Exocrine Pancreatic Insufficiency (EPI)
by Olesia Kennedy
EPI is a disorder which occurs in many canine breeds, in particular the German Shepherd Dog. Since the first publicly announced case of this disorder in December 2006, there are now 7 positively identified cases of EPI in SWDs.
The pancreas has two major functions:
Exocrine pancreatic insufficiency (EPI) is the inability of the pancreas to secrete the necessary digestive enzymes, amylase to digest starches, lipases to digest fats, and trypsin and proteases to digest protein. When these enzymes are not available to help digest nutrients, the body cannot use the nutrients. The body in essence starts to starve. In addition, due to the lack of proper digestion of nutrients, exocrine pancreatic insufficiency is usually accompanied by structural and functional changes in the tissue lining of the small intestine that further impairs nutrient absorption called small intestinal bacterial overgrowth (SIBO). Untreated or misdiagnosed dogs with EPI will either die a painful death by starvation or organ failure.
A trypsin-like immunoreactivity (cTLI) blood test (Texas A & M University labs are most widely used) will show the dog's ability to produce digestive enzymes (lipase, protease, amylase). The normal range is between 5.0 ï¿½ 35.0. The dog must fast 12 hours prior to blood test. cTLI tests range approximately $100.
Treatment of exocrine pancreatic insufficiency may be regulated after some trial and error with enzyme replacement. It is usually necessary for life. Most dogs with EPI respond well to pancreatic enzyme replacement with every meal, antibiotics to reduce the SIBO (small intestinal bacterial overgrowth) condition and a change in diet to a low fat, low-fiber diet. Raw diets are also being met with success. All grains need to be avoided. Sadly, not every vet recognizes the symptoms, misdiagnose these dogs who then eventually die a painful death - - or are put down because the enzyme treatment is so expensive.
Where does EPI come from?Autosomal recessive genes are suspected to be the cause of EPI, but it is unclear if it is by one gene or multiple loci, possibly a polygenic inheritance (traits vary in degrees of severity of the disease). In a simple recessive scenario, an affected animal must inherit 2 copies of the gene, 1 from each parent. Dogs with the genotype PP (normal) or Pp (carrier) will be clinically normal but the carrier will pass the affected gene to approximately half the offspring. As long as carriers (Pp) are mated to normal animals (PP), the offspring will be unaffected but some will remain carriers. If 2 carriers are mated, some of the offspring (approximately 25%) will be affected. BUT even then, one may not know that the dog has the disease. Symptoms may be exacerbated by physical or emotional stress.
What we can do
We now know this condition exists in the SWD lines, however at this point we can only test to confirm if a dog is affected by EPI.
An effort spear-headed by SWDCA member Olesia Kennedy brings together the EPI Global Group and Texas A&M Medical University and Clemson University to identify genetic markers for this insidious disease. If you dog has EPI, or you suspect your dog has EPI, please feel free to e-mail Olesia Kennedy for assistance with enzymes, contacts, testing, or general questions; or visit http://www.epi4dogs.com/
Keith Murphy, Professor & Chair of Genetics, Clemson University, Clemson SC (formerly Professor of Genetics, Pathobiology & Biotechnology Dept of Pathobiology, Texas A&M University, College of Veterinary Medicine)
2004-2005 Grant for PAA from the CHF:
Murphy, K.E. and L.A. Clark (Co-Is). Analysis of a candidate gene for pancreatic acinar atrophy in the German Shepherd Dog. Canine Health Foundation.
Leigh Ann Clark, PhD in EPI, Research Ass't Professor, Dept of Pathobiology. Dr. Clark studied under Dr. Murphy for her PhD and continues to work with him. She received the Texas A&M University College of Veterinary Medicine Fisher Institute Medical Research Award, 2004, for her dissertation, titled: Transmission genetics of pancreatic acinar atrophy in the German Shepherd Dog.
Kate Tsai, Ph.D., Assistant Research Scientist in the Dept of Pathobiology, Texas A&M University, College of Veterinary Medicine and Biomedical Sciences.
Jurg M. Steiner, Med.Vet., Dr.Med.Vet., PhD, DACVIM, DECVIM-CA, Associate Professor with the Department of Small Animal Medicine and Surgery, Texas A&M University, College of Veterinary Medicine and Biomedical Sciences.
And with special collaboration of: David A. Williams MA VetMB PhD Diplomate ACVIM, ECVIM-CA honored developer of the cTLI test.