At 6 months old your doodle had a soft coat you could run a brush through in 2 minutes. At 11 months old there is a dense mat behind each ear and she leaves the room when she sees the brush.
Those two facts are connected. She is not being difficult about grooming. She is being accurate about grooming.
What changed in the coat
Curly and wavy coated crosses grow their adult coat through adolescence. It comes in denser and longer while the puppy coat is still shedding out underneath. The two tangle into each other.
These coats do not drop hair the way a short coat does, so what comes loose stays in the coat. A mat then forms from the skin outward, which is why the surface can look fine.
The friction points go first: behind the ears, under the collar or harness, the armpits, the back legs, the tail and anywhere she gets wet.
Why she now hates it
Brushing a mat pulls on skin. If the last 6 sessions have hurt, the brush now predicts pain, and a dog who has learned that leaves before you start.
Pain frequently presents as a change in behaviour rather than as obvious lameness. A dog who suddenly objects to being handled is a dog to check, not a dog to insist with.
Adolescence adds the rest. Around the onset of the stage dogs respond less to the cues of the person who raised them, and that responsiveness returns later. This is a bad year to need daily cooperation.
Deal with the existing mats first
You cannot train your way through a coat that already hurts. Get the coat comfortable, then teach the brushing.
Check the whole dog with your fingers, down at skin level, not with your eyes. Mats sit against the skin.
Do not bath a matted dog. Water tightens mats, and a wet mat is far harder to get out.
Book a groomer and say plainly that she is matted and that she is finding brushing difficult. Ask for a shorter clip rather than a heroic de-matting session.
Accept the short haircut. A clip off is kinder than hours of pulling, and the coat grows back.
Ask your veterinary practice to look at any skin underneath a mat that is red, damp, smelly or sore.
Then teach the brushing from nothing
Start where the brush is not: put the brush on the floor, pay her for looking at it, and put it away. 60 seconds.
Next, 1 stroke on a shoulder, then food, then stop. One stroke is a whole session at this point.
Work on the easy places first. Shoulders and back before ears, legs, belly and tail.
Keep sessions to 2 minutes and end while she is still relaxed. Working below the point at which your dog reacts is the condition for learning.
Teach a way for her to say no: a chin rest on your knee that means carry on, and stopping the moment she lifts her head.
Pair it with a lickable mat or a stuffed toy so the brush predicts food rather than pulling.
Reward-based training is associated with higher reported responsiveness and fewer reported problem behaviours, and this is one of the places it is easiest to see.
Make the daily maintenance small
2 to 3 minutes a day beats 30 minutes on Sunday. A coat that is brushed daily does not reach the state a weekly coat does.
Line brush: lift a section, brush from the skin out, then work along. Brushing the surface leaves the mats where they are.
Use a slicker plus a comb, and finish with the comb. If the comb does not run to the skin, the mat is still there.
Do the friction points every day: behind the ears, under the harness, armpits, back legs.
Brush after wet and muddy walks rather than before the next one.
Keep the coat at a length you can actually manage. A 6 week grooming cycle and a shorter clip is a reasonable choice.
Behaviour change is built from management plus reinforcement together. Here the management is the haircut and the daily 2 minutes, and the reinforcement is everything you pay for standing still.
Relaxation is trained as a behaviour in its own right, in short repeatable sets below your dog's threshold. Grooming goes better after a sniffing walk than before one.
Safety note
Get help now if your dog has growled at, snapped at or bitten anybody over brushing, a harness, or being handled. Stop the grooming, stop the de-matting, and speak to your veterinarian and a qualified behaviour professional who works with reward-based methods. Never hold a dog down to finish a groom, and never scruff, pin or tell a dog off for growling. Punishment-based approaches are associated with fear, avoidance and defensive aggression, and a growl that has been punished is a warning you no longer get. Book a veterinary examination if the coat has changed suddenly, or if there is sore skin. The same applies if your dog has become sensitive to being touched. Sudden behaviour change warrants one, and pain frequently presents as a change in behaviour rather than as obvious lameness. A child never brushes a dog who is finding brushing difficult.
What to expect
Owners usually describe a few weeks to get a dog comfortable with a brush again, once the painful coat is dealt with. The coat itself keeps changing until somewhere past 18 months old.
Nobody can promise you a doodle who enjoys grooming. A short coat, 2 minutes a day and a dog who is allowed to say no are what get closest.
If handling is one of several things going on at once, the Assessment will sort which to work on first. It is free, takes about 3 minutes, and asks for no email address.
Today's version, in one line: feel for mats with your fingers, book the groomer, and do 1 paid brush stroke on a shoulder tonight.