Do Canine Parasites Feed on Blood?

Ticks transmit various diseases and microscopic parasites to their hosts. Images

Vampires aren't the only creatures who enjoy the taste of blood. In fact, plenty of parasites consume the red liquid coursing through your dog's veins. You've probably heard of ticks and fleas, but these two undesirables aren't the only organisms that feed on canine blood.

External Parasites

Fleas are among the peskiest canine parasites around. They have small, dark bodies and are excellent jumpers; they are difficult to spot and remove manually. They leave itchy red bumps when they bite people or animals to consume blood. A single female flea can lay dozens of eggs every day, so an infestation can get out of control in no time, according to Windermere Animal Hospital. Ticks are another common external parasite on dogs as well as other animals and people. These arachnids are tiny but often grow larger than fleas. They latch onto their victim's skin and bury their heads in the upper epidermal layers, which allows them to drink their fill of blood throughout the day.

Blood Parasites

When it comes to blood-eating parasites, don't forget about protozoa. Several groups of these single-celled organisms are known as blood parasites, which means they actually infiltrate your dog's veins and arteries to consume blood cells directly. Protozoa often spread with the help of external parasites. Ticks transmit protozoa from the genus Babesia, which cause a deadly canine disease called babesiosis. Ticks can harbor the organism responsible for hepatozoonosis, but dogs are infected only if they actually ingest the tick's body, according to the Merck Manual for Pet Health. Protozoan parasites attack individual cells within the bloodstream. The victim's health deteriorates rapidly as the population of organisms grows exponentially.


Many dog owners have heard of worms before. While some of these parasites steal semi-digested food from their host's bowels, several types are actually after their host's blood. Hookworms are a prime example. They latch onto the lining of your dog's intestine and drain blood from the thousands of small vessels that transport nutrients from the digestive tract to the rest of the body. Heartworms also reside in your dog's bloodstream, although they eventually establish themselves permanently near his heart and lungs.


Blood may not seem like a particularly appetizing meal to you, but it's one of the most nutritious substances available to parasites. Rather than locating, consuming and digesting various foods for nutrition, blood-hungry organisms take all they need directly from their hosts' bloodstreams. A few bites from a mosquito or flea usually isn't a big deal for your dog, but parasites can have a big impact on his health when a lot of them are feeding on him. Worms, microscopic protozoans as well as ticks and other external parasites can deplete your pup's blood supply to dangerously low levels if an infestation goes unchecked. Take your pet to the veterinarian at least once a year for checkups, and schedule an appointment if you notice unusual symptoms, including lethargy, weight loss or bloody excretions.