These droppings are very high in protein and iron and are eaten by the immature stage of a flea 's life cycle. A flea bite may leave no mark at all, but it can leave instead a small, red spot surrounded by a reddened halo if the host is sensitive to its bite . Unless there is an allergic skin reaction, there may not be any swelling. But many dogs and cats develop an allergic reaction to flea saliva , occasionally producing severe skin reactions. Most cases are observed in dogs between one and six years of age.
Animals can be different, with different sensitivities and tolerances.
It is possible to have two pets living together in the same environment and have one react violently to flea bites with severe scratching and rubbing, while the other shows little or no reaction . Breaking the cycle with an Insect Growth Regulator, is the secret to flea control. Commonly, these conditions are the result of flea allergies, food allergies, eczema, boredom, stress and anxiety . . . or a combination of these. The severity of itch will dictate the treatment needed. The severity of the itch will dictate the treatment needed.