Cryptosporidium

It is a protozoan (microscopic parasite) that lives in the digestive tract of several types of vertebrates, including cats, dogs, and humans.

The parasite causes profuse liquid diarrhea, which is yellow in color and emits a strong odor. 

The dog can also suffer from dehydration, fever, a decrease in appetite, weakness, lethargy, and weight loss. 

On the other hand, the infection is often sub-clinical, meaning that it is not evident, but can become active in stressful conditions or when the immune system isn't as strong, as in the case of young animals or thos who are immunosuppressed. 

The infection is acquired by the ingestion of the parasite's eggs that are present in the food or water. 

The parasite's life cycle begins when the eggs that are found in the environment are ingested. 

Once in the small intestine, primarily in the ileum, the eggs attach themselves to the surface of intestinal cells inside small vacuoles and reproduce. 

The multiplication of the parasite produces two new types of eggs, some that have a thicker membrane and others with a thinner one. The first kind are expulsed in the animal's feces, whereas the others enkyst themselves and infect other intestinal cells. 

The parasite's life cycle lasts between two days and two weeks. It begins the moment the dog infects itself with eggs present in the environment and ends when the adult parasites in the intestines produce eggs.

The infected animal can excrete the parasite's eggs in their feces for a period of one to eight months! 

The answer is yes, although humans most often get infected from calves who are affected. 

The eggs can be seen under the microscope from a dog's stool sample. However, they are hard to find because of how small they are. 

There are very few medications that have proven consistently effective against this parasite. 

Fortunately, the clinical signs generally disappear spontaneously in dogs who's immune system functions normally. 

However, it might be necessary to provide them with supportive treatments, such as fluids in case of dehydration, appetite stimulants, antipyretics to reduce fever, probiotics to rebalance the intestinal flora, easily digestable food, etc.  

Good hygiene is of utmost importance of course! 

Once again, hygiene is of the utmost importance for the duration of the excretion of parasite eggs.