In this study, clinical findings, virus recognition and the activity of some  lysosomal enzymes such as β-N- acetyl glucosaminidase (β- NAG) Acid phosphatase (ACP) and β- galactosidase (β- GAL) in serum of Egyptian dairy cows and sheep naturally infected by foot and mouth diseases were determined.
In addition, the lysosomal enzymatic activities in vaccinated animals were also performed. The results revealed that the enzymes activity of ACP was increased by 454% and 806% in vaccinated cows and sheep respectively, while the activity appeared to be less in infected animal either in cow by 182% or 580% in sheep. β -NAG activity exerted a relative lower of the percentage change by 3.3% and 99.0% either in cows or in sheep of vaccinated animals. While in diseased animals the enzyme activity of β- NAG was reduced by 5.6% for cows and increased by 767% for sheep. On the other hand, the enzyme activity of β- GAL appeared to be of moderate activity of enzyme release either in vaccinated or infected animals by 119%, 574% for vaccinated cows and sheep respectively and 54.7%, 1171% for diseased cows and sheep respectively. The obtained results revealed that the enzyme activity of the lysosome was altered according to vaccinated or diseased animals. ACP activity approved to be highly activity in the vaccinated cows than in the diseased ones. The activity of β- NAG in sheep exerted a highly percentage change more than in cows in both of vaccinated and diseased animals. β- GAL activity exerted a highly activity in the diseased animals more than vaccinated animals for sheep.
We have concluded that the lysosomal enzymatic activity was highly increased in sheep more than in cows either vaccinated or diseased animals. This study might be open the route for using the lysosomes as adjuvant with FMD vaccine or for increasing the protection against FMD.