People perform best when they feel good and are not coping with physical ailments. The same is true for your dog. Do not expect your dog to be at the top of its game if it does not feel well.
Know your dog’s habits and if it deviates, investigate.
If the hair coat is dull and loosing hair, get to a vet.
Brush the coat daily checking for fleas, wounds and odors. Check under arms, around the eyes, and genitalia where fleas reside.
Any dog “flop-butting” (scraping its rear end along the ground), or licking the anus more than usual? Could be a piece of fecal material stuck in the hair, impacted anal glands, or worms? If suspect, get to a vet.
Bathe your dog but not too often because you could damage the coat.
Trim your dog’s nails regularly. No animal should have to endure long nails.
Brush your dog’s teeth daily using toothpaste and its own toothbrush.
Runny eyes? Take a clean tissue, tear in half, moisten with water, gently wipe away excess matter. Don't use the same tissue on both eyes. It could spread an infection. Suspect foreign matter in eye? Get to a vet.
Know what your dog’s ears look, smell and feel like when they are healthy. Ears are critical to “sound awareness dogs.” If the ears(s) deviate get to a vet.
When in doubt get to a vet.