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Flea Anemia – More Than Just a Nuisance

Most people see fleas as just a nuisance that makes your beloved pets itch. However, fleas can be very dangerous for your cats and dogs, especially small ones.

An Introduction to Fleas

There are approximately 2,000 different species of flea. The most common types found in the United States are the cat flea, Ctenocephalides felis, and the dog flea, Ctenocephalides canis. Contrary to their names, it is possible to find either type of flea on cats, dogs, and other furry mammals.

Every time a flea feeds, it takes blood from its host. When the pet has a few fleas – up to around 50 – the worst signs that you may see are scratching, dogs biting themselves, or over-grooming in cats. These signs are mostly seen in animals that are allergic to flea saliva. In some cases, fleas can go unnoticed because not all animals scratch, bite, or overgroom from fleas because they don’t cause them any distress. It is harder to notice fleas on cats because they groom themselves and remove the fleas.

Since fleas live off blood, when their numbers grow, so does the amount of blood that the pet is losing. For a cat, small dog, puppy, or kitten the amount of blood lost can be detrimental. If left untreated these pets can become anemic.

What is Flea Anemia?

Anemia is a medical term referring to a reduced number of circulating red blood cells (RBCs), hemoglobin (Hb or Hgb), or both. In the case of flea anemia, this is normally the loss of red blood cells.

If fleas are left untreated and their numbers start to grow, their host (your beloved puppy, kitten, or small animal) can become increasingly sick. Many times, these animals slowly start to get weaker and weaker, even though you may not notice. After a certain amount of time, the pet will stop eating, start to vomit, their gums become whiter and the pet is unable to stand. This is when fleas become an emergency.

In some cases, small animals require blood transfusions because of flea anemia. These anemic pets must remain in the clinic/hospital for at least two days with intravenous catheters, fluids, and medications to prevent the possible reaction that they can have from the transfusion. The worst factor is that normally after one transfusion these pets are not able to ever have a transfusion again because of the increased risk of an allergic reaction to the blood. Also, since their environment is contaminated with fleas, when they go home, they are at high risk of continued flea bites, leading to further anemia.

Issues Beyond Flea Anemia

Flea prevention is normally not seen as something necessary in household pets, but flea control should be taken very seriously. Besides anemia, fleas can lead to different blood parasites, intestinal parasites, or diseases. An example of this is the plague that was spread by fleas and rodents.

”In recent decades, an average of seven human plague cases have been reported each year (range: 1-17 cases per year). Plague has occurred in people of all ages (infants up to age 96), though 50% of cases occur in people ages 12-45.” (

Flea Control and Prevention

Flea control can be very hard, especially in Florida during the spring and summer months, though they are normally found year-round because of our warmer climate.

There are many different forms of flea prevention, but with all flea prevention, the flea must bite the host to ingest the medication and die. There is one product – Sentinel – that contains a medication that sterilizes the flea, it does not kill it, to stop the life cycle. Most veterinarians recommend oral prevention for dogs and either oral or topical preventions for cats.

Here at Lake City Humane Society, we recommend Nexgard or Bravecto for dogs and Revolution or Bravecto for cats. There are multiple over-the-counter products, but most of these are not able to keep the burden of fleas at bay.

Please contact the clinic if your pet is having any issues with fleas. We would be happy to help with prevention and tips to help control the flea population at your home.

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