Interesting, when you mentioned testing I just had a memory pop up of a dog named Leo who was featured on a Japanese tv show who could differentiate male from female by not only being in direct contact but from a photo as well. They tried to trip him up by presenting surgically altered, very feminine people, but Leo had no hesitation. I think he would raise his paw for one and not the other, and for photos, they were separated into red an blue baskets. If you think about it, doesn't matter how much wrapping is on something, professional dogs always find the substance, as well as picking up on biochemical changes to alert people with illnesses. Probably easy to train a smart dog.
Interesting, when you mentioned testing I just had a memory pop up of a dog named Leo who was featured on a Japanese tv show who could differentiate male from female by not only being in direct contact but from a photo as well. They tried to trip him up by presenting surgically altered, very feminine people, but Leo had no hesitation. I think he would raise his paw for one and not the other, and for photos, they were separated into red an blue baskets. If you think about it, doesn't matter how much wrapping is on something, professional dogs always find the substance, as well as picking up on biochemical changes to alert people with illnesses. Probably easy to train a smart dog.