The detection of specific DNA sequences by Polymerase Chain Reaction (PCR) has been proven extremely valuable for genetic analysis and diagnosis of a variety of infectious disease pathogens in the veterinary sciences. Genomic techniques applied to veterinary medicine has become fundamental, whether for the detection of pathogens through the use of PCR and its variations or by other techniques that allow the creation and development of recombinant proteins and vaccines for veterinary use. PCR technology has become an indispensable tool in veterinary diagnosis. Other techniques, which play an important prophylactic role for several infectious diseases of veterinary interest, such as recombinant vaccines and sequencing, are important tools in the fight against the most pathogens. In this review, the details of PCR technology are explored, as well as some variations of the technique, such as real-time PCR, as well as other genomic techniques of veterinary interest.