Some canine vaccines against respiratory infections are given as a nasal spray, e.g. https://www.merck-animal-health-usa.com/nobivac/nobivac-intra-trac3 https:

Some canine vaccines against respiratory infections are given as a nasal spray, e.g. https://www.merck-animal-health-usa.com/nobivac/nobivac-intra-trac3 https://www.merck-animal-health-usa.com/nobivac/nobivac-intr...