Posted on 11/08/2007 7:09:03 PM PST by blam
How Well Do Dogs See At Night?
ScienceDaily (Nov. 9, 2007) — A lot better than we do, says Paul Miller, clinical professor of comparative ophthalmology at University of Wisconsin-Madison.
Dogs have good night vision, due in large part to the tapetum, a mirror-like structure which reflects light, giving the retina a second chance to register light that has entered the eye. This is also what makes dogs eyes glow at night. The dog is holding a toy in her mouth. (Credit: Michele Hogan)
“Dogs have evolved to see well in both bright and dim light, whereas humans do best in bright light. No one is quite sure how much better a dog sees in dim light, but I would suspect that dogs are not quite as good as cats,” which can see in light that’s six times dimmer than our lower limit. Dogs, he says, “can probably see in light five times dimmer than a human can see in.”
Dogs have many adaptations for low-light vision, Miller says. A larger pupil lets in more light. The center of the retina has more of the light-sensitive cells (rods), which work better in dim light than the color-detecting cones. The light-sensitive compounds in the retina respond to lower light levels. And the lens is located closer to the retina, making the image on the retina brighter.
But the canine’s biggest advantage is called the tapetum. This mirror-like structure in the back of the eye reflects light, giving the retina a second chance to register light that has entered the eye. “Although the tapetum improves vision in dim light, it also scatters some light, degrading the dog’s vision from the 20:20 that you and I normally see to about 20:80,” Miller says.
The tapetum also causes dog eyes to glow at night.
Adapted from materials provided by University of Wisconsin - Madison.
How do the Shiloh Shepherds compare with GSDs for hip problems, size, temperament, in your opinion? Just curious...
I am not sure what the hd percentages are. We are still working on it. The Shiloh Shepherd does have GSD in ther lines. They are larger than the GSD, have straight backs; . In other words; they are like old GSDs. I love the GSDs and am so glad they have them in their lines. It is my understanding that there is GSD, malmute(for bigger bone and white GSD in their background. I had mentioned color and a lot of the Shilohs have the old GSD colors. You will not see much, if any of Thunder’s colors. Of course, they are like the GSD in so many ways; for example; tilting their heads; talking to you; licking your feet(I am sure many GSD owners know what I am talking about). I think their temperament is like the old GSDs which is a little more mellow; but you know how that goes. It depends greatly what lines you use to breed.
They only used the malamute for a while because the ears on the Shilohs were soft(wouldn’t stand)but the malamute gave them their size and good big and strong bones.
Thanks for that info. The American Mastiff from Flying W is 7/8 OEM and 1/8 Anatolian. They are dry mouth and healthier in general, but of course can’t be shown (CKC registry only). Flying W used to raise OEMs, but Fredericka, an honest breeder, decided she liked the combo so much that she went exclusively to the “American Mastiff.” I love them, they have all the good points of the OEMs plus are healthier and hardly ever get slobbery. ;-D
It’s the only breed I’ll ever own, from now on. Very smart dogs, very kind. And with rheumatoid arthritis, I find my mastiff to be helpful and not difficult. Plus I don’t have to bend over to pet him! LOL!
They are just beautiful. I love the big dogs; my SIL has two of the big black water dogs, duh, the name escapes me at the moment. Newfoundlands.
They are terrific with her grandson, 2 yo, and very smart as well, but she has trouble with the coat, it’s so heavy and long.
I think the Newfoundland is one of the most beautiful dogs I have ever seen. I see them at shows all of the time. They are loveys.
I know the CKC. Mine are NKC and show at IBACA or ARBA. I think I have seen their website and was very impressed. A dry mouth with the mastiffs is a definate plus. LOL
I have aches and pains now due to age and it’s not easy bending over much so that is a plus not having to bend down and pet them. It’s also good for medicine giving and grooming. I use the vacumn hose on them. Thunder really loves it. I am still training the others. Did have five pound pups that I had until they all passed away that actually stood in line waiting to vacumed. LOL
There is a cattle blower out there a friend of mine uses on her shilohs. It will take all the dead loose hair off the dogs. It will get dirt; even ice. She uses it before they come in. Lives on a working ranch in OR. This might help your friend. They really work; but don’t recommend for small dogs as they would probably be blown over the fence. She should look up cattle air blowers. There is one that is really good. If I could find it; I could tell what the name is. I will see if I can find it. I think it is air something; but that could probably help your friend a great deal.
I looked up the Shiloh Shepherd founders website, very impressive. Looks like a woman who REALLY cares about dogs.
LOL. I understand completely. I have had 7 rescue dogs. Still have 2 of them. The others have since passed and I would not trade them for the world. I just fell into the pure breeds. At my age; if you had told me I would be breeding, showing and raising these dogs; I woud have laughed. No way. Funny how things happen. I love the Danes. My family had 7 of them. They are absolutely gorgeous.
One of my rescues; a blue heeler lab mix weighed 90 lbs lived for 17 years. The rest were between 16 and 11 years. They were all big dogs. As you can see; whether they are purebreeds or rescues or mixed or whatever; they are your heart and soul. I loved everyone of them and had the great opportunity of having them with me. I will never forget any of them cats included. It doesn’t really bother me if I don’t breed my guys; but it would be a shame not to carry their lines on.
I have enjoyed our conversation very much. All the best to you and your furkids, they have that “loved” look about them, and I am sure they are great company.
I got mine as a birthday present for my dear husband 3 years before he died; the mastiff was such a comfort to him when he was sick, he often said, “This is the greatest gift I have ever been given.” I think an angel led me to the Wagners, and their wonderful dogs.
I have too.
The ancient Greeks thought that only dogs could see the witch goddess Hecate.
My classics professor explained that they probably got the idea because dogs have better senses than humans. When their dog barked at something the dog’s owner could not see, he might think the dog was barking at Hecate.
I heard something like 50% of men are color blind. I don’t know if I’d say I’m color blind exactly, but I have trouble distinguishing some colors. I had to ask a friend what color a certain shirt was in the clothing store the other day.
Just a note to let you know I saw a mastiff named Angus in the show ring tonight on the Animal Planet, and thought of you. He sure is a beauty.
Oh, thank you. I appreciate that.
My tastes progressed beyond that when I got to be 25.
cats see better is my guess
dogs sure hear well though
wow.....blam your rock history predates mine by a few years...high school class of 75.
were you at that Southern Jam in 1974 with all the southern bands at the bowl in Mobile?
btw....you always have good threads
ps....i saw Hendrix open for the Monkees in late 67.....didn’t know who he was the first few songs I’m ashamed to say....I was 10 or 11
That's because I'm older than you. HS class 1962.
"were you at that Southern Jam in 1974 with all the southern bands at the bowl in Mobile?"
No.
"btw....you always have good threads
Thank you.
"ps....i saw Hendrix open for the Monkees in late 67.....didn’t know who he was the first few songs I’m ashamed to say....I was 10 or 11"
1967 was 'The Summer Of Love' and my only child was conceived that year. That year, I spent sundays in Golden Gate Park listening to a local unknown band named The Grateful Dead who gave free concerts for the hippies every sunday.
I began working in the chip-making business in that year too.
I still love it. LOL
I am also a big blues fan.
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