Various diagrams and photographs reproduced with publisher permission:

Etchison : Topics in Veterinary Medicine, Special Edition - Canine Parvovirus Disease, Pfizer Animal Health, 1995, p. 10

Fossum : Small Animal Surgery, 2nd ed., Mosby, 2002, pg. 199, 206, 259, 264, 266, 1133, 1135, 1141

Hill's Atlas of Veterinary Clinical Anatomy, Veterinary Medicine Publishing Company, Inc., 1989, pg. 15, 79, 83, 86, 87, 88, 89, 90, 95, 96, 97, 98

Hoskins : Veterinary Pediatrics, 3rd ed., WB Saunders Company, 2001, p. 413

Lindsay, Blagburn : The Compendium, May 1991, p. 761

Parasites and Parasitological Resources, web site, The Ohio State University College of Biological Sciences

Scott, Miller, Griffin : Muller and Kirk's Small Animal Dermatology, 6th ed., WB Saunders Company, 2001, p. 344

Slatter : Fundamentals of Veterinary Ophthalmology, 2nd ed., WB Saunders Company, 1990, pg. 156, 157, 165

Sloss, Kemp : Veterinary Clinical Parasitology, 5th ed., Iowa State University Press, 1978, pg. 194, 216, 217