From Middle English, from Old English efen, efn, emn â(â even, equal, like, level, just, impartial, true â), from Proto-Germanic *ebnaz â(â flat, level, even; equal, straight â), from Proto-Indo-European *(hâ)emno- â(â equal, straight; flat, level, even â).
1 Puppies can receive the injectable vaccine starting at 6 to 8 weeks of age, followed by a booster between 10 and 12 weeks of age. 2  For adult dogs or puppies older than 16 weeks, the intranasal vaccine can be given once, and the injectable vaccine should be given twice, two to four weeks apart. Kittens can be vaccinated intranasally as early as 8 weeks of age. 2  Puppies can receive the injectable vaccine starting at 6 to 8 weeks of age, followed by a booster between 10 and 12 weeks of age.
1 Adult cats and kittens older than 16 weeks of age can receive a single intranasal vaccine. 2  Annual boosters are recommended for cats with known risk of exposure. 3  Dogs should receive boosters every 6 to 12 months, depending on exposure risk. For adult dogs or puppies older than 16 weeks, the intranasal vaccine can be given once, and the injectable vaccine should be given twice, two to four weeks apart.