This note is in response to Linda's planned formulation to include
echinacea.  This sounds like a good idea to me (as long as the animal
doesn't receive the echinacea every day of his/her life.  Here is some
information I had saved about echinacea:
 
Echinacea purpurea
 
- Increases the "non-specific" activity of the immune system (stimulates
  the overall activity of the cells responsible for fighting all kinds of
  infection.  Unlike antibiotics, which are directly lethal to bacteria,
  echinacea makes our own immune cells more efficient in attacking bacteria,
  viruses and abnormal cells, including cancer cells.)
 
- Over 500 scientific studies have documented the chemistry,
  pharmacology,and clinical applications of echinacea.
 
- The most consistently proven effect of echinacea is in stimulating
  phagocytosis, that is encouraging white blood cells and lymphocytes to
  attack invading organisms.
 
- increases the number and activity of immune system cells, including
  anti-tumor cells:
- promotes T-cell activation;
- stimulates new tissue growth for wound healing;
- reduces inflammation in arthritis and inflammatory skin conditions;
- Mild antibiotic action: bacteriostatic, anti-viral, anti-fungal.
- inhibits the bacterial enzyme hyaluronidase, to help prevent bacterial
  access to healthy cells.
 
Source:  http://www.herbs.org/greenpapers/echinacea.html
 
Other studies of note:
 
Clinical Study: an extract of echinacea showed an increase of 50%-120% in
immune function over a 5 day period (Jurcic, et al. 1989).
 
Clinical Study: an extract of echinacea significantly increased the
resistance to flu and reduced the symptoms of lymph gland swelling,
inflamed nasal passages and headache (Braunig, et al. 1992).
 
Clinical Study: Of 4500 patients with inflammatory skin conditions,
including psoriasis, 85% were cured with topical applications of
echinacea salve (Wacker & Hilbig, 1978).
 
Recommended Reading
Echinacea, Nature's Immune Enhancer by Stephen Foster.  Healing Arts
Press,1991.
 
Echinacea, the Immune Herb by Christopher Hobbs.  Botanica Press, 1990.
 
Botanical Influences on Illness by Melvyn Werbach and Michael Murray.
Third Line Press, 1994.  See chapters on Cancer,
 
Candidiasis, Immunodepression, Infection, Wound Healing.  Herbal Medicine
by Rudolf Weiss.  AB Arcanum, 1988.
 
Selected References
British Herbal Pharmacopeia, 1992.
Kommission E Monographs: Echinacea. Kooperation Phytopharmaka, , Germany.
Jurcic, et al. Zeitschrift fur Phytotherapie 10 (2), 1989.
Braunig, et al. Zeitschrift fur Phytotherapie 13: 7-13, 1992.
Wagner and Proksch 1985 In: Economic and Medicinal Plant Research, Academic
Press, Orlando, p.113.
Wacker & Hilbig. Planta Medica 33(1): 89-102, 1978.
Chone & Mandakis. Deutsch Med. Wschr. 27: p. 1406
Luettig, et al. J. Natl. Cancer Inst. 81(9): 669-75, 1989.
Stimpel, et al. Infect. Immun. 46, 845, 1984;
Steinmuller, et al. Int. J. Immunopharmac., Vol. 15, No. 5, pp. 605-614,
1993.
[Posted in FML issue 3089]