Start with one small disagreement, add a dash of intransigence, a personality clash or two, mix well and voilà! You’ve got a medical practice civil war on your hands.

Take this true story, for example. A few years back, three specialists in western Canada — two newly certificated and one established physician — decided to create a small group practice together. When the question of how to split office expenses came up, they just figured it would be fair to each pay a third. What they didn’t account for, however, was the fact that the established physician already had a huge patient roster. It soon became apparent that the veteran MD’s work alone was consuming more than 50% of the group practice’s office and staffing resources. Suddenly, that cost-sharing structure didn’t seem so fair. “The new doctors realized they were getting hosed,” says Rick Jamison, the national director of Practice Solutions Consulting, who dealt with this incident. But the veteran refused to renegotiate their deal. The practice fell apart after only a year. “There’s still some animosity against the established physician five or six years later,” says Mr. Jamison.

Many doctors’ partnerships function perfectly amicably. Some, however, do not.

You’ll be unsurprised to learn that the primary, immediate source of strife — the proximate cause — is money. But the real underlying source of that problem is inflexible attitudes, just as in the case Mr. Jamison described. (In another incident he was called in to help sort out, one doctor absolutely refused to use the electronic records the 14 other doctors in the Ontario practice had agreed to use, which set off all sorts of arguments. The one doc and his paper records were ultimately pushed out.)

As often as not, group-practice disputes can be resolved and brewing civil wars defused before the first shots are even fired. Just like in medicine, prophylaxis is preferable to treatment.

The key is a rock-solid contract. “Too often, information about finances between physicians is not documented,” says Mr. Jamison. “More than half of physicians in Canada don’t have a document spelling it out.”

Your group-practice’s contract should include what’s known as a re-opener clause, which permits members to renegotiate the practice’s financial and governance structures before signing on again at the end of the year. The contract should also offer members a way out, if it comes to that, with something along the lines of a 90-day opt-out clause.

Consulting firms can help with contract mediation if you need some objective outside help, while many of the provincial medical associations have programs to help doctors resolve personality clashes.

“Prevention” is the management buzzword here. If you let your group practice’s skirmish break out into a full-blown civil war, it may already be too late to save the union.