Flystrike in cats

Flystrike in cats is particularly relevant right now, in the middle of the summer 2022, when there is the possibility of a record high temperature of 40°C in the UK (today) and across Europe there are very high temperatures specifically in Portugal, Spain and southern France. There is also a drought in northern Italy. This, I believe, is global warming in action. And under these conditions a flystrike is more likely in the assessment of the RSPCA. They say that people should check their pets on a daily basis for a possible flystrike. So, what is it? You might know.

Two useful tags. Click either to see the articles: Toxic to cats | Dangers to cats

It is a seasonal disease which occurs in warm weather and is most often caused by the bluebottle or blowfly which lays eggs on pets (other flies are also responsible such as the botfly or blowflies). I’m going to focus on cats. They may lay the eggs in open wounds or badly soiled, matted fur. In my personal experience, they will also lay eggs on perhaps elderly, infirm cats with a chronic illness, who spend a lot of time outside snoozing and are therefore static for long periods. The key, in my view, is that if cats are still for hours on end when outside a fly might lay their eggs in their fur.

The eggs hatch in 8-72 hours. In 2-19 days, the larvae grow into large maggots. The maggots produce an enzyme in their saliva which digests skin. This causes “punched-out” areas in the skin. The maggots then penetrate the skin. They enlarge the opening and a bacterial infection can take hold. With a severe infestation a cat may go into shock. The shock is caused by enzymes and toxins secreted by the maggots.

If you think that your cat might be the subject of a flystrike the best way to deal with it is to check your cat regularly and simply free-comb out the eggs before they turn into maggots and injure your cat. They are quite visible because they are white.

The RSPCA say that it is a potentially fatal disease and very painful. In medical language it is called myiasis. Rabbits are particularly at risk in their hutches. Perhaps this is because they can overheat. Dr. Samantha Butler-Davies, Veterinary Clinical Services Manager at Vets4Pets said: “Simply put, the hot weather poses a genuine risk of death for rabbits”.

Treatment

If maggots have penetrated the skin the treatment is to clip the affected areas to remove soiled and matted hair and remove all the maggots with blunt-most tweezers. An unpleasant task to say the least. You then wash the infected areas with Betadine solution and dry the cat thoroughly. My book on veterinary medicine says that you should then “use a non-alcohol spray or shampoo that contains a pyrethrin insecticide”. Be cautious about using insecticides as they are nasty chemicals and poisonous. There have been many disasters during home treatments using these sorts of treatments.

They also say that almost all cats with maggots have other health problems which have left them exposed to these nasty invaders and therefore they should be seen by a veterinarian as soon as possible. There are referring to infected wounds which are open to a flystrike. Cats with infected wounds should be treated with an oral antibiotic.

I would like to add a postscript to the above. The Guardian newspaper has an article by Hannah Jane Parkinson. Her story is relevant to this article. She adopted a very shy part Maine Coon cat who she named Miles. Hannah, after much difficulty because Miles was so shy, became very friendly with him and he with her. They had a very close relationship which is the kind of thing that can happen with a timid cat. Once you overcome their timidity, they become great companions.

On one evening and subsequent night she stayed away from her home but she left some water and food. When she came home (I believe the next morning) there was no Miles. “He didn’t come bolting through the cat flap as was customary and, as darkness fell, I began to worry.”

Cat owners know when their cat is not going to come back. Of course, that anxiety can only relate to indoor/outdoor cats. It’s a hazard of that mode of cat ownership.

Eventually Hannah found Miles outside. He was unable to use his hind legs and was soaking wet. He wasn’t bleeding. Her neighbour drove her and miles to a 24-hour veterinarian whose verdict was horrific she says.

The vet said that Mars had become injured (my guess: road traffic) and had fallen victim to flystrike. Comment: there is no doubt in my mind that Miles was unable to move because of his injuries and in staying still for a very long time perhaps a day or two a botfly or other species of fly laid their eggs in his fur next to the skin. The larvae burrowed into him when they hatched. They killed him through internal damage.

Hannah writes that, “The internal damage he had suffered was brutal, and he could not be saved.”

He was euthanised and Hannah still blames herself. She remembers him fondly. The story confirms that flystrike can be very dangerous and fatal sometimes.

Below are some more pages on cat health problems.