Herbs in dog and cat nutrition

Plants contain a variety of different chemicals. Some of them are pharmacologically active and can also be used to produce medicines. In addition, they also contain vitamins, minerals, carbohydrates, amino acids and antioxidants that can have beneficial effects on the health of animals and humans. Plants containing pharmacologically active substances should be handled with care and consideration. It is not always the case that if herbs do not help, at least they do not harm. Some of them contain substances which, if used inappropriately, can cause harm to health. Often these substances are more or less poisonous, others may be harmless on their own but may have negative effects in combination with other substances. It also depends very much on how the plant is processed, whether it is served whole (fresh or dried) or whether an infusion, decoction or extract is used. Extracts contain concentrated substances and are more easily used, so they tend to be more effective than the whole plant. And this applies to both substances that are beneficial to health and those that are risky. A variety of medicinal plants can be used in the nutrition of dogs and cats. However, there are currently very few studies of their effect actually verified on dogs and cats. Herbs are not an essential part of the diet, but if chosen correctly they can have a positive effect on digestion, increase the palatability of the food and support the overall immunity of the organism. They also have anti-inflammatory and antioxidant properties and can help address a range of health issues. Without further expertise, only species that are confidently considered harmless should ever be used. Currently, there are a number of commercial preparations on the market that contain herbal mixtures, and herbs are also often included in industrially produced feeds. In this case, it is important to choose only products from reputable manufacturers that accurately declare the composition of the product and its intended use, and to follow the recommended dosage. Herbal mixtures of unknown origin and composition can be dangerous. Herbs can be used as an adjunctive therapy in the treatment of specific diseases of certain organs and organ systems. An example is milk thistle, used for liver disease. Other plants have adaptogenic effects, that is, they help to increase the body's overall resistance to various stressful situations. For example, ginseng (both true and American ginseng), eleutherococcus aureus (called Siberian ginseng), baikal coneflower, Chinese schizandra or stonecrop have adaptogenic effects. Ginseng should be used with caution as it may cause an allergic reaction in some animals and should not be given to pregnant females. It also reduces blood clotting, so it is not very suitable to combine it with blood thinners or non-steroidal anti-inflammatory drugs. Eleutherococcus tends to be included in commercial herbal mixtures for dogs and cats and is a frequently used adaptogen, especially for elderly or debilitated animals. Other safe and widely used herbs include dandelion (leaf and root), chamomile, valerian, echinacea, licorice root, calendula, milk thistle, nettle or rosemary. The leaves and roots of dandelion help normal digestion and liver function, stimulate urinary tract function and have antioxidant properties. Chamomile has anti-inflammatory properties and is used for supportive treatment of the digestive and respiratory systems, as well as in the treatment of wounds and skin changes. Valerian relieves stress and anxiety, induces pleasant feelings in some cats and brings them peace and calm. It contains most of its active ingredients in its roots. Echinacea supports a healthy immune system and can help treat chronic respiratory infections. Similarly, licorice root can help treat respiratory and digestive problems as well as skin eczema. Calendula is mainly used for skin problems, is anti-inflammatory and is also effective against fungi and yeasts. Milk thistle contains the substance silymarin, which has significant protective and regenerative effects on the liver. It is contained in the whole plant, but the seed has the highest effect. Nettle increases the body's defences and helps to ensure normal kidney and urinary tract function. Rosemary is a culinary herb, but it also has significant antioxidant and stimulant effects. Rosemary oil is used in animal feed as a fat antioxidant. Rosemary is not recommended for use in animals suffering from epilepsy as it may increase the incidence or severity of seizures. It is also not recommended for pregnant females as it may cause uterine contractions. Turmeric also has strong antioxidant and anti-inflammatory effects. In dogs and cats, it is of particular importance in the treatment of inflammatory conditions of the musculoskeletal system and has been attributed with anti-tumour activity. The exotic Boswellia serrata, popularly known as frankincense, has a significant effect in the treatment of musculoskeletal disorders. Its resin extract has a strong anti-inflammatory effect and is mainly used in the treatment and prevention of arthritis. Some herbs may also pose a risk to dogs and cats. In addition to the well-known poisonous plants such as digitalis or rowan, species of plants that are apparently harmless and commonly used by humans can also be dangerous. Dogs and cats should not be given onions, spring onions, chives or the often recommended garlic. Substances in these plants (organosulphides) cause the breakdown of red blood cells and can cause anaemia. The popular aloe vera plant is also considered poisonous to dogs and cats and can cause vomiting, diarrhoea and urinary problems. Therefore, it can only be recommended for external use on the skin or to treat wounds. The latex found under the skin of the leaf is responsible for the negative effects of aloe. It contains highly laxative substances that are also suspected of being carcinogenic. In the industrial processing of aloe, the latex residue is removed and only the pure gel is used. The well-known medicinal plant St John's wort can cause photosensitisation, whereby animals develop severe skin inflammation when exposed to the sun's rays. Nettle or mint can also cause skin and digestive tract irritation in higher doses. Other herbs with irritating effects include oregano, tarragon and lemongrass. Chamomile is considered a harmless and beneficial herb, but when collected at home it can easily be confused with similar-looking related species that can cause skin inflammation, vomiting, or allergic reactions. Laurel leaves, used in the kitchen as a bay leaf seasoning, can also be dangerous to dogs and cats. Eating them can cause diarrhea and vomiting, and ingesting large quantities of leaves can also cause obstruction of the digestive tract. When used appropriately, adding herbs to the diet of dogs and cats can have a beneficial effect on their health and well-being. They take time to work, and the effect of the herbal preparation may take several days or weeks to become apparent. More frequent dosing tends to be more effective than one large dose per day, but the manufacturer's recommendations should always be followed. Recommended doses may be adjusted depending on the animal's response. If vomiting, diarrhoea or other signs of intolerance occur; the herbal preparation should be stopped for approximately two days and then half the original dose should be given. If the animal tolerates the lower dose, it may be continued. If the negative reaction persists, the herbal preparation should be discontinued completely.

MVDr. Eva Štercová, Ph.D.