a) Most chronic vomiting and chronic diarrhea in cats originate in the small bowel
b) Many small bowel diseases are segmental
c) Endoscopic biopsies are a very poor way to diagnose most cases
i) Location: stomach + 1-2 cm of duodenum OR colon
ii) Sample Size: about 1 mm piece of tissue; not full thickness
d) Chronic small bowel disease is manifested as chronic vomiting, chronic diarrhea, or both.
2) Typical history
a) "My cat has vomited all of its life. The vomiting was occasional for months to years. Then it became 1-2 times per month. Now it is daily. Otherwise, he/she feels good and eats good."
i) Think small bowel, not stomach.
b) "My cat has had soft stools ("not diarrhea") all of its life. The soft stool was occasional for months to years. Then it became 1-2 times per month. Now it is daily. Otherwise, he/she feels good and eats good."
c) Alternative: "has been losing weight" " has a tremendous appetite."
d) The diarrhea is typically small bowel diarrhea.
e) Small Bowel Diarrhea vs. Large Bowel Diarrhea
a) They are not synthesized in the cat.
b) Folate: absorbed in the upper small bowel.
c) Cobalamin: absorbed in the lower small bowel.
d) If their levels are low, it tells you what part of the bowel is diseased.
i) Low folate: rare in the cat.
ii) Low cobalamin: common in the cat.
iii) Most chronic small bowel disease occurs in the jejunum and ileum.
(1) This explains why endoscopic biopsies fail to be diagnostic.
e) Recovery from chronic small bowel disease requires successful treatment.
i) Cobalamin/B12 injections.
f) Diagnosed with fasted blood sample: IDEXX and Texas A&M GI Laboratory.
g) Treatment for low serum cobalamin
i) 100-250 mcg/cat SC q7d for 6 weeks followed by 100-250 mcg q14d for 6 weeks (3 injections), and another injection (100-250 mcg) 4 weeks later.
ii) Using the 1000 mcg/ml concentration, this is a very tiny dose (0.1-0.25 ml). I give 1 ml (1000 mcg) per dose because it is not toxic and often stimulates the appetite at this dose.
h) Treatment for low serum folate
i) Rarely, if ever, needed.
ii) 5 mg q24h PO. (1 mg tablets available)