Final answer:
Veterinarians in Ontario must report immediately notifiable hazards to the Chief Veterinarian of Ontario as soon as they suspect or diagnose them, to protect both animal and public health.
Step-by-step explanation:
Under the Ontario Animal Health Act, veterinarians are required to report an immediately notifiable hazard to the Chief Veterinarian of Ontario without delay upon suspicion or diagnosis. This rapid reporting is crucial to prevent the spread of diseases that can be significant to animal health and potentially public health, including zoonotic diseases such as the highly pathogenic avian flu virus H5N1. While not explicitly specified in the provided information, this requirement aligns with the protection of animal welfare and public health, similar to the Animal Welfare Act (AWA) and the Public Health Service Policy on Humane Care and Use of Laboratory Animals (PHS Policy) in the United States, which involves veterinary oversight and reporting as part of ensuring humane and responsible animal care and research practices.