Systematic review of published cases and a hospital-based case-control
study were completed to evaluate breed as a risk factor for atresia c
oli in cattle. Systematic review of 37 published studies indicated tha
t atresia coli has been diagnosed in 10 cattle breeds and 12 countries
, with the marked preponderance of cases occurring in Holstein-Friesia
n calves (485/514 cases, 94%). Epidemiologic analysis based on 28,373
cattle < 2 mo of age admitted to North American veterinary schools bet
ween 1964 and 1993 identified 291 cases of atresia coli in 13 breeds,
with the marked preponderance of cases occurring in Holstein-Friesian
calves (228/291, 78%). Holstein-Friesian cattle were at significantly
greater risk for the condition than all other dairy cattle breeds (cru
de odds ratio 4.55, P < 0.0001) and all other cattle breeds (crude odd
s ratio 7.12, P < 0.0001), whereas there was no difference in the odds
ratio between dairy cattle (not Holstein-Friesian) and beef cattle (c
rude odds ratio 1.68, P = 0.11). Atresia coli probably occurs secondar
y to vascular insufficiency of the developing colon. Holstein-Friesian
cattle may be genetically predisposed to atresia coli, possibly becau
se their developing colon grows at a faster rate and/or to a greater e
xtent than that in other cattle breeds. Early or vigorous palpation pe
r rectum of the amniotic vesicle appears to increase the risk of atres
ia coli in a genetically predisposed fetus, probably through palpation
-induced damage to the developing colonic vasculature. (C) 1997 by Els
evier Science Inc.