photos and descriptions of worms at bottom of page
I treat every horse that I bring onto the
property like it hasnt been wormed. I dose them with Panacur or Safeguard at the
recommended dosage. It is a safe wormer for horses with a heavy infestations.
Paste wormers are safe and effective ways of controlling internal
parasites. They are available through your local veterinarian, feed stores or order
WORM YOUR HORSES
EVERY 6 - 8 WEEKS :
Recommended wormer rotation schedule for the three classes of wormer (
fenbendazole, pyrantel and ivermectin ). Rotation simply means to use a
different class of wormer rather than using the same wormer all of the time. Some of
the wormers are better at controlling certain internal parasites than others. The
schedule below takes into account when certain parasites are likely to be found in the
pastures and passed on to your horse through ingestion.
FOR MINIATURE HORSES:
Adults: 300 # dose for under 34" minis
Foals/Weanlings: 150# dose
It is now being
suggested that horses should be wormed in March/April and in September/October with
products containing Ivermectin and Praziquantel. This will kill tape worms in the horses.
Another option is double dose of Pyrantel. "IVERMECTIN GOLD" contains both of
Brand names of products indicated in blue below:
fenbendazole - a safe and effective wormer paste for the control of large and small
strongyles, ascrids & pinworms in horses. Panacur,
Anthelcide EQ, Safeguard
1.87% ivermectin - Paste wormer and boticide that
controls bots, ascrids, large and small strongyles, pin, hair, stomach and threadworms. For
use in all horses of any age, including pregnant or nursing mares. For safe effective
control of 34 species & stages of worms and bots. Foals should be treated initially at
6 - 8 weeks of age and routine treatment repeated as appropriate. Equimax, Equimectrin, Zimectrin or IVERMECTIN GOLD**
May/June Strongid Paste, Strongid C, Rotation 2, Exodus Paste
pyrantel pamoate - Removes internal parasites in all types of horses and ponies: large
strongyles (bloodworms), small strongyles, pinworms & roundworms. Horses and ponies (
over 8 months) should be treated every 6 weeks. Mares should be treated 1 month before
foaling and again 10 days after foaling. Foals dose (2-8 months of age) every 4 weeks.
Anthelcide EQ, Safeguard
Equimectrin, Zimectrin or IVERMECTIN GOLD**
Paste, Strongid C, Rotation 2, Exodus Paste
Type of Worm
Also known as
bloodworms or roundworms. Eggs that are present in manure hatch into
larvae and can be consumed by a grazing horse. The larvae continue to
develop in the intestinal tract. Strongyles will travel through blood
vessels to various organs until they reach the intestine again.
Extensive damage can be caused to the lining of the blood vessels.
Horses with this type of parasitic infection may lose weight, become
anemic or develop colic. In the worst case scenario, the intestinal
blood supply may become completely blocked causing sever, sometimes
fatal, colic. Blood vessels in extremely infected horses may swell and
even rupture, causing sudden death.
Small strongyle larvae
lay dormant in the intestinal wall waiting for the right conditions to
materialize. When this happens they may become encysted. If this
occurs, small strongyle larvae are not vulnerable to most dewormers.
Severe damage may be
caused to the intestinal wall if large amounts of small strongyle emerge
simultaneously. Diarrhea and colic may be apparent. Wright loss, poor
coat condition, slowed growth and loss of condition are other signs of
small strongyle infection.
Ascarids are also
called large roundworms. These parasites are found more often in young
horses than older horses. They can grow to 12 inches long and can be
found in the hundreds in the small intestine. This can lead to poor
nutrition. Common signs of ascarid infestation is coughing, colic and
diarrhea. They can cause blockage or even travel through the horse’s
lungs causing pneumonia.
Ascarid eggs are
acquired through feces from other horses which can be found in
contaminated hay or water. Once the eggs hatch in the intestinal tract,
the worms push through the intestinal wall. It usually takes about a
week for the worms to reach the lungs. After leaving the lungs,
ascarids continue to travel to the horse’s mouth to be swallowed again.
They reach full maturity in approximately 2 to 3 months. At this time
the parasites lay eggs that are passed in the feces and the cycle begins
Pinworms are less
dangerous to a horse’s health but are still annoying. They cause severe
anal itching which causes the horse to rub its tail and the anal region
creating bare patches and sometimes injury around the tail and broken
Pinworms can be
acquired by drinking contaminated water or eating infested hay, grain or
grass. Maturity is reached within 3 to 4 months. Pinworms then crawl
part of the way out of the anus and lay eggs on an outside surface.
After the eggs hatch outside of the horse’s body, the parasites become
infective within 72 hours. However, they can stay alive unhatched for a
Tapeworms are spread
through mites that can be found on plants located in a grazing
pasture. The mites consume the eggs found in an infected horse’s
manure. Grazing horses can swallow the mites and become infected. This
infection can lead to colic, digestive problems and even
malnourishment. It is estimated that approximately 40% of the horses
living in the United States are affected.
Bots are the immature
larvae of the botfly, which resembles the honeybee in appearance.
Because of the widespread presence in a horse’s environment, most horses
will become infected. These parasites are most commonly found in the
early fall and late summer. Adult female botflies lay eggs on the
horse’s hair by attaching themselves to the nose, throat, forelegs or
chest. As a horse licks itself, the larvae attach themselves to the
gums, cheeks and tongue. After 3-4 weeks, the bot larvae travel to the
stomach and attach to the lining where they will remain for several
months causing irritation, blocking the opening to the small intestine
and interfering with digestion. After 8-10 months have passed, the
parasite is passed through feces and the process starts again.