Animals – Autumn disease watch list

Here are three diseases owners of grazing animals should be on the lookout for during autumn and, with winter only two months away, a couple of things we should be planning for.

Barber’s pole worm can cause ill-thrift (failure to grow) in ruminants and camelids, such as alpacas. In this respect it behaves like other pathogenic worms, but unlike other worms this worm can impose a severe burden in livestock very quickly. In certain environmental conditions, death from anaemia can occur before any diarrhoea is seen. These conditions are warm ground temperatures and significant levels of moisture, especially after a dry period. Late summer and autumn is the risk time. The only warning signs you might see are animals becoming slow and weak and the colour of the mucous membranes, such as the gums and inside of the eyelids, are no longer salmon pink, but pale.  

Facial eczema can also strike ruminants and camelids in late summer and autumn. This disease is caused by a microscopic fungus that loves to grow in warm, moist conditions in the vegetable matter litter layer at the base of pasture. The nature of the pasture and the lie of the land are important factors in how well the fungus grows. One paddock on a property may be “hot” while another is not. The spores of this fungus contain a toxic chemical. When it is eaten in high enough quantities, it damages the animal’s liver.

Damage can be accumulative over some months. Although the animal will not be thriving as well as it should, the first thing noticed is usually photosensitivity. The damaged liver cannot clear the chlorophyll being eaten. It builds up in the circulation and when hit by sunshine it releases energy and burns. The name “facial eczema” comes from the sunburn symptoms seen on the faces of white, woolly sheep. In black and white cattle it is stunning how black areas can be completely normal and white areas are red and blistered. This disease can be cruel and can be fatal.

Ryegrass staggers is another summer and autumn disease caused by fungi. In addition to ruminants and camelids, this disease also affects horses. It is more sporadic in nature and most affected animals recover completely. The offending fungus  is found inside plants (perennial ryegrass, mostly) and it gets in there at the seed stage only. The fungus can affect the brains of grazing animals. They will tremor, have jerky gaits and fall over.
Finally, a brief note on shelter. As animal welfare regulations tighten, come October it will be illegal to habitually tether a goat that does not have access to food and water, and access to shelter from the sun, wind and rain at all times. October will also see the introduction of instant fines for some of the less serious animal welfare breaches.

David Haugh, Wellsford Vet Clinic
www.vetsonline.co.nz/wellsfordvet