What Internal Parasites Do Dogs Have?

1 Overview

What Are Internal Parasites in Dogs?

1. Tapeworm

The adult is segmented, absorbing nutrients needed for the host’s digestion through surface osmosis. The attachment organ on the scolex adheres to the intestinal mucosa between the intestinal villi, parasitizing the host intestine. Mild infection often has no clinical symptoms; severe infection causes hemorrhagic enteritis. Some show strong excitement, some show limb twitching or paralysis. Continuously shed proglottids attach around the anus and irritate it, causing itching or pain, and the dog rubs on the ground, with hair loss at the tail base.

2. Dog hookworm

The dog hookworm has 3 pairs of sharp teeth in its mouth, firmly attaching to the host’s intestinal villi through the teeth and biting to draw large amounts of blood as nutrition, causing the host digestive symptoms such as bloody stool (black stool) and abdominal pain. Bleeding at the bite site can cause chronic anemia.

3. Coccidia

Canine coccidia parasitize the host’s small-intestinal epithelial cells; both types multiply by division and destroy the parasitized cells. Especially in puppies, it causes diarrhea, sometimes with blood in the stool, indigestion, anemia, and weakness. Unlike the parasites above, coccidia are invisible to the naked eye.

4. Whipworm

The whipworm’s scientific name is Trichuris (whipworm); its body is thick at the front, thin in the middle, thick at the back, mainly piercing into the cecum mucosa through its front end and parasitizing deep in the cecal mucosa. It absorbs blood, using plasma and digested red blood cells as nutrients. In severe cases it can also parasitize the small intestine, showing long-term diarrhea, mucobloody stool, and foul odor.

5. Toxoplasma

This toxoplasma parasitizes many animals including humans, dogs, and cats; only the cystic form excreted in cat feces can develop externally for 1-2 days to become infectious. This parasite mainly travels with the blood to all parts of the dog’s body-brain, heart, eyes-causing decreased immunity. Although most are latent infections, it can also become active, mainly invading the dog’s respiratory and nervous systems. Main symptoms in dogs include fever, cough, difficulty breathing, reduced appetite, confusion, increased eye/nose discharge, vomiting, pale mucous membranes, movement disorders, premature birth, and abortion.