The worldwide interest in herbal products has grown significantly. cattle, horses, sheep, goats and pigs represent about 70% of the animals treated with herbal remedies, followed by poultry (9.1%), dogs (5.3%) and rabbits (4.3%). This is not only due to a general trend towards the usage of natural products for curing illnesses but also due to the availability of considerable evidence regarding the efficacy of herbal remedies. Furthermore, deeper knowledge of their composition has been acquired through the introduction of new analytical techniques. At present, the use of natural products is a useful tool in domestic animal therapy too. It is well know that animals can resort to natural therapy by themselves. ‘Zoopharmacognosy’ refers to the process by which animals self-medicate, by searching for herbs to treat or prevent diseases. This process has revealed that in many cases, instinct provides animals with therapeutic information, allowing them to choose the plant best capable of treating their disease. The development of intensive farming in industrialised countries has led to a progressive neglect of veterinary phytotherapy due to the compatibility of synthetic drugs with the modern concept of efficient animal breeding. The ever-growing use of synthetic drugs can be attributed to the growing ease of their preparation and administration, making them suitable for the pressing pace of modern development. With respect to pet animals, for whom humans tend to care for as well as or better than they do for themselves, the use of natural products is becoming more and more important. In fact, there is a growing preference for natural rather than synthetic products because people think, rightly or wrongly, that natural products produce less side effects and undesirable consequences.
Cardiovascular system: Cardiovascular system therapy is primarily used in treating pet animals and horses because it is not cost-effective for farm animals. Hawthorn (Crataegus spp.) contains procyanidines and flavonoids which have a slight inotropic action and act as peripheric and coronaric vasodilators; it is used in pets for arrhythmia and cardiac failure, and is not very toxic. Some herbalists suggest that Lily of the Valley (Convallaria majalis), which contains convallotoxin and convalloside glycosides, can be used as an alternative to digitalis for the treatment of cardiac failure. It has also been found that syrup from the wild pansy (Viola tricolor) is helpful for restoring strength to racing pigeons returning from long racing flights. Although little is known about its mode of action, coriander (Coriandrum sativum), in either whole herb or seed form, is recommended as a heart tonic for horses.
Skin : Synthetic products, e.g. the pyrethroid insecticides that are related to the natural pyrethrines derived from Chrisantemum cinerariaefolium, are widely used in treating skin diseases, especially for ectoparasites in farm animals. Herbs are more commonly used against ectoparasites in pet animals. Many different plants are used for this purpose, generally those containing large amounts of terpenes. Celery (Anethum graveolens), caraway (Carum curvi), coriander (Coriandrum sativum), laurel (Laurus nobilis), peppermint (Mentha piperita), virgin-tree (Sassafras albidum), chamomile (Matricaria chamomilla), quassia wood (Quassia amara) and parsley are only a few examples. Eucalyptus (Eucaliptus globus) can also be used against parasites. In fact, koalas which feed exclusively on eucalyptus leaves seem to be free of cutaneous parasites. Pyrethrum powder and a lotion made from lemon juice are used against flea infestations that are frequently found in dogs. These infestations can be particularly dreadful because they give rise to allergic reactions that often become chronic. Garlic (Allium sativum) is also an active flea repellent and can be used for preventative purposes; its oral administration is also recommended for all types of parasitosis. Tobacco and derris powder are natural insecticides for external use that are well known in veterinary medicine. Animal kennels are often fumigated with cayenne pepper to protect them against fleas.A lotion prepared from garlic, lemon, elder (Sambucus niga) leaves, violet (Viola odorata) leaves, wormwood (Artemisia absinthium) and clover (Trifolium pratense), is used against mange, a common cutaneous parasitosis seen in domestic animals. A dressing prepared from tobacco powder and fresh lime can be applied to the backs of cows for treatment of warble fly. This dressing is applied with a stiff brush and the treatment is repeated frequently throughout the spring and summer. A speedy cure for ringworm, a common fungal disease seen in domestic animals, is provided by a dressing of pure, freshly-squeezed lemon juice which forms a glaze over the skin surface, thus making oxygen unavailable to aid fungus growth. The Burdock plant (Arctium lappa), which contains fungicide and bacteriostatic substances, can be used for a number of cutaneous ailments. In fact, a brew of Burdock leaves can be administered orally for depurative cleansing, and the fresh leaves themselves can be applied for cicatrization. The leaves from many other types of plants, e.g. violet (Viola odorata), nasturtium (Nasturtium officinale), comfrey (Simphyturn officinale) and nettle (Urtica dioica), also have healing effects on animal skin. They not only revitalise the skin and make animals’ coats shine but also have anti-itching, disinfectant, and star-healing effects. Grape vine, geranium, mallow and cabbage leaves are used for the healing of wounds. They are applied on the wound with a light bandage which must be changed every three hours. A brew of comfrey (Consolida maggiore), elder or rosemary flowers and leaves can be used to disinfect wounds. Plantain leaves yield very soothing mucilage which treats the inflamed areas surrounding wounds very well. In addition, the jelly from most cacti leaves is helpful in the healing of old wounds; a brew of flowers and leaves of Filipendula olmaria is helpful in stanching wound bleeding.
Additional uses : Herbal treatments seem to be particularly efficacious against mastitis. Raspberry leaves, herb-robert (Geranium robertianum), southernwood (Artemisia abrotanum), Brassica oleracea, Avena sativa, Anagallis arvensis, Linum usitatissimum, Scrophularia canina and Buxus sempervirus are useful to treat or prevent mastitis in cattle because of their anti-inflammatory and emollient properties. Externally, cold poultices of Runex aquaticus or elder leaves can be applied. When ulcers are present, poultices soaked in a brew of sambuco leaves can also be administered; antiseptics such as garlic and sage are also advised.
Aromatic herbs such as thyme, marjoram, sage, lavender and rosemary can add a pleasant taste to milk, whereas mustard, fenugreek (Trigonella foenum-graecum), nettle and cress can lend it a pungent taste. Sedge (Acorus calamus) leaves and molasses sweeten the milk, whereas linseed, sunflower seeds, oats, carrots, elder flowers, pine berries and marigold increase its fat content and darken its colour. Fennel seeds and leaves, borage (Borrago officinale), balm-mint (Melissa officinalis), marshmallow (Althea officinalis), milk worth (Polygala vulgaris), anise (Pimpinella anisum) and sweet clover (Melilotus officinalis), are all indicated to increase the milk production in ruminants.In order to stop the secretion of milk in cows before parturition, the frequency of milking must be progressively reduced and the diet modified. On the contrary, milk thistle (Silybum marianum) increases lactation in cows by probably increasing the levels of circulating prolactin. Some plants can aid in reducing the milk yield, e.g. mint, periwinkle (Vinca minor), herb-robert and asparagus. The powder from the ripe fruit of Capsicum annum can be used as a heat and rut inducer in cattle and other species. The same is true for the rhizome extract of Cimicifuga racemosa whose link with oestrogen receptors has been demonstrated in the rat uterus. For the prevention and therapy of pseudo-pregnancies in bitches, plants which promote oestrogen secretion and inhibit progesterone secretion, e.g. mu-weed (Artemisia vulgaris), pot-marigold (Calendula officinalis) and groundsel (Senecio vulgaris), are indicated. Dogs and cats with spontaneous tumours, treated with the immuno-stimulating polysaccharide acemannan, derived from Aloe spp. by intraperitoneal and intralesional routes, showed improvement when assessed for tumour shrinkage, tumour necrosis or prolonged survival. The extract of the gel has also been used in veterinary science for external treatment in animals, including allergies, fungal infections, inflammations, pains and itching. Melissa officinalis, Valeriana officinalis and Crataegus oxyacantha have been useful to prevent or alleviate psychological problems in domestic animals. Valeriana officinalis in association with Passiflora incarnata reduced anxiety and irritability in pigs during transport vibration. Other plants (Lavanda officinalis, Humulus lupulus, Scutellaria lateriflora and Magnolia acuminata) have been used for nervousness and restlessness.
Conclusion : Herbal drugs contain active compounds that may find their application in veterinary medicine. They are used to medicate or prevent disturbances and diseases that involve not only large animals but also dogs, poultry and rabbits. Natural products are often used as antibacterials, antimycotics, antiparasitics, disinfectants and immunostimulants. In this paper, we have reviewed the herbal drugs most commonly utilized in domestic animals.