What is the ruling on saying "May Allah honor you" when mentioning an animal, and what is the evidence for that, knowing that humans are honored?

There is no evidence in the Sunnah for the desirability or obligation of saying "May Allah honor you" when mentioning an animal. The Prophet, peace and blessings be upon him, did not say that when mentioning dogs or donkeys. However, there is no harm in saying it if people find it objectionable not to say it and think ill-mannered of the speaker, or if it is known that the listener dislikes hearing certain words.