The second sentence of the original text contains an example of what is traditionally called the first conditional. This combines the present tense (in the dependent clause starting with if) and the future with will (in the main clause) to state the consequences of a future event.
If you do that again, you will regret it.
This combination of 'tenses' is not what is generally regarded as a tense shift. Tense shift typically occurs when the speaker changes the time perspective of a narrative. Sometimes this shift is simply ungrammatical:
She was sound asleep because she has taken a sleeping pill.
But the shift is often used correctly for dramatic effect:
I was walking down the street minding my own business, when suddenly
this guy runs up and starts yelling at me.
The OP's reworded sentence:
But put the animal to your nose and you find ...
is a variation on the so-called zero conditional containing the present simple in both clauses. This conditional generally conveys a greater sense of the inevitability or certainty of the consequence. As such this conditional is often used for natural laws:
(If you) heat ice, it melts.