6 year old yorkie

Question
Our yorkie isa male,  6 years old. He weighs about 8-10 pounds depending on if he has been sick.  Two years ago he contacted Lymes disease and was treated.  To this day he still has the antigent in his blood.  We ran a test and it was determined that it was passive (5/2005).  Ever since he had that episode with Lymes, he is more prone to diahrea or vomiting or both which can be brought on by anything from leaving him while we go on a trip, to maybe something he ate.  Not boarding but leaving with a friend, which happended last year.  We have cut out most table foods, although my husband still feeds him cheese and maybe little bits of meat (beef only)or vegtables.  He is on a Prescription diet of W/D.  I also cook hamburger, well drained and rice and add it to the W/D.  He eats twice a day, morning and supper time.  My question is since the first of this year, he has been having an "off day" every 7-10 days.  He will be lethargic, won't eat and then will throw up yellow (bile?), no diarhea  I have been giving him Pepto Bismol, as my vet did not want me treating him with Metrodiazol very often. She took over for her father, who at one time wanted to put him on a low dosage of it for the rest of his life.  I put him back on the steroid this past week, when he had an episode where he was vomiting water only and towards the end it was tinged with blood, after 3 episodesof vomiting.  We also just ran a series of blood tests to determine if there were any abnormalities there and it came back fine.  Any ideas what could be his problem, or is it just a very very sensitive stomach??  The fact that it happens pretty consistently every 7-10 days makes me wonder if his system is having a build up of something and purges it.  

Thank you for any help.  

Answer
I would be concerned about Addison's Disease.  An ACTH Stimulation Test must be done to check for that, however, he can not be on steroids for a bit before having the test.

I would recommend changing his diet to an ALL NATURAL diet that is free of corn, soy, by-products, dyes and preservatives as this is less for his body to process.....get him off of the w/d.  Some good brands are Prairie, Verus, Wellness, Natural Balance, Nutro Natural, Royal Canin, Eagle Pack....ideally I would try a fish and potato diet as the higher fatty acids would be beneficial as a natural anti-inflammatory and the fish, being a novel protein source, can help treat irritable bowel disease as well.  If need be, you can add fiber to his diet by giving him canned pumpkin.

In addition, I think he would benefit from digestive enzymes and probiotics to keep his intestinal tract healthy.  I like DANCING PAWS Shake N Zyme www.dancingpaws.com and use that for my cat with bowel problems.   And B complex vitamins would help with the bouts of lethargy...I would give him 25 mg a day.

Good luck
Dr. Fry