Page 66 - The Veterinary Care of the Horse

supply to sections of the intestine, causing severe colic and death (see figure 17.10). Some

species of large strongyle larvae migrate to the liver and the abdominal cavity where they
VetBooks.ir may cause hepatitis and peritonitis. The larvae then return to the large intestine where they
develop into adult worms. In warm, moist conditions, the whole life cycle can occur in six

months. Infective larvae can survive on the pasture over winter.

Clinical signs Anaemia, anorexia, weight loss, reduction of growth rate, rough coat with
delayed shedding in spring, pot-bellied appearance, diarrhoea, oedema, poor performance,
colic and death. 1-3 year olds are particularly susceptible

Treatment and prevention Disease caused by the large strongyles can be effectively

prevented and treated with the use of a suitable worming programme. In recent years, modern
medications have reduced the incidence of these worms significantly. When disease does
occur, supportive treatment is given as necessary. Surgery is sometimes required to remove a

severely diseased section of gut that has lost its blood supply. If the damage is widespread,
euthanasia may be necessary.

TAPEWORMS – Anoplocephala perfoliata

Adult size and colour Up to 8 cm × 1.2 cm (3 in × in), yellow/green/grey in colour (Figure
2.17)

Figure 2.17 Tapeworms