Herd Health

from March 2021 Charolais Connection

Calendar of Events

hERD hEAlTh Congenital versus Hereditary Defects in Calves

Every year during calving season, veterinarians help deliver or discuss abnormal calves. Being twisted up, having abnormally large heads or extra limbs can all be problems calving. In these cases, we often have non-viable calves. Producers question us about these calves, and sometimes the purebred producers may be questioned as well because the sire was one of their bulls. This article will shed some light on how to classify these cases and explain their probable causes. Suffice it to say that these are almost never hereditary defects and are just flukes that really have nothing to do with the breeding itself.

If a very abnormal calf is born this spring take a few pictures of the abnormality for your records. We want to determine what system is involved, be it the skeletal, ( also spine versus the rest) ocular, oral (such as a cleft palate), integumentary system (such as no hair). Sometimes it’s an umbilical hernia, or the internal organs are twisted, deformed, missing etc. There are the fetal monsters such as the cyclopean, two headed calves, Siamese twins or the very consistent defect of the schistosomas reflexus calf (born essentially inside out). Some of these calves are so abnormal a fetotomy needs to performed with them cut up inside the cow, or the worst case scenario, a caesarean section to deliver them. All this for a non-viable calf. Other times calves are born quite viable but with slight abnormalities, such as a small deformed extra limb, mild cleft palate or an inguinal hernia to name but a few. Some of these minor abnormalities can be surgically repaired and go on to be a somewhat normal calf. Others are born with severely contracted tendons and are treated based on severity. They may be left, or have the toe rasped, pain killers given and the leg forcefully extended to splints applied. In severe cases, flexor tendons may be cut to allow a somewhat normal extension of the limb.

Congenital defect just means ‘born with it”, and the severe ones are usually chromosomal aberrations that often come with multiple problems. This means a total individual calf ..continued on page 61