Many aspects of feline health remain a mystery, even to experts. Our cat-owning reporter learned this the hard way.

However, heavy infestations, especially in kittens, can lead to more severe digestive symptoms, weight loss, anemia, malnutrition, and restricted growth. "We'll see cats coming in, for example ...

Cats with severe flea infestations can suffer from skin damage, an allergic reaction, and anemia from blood loss. Fleas can also spread parasites like tapeworms and may transmit diseases.