Final answer:
The two most common agents involved in feline respiratory disease complex for which vaccines exist are calicivirus and herpes virus.
Step-by-step explanation:
The two most common agents involved in feline respiratory disease complex for which vaccines exist are:
- Calicivirus: This virus is a major cause of feline upper respiratory disease and can cause fever, sneezing, and oral ulcers in cats.
- Herpes virus: Also known as feline herpesvirus 1 (FHV-1), this virus is another common cause of respiratory disease in cats and can cause symptoms like sneezing, nasal discharge, and conjunctivitis.
Vaccines for both these viruses are available and can help prevent the development and spread of respiratory diseases in cats.