The father was grandson of James Simonds (born in 1717), who early left the original family home at Redenhall, Norfolk, for Halesworth, Suffolk.
Settling in London, and disposing of his practice at Twickenham, he was active in the movement for obtaining the charter which was granted on 8 March 1844 to the Royal College of Veterinary Surgeons, of which in due course (1862–3), he became president.
He took a prominent part in the efforts of the Royal Agricultural Society to popularise information amongst farmers as to the diseases of animals, and he investigated their causes and means of prevention.
The privy council office, owing to doubt of its legal powers, delayed the issue of an order for the slaughtering and burial in quicklime of all diseased animals, until the infection had spread over a great part of England.
He remained senior consulting veterinary surgeon to the Royal Agricultural Society until his death, at the age of ninety-four years, on 5 July 1904.