The Tax Court decided a farmer was allowed to claim cat and dog food because they were outdoor pets meant to keep wildlife away from their blueberries. Dog food is also deductible if it is for a service dog.
Declare income from all sources - legal and illegal. If you fail to claim income earned illegally, if you are convicted of the crime, you can expect to hear from the Canada Revenue Agency (CRA) about unpaid income taxes.
If you attend school outside of Canada, the tuition should be tax deductible as long as the school is recognized by the CRA.
Lunch time supervision costs are considered child care expenses and can be claimed on your return. This also applies to before and after-school programs.
Unusual Tax Deductions Denied
The cost of trips to Las Vegas and Arizona cannot be claimed as a medical expense even when your dermatologist recommends trips to warmer climates where the natural sunlight will help treat a psoriasis condition. (Goodwin v. The Queen  4 C.T.C. 2906)
The cost charged to a professional football player for balls he threw into the stands cannot be claimed as an expense against his employment income. (Ellis v. The Queen  4 C.T.C. 2373)
Losses incurred by a pathological gambler could not be deducted against his income from other sources because he did not have a "reasonable expectation of profit." The taxpayer in this case embezzled money from his employer to fund his addiction. (Molony v. The Queen 90 D.T.C. 1394)
The cost to an actress of going to post-production wrap-up parties was disallowed because it was not clear whether she worked in all of the productions. (Riley v. The Queen  4 C.T.C. 2961)
The cost of a haircut is not deductible against employment income even when you are a serviceman and you are required to get one every two weeks. (Rouillard v. The Queen  4 C.T.C. 2065)
The argument that the Income Tax Act is "not susceptible of discernment by the average occupant of this land" is not a valid defense against the charge of failing to file income tax returns.