**Viruses and bacteria are involved in the complex
**Viruses and bacteria are involved in the complex
−
** The most frequent aetiologic agent is FHV-1, and less frequently feline calicivirus and/or [[Chlamydia and Chlamydophila species|''Chlamydophia psittaci'']]
+
** The most frequent aetiologic agent is FHV-1, and less frequently feline calicivirus and/or ''[[Chlamydophia psittaci]]''
**All three agents infect URT respiratory epithelium, although FHV-1 has the highest affinity for this epithelium
**All three agents infect URT respiratory epithelium, although FHV-1 has the highest affinity for this epithelium
***Feline calicivirus more frequently infects the oral mucosa -> ulcerative stomatitis
***Feline calicivirus more frequently infects the oral mucosa -> ulcerative stomatitis