Pros
Good oppoturtinity to start learning about dog medical care, rewarding success stories from adoptions, benefits include reduced cost boarding and vaccines for your pets, meet a large network of people in the rescue and veterinary field, coworkers and atmosphere are very friendly and casual, customer interactions tend to be very positive and not stressful when pertaining to boarding.
Kontras
Often understaffed in the front office and kennel staff areas, stressful on days where the public can come see the facility and dogs for adoption (once monthly), nonprofits don't offer very competitive pay, current management isn't too realistic of expectations of their employees, dealing with volunteers who aren't accountable for their mistakes that make your job more difficult at times, dealing with potential adopters can be demanding but employees have to make them happy.