408
Important Helminth Parasites of Poultry
in the musculature of the gizzard and thereby weaken it. They have also
some toxic effect on the host. In heavy infestations they produce emaciation,
droopiness, weakness and anaemia. The gizzard lining may be haemorrhagic
and necrotic and the wall flabby. Sometimes the gizzard is weakened to
such an extent that a rupture in the form of a large sac occurs. Infestations
with the above stomach worms are serious, as on account of the location
of the parasites in the final host and the migratory habits of the intermediate
hosts, treatments and prophylaxis are obviously difficult. General hygienic
measures and the keeping the birds off stagnant waters and swampy places
may help control the infestations.
A small, strongyle worm—Amidostomum nodulosum—also occurs in the
mucosa of the gizzard, and at times of proventriculus and oesophagus, of the
goose and duck. The life-cycle of these parasites is probably direct. The
worms are extremely pathogenic to young geese and may be responsible for
heavy losses among them. Adult birds develop a marked resistance to the
effects of these parasites and serve as carriers. The worms burrow into the
mucous and submucous tissues of the gizzard and proventriculus, sucking
blood and causing irritation, inflammation and haemorrhage. They are also
suspected to have a marked toxic effect on the bird. In heavy infestations,
the affected birds show inappetence, emaciation and anaemia. Diarrhoea,
incoordination of movements and prostration are not uncommon. Treat-
ment with carbon tetrachloride in doses of two to four c.c. in capsules has
been found to be very satisfactory. The proper dose of the drug should be
ascertained before giving it to the whole flock. Prophylactic measures are
the same as for the other round-worms which have direct life-cycle.
Manson's eye worm of poultry—Oxyspirura mansoni—occurs in the
conjunctival cavity, between the lower eyelid and the ball or under the nicti-
-ating membrane of the fowl, turkey and peafowl in several countries. The
eggs are passed down the lachrymal ducts and voided with faeces. Cockroaches
serve as the intermediate hosts of the parasite, through the in-
gestion of which the final host acquires infection. The larvæ are liberated
in the crop and travel up the oesophagus, pharynx and lachrymal ducts and
finally reach the eye through the naso-lachrymal ducts. The presence of a
few worms does not cause any apparent inconvenience, but in severe in-
festations, when as many as 50 worms may be present, an acute irritation
of the mucous membrane is produced. The bird becomes uneasy and scratches
the eyes with its claws. Acute inflammation with excessive lachrymation
and accumulation of a cheesy material cause the adhesion of the eyelids. The
lesions vary from conjunctivitis to severe ophthalmia, blindness and even
destruction of the eyeball. The worms are located by depressing the lower
eyelid and removed with a small pus scoop. After removing the worms,
irrigate the eye daily with 10 per cent solution of argyrol or with a 2 per
cent solution of cresol. Solutions of sodium bicarbonate and of boric acid
also help to alleviate the inflammation. Control measures are the same as
against the stomach worms or the flukes occurring in the oviduct.