What does a Cat Flea Look Like
Cat Fleas, Ctenocephalides felis, are wingless flattened insects. Adult cat fleas can range in colour from quite light reddish brown to quite dark almost black. It is likely fleas adapt to the colour of their hosts.
Cat fleas are great athletes with huge back legs well suited to jumping. Leaps of over a meter have been reported but most fleas leaps will not exceed the height of a cat, under a foot.
These athletic back legs are also used to quickly propel the flea in the fur of the cat or dog.
The photo shows a flea seen straight down. It's body is very narrow.
Because fleas are flattened and their body slippery, they easily move between hairs, or clothing, helped by their backwards pointing bristles on the feet and body.
The body is not solid but rather a series of scales. This allows the flea a great deal of motion. So a combination of big strong legs, lots of backwards facing hairs and scales, and quite a lot of wiggle in it's body makes the flea a fast mover. Anyone chasing a flea in a cat knows how agile and quick they can be. This also allows the flea to move quickly in carpets or bedding.
Although cat fleas are quite small. 1-3 millimeters, they can easily be seen. The best place to look for them is at the base of the cat's tail, between the legs on the belly and in spots that are hard for the cat to reach. They are hard to catch.
The adult cat flea is only one of the forms a flea can take. If you have adult fleas you most certainly have flea eggs, flea larvae, flea dirt, and flea pupa. These other forms are difficult to see and usually hidden in the bedding or carpets.
The cat flea is not restricted to cats but is the most common flea that bites dogs in North America. Raccoons, mice and rats, skunks, coyotes, opossums can all be bitten by cat fleas.
The Dog Flea, Ctenocephalides canis, is less common but is almost indistinguishable by eye from the cat flea. It can be found on cats as well as on dogs and other animals. Since treatment is similar for both kinds of fleas exact identification is not relevant. Treatment of dogs or cats differ because cats are much more likely to get easily poisoned than dogs are. Never use dog flea medicine on cats.
Flea combs are not very useful in ridding cats and dogs from fleas because you simply can't catch enough to make a difference, but they can be very useful when checking if the cat or dog has fleas. Flea combs can also be very useful if you are bathing your pet and the fleas are congregating on the head. You can then use the comb to remove the fleas.
I took these flea photos using a microscope and a small camera. It represents 3 different fleas I caught on my cats. One of the fleas I caught I put in the freezer hoping to kill it. When I took it out a week later it started to wake up, as it thawed, much to my surprise. They are tough! The video is of this flea as it starts to warm up. Eventually it got too fast to photograph as it started jumping. The video show the live flea slowly waking up.
What does a Cat Flea Egg Look Like?
After a blood meal female fleas will lay eggs. Cat flea eggs look like translucent oval dots. The flea eggs are about .5 mm long.
Knowing what a cat flea egg looks like does not mean you are likely to see them. Because they quickly dry after being laid on the cat, they become slippery and harder and fall out of the cat's fur. The best place to look for flea eggs is in the cat's bed and in places the cat likes to sleep. If your cat has a large infestation then looking with a magnifier at the base of the tail, or on the belly might be useful. If there are enough fleas on the cat to see eggs, you will see fleas or flea dirt much more easily.
If there is flea dirt on the cat or in the cat's bed then it's likely there are eggs mixed in. The flea dirt will be dark, the eggs will have a whitish appearance.
Cat flea eggs quickly hatch into a flea Larva after 2 days to 2 weeks, depending on conditions. A warm humid environment is the best for fleas. What do cat flea larva look like?
What do Cat Flea Larva Look Like?
Cat Flea Larva are translucent wormlike creatures about 3 mm long, with small bristles.
The larva will have dark stuff inside. Although photographs of flea larva makes then look like they are reddish when they are back lit, they usually look transparent with blackish stuff inside. The Larvae are active and don't like light. They will move away quite fast and burrow into the bedding.
The cat flea larva eat cat dirt (adult flea poo) and other organic matter. Since this is essentially cat blood it is reddish and if you can shine a bright light behind the larva its appearance will be reddish.
Not all eggs fall off the cat and larva can be found on the animal. If your cat has a large enough infestation, and will sit still while you check him out with a magnifier, you might see some of the larva.
After about 2 weeks, the larva transforms itself again and spins a cocoon and pupates. What does a cat flea pupa look like you ask?
What does a cat flea pupa look like?
Flea pupa are more difficult to see or rather more difficult to recognize than other stages of the flea life cycle. The flea cocoon is sticky and dust and dirt will stick to it. It is about 3-4 mm across. The pupating flea looks just like a piece of dust. If you can see eggs or flea larvae then most likely you can also see flea pupae. You just don't know that's what you are seeing because its appearance is just like the debris around it.
University of Florida has photo of Cat flea Pupae in their article on flea life cycle.
Although you will not see pupae easily you will see flea dirt. What does flea dirt look like?
What does flea dirt look like?
Flea dirt makes a rich food source for flea larva. It can be found on the animal or in the bedding. It looks like little black dots. Sometimes the flea dirt will be elongated and curved.
An easy way of figuring out if it is flea dirt is to place the animal on a white surface such as paper or a white cloth, and ruffle the fur. If there is dirt it will fall on the white surface. If you wet these specs using a damp paper towel, and the speck turns reddish brown then it's flea dirt, it will go reddish brown because of the blood content. If you wash a dog or a cat that has a lot of fleas, the water will turn red-brown from the flea dirt.
Finding flea dirt is probably the easiest way of being sure your cat has fleas.
If your cat goes outside or is exposed to animals that do and you are not treating them, there are almost certainly fleas around.
Freezing does not kill fleas. I once put a flea I found on one of my cats, late at night, in the freezer. I wanted to photograph it and I did not want it to dry out. I absolutely expected the flea to freeze and die a relatively painless death. When I put it under the microscope it gradually started moving and eventually was able to jump. Sadly for the flea, it got squished.
This shows how important it is to continue treating cats and dogs even after a few frosts.
What if I can't find any fleas?
If your cat is scratching, or biting himself suddenly then it likely has fleas. If there are not many you can easily miss seeing fleas or flea dirt. The scratching will however alert you to the presence of fleas. Another sign is flea allergy. It is quite often the only sign that people see. A bumpy irritation, often on the lower back in front of the tail is seen. This can get infected and crusty. It might even smell bad. Cats and dogs allergic to flea saliva, don't need a lot of flea bites to react. Just a few bites will trigger the reaction. Here is my page on allergies in cats
If your cat goes outside he most certainly has been exposed to fleas. If you have a dog that goes outside then he will share his fleas with cats in the household.
If you suspect fleas, you can try a flea trap. These attract fleas using a warm light. The fleas get stuck on sticky paper and you can see if you have fleas by checking the trap. Traps are useful to show you WHERE there are fleas but they don't catch enough to control them.
The photos come mostly from Wikipedia, the flea dirt is Dr.Zak's picture from Wikipedia.
This article is provided for information only. It is not to be used instead of consulting a VET. If your kitty is sick get some help.