Heartbeat of Dog Recorded to Help Detect Animal Ills.
The Ithaca Journal, May 12 1950, P. 2

'A terrier's heartbeat on phonograph record offers Cornell University veterinary students a new way to detect faulty "tickers" in small animals. This is the first time this type of educational device has been used by the Veterinary College.
  Credit for the recording goes to Dr. Irving Stern, medical interne in the small animal clinic, who points out that the purpose of the record is to aid students to correctly diagnose heart ailments.
  Supervised by Dr. Stern and transcribed by radio specialist T. D. Richards of the Department of Extension Teaching and Information, the record was made by means of a tape recorder connected to a stethoscope and a phonograph record-cutter. The recording is that of a 12-year-old rat terrier's heartbeat that suffers from an unusual type of cardiac irregularity.
  "The advantage of this medical recording," says Dr. Stern, "is that all students may now hear the same type of heart defect at one time and interpret it correctly. Furthermore, since animals under inspection are usually uneasy and distract students, this transcription eliminates that confusion. In this way, instructions are clearer and more understandable."
Dr. Stern also points out that formerly it was difficult to obtain an animal with the right abnormality when that type of defect was studied. This is changed now by a permanent recording of the sound on file for future use.
  These medical sounds will be as near as the classroom phonograph, says Dr. Stern.'