The fruit on my pear tree looks sick. I spray with Bonide Fruit Tree Spray...
This is a nice picture. This helps a lot in diagnosing the situation. Your pear has scab, a very common fungal disease. The captan in the Bonide is effective against this disease. The most important application period is from first green tissue to early June. If you space 3 to 4 sprays in this interval this will help to control scab.
Actually, only the captan component is needed until the fruit start developing after bloom. You may be able to find a product with just captan or just myclobutinol (product name Immunox) and save the Bonide until after petal fall.
The dormant sulfur sometimes helps to suppress pear psylla, an insect that gums up fruit and turns them sooty, but as a dormant spray does not help to control scab.