rabbits/