Dog licking that will not stop: paws, surfaces and people

Quick answer

The front of the wrist and the top of the foot are the classic sites for a licking lesion, and they are also the easiest places for a dog to reach while it lies down.

"Compulsive licking" is three different behaviours wearing one label. A dog licking its own paw, a dog licking the carpet or the wall, and a dog licking people obsessively are separate problems with separate causes, and the first is very rarely a behavioural problem at the start.

The order matters more than the technique. Look for a medical cause first, because a dog that licks one spot is usually telling you that spot itches or hurts, and behaviour work applied to an itchy dog fails and wastes months.

• Note exactly where the licking lands. One spot on one limb means something different from all four paws, and both differ from the floor.
• Rust or reddish-brown staining of white fur is saliva, and it takes weeks to develop. It tells you the behaviour is older than you think.
• A dog that licks surfaces excessively has a meaningful chance of an underlying digestive problem, and that is worth investigating before assuming anxiety.
• A cone stops the damage. It does not treat the cause, and used alone it moves the behaviour rather than ending it.
• Film the dog when it is alone. Most owners only see the licking that happens in front of them.

Decide in 60 seconds

One word, three behaviours

Self-directed licking. The dog licks its own body: a paw, a wrist, a flank, the base of the tail, a surgical scar. Almost always begins with a physical sensation, whether itch, pain, or the abnormal feeling of a nerve that has been damaged.

Surface licking. The dog licks floors, carpets, walls, concrete or furniture. This one is strongly associated with the digestive tract, and treating it as an anxiety problem is one of the most common errors owners are led into.

Social licking. The dog licks people, obsessively and beyond ordinary greeting. This is largely learned and maintained by attention, but it can also be appeasement in a dog that is anxious about the person it is licking.

Deciding which of the three you have takes one evening of watching, and it changes everything that follows.

Why a licking loop keeps itself going

Start with any cause of sensation: a flea bite, an allergic itch, an arthritic joint, a healed nerve injury.

The dog licks. Licking is mechanically soothing and it releases endorphins, so it produces immediate relief. That is a reinforcement schedule as powerful as any food reward.

The licking then damages the skin. Hair is broken off, the surface is kept wet, and bacteria are driven down the hair follicles into the deeper skin. That deep infection is itchy and sore in its own right.

Chronic inflammation thickens the skin and, over time, the density of nerve fibres in the area increases. The site becomes more sensitive rather than less.

At that point the original cause is no longer needed. The lesion generates the sensation, the sensation drives the licking, and the licking maintains the lesion. This is why a lesion that started as a flea allergy in the spring can still be there in the winter with no fleas in sight.

The clinical consequence is that established lick lesions need all three attacked at once: the original cause, the deep infection, and the behaviour. Fixing one of the three usually fails.

Paw and limb licking: the causes in the order to rule them out

Parasites. Fleas first, every time, whether or not you have seen one. Then mites, particularly sarcoptic mange, which is intensely itchy and typically involves the ear margins, elbows and hocks.

A foreign body or injury. Sudden, intense, focused licking of one foot in a dog that was normal yesterday points to a grass seed, thorn, splinter, cut pad, broken nail or a stone bruise. Look between every pair of toes and at the pads.

Skin infection. Bacterial infection and yeast overgrowth both make paws itchy. Yeast-affected paws are typically greasy, brown-stained, thickened between the toes and carry a distinctive smell.

Allergic skin disease. Atopic dermatitis has a recognisable distribution: paws, face, ears, armpits and belly. It is seasonal at first in many dogs and becomes year-round later. Food-responsive disease looks the same and is separated by a properly run elimination trial rather than by a blood test.

Pain underneath. This is the one that gets missed. A dog licking persistently over the carpus, elbow, hock or stifle may be reporting the joint, not the skin. Any single-site lesion over a joint should have that joint examined and, if the picture fits, imaged.

Nerve damage. After trauma, surgery or a disc problem, a dog may lick or chew at a limb that feels abnormal. These cases can escalate to self-mutilation and need specific treatment, because ordinary anti-itch approaches do nothing.

Compulsive disorder. A genuine behavioural condition exists, but it is a diagnosis reached after the above, not before. It is more likely where the licking happens in bouts that are hard to interrupt, occurs across contexts, and coexists with other repetitive behaviours.

Surface licking and the gut

A dog that licks the floor, the rug, the wall or the sofa repeatedly is doing something quite different from a dog licking its own leg.

When dogs presented for excessive surface licking have been investigated properly, digestive disorders have been found in a large share of them, and treating the digestive problem has reduced or stopped the licking. That finding has changed how this presentation should be approached.

So the first questions are digestive ones. Is there burping, gulping, lip smacking, an empty-stomach retch in the morning, grass eating, noisy abdominal sounds, soft or variable stools, or food that is eaten and then refused?

Nausea in dogs shows as lip licking, repeated swallowing, drooling, restlessness and grass eating, and it can be constant and low grade rather than dramatic.

Mouth pain also causes repeated lip licking and swallowing. Looking inside the mouth, and having the teeth assessed properly, belongs early in the work-up rather than at the end of it.

There are neurological possibilities as well. Licking with a vacant expression, snapping at invisible flies, or brief episodes the dog cannot be pulled out of can be focal seizure activity, and video of an episode is what separates that from a habit.

In an old dog, new repetitive licking that appears alongside disorientation, changed sleep patterns or altered interaction belongs to the cognitive decline conversation, not the training one.

Licking people

Some of this is normal. Dogs lick faces and hands in greeting, and it is a social behaviour with deep roots.

It becomes a problem when it is relentless, when the dog cannot settle without doing it, or when it is directed at a person who does not want it.

Two things maintain it. The first is attention: even pushing the dog away is a response, and an intermittent response is the strongest kind of reinforcement. The second is taste, because human skin carries salt, food residue and cosmetics.

Manage it by making the behaviour reliably uninteresting and by giving the dog something else to do on arrival: a settle mat, a scatter of food on the floor, a toy to hold. Removing attention in silence works, provided everyone in the household does it consistently.

If the licking is frantic, accompanied by a lowered body, flattened ears and a tucked tail, it is appeasement rather than affection, and the question becomes what the dog is worried about.

What the skin tells you about how long this has been going on

Rust-coloured staining of pale fur is saliva, not dirt, and it takes weeks of contact to develop. A dog whose owner has noticed licking for three days but has stained fur has been licking for far longer, probably out of sight.

Hair broken off short at the same length across an area means chewing rather than a hair loss disease, where hair falls out at the root.

Thickened, hairless, raised and firm skin at a single site means the process is chronic and that deep infection is likely to be present. These lesions need long courses of treatment, and a two-week course of anything will not resolve them.

Moist, red, hot, rapidly spreading and painful areas are acute moist dermatitis, the so-called hot spot, which is a different and urgent problem that can enlarge within hours.

Where breed, age and season change it

Large and giant breeds, including Labrador and Golden Retrievers, Dobermanns, German Shepherds and Great Danes, are over-represented for single-site lick lesions on the front limbs.

Dobermanns are the breed classically associated with flank sucking, and Bull Terriers with spinning and other repetitive behaviours, which shows that a genetic contribution to compulsive behaviour in dogs is real. Breed does not make the diagnosis, but it changes the prior probability.

Age matters. Licking that begins in a young dog, seasonally, alongside ear and face rubbing, is most likely allergic. Licking that begins in a middle-aged or older dog, especially at one site, raises pain and internal disease.

Season matters for allergy and for grass seeds, which are a summer problem in many regions and produce sudden, dramatic, single-foot licking.

Coat matters too. In a thick-coated dog the lesion is hidden until it is advanced, so part with the coat and look at the skin rather than judging by appearance.

Where the usual advice fails

"It is boredom, give it more exercise." Exercise and enrichment help a dog that is under-stimulated, and they are worth doing regardless. They almost never resolve an established lick lesion, because by then the lesion is generating its own signal. Enrichment alone, applied to an itchy or painful dog, delays the diagnosis.

Foraging and problem-solving belong in the plan, but as part of it. They are what fills the time a dog used to spend licking, once the medical cause is being treated.

"Put a cone on and it will heal." A collar is the right tool to interrupt damage while treatment works. Used alone, the dog licks the moment the cone comes off, and some dogs become frustrated enough to redirect to another site.

"Use a bitter spray." Many dogs habituate to them, some like them, and applying an alcohol-based deterrent to a raw lesion hurts.

"Tell the dog off when it licks." Punishment adds anxiety to a behaviour that is often already anxiety-linked, and it teaches the dog to lick where you cannot see. Owners then report that the dog only does it when left alone, and the case is misfiled as separation distress.

"Try a hypoallergenic food from the supermarket." A food trial only answers the question if it is run properly, with a single novel or hydrolysed protein source, no treats, no flavoured medications, and enough weeks to be meaningful.

"Antibiotics for a week." Deep skin infection under a chronic lesion needs much longer courses, guided by the response and sometimes by culture. Stopping when the surface looks better is a common route to relapse.

The routine while the cause is being found

Sleep is part of the plan. Chronically under-rested dogs are more reactive and more likely to fall into repetitive behaviour, and a settled, undisturbed sleeping place is the cheapest intervention available.

What the vet will want to know

Where exactly the licking is directed, ideally with photographs over time.

When it started, whether it was sudden or gradual, and whether anything changed at the same time: a house move, a new pet, a new food, a surgery, a walk somewhere new.

What parasite prevention is used, on which animals, and when the last dose was given.

Whether the licking happens when the dog is alone, and what the camera shows.

Digestive history in detail for a surface-licking dog.

Whether the dog is lame, stiff after rest, slower on stairs or reluctant to jump into the car.

Everything already tried, including shampoos, sprays, supplements and any medication, with dates and the response.

For an older dog, changes in sleep, orientation and interaction.

What never to do

Do not apply human antiseptic creams, essential oils or tea tree products to a lesion the dog will lick.

Do not use a dog's own licking as a diagnosis of anxiety without first ruling out itch, pain and nausea.

Do not punish the behaviour, and do not use a shock or spray collar on it. It makes anxious dogs worse and hides the problem from you.

Do not bandage a lick lesion at home. A wrap on a limb that is left on too long or applied too tightly causes serious injury, and a covered wet lesion gets worse.

Do not stop a prescribed course early because the skin looks better. Deep infection resolves later than the surface does.

Do not let a dog lick your skin where medication, hormone gel or a strong cream has been applied.

Do not accept "it is just a habit" for a lesion that is thickening, spreading or bleeding.

When to get help

Book promptly for any lesion that is raw, ulcerated, spreading, thickened or bleeding, for sudden intense licking of one foot, and for licking that appears for the first time in an adult or older dog.

Book with a note about digestion for any dog that licks floors, walls or furniture, and mention every digestive sign even if it seems trivial.

Go the same day for a rapidly enlarging hot, painful, moist patch, for a swollen painful foot, and for licking accompanied by collapse, vacant episodes or repeated retching.

Ask for a referral to a veterinary behaviourist once medical causes have been addressed and the behaviour persists, particularly if it happens in bouts the dog cannot be pulled out of. Combining behaviour work with medication is standard for genuine compulsive disorder, and it works far better than either alone.