48 REPORT ON INJURIOUS INSECTS FOR 1907. 



PARASITIC DISEASES OF ANIMALS. 



RED WORMS. 



Sclerostomum annatum, Duj. 



A Warwickshire correspondent wrote describing a disease his 

 horses were suffering from in February last. A visit was paid to the 

 farm, and a careful inspection made of, and a Report upon the same. 



The cause of the disease was a small nematode worm, commonly 

 known as u Red Worm," the "Red Strongyle," or the "Armed 

 Sclerostome." It is a common parasite in this country and throughout 

 Europe. 



LlFE-HlSTORY. 



The eggs of the worm pass from the horse, and either on damp 

 ground or in w 7 ater they develop in two or three days into tiny 

 white worms. Should the eggs fall on to dry ground they will retain 

 their vitality for some weeks. 



The embryos are taken into the intestinal canal of the horse, either 

 in the drinking water, or off damp grass. On reaching the intestines 

 they commence to burrow their way into the mucous membrane of 

 the intestinal wall and ultimately pass into the blood system. They 

 are now carried with the blood stream, and on reaching the main 

 arteries form an aneurism swellings caused by thickening of the wall 

 of the vessel. 



These swellings vary in size from that of a pea to a man's head, 

 but average that of a walnut. 



In the clot of blood occupying each swelling the embryo worms 

 live. By this time they have developed to a length of about five- 

 eighths of an inch, and now assume a pink or reddish colour. 



The fact of the formation of these aneurisms is what constitutes 

 this parasite so serious a danger, for, owing to clots passing from the 

 swellings, small arterial blood vessels become blocked. Short and 

 violent colics often ensue from this cause, or the small blood vessels 

 may rupture and cause the death of the animal. Owing to the 

 diminished blood supply to the intestinal region chronic indigestion 

 troubles are set up. 



Ultimately the parasites are carried by the blood stream to the 

 walls of the intestines again, and burrowing back they reach the sub- 

 mucous layer, where they form cyst-like tumours, varying in size from 

 that of a pin head to that of a hazel-nut. Here they remain for some 

 time, finally escaping by a hole at the summit, and passing into the 



