Page 74 - The Veterinary Care of the Horse

coughed up and swallowed, then pass out of the donkey in the droppings. The larvae hatch

and if swallowed by a horse or donkey will migrate from the intestine to the lungs via the
VetBooks.ir bloodstream or lymphatic vessels. Here they mature into adults in the bronchi. In a donkey,
the adults will lay eggs, but in many horses the cycle is not completed and no eggs are laid by

the adults.

Clinical signs The donkey is able to tolerate the parasite without any symptoms in most
cases. Occasionally, there may be an increased respiratory rate. Horses with lungworm
usually cough, especially during exercise and may have an increased respiratory rate and a

nasal discharge. Worms may be visible in the bronchi on endoscopy.

Treatment and control Lungworm are effectively treated with a suitable anthelmintic.

NECK THREADWORM – Oncocerca spp (see page 574)

Diagnosis of worm infestation

Diagnosis is usually made on the clinical signs, the grazing and worming history and the

following laboratory tests.

FAECAL EGG COUNT (FEC)

A fresh sample of the horse’s droppings is mixed with saline and examined under the

microscope for worm eggs. The eggs from different species of worm have a different
appearance and can be identified and counted. The result is given as the number of eggs per
gram (EPG) of faeces. It is used for strongyles and ascarids. (Figure 2.23.)