Tuesday, 20 April 2010

ABC Wednesday N is for Noses

Dogs' noses are incredibly receptive.
Buddy Liver Spots is quite deaf and almost blind and relies on his nose to find his way around. To hear him snuffing about in the wee small hours one might imagine a steam engine approaching!

His sense of smell is a dog's most sophisticated sense and a large part of the canine brain is dedicated to interpreting scent. A human nose has 5 million olfactory cells. An average canine nose has over 200 million receptors. The canine sense of smell is thought conservatively to be 50 to 100 times better than a human's. Some have suggested it may be as much as 1000 times better. Scientists explain this by saying that human scent cells may cover about one square inch while a dog's scent cells can cover 60 square inches.

Dogs can pick up some odours in concentrations of one part per trillion. Bloodhounds have 300 million olfactory cells in their noses and it is a matter of record that one bloodhound followed a scent trail for 114 miles.
Even when fast asleep a dog can be brought to sudden wakefulness within seconds through the careful placement of food near its nose.Humans have exploited this remarkable sense, training dogs to discover drugs, detect guns and explosives, find bodies in collapsed buildings, rescue people lost on moors or mountains. Some dogs have been trained to alert their owners to the onset of heart attack, migraine, epileptic seizure, diabetic imbalance, often as much as 30 minutes before onset. It is thought that a change in metabolism or body chemistry generates a different smell detectable to the dog. Studies are currently being conducted to test the dog's ability to detect cancer cells.
Cats' noses are also very sensitive.
A cat's sense of smell is fourteen times greater than a human's. A cat that loses its sense of smell will not be able to function effectively. If an outdoor cat it will be unable to hunt, as it depends on smell more than any other sense to find prey. If it cannot smell even an indoor cat will not eat – cats always sniff their food thoroughly before eating.
The vomeronasal organ (Jacobson's Organ) is functional in both dogs and cats and allows a greater intensity of smell. It is found just behind the upper front teeth and connects directly with the nasal cavity. Cats can often be seen demonstrating the Flehman Response, when, stimulated by a scent, they will open their mouths to enable the vomeronasal organ to open the ducts to the nasal cavity. Some people describe this as a smile, though I have always thought of it more as a sneer!
Thank you to Denise Nesbitt and her team for their efforts in organising and hosting this meme. Find more Ns here and add your own, if you will.


  1. What an interesting post, Janice! I know dogs noses are very sensitive, and cat's too, but didn't realize just how sensitive!! Fun one for the day! Enjoy your week!


  2. That was interesting. Waking up at the smell of food was, though, an ability of some of my children, too :-)

  3. Yes, very interesting!! cute noses, too :)

    N is for numismatic!

  4. very cute pictures, great post :)

  5. You must have had quite a time photographing all those noses - we've had 3 dogs in the past 30 years and they all have had varying degrees of "good noses." This was very interesting and I thank you!

  6. Totally fascinating. I learned a lot about noses. Great post today.

  7. Very informative. the nose knows!

    ROG, ABC Wednesday team

  8. Great N! And I have observed my cats opening their mouth after smelling something, but never knew why they did it. Thank you for the information.

  9. I really enjoyed reading all this about noses (in fact, I almost did "nosebleeds" but thought people might be a bit put off). Great photos of all your pets, too!

  10. what a clever ideas of posting an N!

  11. What a great post and I love the photos. I wondered about the cat too as I have lived with them and often remarked about their remarkable sense of smell. A

  12. Now that is an impressive post - full of fascinating info!
    I find it so intriguing that dogs can sense illness in their masters. What a life-saving ability that is.
    Thanks for a great post.

  13. Cute noses. I wanted to post my cat's nose because it is all white and pink with one black spot on it, but I had no other pictures to go with it. I suppose I could have posted my nose -- but I don't think that would be of much interest!

  14. Very informative post - I didn't know all those details about dog's noses - and cat's, too. And they put them to such good use. Was interested in their ability to detect health problems, - what good and faithful creatures dogs are, - and cats can be pretty intriguing too!

  15. Wonderful and informative post. It is amazing how Buddy find its way just by his nose.

    ABC @ Nandi Teertha Temple

  16. Such sweet noses ! I like the expression of a steam engine, lol ! My cat Pookie must have a congested nose because she snores like a man ! It's really terrible !

  17. I love reading about the biology behind senses and the facts and figures too! I knew about the vomeronasal organ, and the Flehmen response - it's also the reason dogs taste things that smell particularly interesting to them - grass that other animals have peed on, for instance.

    But the actual statistics escape me after a very short time, so the details on just how many more olfactory cells dogs have was handy, since OH and I were discussing this just yesterday and I had no figures for him. )

  18. Fascinating! I remember reading a science fiction story about a cure for the common cold that had been derived somehow from the fact (they said) that a dog doesn't suffer from colds. The result was that humans ended up with a dog's sense of smell -and were horrified. :)

  19. Thanks for visiting my blog.
    This was really a great collection of noses:-)
    Have a nice evening!

  20. Well, I knew dogs and cats had sensitive noses...but I had no idea they are THAT sensitive. I enjoyed this post!

  21. An interesting set of noses and facts. Made me wonder why dogs have cold noses. I love the Monty's whiskers photo.

  22. Lovely post for ABC Wed.

    On behalf of the ABC Wed. team thanks for playing.


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