Thomas Aitken Dollar was born 3 October 1833. He had been a student of William Dick (1793-1866), veterinary scientist, at the then Edinburgh Veterinary College. He was awarded the Highland and Agricultural Society's certificate in 1851. Dollar was the founder of the equine veterinary practice T. A. Dollar and Sons, Veterinary Surgeons, New Bond Street, London. In 1880, he was Vice-President of the Royal College of Veterinary Surgeons. By the time of Dollar's death, the veterinary practice was the largest in London with a presence (veterinary forges) in Baker Street, in Westminster, in Blackfriars, in Lambeth, in Belgrave Square, in Chelsea, and in Paddington. The practice also had paddocks at Wells House Farm, East Acton. During the 1880s, his sons John Archibald Watt Dollar (1866-1947) and William Watt Dollar (1860-1938) joined the veterinary practice.

Thomas Aitken Dollar died on 26 September 1909.