Inflammatory bowel disease is one of the adverse side affects associated with vaccination.
From Dr. Pitcairn's Complete Guide to Natural Health for Dogs & Cats, (Dr. Pitcairn is a DVM with a Ph.D. in veterinary immunology) Under "Vaccination: Replacing Acute Illness with Chronic Disease," p. 274-275: "While immunosuppressive states are not common in dogs, reports of their occurrence are on the rise. I believe the massive vaccination program for canine parvovirus, which began some thirty plus years after we began vaccinating cats with feline parvovirus (panleuokpenia virus), is creating this situation in dogs. .... we have been seeing inflammatory bowel disease in dogs over the past five to ten years. Prior to this it was virtually nonexistent. I am certain that vaccination for parvovirus and coronavirus is a major cause. I commonly see inflammatory bowel disease that arises within a month or two after vaccination for one of these viruses."
Excellent information on veterinary vaccines is available at the links below:
Duration of Immunity to Canine Vaccines: What We Know and Don't Know, Dr. Ronald Schultz http://www.cedarbayvet.com/duration_of_immunity.htm
World Small Animal Veterinary Association 2007 Vaccine Guidelines http://www.wsava.org/SAC.htm
Scroll down to Vaccine Guidelines 2007
The 2003 American Animal Hospital Association's Canine Vaccine Guidelines are accessible online at http://www.leerburg.com/special_report.htm
The 2006 American Animal Hospital Association's Canine Vaccine Guidelines are downloadable in PDF format athttp://www.aahanet.org/PublicDocumen...s06Revised.pdf
Veterinarian, Dr. Robert Rogers,has an excellent presentation on veterinary vaccines at http://www.newvaccinationprotocols.com/