Larvae - growth and emergence of larval stages, esp L 5 , causes: 
·Distension of glands 
·Local pressure necrosis 
·Metaplasia of columnar to cuboidal epithelium 
·Loss of epithelial (cellular) bridges 
·Leakage of albumen, uptake of plasma pepsinogen, loss of ·Hcl, no pepsin production - neutral pH 
·Dyspepsia (heartburn), off-feed 
·Some scouring, loss of condition 
·Migration of intestinal bacteria into abomasum 
·Possible septicemia 
·Edema of all tissues including gut wall (leaves of abomasum), peripheral tissues 
·Exacerbated by pre Type II larval population due to numbers.