Endolysins are enzymes produced by bacteriophages at the end of their replication cycle. These enzymes degrade the peptidoglycan layer, resulting in lysis of the infected bacterial cell and release of the newly matured bacteriophages. Recombinantly produced and purified endolysins constitute a novel class of enzyme-based antibiotics (enzybiotics) that fulfill all innovation criteria defined by the WHO. Endolysins are currently developed for human therapy with the first clinical trials showing a high safety profile and superior results. However, the application potential of endolysins is much wider, including veterinary applications. We will investigate a pre-selected and highly efficient endolysin for the treatment of infectious diseases in veterinary medicine. Our approach takes the One Health principle into account since reducing the amount of critically important antibiotics (for human use) in veterinary medicine will slow the progress of the global antibiotic resistance crisis.