Echinacea under the Spotlight

Echinacea is the world’s most used herb by humans and as we would expect has been exposed to its fair share of research, much of which is directly applicable to horses. Its traditional use has been to boost the immune system and it is widely used as a prophylactic and in acute upper respiratory infection.

There are three species of Echinacea, also known as Purple Cone flower, that you may come across. They are Echinacea angustifolia, E. purpurea and E. pallida. The most common is E. purpurea. It is the most widely grown world wide and therefore the easiest for manufacturers to obtain. When buying Echinacea products you should know which plant has been used, but it is even more important to look at the part of the plant that has been used.

A little bit of Chemistry

Echinacea like all plants contains a vast number of chemicals. We don’t know what many of them do but as herbalists we believe that they all have a role to play in the effectiveness of the herb, on us or our animals. We do know however that one of the really important chemicals and a useful marker are a group called alkamides. Alkamide levels in the raw herb or in the final extract are a measure of quality. They also provide us with another consumer friendly measure; the tingle test, which is a lot easier for us as users to try for ourselves. The alkamides give Echinacea a characteristic tingle to the tongue. You can detect this by chewing a piece of the fresh or dry root or by tasting a preparation. You only need a small amount to taste and before buying you should ask your supplier for the opportunity to do this. The better the tingle the better the quality. You will also notice a slightly metallic taste. To begin with you will find this an odd sensation and this is the reason that we do not recommend that you give Echinacea to horses undiluted. It is much better mixed in the feed. After tasting Echinacea you should also notice an increase in saliva production. This is known as a sialagogue effect, and is the main reason why you should not give cats and dogs Echinacea directly. Again mix it in the food. These animals produce copious amounts of saliva anyway, and an increase in this volume can cause excessive foaming and restriction of the airways.

Which parts are best?

Crop & Food Research in Otago, New Zealand has being doing work on Echinacea over a number of years and has come up with some interesting results. One of the most valuable is the distribution of alkamides in the plant. Which bits are best. It is not necessary to go into all the detail here but Crop and Food have shown that the highest concentrations are in the roots. This is what herbalists have always believed but it is nice to have it confirmed. Interestingly the market prices for raw herbs also reflects this.

Types of Preparation

When you go looking for Echinacea you will probably find three main types of preparation. Firstly dried herb. This is purely the raw herb dried and chopped. It may include roots but is probably just tops. Secondly you will find liquid extracts. In our view these are the best. Thirdly you will find tablets.

When reading labels it is important to understand the terminology. If the label says “Root” it will mean root. However if it says “herb”, as in “this preparation of Echinacea purpurea herb extracted in our special way”, it usually means that it contains only tops and no roots.

When you use a plant it is important that the active ingredients are able to get into your, or your horse’s body. To this they need to enter the bloodstream via the gut. Herbalists use alcohol to extract these bioactives and experience and research has shown us that alcohol is a better extraction medium than water. If you feed your horse dried, raw plant material then you are effectively carrying out a water extraction in the stomach, and will end up with a poor rate of extraction. For a few herbs a water extraction is ok but Echinacea is not one. Alcohol also enters the bloodstream quite quickly, which is what you want rather than it being held back in the stomach. By using liquid extracts you can often see the result in less than half an hour, and in yourself feel it even more quickly than that.

So which Echinacea should you buy? Obviously the final choice is up to you but wherever possible I always look for a liquid extract of Echinacea purpurea made from root only

Does it Work

Echinacea has been used by the North American Indians for thousands of years but it is only in the last 100 years or so that it has been used outside North America. Scientific studies on humans confirm its traditional use and as we know the herb is in common use all over the world, mainly as a boost to the immune system in times of stress. In humans it can be used to treat not only acute infections of the upper respiratory system, but also longer term immune system insufficiency. Surprisingly there seem to have been more tests carried out on humans than on animals, although there are two recent and very interesting papers that used animals.

There are two comments you may hear about the use of Echinacea in humans but which people may apply to horses. Firstly you may hear that it should not be taken long term. There is no good reason for this and there is no evidence to suggest that long-term usage will have an adverse effect on immune function. Secondly there is one published clinical study which has led to the suggestion that Echinacea depletes the immune system when used continuously for periods longer than several days, a phenomenon known as tachyphylaxis. Confusion has arisen over this study because it was not appreciated that the test dose was only administered for 5 days. While Echinacea was given, phagocytic (immune system) activity remained higher than controls. Only when the Echinacea was stopped did phagocytic activity decline to normal (pretest) values, demonstrating a typical wash-out effect. The study in fact demonstrated that there is a residual stimulating effect which lasted for about 2 days after Echinacea was stopped. The 2005 study by Sandra Miller, discussed below, has confirmed the benefit of long term use.

Although horses have been given Echinacea for years only recently has a specific test been carried out to study the effects. The Equine Research Centre in Guelph, Ontario published the results of an extensive series of tests on the effect of Echinacea on horses. The results not only confirm what herbalists believed but also yielded some interesting new effects that were previously unknown. As we would expect the tests showed that whilst on twice daily doses of Echinacea the horses had increased immune function. The unexpected and interesting results showed that whilst on the Echinacea the horses also showed increased size and number of red blood cells. The effect of the improvement in blood quality was most noticeable from the 28-day mark on. The significance of this is quite far reaching.

As we know red blood cells carry oxygen to muscle tissue and put simply the more oxygen there is the better or harder a muscle can work. So if we increase the number of red blood cells and increase the amount of oxygen each can transport this should help in the performance of the muscle... and we would hope the horse. As far as we know no tests have been carried out to challenge this theory. It is then a short step to think about the effects on horses of long term Echinacea combined with Schisandra which helps to slow the build up of lactic acid in the muscle.

The paper by Dr Sandra Miller of McGill University reported on the long term effects of Echinacea on mice. Her results showed that daily consumption of Echinacea has a prophylactic effect. It extended the life span of aging mice, significantly abated leukemia and extended the life of leukemic mice. In her paper she says ‘given that humans are 97% genetically common with mice and that virtually all our basic physiology is identical, it is neither unjustified to extrapolate these observations to humans...’ . Neither would it be too ambitious to think that Echinacea will have the same effect on horses, although a study would take a long time.

One other recently published paper is also worth mentioning. It was published in The New England Journal of Medicine and reported the total lack of effect of Echinacea on a group of volunteer humans infected with a cold virus. The article was picked up by the main stream press and widely reported. Unfortunately it took a bit of digging to find out that the subjects had only been given the equivalent of only 0.9 gms of Echinacea a day. This is well below the sort of dose that a herbalists would prescribe especially in an acute infection. Not surprisingly the Echinacea had little effect. This study does however serve a useful purpose; it reinforces the importance of giving a sufficient dose. In humans in acute respiratory infections a dose of 30ml (of a 1:2 extract) in a day would be high but not excessive. Horses can easily handle 5 times the human dose.

How should I use Echinacea ?

The tests discussed above show that Echinacea boosts the immune system. Like us, horse are under constant immune challenge, but are usually able to cope very well. This is because they have built up an immunity to the viruses and bacteria that they regularly come across in their home environment. Horses and humans often catch colds at the change of season and if they travel a lot. How many horses have runny noses in the Autumn? Are they in contact with other horses that already have colds? Remember most respiratory infections are viral in nature and most of the viruses that cause them are transmitted through the air.
Stress causes a dampening of the immune response so any situations that stress a horse can lower its resistance and allow an infection to gain a hold. This will include travelling, experiencing new situations or even such apparently benign events such as having a new paddock mate. In humans, sugar has been shown to depress the immune system. Although we have found no trials that have been carried out on horses it is reasonable to assume that the same thing happens. This means of course that if you are using a high molasses feed you may well be inadvertently suppressing you horses’s immune system every time he is fed.

How much to use ?

As we have seen the choice of product is important. Having found what you need, also make sure that you give sufficient dose. If you do some research you will find a wide variation in dose recommendation. We have found that a dose rate of the equivalent of 5 gm of plant material per day is appropriate as a preventative, if your horse is healthy. The Echinacea that we make has the equivalent of 1 gm of root per 2 ml, so a dose of 10 ml twice daily would be appropriate

So if you are going to a show or moving your horse to a new environment we would normally put Echinacea in the feed for about 5 days prior to the show. It is also a good idea to continue for about that period after the show as well. Bacteria and viruses take a while to incubate in the body so it is worthwhile to keep your horse protected during that period.

If you feel that your horse is coming down with a cold you can safely increase the dose by up to 10 times. ie 200 ml over the course of a day, depending on the severity if the infection. In an acute case it is best to give lots of little doses rather than a few big ones. We would typically give doses at three hourly intervals. The Echinacea should help him to recover and shorten the length of the illness.

Can I overdose ?

All the literature, with reference to humans again, indicates that the toxicity and hence risk of overdosing with Echinacea is very low. It is often said that you will get drunk on the ethanol before you suffer any ill effects from too much Echinacea.

How do I give it?

Because of the fairly unusual taste and sensation that Echinacea produces it is best to mix it in feed. If you need to give many doses over the day, divide the feed in to lots of small portions.

Echinacea is a very useful herb but remember if you are worried about your horse don’t hesitate to call the vet

Sources: 

Graph sourced from Equine Canada Magazine and Echi-Fend
Echinacea: a Miracle Herb against Aging and Cancer? Sandra C. Miller 
eCAM 2005;2930309-314

©2005 James Hart