Dr. William R. Haagenson, a graduate of the Ohio State University College of Veterinary Medicine, has been associated with Nassau-Suffolk Animal Hospital since 1992, and was past Medical Director. Although he treats all breeds of animals, he is known particularly for his expertise in treating English Bulldogs and their unique medical conditions. Dr. Haagenson has been recognized by several bulldog organizations for his exceptional knowledge and treatment of this breed. He has received a number of awards, most recently from the Long Island Bulldog Rescue, and has been consulted on issues relating to this breed from Vancouver, Las Vegas, and throughout the United States. Dr. Haagenson has been invited to do veterinary relief work in Bermuda and to participate in a spay and neutering program for the Humane Society in Belize.

Dr. Haagenson is known as an especially concerned and diligent veterinarian, a skilled surgeon, and an expert diagnostician. Always available to his clients and patients, he is a strong advocate for the health and well-being of all animals. He is a firm believer in educating the public in proper animal care. In the past, he demonstrated a spay procedure at the New York State Fair in Syracuse.