Diseases from Fleas on Dogs

Fleas on dogs can cause more than just an itch on a pup. Fleas and ticks can cause serious diseases that can make a dog feel uncomfortable and ill. Because of this, it is up to a pet owner to maintain a flea-free environment and help the dog defend himself against fleas.

Atopic Dermatitis Caused by Flea Bites

A dog can develop an allergic reaction on his skin if he is allergic to fleas. Dogs can be allergic to the saliva a flea can leave behind. As a result, hair loss, hot spots, excessive licking or scratching, hives, red bumps, a rash and even wounds can appear as a result of the allergic reaction cause by flea saliva.

Parasites Hosting Other Parasites

A common problem seen in dogs that have been bitten by fleas is a parasitic infection. While a dog can be a host to a flea, a flea can play host to tapeworm eggs. After tapeworm eggs are eaten by flea larvae, which can happen when a dog’s environment is infested with fleas and tapeworms, a dog can unknowingly eat the larvae. After ingestion, the tapeworm eggs will hatch in the dog and live in the intestine and lay more eggs. The eggs are then excreted in a dog’s feces. Symptoms of a tapeworm infection in a dog include vomiting, loss of appetite and lethargy.


A dog can become anemic if he has been infested with a large number of fleas and/or ticks. This is seen a lot of times in dogs that are left outside and are neglected. A dog can become anemic if he is host to a large amount of fleas or ticks that drink large amounts of his blood. Flea anemia is hard to detect sometimes, but can cause a dog to feel weak and parts of his body to become pale (like the gums).

Lyme Disease and Rocky Mountain Spotted Fever

Ticks can cause a dog to develop serious diseases as the blood-sucking pests can become hosts to dangerous bacteria and parasites.

Borrelia burgdorferi is a type of bacteria that can be transmitted from a tick to a dog when the tick drinks the canine’s blood. This bacterium causes Lyme disease, which can cause a dog to have joint pain, a fever, enlarged lymph nodes and a cough. In rare cases, a dog’s major organs can be affected by Lyme disease if left untreated.

Rickettsia rickettsii is a parasitic organism that causes Rocky Mountain spotted fever. The disease is caused when the organism is transmitted from the tick to a dog when his blood is being consumed. Rocky Mountain spotted fever can cause the inside of a dog’s eye to become inflamed, joint swelling and pain, and a fever.

Fleas need to be controlled and kept off a dog. This is a responsibility a pet owner must consistently uphold so her dog does not become ill with the diseases fleas can bring.