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Protozoal Microorganisms of the Gastrointestinal Tract in Rats

Protozoal Infection in Rats


The digestive tract in rats is home to a wide variety of microorganisms, including protozoa, single celled organisms that play an important and beneficial role in the digestive balance. In some cases, however, protozoa can be of a parasitic variety, and can bring harm to the host animal.


Under healthy conditions the beneficial microorganisms are higher in number than the harmful microorganisms. But when a rat is stressed or in a diseased condition with a lowered immunity, the balance between the beneficial and harmful protozoa is tipped in favor of the harmful ones, which can allow for intestinal infections. There are also some species of harmful protozoa that can be transmitted to rats through various sources, most notably infected feces, and which can also lead to intestinal infections.


Protozoal infection is a relatively common finding in young rats.


Symptoms and Types


  • Weakness and lethargy
  • Lack of appetite
  • Diarrhea
  • Weight loss
  • Loss of body condition
  • Rough hair coat
  • Bleeding (which, in severe cases, can lead to death)



  • Stressful conditions
  • Lowered immunity – imbalanced intestinal bacteria and organisms
  • Contaminated feces – fecal-oral route




Your veterinarian will make an initial diagnosis by observing the rat's symptoms. He or she can then confirm the diagnosis by examining the feces under a microscope for the presence of protozoa.