Capillaria

Capilaria - Courtesy of the Laboratory of Parasitology, University of Pennsylvania School of Veterinary Medicine

Similar to Trichuris, but the difference between anterior and posterior ends of the body is not so pronounced
Some species have direct life-cycles, others use intermediate or transport hosts
Species have different predilection sites
Of greatest importance in birds, although species do occur in the urinary bladder and liver of cats and dogs