While multiple DNase activities occur in the excretory/secretory products (ESPs) of the adult Haemonchus contortus, the DNase activities in ESPs of the infective larvae (L3) have not been studied. Thus, the DNase activities in ESPs of H. contortus L3 were investigated and compared to those of adults for developmental stage-specific analysis. The DNase activities had relative molecular masses (M rs) of 34 and 36 kDa upon zymographic analysis at pH 5.0 and 7.0 when the larvae were incubated for over 48 h. The 34 and 36 kDa DNases of L3 ESPs were also detected in adult ESPs with similar characteristics. However, the 37 and 38.5 kDa DNases of the adult ESPs were not detected in the L3 ESPs. Since the 37 and 38.5 kDa DNase activities were mainly detected in adult ESPs, these activities appear to be specific to the adult stage whereas the other ESP DNase activities appear to be expressed during multiple stages of the parasite's life cycle. While the difference in DNase activities of L3 and adults remains obscure, the role of DNase in larval development should be further clarified and the identification of stage-specific developmental markers will lead to the discovery of specific factors that stimulate larval development.

A 3-year-old colt Thoroughbred horse was referred with obvious lameness (3/5G) and mild heat and pain on left hoof of forelimb. He was diagnosed with quarter cracks that have a typical conformation of sheared heel, which are a different length and height between medial/lateral heels. Various materials and techniques were carried out to repair quarter cracks by using many different kinds of clips, bar shoes on fifth times for about 10 months. It worked on him without pain and heat on the cracked hoof, and then he could retrain for racing from the 36th weeks beginning of therapeutic shoeing. We suggested that especially fiberglass reinforced plastic (FRP) material and therapeutic shoeing were a great help to treat quarter cracks induced by sheared heel.