Losing weight
“My three-year-old English setter eats like a horse but is still as thin as a rake. And getting thinner. He frequently has diarrhoea, no matter what I feed him. I am tempted to try raw. Will this help?”
Ah! Once again the ‘will raw help’ dilemma when the real question should be: “What do you think is wrong with my dog?” And, of course, the answer to that is, I am not sure. Though I am fairly confident something is amiss that a simple diet change will not correct. There are a number of possibilities, the list of potential diagnoses including the following:
• Diabetes
• Inflammatory bowel disease
• Intestinal bacterial overgrowth
• Liver/kidney problems
• Parasitic disease
• Some tumours
• Other complicated stuff
• Exocrine pancreatic insufficiency
We will rule out diabetes, as you don’t say
he is thirsty. Also, I presume he has had some basic antibiotic treatment and that you have wormed him (if not, do so immediately). Given his age, breed and continued weight loss despite a voracious appetite, the most likely problem is the last in our list, which is Exocrine Pancreatic Insufficiency (EPI).
What is EPI?
EPI can be congenital, inherited (especially in German shepherds, collies and English
Vet’s advice Neil Mcintosh SG’S gundog health expert
setters) or acquired (usually as a result of recurrent chronic pancreatitis). Most commonly, there is progressive atrophy of the pancreatic acinar tissue, which results in inadequate production of pancreatic digestive enzyme. Consequently, the patient eats well but digests little. Weight loss occurs, along with poor body and coat condition. Faeces are often soft, bulky and smelly and coprophagia (a dog eating its own faeces) is common.
The grave situation is compounded by secondary bacterial overgrowth (so affected dogs may appear to improve for a short while when given antibiotics) and malabsorption of Vitamins B12 and E.
How do you diagnose EPI?
Well, in the good old days (which were bad, actually), we used to mix up some faeces to form a thin soup, then we placed a strip of X-ray film into the mix. After a few hours we would take it out and, hey presto! If there was digestive enzyme present then the A dog with EPI should be placed on a highly digestible, low-fat diet
gelatin coating would have been removed from the X-ray film as a result of proteolytic activity. If the X-ray film was left intact then there was obviously no enzyme and the patient was declared to have EPI. Cheap and simple. But, unfortunately, not accurate and full of false positives and negatives.
Happily, modern times have brought us the ability to measure Trypsin-like Immunoreactivity (TLI) on a simple blood sample and a low level of this is diagnostic for EPI. Let me explain. Trypsin is a proteolytic enzyme, normally produced and contained within the pancreas, that is involved in the digestion of protein. Immunoreactive trypsin is a precursor of trypsin that has no proteolytic activity and is present in blood, where it can be measured. All that needs to be done is to fast the patient for 12 hours prior to sampling, to avoid lipaemia (fat in sample). Low levels of TLI are diagnostic for EPI (high levels can indicate inflammation of the pancreas). In affected dogs, Vitamin B12 will also be low and this is typically measured at the same time, along with folate levels, which are an indicator of small intestinal bacterial overgrowth.
Can EPI be treated?
Simple answer, generally speaking, is ‘yes’. Treatment involves: • Pancreatic enzyme replacement • Highly digestible, low-fat diet • Vitamin B12 given by injection • Possibly antibiotics for a month
And the end of the story is?
We all lived happily ever after. The diarrhoea stops within a week, weight gain occurs over a month and the excessive appetite reduces as normal body condition is reached. Affected dogs may struggle with the rigours of work and, of course, the enzyme replacement costs.
Note also that the predisposition to develop EPI is inherited in some breeds, which is food for thought, don’t you think?
“the patient eats well but digests little”