In dogs, currently erythromycin is considered the drug of choice in treating campylobacter. That being said, we are seeing cases with drug resistance with this bacteria, so ideally a culture and sensitivity is performed to determine the best drug in each individual situation. This is a bacteria that can also make humans ill, so precautions should be taken to prevent transmission including good hygeine/hand washing and avoiding the pet being around people with suppressed immune systems. You can read more about this disease at
http://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=2232 and
https://www.cdc.gov/campylobacter/index.html