Flystrike in Guinea Pigs

What is flystrike?

You might have heard of flystrike in guinea pigs but you may not realise how much of a threat this can pose to your pet. Flystrike not only affects guinea pigs but can also affect rabbits, sheep, horses as well as other animals and pets who may have an open wound or for some reason can’t clean themselves properly.

Flystrike (scientific name “myiasis”) is a painful and dangerous condition whereby flies lay eggs on your guinea pig (usually their bottom) or in their housing which hatch into maggots.

These maggots then begin to eat away at the flesh of your pet burying deeper and deeper and releasing deadly toxins which can lead to toxic shock and death if not treated immediately by a professional.

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Once this infestation has taken hold, your pet’s condition can deteriorate extremely rapidly, in fact, the fly eggs can hatch within hours in the hot summer months, so it is vital you take immediate action and call your vet who will treat it as an emergency.

If you have a fly problem indoors you can use a wall hung fly zapper or a portable racket zapper to help get rid of them. In the outdoors, a fly mesh can help protect your guinea pigs to some extent.

What causes flystrike?

Flies thrive on damp, smelly environments. Guinea pigs will attract flies if they have any of the following:

A dirty bottom
Fur that has become wet with urine
Sores and open wounds
A dirty hutch or cage

The hot summer months is when this condition is at its most prevalent. There are lots of flies around in this weather and the hotter it is, the faster the fly eggs will hatch into maggots.

However, summer is not the only season when it can occur so you should be vigilant throughout the year, even in the colder months.

This condition can occur even on a clean pet but if your guinea pig has problems cleaning themselves thoroughly for any reason (eg, they are overweight, have tooth or bladder problems), they are at a higher risk of getting this deadly condition as they will be more attractive to flies looking for somewhere to lay their eggs.

If your guinea pig is ill and suffering from diarrhoea or particularly smelly urine, this will make them a more likely target for flies.

The cleaner you keep your pet and their housing, the less risk they have of encountering this awful condition.

Symptoms of flystrike

Flystrike symptoms are not always noticeable until it is too late. This is why it is important to understand how to prevent this condition.

If you see flies in or around your guinea pig cage or hutch, check your guinea pig to see if they have any signs of flystrike.

Flies will usually lay their eggs around the guinea pig’s anus so you might see maggots in that area. However, they may also be visible on other parts of your guinea pig or in their hutch. Sometimes people mistake the maggots for worms so if it looks like you have worms in the cage, this may also be fly strike.

You might notice wounds on your guinea pig which is a sign that maggots have begun eating away at the flesh. Your pet may also not appear to be their usual selves.

American Crested Guinea Pig looking out of his wooden hideout — Mr Jaffas in his wooden hideout

If you notice signs of flystrike on your pet, please follow the instructions below.

What should I do if my guinea pig has flystrike?

If you think your guinea pig might have flystrike, you should call your vet straight away, explain your concerns and make an appointment as soon as possible. Any reputable vet will give you an emergency appointment if they know your guinea pig has flystrike.

Discovering flystrike in its early stages and getting the medical attention they need as quickly as possible can save their lives.

Don’t wait to see if they get better as it is vital they get immediate treatment to prevent their condition deteriorating. If they don’t get the professional treatment they need, your guinea pigs may not make it.

It is sometimes suggested that you should remove the maggots with tweezers but this can cause distress leading to toxic shock in your pet. The same goes for putting your pet in water to get rid of the maggots – it is NOT ADVISABLE for you to do either of these.

It is better to get them to your vet straight away and for them to receive treatment from a skilled professional.

You should take all guinea pigs who are with the one who is affected to the vet. There is a chance that if one has the condition, the others may also have it. Even if you don’t see any symptoms in your other guinea pigs, you should still get them checked over to make sure they are ok.

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What is the treatment for flystrike?

The vet may sedate your guinea pig and trim the fur around the affected area so they can more easily remove the maggots and eggs.

If this is possible, they may also give your guinea pig some medication to kill the maggots that have worked their way in to your guinea pigs flesh. Medications they may give you may include antibiotics to fight infections, fluid therapy, anti-inflammatories, anti-parasitic drugs and antiseptic creams.

Abyssinian guinea pig in a clean cage and Sheba Mini Yak guinea pig in the log house hideout — Sunny Pig and Sparkles (in the log house)

Will my guinea pig recover from flystrike?

Your guinea pig can recover from flystrike if it’s caught in the early stages and your vet will do all they can to treat this condition.

However, sometimes it is just spotted too late. If maggots have penetrated too far into your pet, your vet may recommend your guinea pig is euthanized (or put to sleep).

This is a last resort and something no vet would take lightly. However, this is an extremely nasty condition and if it is left too long, there may be no effective treatment that can help them and your guinea pig will sadly deteriorate and suffer a lot of pain.

The most humane thing to do in these circumstances is to release your pet from the pain.

This is why it is important to take preventative measures to stop your pet from getting flystrike.

How can I prevent flystrike?

There is no vaccination for flystrike so the most important prevention advice is to keep your guinea pigs and their hutch clean. However, it is also critical that you are watchful and follow all the steps below to protect your guinea pigs against flystrike.

Clean your guinea pig’s cage on a regular basis. Never let it get to the point where it smells bad and use a pet-friendly disinfectant to clean the housing. Soiled bedding should always be removed on a daily basis and a full cage clean should be carried out at least every week.
Make sure your guinea pig’s coat is kept clean. If you have a longer-haired pet you should groom him daily and you might need to trim his fur to prevent it getting dirty. You may also need to bathe him every few months . Never leave him dirty and smelly as he will be a fly magnet.
Check your pets twice a day. This will ensure that you notice anything early and can save your guinea pig’s life. Give a thorough check of their fur and especially around their bum area.
Keep your pet indoors. Although it is not just outdoor guinea pigs who get flystrike, it is less likely there will be so many flies indoors and you can keep a closer eye on them.Take a look at recommended guinea pig cages here…
Feed your pet a good daily diet. This will help prevent diarrhoea or other health problems that can encourage flies to their housing. Too much fruit or a generally bad diet can cause problems.
A guinea pig with arthritis, tooth problems, bladder problems or obesity can find it difficult to keep clean. If you find your guinea pig isn’t keeping himself as clean as usual, make an appointment with the vet for a check up to make sure he hasn’t got any health issues.
Ensure any wounds are looked at by a vet, kept clean and inspect them daily and heed your vet’s advice regarding care of any wounds until they have healed
Don’t leave food bowls with fresh fruit or vegetables in their cage as flies will be attracted to rotting vegetables and fruit. Once their mealtime is over and they’ve lost interest, remove the bowls and discard the remaining food.
If you have a fly problem, it is worth considering covering the housing with an insect mesh which will prevent flies getting into the cage or hutch.
If you see flies near the housing, you should ensure you check your guinea pigs more regularly, keep them clean and preferably bring them indoors if they are outside.
If you see eggs on your guinea pig’s fur, remove them and take them to the vet straight away for a check up. You may have caught them early but be sure it doesn’t get worse or they may not get better. Remember, these eggs will hatch within hours.

How to safely reduce the number of flies indoors

We have a fly zapper that attracts flies via UV light hung up near our back door which is where the flies tend to come in. It not only kills the large flies and blue bottles but also zaps fruit flies and mosquitoes. This really helps keep down the fly population in our home and gives added protection for our indoor guinea pigs.

UV Light Fly Zapper hung on the wall — UV Light Fly Zapper

I wouldn’t recommend having it in the same room as your guinea pigs because it does make a rather startling zapping sound when it gets a fly. But if you put it where the flies come into your home (by the front or back door for example) this should minimise the number of flies getting to your guinea pigs..

You could also try a similar product that is in the shape of a tennis racket and you can zap flies as you find them – it’s called “The Executioner”. Kids may find this quite entertaining!

The Executioner, a tennis racket styled fly zapper — Fly Zapper – The Executioner

How to keep flies away from guinea pigs & their cages

You can purchase sprays specifically designed to safeguard guinea pigs from flystrike. Among the available options, my personal favourite is Small Pet Select Pestavert. This organic solution guarantees 100% safety for both animals and humans alike. Enhanced with the delightful scents of lemongrass and cinnamon oils, it offers an absolutely divine fragrance.

If your guinea pigs are housed outdoors or if you have a fly problem indoors then it is better to be safe than sorry and to use a flystrike spray on your guinea pigs as a preventative measure. Always read the instructions carefully before applying.

An insect mesh will help keep flies out of the hutch or cage. The mesh isn’t expensive and offers good protection for your guinea pigs.

Do not use any type of household fly spray on or anywhere near your guinea pig. These are not designed for pets and are extremely dangerous!

Flystrike can kill your guinea pig

We hope this has helped you understand how horrific flystrike can be and how you can prevent this happening in your guinea pigs. In summary, keep them healthy and clean, keep the hutch clean, be vigilant and use fine netting to prevent flies getting in to their housing as an extra precaution.