This is a list compiled by veterinarians of herbs recommenced for your pet. To be safe, talk to your vet before using them, especially if your pet is taking drugs of any sort.
Aloe (Aloe vera) for constipation and skin irritation
Calendula (Calendula officinalis) for skin injuries
Chamomile (Matricaria recutita) for skin irritation (topical), stomach problems, mild stress
Comfrey (Symphytum officinale) for skin injuries (topical only)
Dandelion (Taraxacum officinale) for water retention, liver, spleen, blood issues
Echinacea (Echinacea angustifolia or Echinacea purpurea) for immune support, nasal congestion
Ginger (Zingiber officinale) for Nausea, motion sickness
Ginkgo (Ginkgo biloba) for old age, mental dullness
Goldenseal (Hydrastis canadensis) for infections, bronchial inflammation
Hawthorn (Crataegus laevigata) for heart irregularities
Milk Thistle (Silybum marianum) for liver problems
Red Clover (Trifoliaum pratense) for ulcers, sores, burns and as a nerve tonic
Slippery Elm (Ulmus rubra) for diarrhea, constipation, coughs
Valerian (Valeriana officinales) for stress, pain, aggression