This is a bit about why dogs senses are how they are and how selective breeding has impacted breeds.
As I'm writing this I currently in the garden and have a small fury, ball in mouth (looking much like a stuffed pig at a hog roast) trying desperately to gain my attention by crying at the highest note her little voice can go, I may have to go and play with her before I can get any more of this written....
It is clear thatas the human environment has evolved, the use for canine has changed dramatically. Adaptions to the canine senses have been a result of evolutionand selective breeding by humans. Wolves and dogs have always had a good way ofadapting their senses; if one sense is not functioning as it should the other senses will compensate.
One way canines have adapted their senses is vision. A study carried out by Jonica Newby, DVM showed evidence that a dogs vision is directly effect by the length of the muzzle. Brachycephalic dogs that evolved with short noses have a higher density of vision cells that are arranged in area centralis this means these dogs see very alike to humans “Could mean shortfaced dogs are more attuned to reading the facial expressions of their owners” (TheBark, 2004). This was adapted through years of selective breeding however it is arguable that the facial recognition that dogs have developed is a more evolutionary process.
Similarly there is evidence to suggest these brachycephalic dogs have had their sense of smell hampered due to selective breeding "The whole brain had rotated in more pug-likedogs… and the olfactory lobe had shifted to the bottom of the skull.”- MichaelValenzuela (2010) a study into brachycephalic brains showed that their brains had morphed and the lobe used for scent in the brain had largely shifted position compare to the more wolf-like breeds.
Although Dogs have exceptional hearing over years of both selective breeding and evolution, hearing has declined greatly from how good wolves hearing once was, this is because certain breed don’t use their hearing as much and the physical appearance of the ear has evolved and changed a great deal. Dogs have adapted scent andsight so well hearing has not been a main sense, an example of this is how dogs have adapted the shape of their ears to assist in collecting scent particles.However dogs still use hearing for a variety of things such as guarding properties and protecting owners at night.
Finally taste has been altered over time by evolution. A combination of relying on humans, more variety and having a cushy life dogs have evolved to become fussy eaters. Dogs have developed an inbuilt trust in what humans feed them, they can take a treat without sniffing it first so the harmful v. harmless instinct has begun to be overtaken by favourites and dislikes. This is evident in smaller dogs the breeds bred to be companions and ‘lap’ dogs as they seem to be more spoilt by owners as people attach to them like children, as a result smaller dogsare very discriminative of food stuffs. “If you asked your child would she rather eat spinach or a Twinkie, the answer is obvious”- Louise Murray, DVM (2012)
Again I'm not trying to go too in-depth just making food for thought, hope you liked it!
Happy Wagging, Freya xx