Why does my dog chase his tail, and when is it a problem?

Your four-month-old puppy spins after his tail every evening, right when tiredness hits, and the whole family laughs. Or your two-year-old German Shepherd has spent the last few weeks whirling round the kitchen until he skids on the tiles, and he does not stop when you call him. Or you have a dog who chews the tip of his tail until there is no hair left on it. The first is normal. The other two need a vet visit. Below is how to tell them apart and what to do in each case.

Why does a dog chase his tail?

The first thing to do is film it. "He spins a lot" tells neither the vet nor a trainer anything. Three things matter: how often it happens, how long each episode lasts, and whether he stops when you call him with something good in your hand. Most of the picture comes out of those answers.

Play and discovery, in puppies. Up to about six months, a puppy is finding out that there is something behind him that moves on its own, much as a baby discovers its feet. Episodes last a few seconds, come mostly in the evening when he is tired and wound up at the same time, and stop on their own or at the first noise. They fade by themselves, as long as nobody turns them into a party piece.

An audience. The whole house laughed, someone got their phone out. To a dog, laughter and everyone's eyes on him are a huge delight, and whatever brings him delight he will happily repeat. A dog who only spins when someone is in the room, and glances at you between turns, has learnt a trick and performs it on request.

Boredom and energy with nowhere to go. A young dog from an active breed is shut in for nine hours and goes out twice a day, briefly, on pavement. In that house his tail is the only thing that moves. The spinning usually comes alongside chewed furniture, digging at the sofa and barking at the window.

Letting off excitement. The doorbell goes, he does not get what he wants, two people are arguing in the kitchen, he is shut in his crate and wants out. Spinning is the release valve. You recognise it because it turns up in the same situation every time and ends when the situation does.

Compulsion. This is repetitive, pointless behaviour that takes up part of his day, that he cannot stop, and that carries on even when he is home alone. Bull Terriers and German Shepherds are the breeds described most often, which points to an inherited component. It also shows up more in dogs taken from their mother too early and in naturally timid dogs. A compulsive dog stares fixedly at his tail, does not answer to his name, sometimes growls at his own tail, and can end up injuring himself.

Pain, itching, illness. Full anal glands make him whip round towards his tail and scoot his bottom along the floor. Fleas and allergy make him chew the base of the tail, where the skin is red. It can also be a knocked tail or one caught in a door, or pain in the lower back. Less often there are focal epileptic seizures: he spins for a few seconds looking "absent", with a blank stare, then comes round and seems muddled. Your vet rules all of these out before any training plan. No amount of training empties an anal gland.

What do owners get wrong?

Laughing and filming for friends comes first. Two weeks of clips and a puppy's discovery has become a performance with an audience.

Punishment comes second: shouting, shaking him, a squirt of water in the face. When the spinning comes from stress or excitement, punishment is petrol on the fire. It stops now and comes back harder an hour later, and the dog learns something extra on top: to keep away from you when he feels bad.

Then there is "leave him, he'll tire himself out". A dog who has been spinning for an hour is not tired; he is stuck in a loop he does not know how to leave. Every hour adds repetitions, and repetitions wear the groove deeper. With a compulsion, time is on the wrong side.

Physically blocking it fixes nothing. You hold the tail, put a cone on him, bandage the tail, and he learns to spin in a cone and chews the bandage. The cause stays where it was.

"It's the breed, they all do it" is something Bull Terrier owners hear on every corner. Being common in a breed does not make it harmless. That is precisely the breed in which spinning turns into a compulsion and ends in injuries.

And last: training before the vet visit. A month of "on your mat" and "find it" with a dog whose anal glands are full is a month wasted for both of you and a month of discomfort for him.

How do you help him, step by step?

It all starts with a video and a vet visit; then you reorganise his day. A healthy puppy who spins in the evening only needs steps 3 and 4. A compulsive dog needs all of them, plus the vet.

1. Three days of filming and a diary

Write down every episode: the time, how long it lasted, what happened in the minute before, who was in the room, whether he stopped when you called him with food. Film at least two complete episodes, start to finish, including how he stops. After three days the pattern shows up: same time, same place, same thing beforehand. Or there is no pattern at all, which is just as useful to know.

2. The vet visit

Go to your own vet if it happens every day, if he bites or chews his tail, if he scoots, if it started suddenly in adulthood or if he looks "absent" on the video. Show them the video and the diary. An examination of the anal glands, the skin at the base of the tail and the tail itself settles most cases; for the rest, the vet decides what further tests come next.

3. No audience

The whole household, one rule, starting the same day: when he starts to spin, nobody looks, nobody laughs, nobody gets a phone out. You get up calmly and go into another room. When he stops and follows you, make a fuss of him, praise him, stroke him and give him something tasty for coming. Within a week or two, a dog who spun for spectators stops, because there is nobody to spin for.

4. A structured day, with his nose at work

• Food no longer comes out of a bowl. Scatter it round the house, stuff it into food toys or roll it up in a towel. Ten minutes of searching, twice a day.
• The morning walk becomes a sniffing walk: long line, he picks the route, you keep quiet. Thirty minutes.
• Something to chew every day, for twenty minutes. Chewing calms him, and a dog with busy jaws does not spin.
• Sleep matters a lot. Puppies need 16–18 hours a day, adults 12–14. A dog short of sleep is wound up in the evening, and the evening is exactly when he spins. Give him a quiet spot away from foot traffic and a bedtime.
• Less ball-throwing. For dogs prone to this, chasing a moving object is the same loop with a different target.

5. Interrupt and give him something else to do

At the first sign (eyes turning towards the tail, a sideways step, a short whine) say something cheerful and offer an alternative: "find it", with a few treats dropped on the floor, or "on your mat", where you praise him and he gets a treat. Whatever he does instead of spinning brings him praise and something good every time; spinning no longer brings him anything, no laughter, no attention. If an episode is already under way and he does not stop when called, do not shout over him. Leave the room rustling the treat bag, or pick up the lead and go outside. Hardly any dog spins outdoors.

6. Less stress at home

The diary usually shows you what is weighing on him: ten hours alone, friction with the other dog, a house move, a new baby, the crate used as punishment. Work on that, and the tail follows. For a compulsive dog, your vet may also discuss a medication that makes the plan possible. We do not name drugs here, but it is worth knowing they exist and that for some dogs they are the difference between a plan that works and one that does not.

The first week

When is it a medical problem?

In an adult dog, tail chasing is more often about the body than about behaviour. These signs need a vet visit before anything else:

• he bites or chews his tail, has bald patches or sores at the base of the tail;
• he scoots, or whips round towards his tail as if something had nipped him;
• the tail hangs limp and hurts when touched (a knocked tail, one caught in a door, or "limber tail" after swimming in cold water);
• episodes with a blank stare, trembling, drooling or confusion afterwards, however brief;
• it started suddenly in an adult dog who never used to do it;
• he spins when he is alone too, for minutes at a time, every day.

A compulsion is a medical diagnosis, and trainers have no business labelling it. Your vet makes it, sometimes together with a behaviour professional. Tell your own vet exactly what you filmed: how long, how often, whether he stops when called.

How scent work helps

Scent work is one of the few things that gives a dog with repetitive behaviours something more interesting than his own tail for half an hour, and sends him home tired in the right way. In our sessions we see dogs who spin at home and show no sign of it on a trail: nose down, head busy, the tail just a tail. Back home, in the hours afterwards, the episodes thin out. Scent work does not replace the vet visit, or medication when it is needed. It is, though, the cheapest part of the structured day in step 4: ten minutes of searching round the house three times a day, and a sniffing walk every morning.

When should you call in a professional?

• episodes last more than a few minutes, every day, and do not stop when you call him;
• he has injured himself, however slightly;
• it started in adulthood and the vet found no cause;
• he is from a predisposed breed and the episodes have been getting longer over the last few weeks;
• you have kept to the plan for four weeks, with a diary, and the episodes have not become less frequent.

For a compulsion you work with your vet and a behaviour professional, and sometimes with a vet who specialises in behaviour, where there is one. The assessment starts from your videos and your diary. Afterwards you know whether you need a behaviour programme, medication or both.