Older dog, opting not to respond

[FELICITY STUART]

We have a 3.5 year old dog, we followed training when she was a puppy, all positive reinforcement guidelines, she was happy to sit/stay/ fetch/rollover. Over the last six months she has become Barky, and disregards instructions, slowly responding partially, ie moving to her bed incredibly slowly. No longer fetches ball, barks increasingly at noises , the stimulus gets smaller, it is now us  sniffing that upsets her, 

Do we need to start again at the beginning?

[Adrienne Farricelli]

Hello, welcome to the forums, 

I apologize for the delay in responding. 

I am sorry to hear that your dog is lately not being responsive as she once was. Based on your description, I feel it's imperative ruling out medical causes first. A sudden shift in responsiveness, increased vocalization, and sensitivity to stimuli could indicate pain and underlying medical issues. I would therefore highly suggest starting with a medical examination, including bloodwork, orthopedic assessment, and possibly neurological evaluation.

Once medical issues are ruled out, then it's time to assess  this from a behavioral standpoint. 

Increased barking and sensitivity suggests anxiety or fear-based reactivity. Has there been a significant change in her environment, routine, or household dynamics?

In these cases, it's important to to avoid any form of corrections-even demonstrating frustration can cause a dog to become more anxious and less responsive. 

Reduce exposure to triggers if you're able to identify them. You mentioned that she is increasing more and more reactive to stimuli, which tells us her anxiety is generalizing to other settings. In these cases it's therefore important keeping her as much under threshold as possible. 

Use desensitization and counterconditioning to help her developing coping skills. 

Use high-value reinforcers (favorite treats, toys) to make training enjoyable again. Keep sessions short, predictable and most of all, low pressure. 

Increase mental stimulation with food puzzles, sniffing games, and structured routines to reduce anxiety and frustration.

If symptoms persist or escalate, please consult with a board-certified veterinary behaviorist for a tailored plan, including potential behavior modification and medication support.