Mars, the fourth-largest privately held company in the U.S., has agreed to buy the pet diagnostics and specialty products company Heska (NASDAQ: HSKA) for $120 per share. This buyout agreement represents a 23% premium relative to Heska's closing price last Friday. Through this deal, Mars will gain Heska's rapidly growing suite of pet diagnostics products, which are quickly becoming an integral part of the veteinary practices across a wide range of geographies.