What Do Cat Fleas Look Like?
Cat fleas (Ctenocephalides felis) are extremely common parasitic insects who feed on the blood of domestic cats. Interestingly, over 90 percent of the fleas we find on dogs are also cat fleas!
As many as 1 in 4 cats are carrying fleas. With this fact in mind, you’ll definitely want to know how to identify cat fleas. But what do cat fleas look like? And how can you tell if your cat has them? Luckily, we have your back.
Cat Flea Anatomy
Adult cat fleas are very small, and it’s not particularly easy to get a good look at their anatomy because of their size and tendency to jump around. So, what do cat fleas look like if we’re looking at them through a microscope?
Cat fleas are wingless insects with three pairs of legs attached to their thorax, which is the part of the body behind the head. Their third pair of legs is larger than the other two pairs and allows them to jump. Cat fleas have a large abdomen, which is the back segment of their body.
Often described as “laterally flattened,” cat fleas look like their sides have been squished towards each other. They’re covered with hard plates known as sclerites. Their flattened bodies and the presence of sclerites make them very hard to squash. These sclerites have tiny hairs or spines on them which are directed backwards, allowing them to move easily through the cat’s fur.
Another unique feature of Ctenocephalides fleas is that they have both a pronotal and genal comb. These “combs” are a series of spines, and their location around the mouth and head of a flea can be used to differentiate flea species. A genal comb is one that is located above the mouthparts while the pronotal comb is located near the start of the thorax.
Cat fleas have two small eyespots, one on each side of the head. While these eyes don’t form normal visual images, they are sensitive to light, producing visual cues that the flea can use to navigate its environment. Their mouthparts, which they use to collect a blood meal from their host, are found at the bottom of their head.
What Do Cat Fleas Look Like to the Human Eye?
Adult cat fleas are very small, with females being around 2.5 mm in length and males being around 1 mm in length. Some people describe fleas on cats as looking like black specks or coffee grounds. Cat fleas are around the size of the tip of a ballpoint pen or smaller.
The easiest way to see adult fleas is to use a quick-acting insecticide to kill the fleas and then a flea comb to collect fleas. However, keep in mind that cats are fastidious groomers! This means that it can be very hard to actually catch a flea on your cat before they’ve groomed it off of themselves.
You’re more likely to see these small, dark, oval-shaped insects if you part the fur and look at the skin. Cat fleas can be fast little bugs, so you may see them weaving in and out of your pet’s fur as they move around. Cat fleas can also jump long distances, so you may see them catapult off your pet’s body. In this way, they sometimes seem to “disappear” when you see them.
Although fleas often feast around a cat’s flanks and rump, you may have an easier time finding them up around the neck of your cat. This is because your cat is much more likely to successfully groom off the cat fleas on the back half of their body. Given the medium to dark brown color of fleas, they are easier to find on cats with light fur.
What Do Flea Eggs Look Like to the Human Eye?
Adult female fleas shed eggs within two days of meeting male fleas on your cat. Impressively, one female flea can create 25-50 eggs in one day. These glistening, white flea eggs are only around 0.5 mm in length, making them very easy to miss.
While it’s possible to find these eggs on your cat, most of the eggs fall off into the environment. If you’re going to find them on the cat, it will more likely be up around their head and neck where they may have a harder time grooming the flea eggs off. You may see these eggs in the cat’s bedding, and they’d be nearly impossible to see on a carpet.
What About Cat Flea Larvae?
After around 3-4 days, these eggs hatch into larvae. Cat flea larvae are a bit larger than adult fleas, measuring up to 5 mm in length. The larvae appear like tiny white worms or maggots with small white hairs on their body. You may occasionally find larvae on your cat, but most of the larvae will develop in the environment. The cat flea larvae will feed on organic debris in the environment, including the droppings of adult fleas.
What Do Flea Pupae Look Like?
After around two weeks, the larvae will develop into pupae, which finish their development in silk cocoons. These 5 mm cocoons are sticky and thus become covered with environmental debris, making them very hard to see. The pupal stage can be brief (around 8 days) but can last up to 30 weeks depending on environmental conditions. Adult fleas will hatch from the pupae. The adult fleas jump onto your cat and feed on blood, allowing them to continue their life cycle.
Other Signs Your Cat May Have Fleas
Because it’s so difficult to spot a flea on your cat, sometimes you must rely on other signs to help you determine that your cat has fleas.
One thing you might find is flea dirt, which is a nice way of saying flea poop. Flea dirt can look like black pepper flakes in your pet’s fur and is often noted on the skin along the base of their furs. You can find flea dirt anywhere on your cat but may have more luck locating it up along the neck where cats have more difficulty grooming.
If you were to take some of this flea dirt and place it on a damp paper towel, you would see a reddish ring around the flea dirt. This is because flea dirt is digested blood.
Other signs that could signify that your cat has fleas include:
- Itchy skin (pruritus), which makes your cat scratch at themselves and groom more than usual
- Redness or pink tinge to skin due to inflammation (erythema)
- Single, raised red or pink spots on the skin from flea bites on cat
- Symmetrical hair loss, usually affecting the sides, rump, tail-base, and thighs
- Vomiting hairballs from overgrooming
- Scratch marks from itching
- Tapeworms (your cat can get tapeworms from swallowing fleas)
Cats who are allergic to flea saliva can develop flea allergy dermatitis, which causes moderate to severe skin inflammation and crusts or small bumps (papules), often around the neck and lower back. These cats will be excessively itchy and uncomfortable and are more likely to develop a secondary skin infection.
Flea Prevention for Cats
Cat fleas have worldwide distribution. Anywhere there are fleas, your cat is at risk for developing an infestation. Luckily, many monthly preventative medications are available to protect your cats from fleas, most of which are spot-on treatments. Other options include chewable tablets, flea collars, and flea sprays.
Some flea and tick preventatives are available over-the-counter while some require a prescription from your veterinarian. Do not use products that contain permethrin, as this can cause vomiting, diarrhea, tremors, seizures, and death in cats. Any product you use must be labeled as safe for cats.
Examples of ingredients which are safe for most cats and can help kill and prevent fleas include fipronil, fluralaner, imidacloprid, selamectin, and more.
To prevent your cat from getting fleas, make sure you are also using prevention on the other pets in the home, too. Fleas can move between dogs and cats. Remember that most fleas on dogs are actually cat fleas. Keeping your cat indoors can also prevent a flea infestation.
