By Paul Redmond, MVB, MRCVS, Cert DHH, Duntahane Veterinary Clinic, Fermoy, member practice of Prime Health Vets
IT was a Sunday when Dan called. He was in a spot of bother with an in-calf heifer.
When I got out to him, he was milking the last cow, and we chatted while he finished up. It was shortly after Christmas, and we talked about the children coming home for the holidays, they are all grown now and have their own lives to lead, but it’s a great time of the year to have them around.
When Dan was finished with his bits and pieces, we made our way over to the slatted house where the heifer was with her comrades waiting patiently for their calving day to arrive.
Dan had noticed her standing in a corner with her head pressed against the wall.
As he drove my patient up through the group, so that we could pen her, she got a bit anxious, as she found herself alone, and then she exhibited a classic symptom. She began to circle uncontrollably to her right in a never ending fashion until she fell to the ground.
Dan held her by the nose tongs as I proceeded to examine her. She had an elevated temperature and her heart was racing. Lung sounds were normal, and her rumen was functioning. She had sight in both eyes, as she reacted to the motion of my hand towards her eyes. I looked at her face to see if one side or the other was drooping or lopsided but I could not make out any difference.
This symptom of circling is a tell-tale one for Listeriosis, which is an infection of the brain caused by the bug called Listeria Monocytogenes.
This bug is apparently everywhere. It has been found in 42 different types of animal and almost as many species of birds, and in fish, water, sewage, feedstuff and earth.
The classic form of the disease is associated with animals eating mouldy silage or other food, and leads to the meningitis-like signs such as the circling by Dan’s heifer. These animals progress to show other signs like the drooping of one ear, drooling of saliva from the mouth on the same side, while the animal may be blind on the opposite side, or be totally blind, depending on how fast the disease develops.
Eventually the animal will go down and there, in most eventualities, will remain. Because of paralysis of head and throat muscles, the animal finds it increasingly harder to eat and drink. Sometimes the disease follows a very fast course and, unfortunately, the animal does not recover, and dies.
Sometimes we don’t get to see too many of the symptoms described in the books, but we have to make a call and decide the proper course of treatment.
If the animal has stopped eating and drinking, we must give it lots of electrolytes to try to keep it alive while antibiotics hopefully get to work.
Reports tell us that up to half the cattle that get this disease will not make it, and three quarters of the sheep that get it will die.
I am an optimist who likes to gamble on the half that is going to survive.
Sometimes we come across a case of abortions in a herd caused by Listeria Monocytogenes. Like a lot of abortion outbreaks, the actual incident of infection probably took place weeks before we actually see the first abortion.
Again, this is often due to eating spoiled silage.
Whenever you experience an abortion in your herd, you should always contact your vet about getting bloods done, and book the foetus and associated material into the state post mortem laboratory, to give yourself some chance of finding out the cause.