Intestinal Parasites in Rats

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Worms and Protozoa in Rats


Worms, or helminths, are parasites that inhabit the gastrointestinal tract in rats. Intestinal parasites in rats are of two types: helminths and protozoa. Helminths are multicellular worms, like tapeworms, pinworms, and roundworms. Protozoa have one cell and can multiply at a rapid rate. These intestinal parasites infect the digestive system of the rat and sometimes more than one worm type can be seen infecting the same rat.


These worms are mainly spread as a result of poor hygiene, and when rats come into contact with feces from an infected rat, as the eggs are released from the intestinal system through the fecal matter. Intestinal protozoa are known to spread through contaminated feces, but pinworms can also infect rats by way of the respiratory tract, as their eggs are capable of becoming airborne and inhaled. Unhygienic living conditions are the main culprit, when feces is left in the rat's living environment, as is the absence of routine healthcare with regular visits to the veterinarian.


Symptoms and Types


Infection with helminths (worms)

  • Diarrhea
  • Changes in appetite (loss or increase)
  • Weight loss
  • Excessive licking and chewing of rectal area and base of tail
  • Bits of worm or whole worms in feces
  • Severe infection can lead to blockage or perforation of the intestines
  • Tapeworm infections can cause liver enlargement by forming cysts in the liver


Infection with protozoa

  • Change in appearance of feces
  • Diarrhea
  • Vomiting
  • Weight loss




Worms, eggs, or protozoa are often transmited through the feces of infected rats and/or infected bedding or litter. Pinworm eggs, meanwhile, are so small that they can be inhaled while floating in the air. Contact with carrier insects like cockroaches, fleas, and beetles can also lead to parasitic infection. Cats are also carriers of tapeworms and can transmit the parasites to rats.




Pinworms can often be seen near the anal area of the infected rat. Diagnosis is verified by identifying the worms or their eggs through a fecal examination. In case of infection by protozoa, the presence of these single-celled organisms is also verified by analyzing a sample of feces.