why does a dog always shake its leg if you scratch it in a certain spot?

A mighty good question i got the answer for u to~~~~~~~ “Tickle a dog's tummy, and you could get a knee-jerk reaction.

There is a certain area on a dog's body that is referred to as the

"saddle region." It vaguely consists of the back, sides and flanks of

the pooch. Rubbing or scratching a dog in the saddle region (the exact

spot varies according to the individual pet) will cause the hind leg

to simulate a scratching motion. This is called the "scratch reflex."

The dog's spinal nerves pass all the way to his chest and abdomen, and

stimulation of these nerves will cause a feeling of "itchiness"

(similar to the irritation of a flea) somewhere on his body, causing

the rear leg to involuntarily attempt to scratch it. The leg extends

to different lengths or reaches to varying heights depending upon the

area that is stimulated."

Seeing a dog shake their hind leg is indeed a funny looking reflex!

“Tickle a dog's tummy, and you could get a knee-jerk reaction.

There is a certain area on a dog's body that is referred to as the

"saddle region." It vaguely consists of the back, sides and flanks of

the pooch. Rubbing or scratching a dog in the saddle region (the exact

spot varies according to the individual pet) will cause the hind leg

to simulate a scratching motion. This is called the "scratch reflex."

The dog's spinal nerves pass all the way to his chest and abdomen, and

stimulation of these nerves will cause a feeling of "itchiness"

(similar to the irritation of a flea) somewhere on his body, causing

the rear leg to involuntarily attempt to scratch it. The leg extends

to different lengths or reaches to varying heights depending upon the

area that is stimulated.

Veterinarians who suspect spinal or neck damage in canines use the

scratch reflex as a diagnostic tool, much like when doctors tap humans

just below the kneecap to test nerve reactions.”

There is a certain area on a dog's body that is referred to as the

"saddle region." It vaguely consists of the back, sides and flanks of

the pooch. Rubbing or scratching a dog in the saddle region (the exact

spot varies according to the individual pet) will cause the hind leg

to simulate a scratching motion. This is called the "scratch reflex."

The dog's spinal nerves pass all the way to his chest and abdomen, and

stimulation of these nerves will cause a feeling of "itchiness"

(similar to the irritation of a flea) somewhere on his body, causing

the rear leg to involuntarily attempt to scratch it. The leg extends

to different lengths or reaches to varying heights depending upon the

area that is stimulated.

I actually read this somewhere recently. The article said that the reason the dog shakes its leg is because when you are scratching in a certain spot they think it feels like fleas and they are trying to scratch it themselves.

Most likley it means your dog likes it. I t normally only happens when you rub a certain spot. It is not bad. It is actually kind of cute in my opinion. IF you are still unsure ask you vet. at your dogs next check up. I find it really only happens with puppys and they seem to stop after one year. But rest assured if your dog is older than that. It is nothing serious. I should not be flees or anything similare to that. You should find that, if it is constantly scratching that it is a possibility it has flees, either get it to the vet, or try a flea remover.

That means the dog is enjoying it

Its a reflex; just like if a dr taps your knee your ankle jerks.

Usually it means it has fleas and it thinks it feels good when you try to scratch it out. Sometimes it just like being scratched there, like its their favorite spot.

It's just a nerve being stimulated.

it feels good and it tickles. the same as some one tickles your foot or ribs.they like it if they didn't you would know