Just briefly sniffing, while I carefully watch, is okay.

Anything more is not.
Amaryllis plants and bulbs are toxic to dogs.
Therefore, these plants - except when I'm photographing one - are normally always kept totally out of Chihuahua reach.
I watch the girls extremely carefully whenever an amaryllis is down at their level.
A quick 2 second sniff is okay. A 5 second one is not. That means the plant has evoked too much of attention.