In July of 1906 New York City opened a tuberculosis sanatorium and kept horses on site for their blood, which could be used for vaccinations. The sanatorium is long gone, but the unit has been retiring police horses here since the early '80s, according to city officials. The Antitoxin Laboratory was associated with but a separate entity from the sanitarium. They developed anti toxins and various vaccines for Diphtheria and Tetanus especially during WWI.
In 1983, the city sold the land, but included a covenant in the lease that required the buyer, Biotech Inc., to care for the old horses for as long as the city maintained mounted patrols, plus 10 years.
In return, the company could draw horses' blood for biological products. The company took blood samples from them for their research. The company planned to develop a synthetic blood substitute, But their research did not pan out and the company folded a few years ago.
I don’t know if there are any plans for the former BioTech Inc. laboratory, but as of right now, it’s still sitting vacant.