Symptoms. Dia^^nosis. 455 



lying tissue from the thickened epithelial covering. There is a proliferation of the 

 gastric glands and microscopically small adenomalike formations subsequently de- 

 velop in the tissues below the base of the ulcer. After the detachment of the 

 larvae cicatricial nodules remain in the mucosa. 



Symptoms. Aside from those very rare cases which go 

 on to perforation, the invasion of a larger number of Gas- 

 trophihis larvse leads, particularly in foals, to symptoms similar 

 to those of strongylosis in lambs (stomach-worm disease of 

 lambs, Kroning). According to the intensity and the time of 

 the infection and the nutritive condition of the affected animals, 

 the symptoms come on either towards the end of the period of 

 pasturing or shortly after the stabling of the animals, or occa- 

 sionally only during winter. In the foreground of the clinical 

 picture are variable appetite, poor appearance of the animal, 

 pale discoloration of the mucosae, marked emaciation and occa- 

 sionally symptoms of colic. The heartlieat becomes thumping, 

 the pulse weak, the general condition poorer and poorer, and 

 the animals, which finally suffer from a complete lack of appe- 

 tite, have dwindled down to mere skeletons, so that they finally 

 cannot get up from the floor any longer. If proper treatment is 

 not instituted the animals may die from six to eight week after 

 an intense invasion (Kroning) or perhaps only after two to 

 four months; in milder cases spontaneous recovery occurs. 

 Kater observed in a horse the picture of stenosis of the duo- 

 denum ; Tegg that of pylorus stenosis ; Rexilius saw increasing 

 cachexia, lack of appetite and increased thirst. 



The presence of larvae of Gastrophilus hgemorrhidalis and 

 (t. nasalis causes an irritable condition of the rectum, which 

 leads to symptoms of gastric catarrh (frequent defecation, 

 straining, itching, eventually excitement and restlessness, sim- 

 ilar to those in colic) ; straining may exceptionally lead to pro- 

 lapse of the rectum. 



Diagnosis. The greatest significance must be attached to 

 the history of the case (onset of the disease shortly after a 

 rather long period of pasturing) with a negative result of the 

 examination of the various organs. Additional evidence is 

 forthcoming if Gastrophilus larvae are expelled from time to 

 time per rectum and if such larvae are found attached to the 

 rectum. Cachexia of foals (see page 342), can be excluded by 

 the fact that it disappears entirely during pasturing or at least 

 improves considerably. The presence of ascaris in the intes- 

 tines can be ascertained by finding the worms of their ova in 

 the feces. The exclusion of sclerostomiasis is always very 

 difficult and often can be made only on postmortem examina- 

 tion ; both diseases may occur simultaneously. Infectious anemia 

 attacks horses without difference of age and, in chronic cases 

 which alone have to be considered with reference to differential 

 diagnosis from gastrophilus infection, causes repeated attacks 

 of fever with little disturbance of appetite. 



