Actually cedar and pine do have a lot in common. The most common being phenols, that sweet aromatic scent. They are caustic, poisonous, acidic compounds that are very commonly used in cleaning products. Pinesol and Lysol are a few of the brands that use these phenols.
They have been shown to increase liver enzymes and cause liver and kidney disease in small animals.
Phenols are present in all softwoods, so sticking to hardwoods is recommended.
http://www.afrma.org/rminfo2a.htm