It started with a laser pointer, or sunlight off a watch face, or the shadow of the washing line on the kitchen wall. Now your dog is scanning that wall at 9pm.
Take this one seriously. Of the adolescent behaviours we write about, this is the one where getting help early matters most, and where waiting costs you the most.
Why it is different from ordinary chasing
Chasing a squirrel ends. The squirrel goes up a tree, your dog loses, and the behaviour stops until the next squirrel appears.
A shadow never ends. There is nothing to catch, nothing to finish, and no point at which your dog gets to come down. The behaviour feeds itself.
Owners commonly describe it spreading, too. A dog who started on torchlight begins on window reflections, then on the flicker of the television, then on nothing anybody else can see.
We are not going to name a disorder here. That is a diagnosis, and it belongs to your veterinarian and a qualified behaviour professional who can watch your dog in person.
The veterinary appointment comes first
Sudden behaviour change warrants a veterinary examination, and pain frequently presents as a change in behaviour rather than as obvious lameness. There are medical questions here that no amount of training answers.
Book it this week, rather than after a month of trying things at home.
Take a video. Thirty seconds of your dog doing it in your own kitchen is worth more than any description you can give at the desk.
Write down when it happens, for how long, and what was going on beforehand. Time of day, who was home, whether a walk had happened.
Ask about a referral to a veterinary behaviourist or a qualified behaviour professional who uses reward-based methods. Ask at the first appointment rather than the third.
Safety note
Get help now if your dog cannot be interrupted, will not eat or sleep, is losing weight, or has damaged their mouth or paws. The same applies if the chasing has started to include spinning, tail chasing, flank sucking, or snapping at the air. Speak to your veterinarian today and ask for a behaviour referral. Do not use the laser pointer again, not once. Do not try to stop the behaviour with a shout, a spray, a rattle can, or any kind of correction. Punishment-based approaches are associated with fear, avoidance and defensive aggression. A review of aversive methods found them associated with worse welfare outcomes and no training advantage.
Management, starting tonight
Management does most of the work while you wait for the appointment. The aim this week is fewer rehearsals, not a trained dog by Friday.
Throw the laser pointer away. Not into a drawer. There is no safe version of that toy for a dog who has started this.
Close the blinds at the hour the light comes through, and move the lamp that casts the shadow. Removing the trigger beats interrupting it 40 times.
Turn lights on rather than off. A brightly and evenly lit room gives your dog fewer moving edges to find.
Move the water bowl, the fish tank, and anything else that throws a moving reflection out of the room your dog settles in.
Get everyone in the house on this, including the teenager with the phone torch. One person starting it up for fun undoes the week.
Then give the behaviour somewhere else to go
Feed one meal a day from a snuffle mat, a scatter across the lawn, or a food toy. Sniffing and licking are the shape you want more of.
Put a safe chew down in the room and at the hour the chasing usually starts, before it starts rather than after.
Practise settle on a mat: 1 treat dropped between the front paws every 5 seconds, then every 10, in sets of 60 seconds.
If you must interrupt, do it early and kindly. Walk in, say one cheerful word, and scatter 6 treats on the floor away from the wall.
Keep walks sniffing-led rather than ball-led for now. A ball thrower is the outdoor version of the same repetitive chase.
Relaxation is trained as a behaviour in its own right, in short repeatable sets below your dog's threshold. That is the half of this you can start tonight.
Working below the level at which your dog cannot cope is the condition for learning. So practise in the room and at the hour when the wall is boring, not while they are mid-chase.
Behaviour change is built from management plus reinforcement together, and reward-based methods are what the veterinary behaviour guidance recommends. Neither half of that replaces the appointment.
What to expect
Some of this quietens once the trigger has been gone for a few weeks. Some of it does not, which is exactly why the referral is worth making early rather than late.
The Assessment will not diagnose this, and neither will we. It is free and takes about 3 minutes. It is a reasonable way to order the rest of your dog's week while you wait.
Today's version, in one line: bin the laser pointer, close the blinds at the usual hour, and put a chew down before it starts.