Your Dog's Scratch Reflex: How to Hit the Right Spot

Your dog's scratch reflex is the reason they kick out their leg when you scratch them, but it's more complex than it sounds.

Published February 20, 2023
Woman scratching dog's belly

Ever wonder why your dog kicks when you scratch their "sweet spot"? That's their scratch reflex. It's an involuntary response to stimulation of the nerves under a dog's skin, kind of like the kicking reflex you have when the doctor taps your knee with a rubber hammer. If your dog has a scratch reflex when you rub their belly, back, or sides, it's nothing to worry about. But if you rub your dog's ear flaps and they exhibit the reflex, it could mean they have parasites. Find out about the different types of scratch reflexes in dogs and whether you should be worried if your pup shows this behavior.

Is My Dog's Scratch Reflex Bad?

Most of the time, a dog's scratch reflex is perfectly normal. Experts believe dogs developed this reflex as a way to protect themselves from parasites. If a flea or mite stimulates the skin sensors around a dog's belly, back, or sides, it will send a signal to their spinal cord, prompting them to kick their leg to get rid of whatever caused the sensation. Even when it's your fingers tickling your dog's skin instead of a bug, you can still trigger this scratch reflex.

Fast Fact

A dog's scratch reflex "zone" is a saddle-shaped area that comprises their back, sides, and belly.

Is It Safe to Keep Scratching My Dog?

Because it's a movement your dog can't control, you might question if it's safe to keep scratching when they're doing this scratch reflex kick. There's no need to stop if your pup seems to enjoy themselves. Just make sure you're scratching gently to avoid irritating their skin, and keep an eye on your pup's attitude. If they seem agitated or annoyed, stop the petting session and let them take a breather.

Your Dog's Scratch Reflex and Mange

While a scratch reflex triggered on the skin around a dog's saddle region shouldn't be a cause for concern, there is a type of reflex that isn't always a positive sign: the pinnal-pedal scratch reflex. This reflex occurs when you rub a dog's ear flap (referred to as the pinnae, hence pinnal), and it causes them to kick their back leg (pedal) involuntarily.

This type of scratch reflex is really common in dogs with sarcoptic mange. Studies have shown that up to 90 percent of dogs with scabies have a pinnal-pedal reflex, so vets will often use this as a non-invasive test to gauge if a dog is infected.

Don't panic if you rub your dog's ear flap at home and they kick with their back leg. This doesn't definitively mean your dog has scabies. Allergies, ear mites, ear infections, or other skin conditions can cause a pinnal-pedal reflex. However, it does mean your dog is pretty itchy. Speak to your vet about whether it's something you need to address and how you can provide your dog with some relief.

The Good, the Bad, and the Scratchy

Most dogs love being scratched, but if your dog suddenly becomes very sensitive to scratches or you feel like their scratch reflex is getting worse, it could indicate a problem. Allergies and external parasites are a few of the biggest culprits of excessive scratching, though neurologic problems can also cause phantom scratching. See your veterinarian if you're concerned, and consider routine parasite prevention to keep your dog free of pests. But if your dog carries out the occasional scratch reflex kick with no other concerning signs, there's nothing to worry about. Let them enjoy the petting while you enjoy the time spent together.

Your Dog's Scratch Reflex: How to Hit the Right Spot