De-worming Wisdom
Are you winning the war on worms?
Alternative and complementary approaches to chemical products provide new ammunition.
by Stacey Mathias Geer
It’s a complicated world for horse owners these days. With
alternative medicine rising like a tidal wave in popularity and routinely
butting heads with the medical establishment, and debates surfacing between the
old and the new, anecdotal versus “scientific” evidence, and a whole myriad of
opinions coming forth on how best to achieve that unifying goal of “good
health,” it’s probably no surprise that even the seemingly innocuous practice
of routine deworming is being called into question.
There are some very compelling reasons coming from all sides
as to why horse owners should be scrutinizing their deworming
programs, exploring alternatives, and reducing as much as possible the use of
chemical anthelmintics.
Why should we be reducing our reliance dewormers?
There is no question that chemical dewormers
are and probably will continue to be a most invaluable weapon in the battle
against parasites. However, with the issue of parasite resistance becoming a
sweeping concern, it stands to reason that deworming
for no other reason than the date on the calendar, might not only be needless
and expensive, but could contribute to the creation of more troublesome and
dangerous parasites.
Resistance has been documented against both the Benzamidole, and Pyratel classes
of drugs, and although the horse industry has been lucky so far in that
parasite resistance has not yet been seen against any of the Ivermectins, it has appeared in ruminants where deworming tends to be more frequent. One can assume that it
is only a matter of time before parasite resistance to Ivermectin
shows up in horses as well. In addition
to this very serious problem, some also criticize the negative effects of
constantly administering a chemical into the body.
“Chemical dewormers are very hard
on the microflora because they target more than the
worms, and residues and or metabolites affect the pH and structure of the microvilli in the intestinal tract,” said Dr. Steve D. Tuekam, DVM MSc, Ph.D and Technical and Export Director with Ultrateck/Vetagri Inc, a distributer
of Ultra BioLogic horse products. This is a situation which would not only make
the horse’s resistance to disease lower, but also make him more susceptible to
re-invasion, and therefore propagate the continual need for deworming.
However, Trisha Dowling,
Putting conflicting opinions on resistance and health issues
aside, there is also the concern of any chemical’s effects on wildlife and the
environment, since proper disposal of any left over product is absolutely
necessary, but not always practiced. Ivermectin class drugs, for instance, can be toxic to fish
and could be hazardous to all of us if inadvertently leached into water supply.
And, Moxidectrin in particular is harmful to dogs. So
where does this leave the hapless horse owner? In a quandary, trying to decide
what is best for the health of her horse, best for the horse as a species, and
best for the health of our environment in general.
The Importance of Routine Fecal Monitoring
Fortunately, there are some very simple ways to reduce the
need of chemical anthelmintics. The best and probably
most under-used method is fecal monitoring. Fecal monitoring involves
collecting a fecal sample and sending it to the lab for an egg count –
something we have our vets do regularly for our cats and dogs. It generally
costs no more than the price of deworming, and if you
have a large number of horses the entire herd does not have to be done.
However, which horses should be tested is something that should be discussed
with a veterinarian.
Fecal monitoring is advantageous in that it not only tells
how effective a deworming program is, it takes the
guessing out of how frequently a dewormer should be
administered. It can also indicate which parasites are particularly troublesome
to a particular horse or herd, allowing the owner to choose a dewormer from the class of drugs that is most appropriate.
But, fecal monitoring is not the complete answer to the problem. Bots, pinworms, and tapeworms cannot be
detected. (Although horse owners can generally tell if they have a bot problem by the eggs appearing externally on the horse,
and pinworms are indicated by the trademark rubbing of the tail.) In addition,
a negative fecal count doesn’t necessarily mean that a horse doesn’t have worms, it only means that adult worms had not laid eggs in
the intestinal tract at the time the fecal sample was collected. But, by doing
an analysis at least four times a year, you can get a fairly accurate picture
of what’s going on inside your horse.
Even with its drawbacks, fecal monitoring is still
considered by vets to be a very reliable aid in monitoring the efficiency of
any anti-parasite program.
Herbal Dewormers
Another avenue worthy of exploration is the use of herbs
with anthelmintic properties, either as a replacement
or a complement to chemical deworming. However, horse
owners are wise to tread cautiously here, as Wendy O’Neill, president of the Nutraceutical Alliance Inc. in
“The primary problem is safety, as many products that are
useful for killing parasites are also toxic to the host.”
However, she added that there is some evidence showing that
products such as diatomaceous earth, garlic, and artemisia
(wormwood) do have antiparasitic action. Here is a
list of just a few botanicals worthy of further research and consideration:
• Diatomaceous Earth
Made by grinding up the fossilized remains of one-cell
diatoms from lakes and sea floors, diatomaceous earth has a mechanical action
rather than a chemical one. The microscopic shards pierce the exoskeletons of the parasites
causing them to dehydrate and die. Diatomaceous earth is also used externally
as a repellent against flies, and even lice. It is quite dusty, however, and
could be a lung irritant, and is best either dampened or fed with an adhesive
like honey or molasses. Diatomaceous earth also contains valuable trace
minerals which also could help promote resistance against parasites. However, it should be noted that only “food
grade” diatomaceous earth should be used as the industrial version is heated
and treated with chemicals, and can be toxic.
• Garlic
Called nature’s antibiotic, garlic is also reported to be
anti-fungal and anti-parasitic. It’s high in sulphur
which is mildly toxic to parasites. It is also a noted immune system builder
which may help over-all resistance. Garlic is completely safe to feed at
moderate levels, and is cheap enough to go on the list of “can’t hurt, might
help” herbs.
• Pumpkin Seeds
Raw pumpkin seeds are much loved by horses, and are a safe
treat to add whole or
ground up with feed. They are especially high in zinc which helps
expel parasites, and contain cucurbitin, which is especially toxic
to tape worms. Pumpkin seeds also fall into that “can’t hurt, might help”
category, and are a nice extra to add a little variety to the diet.
• Artemisia
Also known as wormwood, this plant is known to be one of the
most effective herbal dewormers. The active
ingredients are absinthine, and thujone.
(Incidentally, this is the very plant from which the bright green
hallucinogenic drink Absinthe, which was popular at the turn of the century,
was made). The dried leaves are usually fed as a powder. However, due to the
toxic and narcotic nature of the plant, anyone considering this herb should
talk to a qualified herbalist familiar with horse physiology.
There are also plenty of combination remedies on the market
that interested horseowners can investigate.
Ultra-biologics makes a natural dewormer
called DW-123 made from garlic, diatomaceous earth, and lactobacillus
acidophilus which is meant to be added daily to the feed and is designed to
replace chemical dewormers. The company does
recommend fecal monitoring four times a year, as the dose can be doubled during
troublesome times of the year, and eliminated during others.
For those more comfortable with paste format, there is Worm
Check which contains garlic, cloves, acidophilus and diatamaceous
earth which is suggested for use every two to four months depending on
situation and fecal counts. After six tubes, customers are entitled to a free
fecal test, and will be sent a collection kit.
And, from Horse Sense Herbs, there is dewormer
I and dewormer II (the latter for severe
infestations), which are made from Chinese Herbs, and according to
spokesperson, Arno Leblic,
can be used to replace or compliment chemical dewormers.
“If a horse owner feels more comfortable with chemical dewormers, a combination of herbal and chemical dewormers is
suggested,” said Leblic. “The herbal dewormer will help maintain a balance of acidity/alkaline
within the digestive system.” Leblic said that maintaining this balance can extend the
time between chemical dewormings, a practice that he believes disrupts pH levels. “It is one thing to eliminate unwelcome parasites, however, the territory (created by the use of
chemical dewormers) may permit a faster return of
worms.”
Horse owners should be wary when purchasing a natural dewormer and should research each ingredient
carefully. Black walnut is often an
ingredient in dewormers. Although black walnut has
been used successfully in horses, in combination with other herbs, with little
adverse effect, it does contain the compound, Juglone.
This compound is responsible for the violent laminitis reaction in horses
exposed to minute quantities of black walnut bedding shavings and, therefore,
should be avoided completely until there is more conclusive research.
The market is beginning to flood with herbal preparations
for dewormers, and O’Neill advises the public to
understand their limitations.
“Research on dewormers can be very
challenging as it often requires the examination of post-mortem tissue. The fecal egg count is not a conclusive end
point to measure, because all it tells the investigators is that there is a
reduction in egg counts. Egg counts may
be lower when experimental animals are fed experimental dewormers,
and this in itself is a good indicator, but it does not tell us anything about
what is happening to the viability of the parent parasite.”
And then there’s homeopathy
For those interested in trying an alternative to replace or
supplement chemical deworming, but are worried about
the safety of herbals, homeopathy is a viable option, as the dilution process
makes toxicity problems non-existant. “Cina” or “wormseed” is said to be useful against all Ascarids, pinworms, and small and large strongyles.
The company, “Everglo” makes a homeopathic nosode called “Horsewormer” made
from Cina, and parts of parasites, which they claim
also releases parasites in dormant stages within the tissues outside the
gastrointestinal tract. However, fecal monitoring is again advised, with the
understanding that scientific research is still limited in this area.
Promoting a hostile environment
Of course, the best way to keep parasites away is to create
an inhospitable environment for parasites to exist. A clean living area should
be central to all anti-parasite programs. Stalls should be picked out daily,
manure in paddocks and pastures removed as much as possible. Pasture rotation
and harrowing are also advisable. And, feed should be given so that it does not
come in contact with the ground. New horses should be checked for parasites and
dewormed, if necessary, before being introduced in a
herd.
Nutrition is important, as unhealthy horses are more likely
to be infected with parasites than healthy horses. Horses should be fed plenty
of clean water and good quality forage, and monitored for any possible vitamin
or mineral deficiencies. Copper deficiency, in particular, has been linked to
parasite infestation and can be prevalent where there is a deficiency in the
soil. However, free access to trace minerals should eliminate any possibility
of this.
Horses that have been on antibiotics,
or other chemical drugs might have a pH and micro flora imbalance making them
more attractive hosts to parasites. In such cases, a probiotic
supplementation might be beneficial. Probiotics add
good bacteria back into the body and allegedly increase digestive efficiency
and the uptake of vitamins and minerals. The use of probiotics
is becoming one of the more popular forms of dietary supplementation. Whether
they are effective or not is subject to debate.
“Probiotics contain small numbers
of a few species of bacteria, while the horse’s GI tract contains enormous
numbers of a wide range of bacteria. I am not aware of any real scientific
studies that show the benefit of probiotics in
horses,” said Dowling.
Studies are currently in progress on the effects of probiotics, which might bring us some conclusive evidence
on the subject. Other supplements to be considered are those that help balance
the pH level which, in turn, creates an environment for good bacteria to propogate. Grapefruit seed extract is one such herb that is
said to be useful.
And Finally ...
There is no single, hard and fast rule on how best to
regulate parasites. A horse’s individual environment and constitution must
always be taken into consideration when developing a deworming
program. Horse owners must be careful not to be pigeon-holed into routines, but
rather individually tailor a program that is best for the horse’s situation,
and be ready to adapt it if the situation changes. It is flexible, informed
management, using a variety of tools, that is best for the horse and,
ultimately, best for the environment we all have to share.