Vet on call: Sheep, goats that just won’t suckle

An e-mail enquiry early this week coincided with a case I had attended to earlier. The only difference was that the case involved a nanny goat while the email one concerned an ewe. A nanny is a female or she-goat while an ewe refers to a female sheep.

Margaret, in her e-mail, wanted to know what could be wrong with her ewe. She said the sheep lambs but is unable to feed the young ones, which die few days later.

The udder of the sheep always appears engorged with milk but when she tries to squeeze the teats, they only produce a few drops and dry off. The ewe had given birth three times with the same results.

Ann’s case, on the other hand, was a nanny that she claimed was getting tired of her kid. “You see, the goat stands to be suckled but walks away once she realises the kid is just hitting the udder and getting no milk,” she said on phone. She had also said the kid kept bleating all the time and the sound kept ringing annoyingly in her ears.

I empathised with the farmer because even on the phone, I could hear the sharp loud sound of the goat kid. This reminded me of my experience with hungry kids. Every time I get a phone call while on a goat farm with kids close to feeding time, I have to walk a distance away to answer.

On reaching Ann’s farm at Thindigua, I examined the nanny and found all parameters normal. I also confirmed the udder appeared to have milk but none came out when I tried to expressed. The poor goat kid came running expectantly when it saw me attempting to milk but got disappointed when no milk was forthcoming. It started bleating in protest.

I further examined the udder by deep palpation and I did not find any signs of infection such as pain, hardness or excess warmth. The goat was in good body condition and was also being fed well.

Examination of the kid’s mouth parts revealed normal formation of the jaws, cheeks and tongue.

I diagnosed failure of milk let-down medically known as hormonal agalactia, resulting from lack of oxytocin release by the mother. Oxytocin is the hormone produced by the brain to stimulate the mammary cells to contract and squeeze milk out of the udder tissue into the teat canal. Milking or suckling then expresses the milk out of the teat.

Oxytocin release is triggered by sensory stimulation of nerves in the teat, udder and flanks of the mother goat, which then transmit the stimulation to the brain.

That is why you will notice a kid, lamb or calf repeatedly hitting the udder and the mother’s underside surrounding the udder as it suckles. Further brain stimulation of the mother is caused by the sound and site of the young ones.

If you looked closely at goats or cattle, when they hear the sound of the young ones, you would see that the teats gradually become turgid and heavily pointed when the bleating of the young ones begins.

LACK OF MILK

I treated Ann’s she-goat with an oxytocin injection and antibiotics. The antibiotics help to prevent infection or to treat for any low-grade infection that may not be clinically observable. Fortunately, the goat released milk in 15 minutes, giving Ann and the kid a peace of mind.

Turning to Margaret, she definitely had a different problem with her ewe because she said the udder appeared engorged and the problem had occurred with three consecutive lambings.

The best option for Margaret was to consult a veterinary doctor to examine the ewe physically and, if necessary, take milk or blood samples for laboratory analysis. The apparent engorgement of the udder could have been swelling due to infection.

Both these cases had a problem medically called agalactia, which means lack of milk in plain language. Agalactia can affect any species of mammals including humans. It has many causes including failure of oxytocin release, poor nutrition and diseases that affect how the body handles nutrients; medically called metabolic diseases. Other causes may include infection of the udder and the uterus as well as severe stress.

Transient agalactia may be caused by shock or fear and normally is self-resolving once the causative agent is removed. Obstructive agalactia is seen when there are genetic defects that result in the malformations of the teat or teat canal.

They may also occur due to growth of fibrous tissue caused by infection or physical injury of the teats or teat canal.

Agalactia is treated indirectly by addressing the causative factor. Hormonal agalactia is diagnosed by ruling out all the other causes and confirmed by the response to oxytocin injection. Ideally, milk excretion should commence shortly after injection of the hormone. Some animals may still fail to respond.

In cases of infection of the udder and the uterus, agalactia in all species is mainly treated using antibiotics, anti-inflammation drugs and drugs that help in contraction of the uterus to remove any retained material. In large animals like cattle, the uterus may require flashing with iodine.

The diagnosis and treatment of agalactia is complex. Treatment must also be done as soon as possible from the time of delivery.

If a long time lapses before treatment, then the body shuts down the possibility of milk production altogether and no treatment will be of value. The udder shrinks and milk production will only resume with another pregnancy.