It's generally recommended to brush your dog's coat when it is dry. Brushing a wet coat can potentially cause more tangling and matting, especially in long-haired breeds. Wet hair is more prone to breakage, and brushing may be less effective in removing loose hair and preventing mats.
If your dog's coat is matted or tangled, it's advisable to address those issues before bathing. Brushing before bathing helps prevent mats from tightening when wet, making them easier to remove.
However, there are exceptions. Some dogs have coats that are specifically designed to be brushed when wet, such as those with curly or wavy hair, like certain water breeds. In such cases, using a detangling spray or conditioner designed for dogs can help make the brushing process smoother.
Always use appropriate grooming tools for your dog's coat type, and be gentle to avoid causing discomfort or skin irritation. If you have specific concerns about your dog's coat care, consult with a professional groomer or your veterinarian for guidance tailored to your dog's individual needs.