Hosts : The immature stages are frequently found on small rodents such as meadow mice. The adults are frequently found on dogs (hence the name) and can be recognized by the distinctive white markings on their back. The American dog tick may become greatly engorged, achieving the size of a grape. In addition to man, the other hosts are cat, cattle, donkey, hog, horse, mule, sheep, coyote, deer, fox, wolf, wildcat, badger, opossum, rabbit raccoon, rat, skunk, squirrel, weasel and ground hog. Diseases : American dog ticks are the major carrier of Rocky Mountain spotted fever, which is less common than Lyme disease, but a potentially more serious illness. This tick has also been known to transmit tularemia, and to cause tick paralysis.