Because herbal therapeutics have proven efficacious by the standards of both history and modern medicine, plant medicines are the subject of close scrutiny by major drug companies. For these reasons, herbal combinations offer efficacy combined with safety more often than single drugs. Another advantage offered by herbal medications is in their unique actions. Unfortunately, veterinary herbal medicine has a long way to go before the doses and protocols are formalized. For instance, white willow is commonly used by human herbalists to relieve arthritic pain.
White willow contains salicin, which is similar to the salicylic acid found in aspirin.
Now, if one attempted to treat an arthritic cat with a smaller dose of white willow, the cat might experience a fatal reaction, since cats cannot metabolize salicylic acid. Another example of seemingly harmless herbal medication is the constant use of garlic. Garlic has been well characterized as a powerful antimicrobial, cardiac treatment, and cholesterol lowering agent. In addition, we tend to use it to repel and kill parasites in veterinary medicine. The problem is that garlic belongs to a family of plants that may cause anemia in animals if given for long periods of time.