Medical expenses can become a business expense if the business is structured properly.  

If a Schedule C business employs the business owner's spouse to perform work for the business, then a section 105 plan could be set up to reimburse a certain $ amount of out-of-pocket medical expenses for the employee & family each year.

If the chiropractor has a high deductible health insurance plan that qualifies for a Health Savings Account [HSA] the chiropractor can make a tax-deductible contribution into the HSA and then use these funds to pay for the doctor visits.