How to shave a dog with matted hair effectively and safely?

To shave a dog with matted hair effectively and safely, follow these steps:

1. Use a detangling spray or conditioner to help loosen the mats.
2. Use a slicker brush or comb to gently work through the mats.
3. Use clippers with a guard to avoid cutting the skin.
4. Shave in the direction of hair growth to prevent irritation.
5. Take breaks to prevent overheating the clippers.
6. Be patient and gentle to avoid causing discomfort to the dog.