Dog bite on thumb, didn't break skin. But I have broken skin on otherside around my thumb nail due to biting that skin myself. Risk of what infection?

Human worse. The dog carries fewer and less virulent bacteria in their mouth than humans. Therefore you are at greater risk of infection as a result of you biting the skin of the thumb than the dogs bite.

Related Questions

Dog bite on thumb didn't break skin, but already have a little dry and broken skin on otherside of thumb. Risk of infection? If so what infections?

Low risk of infx. If the dog's tooth did not break your skin than the risk is low. Most dogs carry an organism called pasteurella multocida. If you develop redness, swelling, or pus drainage then you should see a doctor and may need antibiotics. Read more...
Abx for dog bite. If dog bites are more than superficial, they are usually treated with antibiotics due to the bacteria from the dog's mouth. This is almost always true when the bite is on the face. A superficial bite that can be well cleaned with saline water (flush wound very well with pressure) should be fine. Some antibacterial ointment will help. Read more...