and make informed decisions.
Parasites & Horses
Of all domestic livestock, horses have the largest numbers of parasites. Horses that graze on grass in a domesticated living environment are very susceptible, since parasites spend a part of their life cycle living on the grass blades. Horses are at greatest risk of parasitic infection if they are allowed to overgraze their pasture, because overgrazed, nutrient-poor grass favours higher larval populations. They are also at risk under confined conditions, because in tight quarters they are more likely to pick up eggs shed by one another. Horses graze close to the ground and, more than other livestock, are always smelling, nibbling, and licking, whereby they can pick up large numbers of infective larvae.
Once in the horse’s digestive tract, female parasites lay eggs in the hindgut. These eggs are passed to the ground inside the feces. Under proper environmental conditions (including warmth and moisture) the eggs hatch into larvae in the manure. Under cold and dry conditions, the eggs can survive un-hatched for long periods, waiting to emerge when the conditions are right. The infective larvae migrate onto grass blades, where they remain until grazing horses ingest them. They then develop into young parasites in the intestines. In the fall, prompted by the changes in daylight, ingested intestinal larvae penetrate the wall of the large intestine where they encyst and begin another life cycle within the host.
The most common parasites to infect equines are small strongyles, large strongyles, roundworms and pinworms. Small strongyles are the most common, and their encysted larvae can cause colic, anemia, weight loss and mal-absorption. Large strongyles, known as bloodworms, enter the bloodstream and migrate for six to seven months along the walls of the arteries, the liver, the kidneys, the pancreas and the intestinal wall causing tissue damage. They eventually return to the large intestine as young adults.
Roundworms only affect weanlings and yearlings, with encysted larvae migrating to the liver, heart and/or lungs. Infected youngsters will generally show signs like malnutrition, colic, failure to thrive, unhealthy hair coat, pot belly and possible coughing.
Pinworms lay eggs around the anus, causing tail itching and hair loss.
General symptoms that are associated with infections from all worm types can also include poor appetite, diarrhea, itching, skin conditions, fatigue, poor body condition, depression, anxiety and ulcers. Interestingly it is not of benefit for these parasites to kill its host so most horses just continue to get sicker rather than die.
The treatment of equine parasites is not as simple as we think. Not only are there different types of parasites but each horse has different levels of resistance – some horses with a high count have no symptoms whatsoever and other horses with hardly any infestation have no resistance at all and show a variety of symptoms. As well, there is much concern about over-medicating horses with chemical de-wormers leading to the mutation and resistance of the parasites themselves. And conversely, for some horses, herbal and homeopathic treatments are not enough.
Chemical de-wormers came on the scene in the 1960s to target all species of worms. Only one new de-worming medicine has been introduced in the past 15 years and few new ones are expected. In recent years, however, the chemical war on parasites has become less popular for the following reasons:
1) Worms, especially small strongyles and roundworms, adaptive creatures that they are, have learned to build resistance. This has no doubt been spurred on by overly-aggressive parasite drug treatments putting selective pressure on worms to mutate. The indiscriminate and repetitive use of chemical de-wormers on horses, especially those horses who may not even be infested, leads to parasitic mutation, and puts the horses at risk for toxic chemical overload and compromised immunity. Some de-worming practices advocate double dosing for several days in succession! By testing with kinesiology I find that most horses require much lower dosages than the recommended full dose of 450 – 500 kg. And that these lower dosages are just as effective. In some cases the horses require a very small dose three or four days in succession or even once per week for three to four weeks.
2) Too frequent chemical de-wormings or excessive dosages contribute to intestinal imbalances, liver and kidney stress and overall toxicity. A horse’s health is often jeopardized by frequently repeating treatments without results. Be cautious of de-wormers that claim to kill encysted larvae, since in order to do so the drug must chemically alter the intestinal membrane to access the larvae. In sensitive horses this can lead to leaky gut, malnutrition, colic, and weight loss – sometimes extreme. Adverse reactions to all chemical de-wormers may include drooling, colic, swellings, allergic reactions and laminitis.
3) Chemical de-wormers often trigger the unaffected encysted larvae to emerge and develop into adult worms as soon as the drug is gone from the horse’s system. These newly developed adult parasites begin to shed eggs immediately and, depending on the time of year, can begin developing into parasites almost immediately.
4) Chemical parasite control measures shift our focus away from more natural parasite preventions such as controlling environmental contamination and keeping our horses in optimum gut health.
Having said this chemical de-wormers are still often a necessity especially for horses that have a heavy parasite load, have a low level of resistance to parasite toxicity and/or have been left untreated for a long period of time. We also find a use for chemicals after forcing encysted larvae back into the intestinal tract with anti-parasitic herbs. However, these situations are very different from administering de-wormers every few weeks without knowing whether or not your horse even needs them. And given the fact that only 30% of the horses (usually the weakest) in any herd are carrying the majority of the parasite load, this means that nearly 70% of our horses are subjected to unnecessary chemicals on a regular basis. It is highly advisable to make use of fecal parasite tests to determine whether or not your horse even has an overload of parasites. Bear in mind that a fecal parasite count will not indicate the presence of encysted parasites however I do find that those horses with high levels of encysted parasites will most often have a high load of shedding parasites as well. In any case, horses, like all animals including people, are not meant to have a sterile intestinal system – it’s all about balance. A healthy ecosystem relies on a balance of microorganisms including bacteria, yeast and the occasional parasite. If horses are never exposed to parasites, they will never build natural immunity and a stronger resistance.
Chemical de-wormers or not, effective parasite control starts with prevention, environmental control and an optimum immune system. It is important to recognize that random treatment, chemical or herbal, in a parasite laden environment will accomplish very little. Parasite management consists of healthy immunity, balance and environmental control. It is not a relentless war of eradication.
Effective Natural Parasite Control
Poor resistance to parasites is caused by poor feeding practices, inadequate nutrition, stress and a toxic colon. The intestinal environment created by high sugar-carbohydrate diets from excess grass or grain is favoured by disease causing-pathogens and parasites that eventually damage the colon membranes (leaky gut). As discussed earlier, excess sugar fermentation produces a highly acidic environment that encourages the excess proliferation of bacteria, yeast and parasites. Horses in poor condition with toxic colons will be the most favoured hosts and hostesses for parasites. The good news is that you can build up the strength of your entire herd by building up the health and immunity of these particular horses. A natural diet, adequate nutrition, colon support and detoxification through the use of herbal cleansers and anti-parasitics, as well as probiotics , will keep a troublesome overgrowth of parasites to a minimum.
The Do’s and Don’ts of Parasite Control
What to Do
Do perform fecal egg counts to determine who needs treatment, what programs are effective, and which horses in the herd need the most attention. Egg counts are the only way to determine if what you’re doing is working. Horses at risk should be tested regularly since encysted parasites or those that have migrated into other body systems won’t shed.
Do keep stables, paddocks and pastures as clean as possible and free of manure. This breaks the parasite life cycle.
Do give your horse access to free choice weeds, trees, shrubs and brush whenever possible. This allows them more opportunity to select their own herbal de-wormers and intestinal cleansers. It is absolutely fascinating to watch what horses will choose to ingest when given a choice.
Do give your chickens and ducks and any other bug-eating farm critters free access to pastures and manure piles so that they can feed on larvae. Some farms keep their chicken coop on wheels and roll it to different areas in the pasture. Free run chickens are happier and lay better eggs! And chickens, like all animals, like to explore and forage and visit with their human companions.
Do concentrate on parasite programs in the spring and fall when adults and larvae are intestinally active. In springtime, parasites are migrating from the horse to the pasture whereas in the fall the horses eat the larvae which then hatch into adult worms. Take advantage of the lunar cycle too, since worms are more active during the full moon, making them more accessible to antagonists.
Do use herbal remedies and nutrients to prevent and treat parasites by maintaining a healthy colon and a balanced intestinal ecosystem. The best prevention is good digestion and a strong immune system.
Do consider having a kinesiology work-up completed to customize a complete parasitic program (see consultations and services).
What Not To Do
Don’t contribute to the parasite mutation problem and the toxic chemical overload by over-medicating. If you must chemically de-worm, keep it to an absolute minimum determined by fecals and/or kinesiology work-ups and treat your horse with probiotics afterwards.
Don’t chemically de-worm horses that don’t have a parasite problem – this is not appropriate or sensible prevention!
Don’t overcrowd your pastures and paddocks – this breeds parasites and is related to poor overall herd health and immunity.
Don’t harrow pastures in warm, wet weather – this merely spreads parasites in a favourable environment and enables larvae to crawl onto the grass. Wait for hot, sunny weather to harrow.
Don’t spread fresh manure on to the pastures – it must be properly composted first.
Para+Plus (dandelion, elecampane, gentian, kelp, sage, thyme, vervain blue, wormwood, yellow dock) – ¼ cup daily.
Has anti-parasitic, anti-bacterial, anti-fungal and detoxification properties. Combines well with whole flax seed as the seeds help “push” the herbs into the hindgut before they digest in the stomach.
Gentian-Sage Tincture – ½ - 1 tsp daily
(Useful for disrupting and eliminating encysted parasites and larvae.)
Para+Win – one dose daily for 14 days.
A homeopathic formulation for horses with low resistance and high sensitivity to parasites and their toxins. Also helps to expel parasites.
Slippery Elm – 2-3 tablespoons daily
Very useful to protect the hindgut membranes from damage and irritation. It is also well indicated when parasites have encysted into the colon membranes causing pain, irritation, diarrhea and/or colic. Encysted parasites can migrate to the liver, heart and kidneys – at this point it is best to have a consultation done to determine the most effective treatment.
Exercise your horses – exercise improves everything from digestion to immunity to parasite resistance. Ride them, pony them, chase them, hand-walk them…whatever it takes to keep them busy and get them moving. Don’t let them die from boredom.
Feed your horses frequently. Small frequent meals and/or slow feeders encourage strong digestion and prevent stress, ulcers and poor resistance to parasites. Don’t let your horses stand idle for long periods of time without anything to eat.
Marijke van de Water (B.Sc., DHMS) is an Equine Health & Nutrition Specialist, Homeopathic Practitioner and Medical Intuitive. She is the author of “Healing Horses: Their Way!” and “Healing People: The Marijke Method”. She is a regular speaker at equine seminars and conferences and is the founder, formulator and CEO of Riva’s Remedies.
Copyright March 2012