than many other breeds. A working McNab frequently runs for miles a day, using its herding skills to control livestock, and they can become restless if isolated or neglected. Unlike some other herding breeds, McNabs are not hyperactive. Providing a McNab has plenty of exercise, it is content to nap at its owner's side with a watchful and protective eye. McNabs often bond tightly to their family members, including other household pets. They have a keen sense of territory and seldom wander away from home. They are also more likely to defend their territory and family members than many of the more sensitive herding breeds. McNabs can be assertive and demanding, and they do best with guardians who are firm, consistent and skilled in positive dog training methods that don't trigger the McNabs instinct to push back against obstacles. Highly intelligent and quick to learn, the McNab needs to exercise its brain as much as its body. Families considering a McNab for a pet will need to set aside plenty of time to spend with their dog. Health McNabs are hardy dogs with no breed specific health problems. Their average life span is 13–15 years. McNab dogs may carry the MDR1 mutant gene and can be very sensitive to Ivermectin, which is a common ingredient in heartworm prevention medications. This drug and others can cause serious health problems or even death. A DNA test that demonstrates whether a dog has the mutation is available through the Washington State University College of Veterinary Medicine. The test can be completed by sending them a cheek swab through the mail. Activities McNabs have a loose-eyed herding style and tend to work more independently than many herding breeds. They are skilled at both heading and heeling stock, meaning they can turn stock from the front or get behind stock and drive them forward. Originally bred to herd sheep, stock handlers quickly discovered that the McNabs bold nature and working abilities made them ideal for herding cattle. McNabs are also used for herding geese, goats, llamas and gathering horses in from the pasture. Renowned for their incredible endurance, McNabs have been known to cover over a hundred miles a day driving their herds. McNabs are becoming increasingly popular in the world of dog sports. Their outstanding athletic prowess and agility coupled with high intelligence make them ideal competitors. McNabs are now competing successfully in agility