For dogs, celery is an excellent resource to improve heart health and reduce cancer rates. Celery is rich in calcium, potassium, phosphorous, sodium, iron, and vitamins A, B and C. The phytochemical 3-n-butyl phthalide, which gives celery its signature taste and smell, is a powerful tumor-fighting agent and has been found to reduce the rate of tumors in lab animals [source: BARF Diet]. 3-n-butyl phthalide has also been found to reduce lab animals' blood pressure by 12 to 14 percent [source: World's Healthiest Foods]. Celery is reputed to reduce nervousness in animals and act as an acid neutralizer.
Celery contains phthalides, a cholesterol-lowering agent, and coumarin, a cancer-preventing force. Phthalides relax muscles around arteries and cause the vessels to dilate, reducing blood pressure. They also lower stress hormones that can cause blood vessels to constrict.