When bringing a new kitten or cat into your home with existing pets, it is very important to have a fecal and blood test preformed by your veterinarian.
Recently I brought home a new female kitten to join our cat family. As per my normal protocol, I kept her separate from the rest of my cats while I waited for her test results. When I received the email from lab with the results, I discovered she had a bad case of Coccidia. Here is a description right off PetMD web site.
"Coccidiosis is a parasitic type of infection, caused by the Coccidia parasite. It most commonly causes watery, mucus based diarrhea in animals. If it is not treated, over time it can cause damage to the lining of a cat's intestinal tract. With appropriate and prompt treatment, the prognosis is good".
Coccidia can strongly affect kittens and young cats.
My new kitten is now on a sulfur based antibiotic and she is already showing improvement after only 3 days of being treated. She will need to be treated for 21 days. I am confident she will fully recover and have a happy, healthy life.
The reason I am writing about this is to stress the need to test your new family member for parasites. If I had introduced this new kitten to the rest of my cats, I would be treating all of my breeding cats and kittens for this parasite. It could have been fatal to kittens under 6 weeks old. It is extremely contagious easily spread from shared litter boxes and even using the same litter scoop to clean multiple litter boxes.