Colon atresia

Context and challenges

Colon atresia was described in cattle as early as the 1970s and represents the most frequent gastro-intestinal disease. It is a congenital disease (that appears at birth). It appears as a complete occlusion of the colon (large intestine). Autopsies reveal a blind proximal colon that is severely distended with gas, possible extended by a functional but empty terminal colon. It is lethal without surgery. Similar pathologies have been described in other species including the horse, cat and man. Cases have been reported in several cattle breeds (Charolais, Simmental, Prim Holstein). In this latter breed, its frequency seems to have increased recently. In approximately 400 disease declarations made for this breed from May 2003 to September 2004 as part of the "Bovine disease observatory", more than one-hundred could correspond to colon atresia.

Symptoms JM Nicol (2003) Bulletin des GTV, 18, 51-52

The two or three first times the calf nurses, everything is normal. However, a decline in appetite progressively appears. The calf generally stops eating on its third day of life. In parallel, a distension of the abdomen is observed due to the impossibility of the affected calves to excrete fecal material. The anus is present and is usually normal. The rectal bulb contains mucus but no manure. Bacterial growth provokes an autointoxication or a septicemia responsible for death, usually occuring between the 3rd and 8th day after birth.

Causes

In the past, two explanations have been suggested for this disorder. The first is early gestational diagnosis through trans-rectal palpation before the 42^nd day post-insemination. The pinching of fetal envelopes may be responsible for the disorder. In a recent study led in two herds in Israel, calves from a mother having received such a diagnosis during gestation had a 100 times higher risk of atresia than controls. Other authors presented results suggesting hereditary transmission of the disorder in the Holstein breed (classical autosomal recessive genetic determinism). The fact that they managed to increase the proportion of calves affected by selecting mates is one of the most convincing arguments put forward by this group of American scientists.

Launching of a case census

The non-negligeable frequency of this disorder and the possibility (that cannot be completely ruled out at this stage) that it can have a hereditary origin explain why special attention should be paid to it.

The steering committee of the National observatory for bovine genetic diseases proposed to implement a more detailed poll of colon atresia cases based on the veterinarian GTV (veterinarian technical groups) network, insemination cooperatives and dairy testing organizations.

Biological samples (blood, fur/hair) were taken on cow-calf couples in order to initiate a study on the location of predisposing genes.

References

J Brenner et U Orgad (2003) J Vet Med Sci, 65, 141-3
M Syed at RD Shanks (1993) Cornell Vet, 83, 261-2