All About Fleas Pesky and Gross, Fleas Can Mean Big Trouble for Pets

All About Fleas
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vet verified PetCareRx Staff Veterinarian DVM

Fleas can mean more than itching, flea bites can cause sores on the skin and can transmit diseases.

As pests go, fleas are a fairly large nuisance: the insect bites cause discomfort and irritation, and fleas are a challenge to remove from your home, cat, or dog. And, like most biting insects, fleas can be a vector of diseases, passing along problems from one host to the next. While fleas cannot fly, they are capable of jumping up to two feet in height -- which is all the more remarkable given the tiny size of their bodies. Fleas also reproduce at an alarming clip and are capable of laying as many as 600 eggs within a lifetime. That is why preventatives like Vectra 3D are so important. Learn all about fleas and some effective methods of flea prevention for dogs and cats here.

What Are Fleas?

Fleas are parasitic insects that are known for ingesting the blood of pets and to a lesser extent, humans. Bites feel extremely itchy, and for some cats and dogs, this itchiness moves beyond irritation to a serious allergy-like reaction from the salvia in the flea bite, which can cause an allergic response. And, since fleas can bite multiple hosts, they can easily pass along diseases from one animal to the next.

As well as contracting diseases, pets can become anemic due to fleas ingesting a lot of blood during feedings. Due to the volume of their offspring, once a flea is inside your home or on your pet, it’s very difficult to eradicate its presence. Most commonly, you or your pet will get cat fleas -- or Ctenocephalides felis. There are also dog fleas (Ctenocephalides canis), and people fleas (Pulex irritans), but these are less common.

How Do You or Your Pet Get Fleas?

Dogs and cats get fleas predominantly from going outside, but keep in mind that fleas can also hitch a ride inside on your pant legs or shoes. So it’s possible that you could have brought them into your home from a hotel or from a walk-in outside area with fleas. Because they can be so easy to catch -- especially for outside pets -- flea prevention options like medication or flea collars are the best strategy for any pet owner.

Eliminating Fleas

Once you have fleas -- whether they are biting you, living in your yard, or biting your pet -- you’re going to want to get rid of them. Because of the flea’s life cycle, starting as an egg and progressing to larvae through to adulthood, it’s particularly challenging to remove them, and you’ll need to have a few different methods of attack. One medication may kill the flea eggs, but yet another one may be needed to kill the larval or adult fleas. Medications are available through a prescription from the vet or as well through over-the-counter options. If the fleas are present in your home, you’ll need to clean all fabric-based items, like carpets, curtains, and furniture, and you may also need to apply pesticides in the form of foggers or powders.

The important thing to remember with fleas is that it’s far easier to prevent your cat or dog from getting fleas than it is to remove the fleas once your pet and home have them.

What is Flea Dirt?

Flea dirt is another way to tell if your pet has fleas. If you start noticing small black clumps all over their fur, it could mean that your beloved cat or dog is dealing with a flea infestation. When you notice this unsavory phenomenon, it means it's time to start upping your flea and tick prevention game with meds like Comfortis or Advantage for cats. Here’s everything you need to know about flea dirt and what it means for your pet. 

Flea Dirt Explained

Simply put, flea dirt is flea feces, which appears on your pet in small, dark clumps. It is mostly made up of the blood the flea has sucked out of your pet, and it is a clear sign that your pet has fleas!

Here’s a flea fact for you: Most flea dirt comes from female fleas, who, over their lifetime, will digest close to 15 times the body weight of your pet’s blood if you don’t use some sort of treatment.

Where to Find Flea Dirt

Flea dirt is usually easiest to see on the stomach of your pet. This is where their fur is the lightest color and the least thick. Flea dirt can also be found on your pet’s bedding so make sure to check there.

If you have doubts about whether or not what you’re seeing is flea dirt or just normal dirt, there’s an easy test. Grab one of the small black clumps with a wet paper towel. If that black clump really is flea dirt, it will turn a reddish color once it gets wet. 

How to Get Rid of Flea Dirt

In the short term, you can wash and shampoo your dog to clean off the flea dirt. However, the flea dirt will just return as long as your dog has fleas.

The only way to get rid of flea dirt completely is to get rid of all fleas in your home, yard, and on your pet. There are many treatment options available, ranging from spot-on solutions, like PetArmorAdvantage II for Dogs, or Frontline for cats, to oral pills, like Capstar Flea Killer. Use one to keep your dog flea-dirt-free!

Frequently Asked Questions

What kills fleas on pets?

There are several methods to kill fleas on pets. Topical flea treatments are typically applied to the back of the pet's neck or between the shoulder blades and contain insecticides that kill fleas on contact. Examples include Frontline, Advantage, and Revolution. Flea collars contain insecticides that are slowly released over time and can kill fleas for several months. Examples include Seresto and Adams Plus. Flea shampoos contain insecticides that kill fleas on contact and can be used in conjunction with other flea treatments. Examples include Adams Flea and Tick Cleansing Shampoo and Vet's Best Flea and Tick Shampoo. Flea sprays contain insecticides that kill fleas on contact and can be used on pets and in the environment. Examples include Adams Plus Flea and Tick Spray and Vet's Best Flea and Tick Home Spray. There are also oral medications that can kill fleas on pets. These medications work by either killing adult fleas or preventing the development of flea eggs and larvae. Capstar is a tablet that kills adult fleas on dogs and cats within 30 minutes of administration. It is often used in conjunction with other flea treatments. Comfortis is a chewable tablet that kills adult fleas on dogs and cats for up to a month. It is also available in a topical form called Credelio. Nexgard is a chewable tablet that kills adult fleas and ticks on dogs for up to a month. Bravecto is a chewable tablet that kills fleas and ticks on dogs for up to 12 weeks.

What happens if your pet has fleas?

If your pet has fleas, it can cause a number of health problems and discomfort for your pet. Fleas can cause intense itching and scratching, which can lead to skin irritation, inflammation, and even secondary infections. A severe flea infestation can cause anemia (low red blood cell count) in your pet, especially in puppies, kittens, and older or weaker animals. This is because fleas feed on your pet's blood and can cause a significant loss of blood over time. Some pets may develop an allergic reaction to flea saliva, which can cause a condition called flea allergy dermatitis. This can lead to intense itching, hair loss, and skin infections. Fleas can transmit a number of diseases to pets, including tapeworms, Bartonella (cat scratch fever), and other bacterial infections. A severe flea infestation can cause your pet significant emotional distress, as they may constantly be scratching, uncomfortable, and in pain.

Do pet fleas go on humans?

While fleas do not typically live on humans, they can certainly bite and feed on human blood if they are unable to find a host animal nearby. Fleas can jump onto humans from infested pets or other animals, as well as from infested bedding, carpets, or furniture. When fleas do bite humans, they often target areas of the body that are exposed, such as the feet, ankles, and legs. This is because fleas are attracted to warmth and movement, and these areas tend to be more exposed and accessible. It is important to note that while fleas may not live on humans, they can still be a nuisance and a potential health hazard. Flea bites can cause itching, redness, and swelling and can sometimes lead to an allergic reaction. In addition, fleas can transmit diseases such as murine typhus, bubonic plague, and cat scratch fever.

How long will fleas live in a house with pets?

Adult fleas can live up to 100 days on a host animal, but they can only survive for a short time (usually one to two weeks) without a host. During this time, they may lay eggs in the environment, which can hatch into larvae and eventually develop into new adult fleas. The lifespan of a flea can vary depending on various factors such as temperature, humidity, and availability of hosts. In general, the entire life cycle of a flea, from egg to adulthood, can last anywhere from a few weeks to a few months. To effectively eliminate fleas from your home, it is important to use a combination of flea control measures, such as treating your pet with flea medication, vacuuming carpets and furniture, washing bedding and pet toys in hot water, and potentially using insecticides or working with a pest control professional.

How do I disinfect my house from pet fleas?

Disinfecting your house from pet fleas involves multiple steps to ensure that you eliminate all stages of the flea life cycle. The EPA recommends using an insecticide that is specifically approved for indoor use to treat flea infestations in homes. These insecticides have been tested for safety and effectiveness and are formulated to kill fleas at all stages of their life cycle. It is important to carefully read and follow the label instructions when using any insecticide. This includes wearing protective clothing and avoiding contact with the skin or eyes. It is also important to follow the instructions for application and treatment frequency to ensure the best results. Vacuuming your home regularly can help to remove flea eggs, larvae, and pupae from carpets and furniture. Be sure to empty the vacuum bag or canister outside of the house immediately after vacuuming to prevent re-infestation. Washing bedding, clothing, and other fabrics in hot water can help to kill any fleas or eggs that may be present. Be sure to use the highest temperature setting possible for the best results. Using a flea treatment recommended by your veterinarian can help to kill any fleas on your pet and prevent new infestations from occurring.

More on Fleas

What do Fleas Look Like?
How to Kill Fleas in the Yard
What Temperature Do Fleas Flourish In?
How to Get Rid of Fleas in 8 Steps Infographic
My Dog Has Fleas, What Should I Do?

This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis, or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.

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