The ever-present deadly threat to horses health – Hard to detect and hard to get rid of!
Make no mistake about it; they are the most toxic agents in the horses’ body.
Horses are prone to internal parasites, no matter what their breed, where they live or what they’re fed.
Parasites are small gastro-intestinal organisms living a portion of their life cycle inside the horses’ body that lead to colic, gastric ulcerations, respiratory, and digestive problems as well as lung damage and eventually death if not treated with equine medication.
These horse parasites live, breed, sucks blood, sucks nutrients and colonizes in internal organs, body cavities, and tissues and feed on the horse as their host in order to survive and continue its life cycle.
Parasites can survive both in winter season or hot summer conditions either as adult, inhibited larvae or infective larvae in the environment, mostly in the pasture.
In the winter, horse parasites survive freezing. They don’t have to generate heat to stay warm, so the colder it is, the longer they live. In fact, under most winter conditions, the larvae that are present in October almost all survive until April. They don’t disappear in the colder months.
So when trying to think in terms of breaking the life cycle or pattern of infection, the depth of summer is your friend and the rest of the year is your enemy.
The manure/dung piles are the protective environment for these infective, deadly parasites/worms. Cleaning up the manure or horse dung daily is necessary in keeping these deadly, harmful and infective parasites away. These horse parasites can survive in the manure for some period of time. But once this is broken up, the heat and drying can more readily kill them and help decrease the risk for transmission.
Once a pasture during autumn is parasite infected, there is literally nothing you can do in the environment that will help decrease the worms until there is an increase in environmental temperatures again. Any pasture cannot clean itself up until about June the next year if pasture is left dirty in autumn and winter.
The horse parasites during the migratory part of their life cycle get inside it’s host, the horse, damage the intestines, as they attach to the inside of the gut, suck blood and burrow through the body of the host.
How the Horse Gets the Ever-Deadly Parasites
The sole source of parasite infection is pasture grazing as shown above. Some parasites do not transmit in stalls or drylots, or on mud. The ideal parasite transmission conditions are strictly green grass and sunshine. Thus, the pasture horses are most at risk. Pasture that is overgrazed and short-cropped will be more infective than tall grasses. The pasture can be infected vertically when grass is shorter due to the larvae are more concentrated at the thatch layer and can as well be infected horizontally if grass is really short and up grazing closer to fecal piles especially when stressed nutritionally.
If these parasites are allowed to infest the horse and remain untreated they could cause damage to vital organs such as the intestines, lungs, stomach and liver and eventually leads to death. Having an effective worming program will help give your horse a better life of quality.
Most Common Deadly Parasites Life Cycle:
1. Strongyles, the red worms, are readily seen and visible in an infested horses droppings which can either be large or small, which is the most common.
Adults lay eggs in horses large intestine – passed out in feces – eggs hatch/develop 3 stages (3rd stage infective) – horse eats infected worms – worms migrate to large intestine – larvae (worms) burrow into the lining of large intestine (they can lie dormant for quite some time) – adults lay several thousand eggs in large intestine and the cycle starts again.
2. Ascarid (horse roundworm) is a very large yellowish white parasite that may pass out in the droppings & primarily infect horses below 2 years of age.
Horse consumes water/feed/pasture containing infective eggs – eggs hatch – larvae burrow into small intestine – migrate through veins to the liver, the heart, then lungs – migrate around in air spaces in lung – coughed up then swallowed – mature in large intestine – lay eggs and cycle (3 months) is complete.
3. Strongyloides (threadworm) is a horse parasite that infects foals as early as 4 days of age.
The life cycle of the threadworm can be completed in less than 2 weeks, which can result in severe infestation.
4. Stomach Bots are not really worms but instead are the larvae of the botfly. Female botflies lay their eggs by attaching them to the horse’s hair, that don’t come of when you brush your horse. Different species lay their eggs on different parts of the horse. Legs, haw, lips, etc.
Larvae attach/burrow into the tongue and gums – incubate there for 3 weeks – are swallowed and attached to the lining of the stomach (approximately 9 months) – pass out with manure – larvae pupate into adult flies – cycle starts over.
Historically, it is the large strongyles (bloodworms) were the most serious threat and the rest of the parasites described above but those have become scarce today with the advent of Ablerquant equine medication, an Ivermectin based and Praziquantrel dewormer.
There are other species of horse parasites that can also cause some trouble.
Lungworms – the pinworms and the tapeworms (which often cause tail rubbing) are found primarily in colon & rectum.
Adults lay eggs around anus – Eggs drop off & contaminate pastures, bedding, water, feeding areas – Horse eats eggs in food or water & life cycle renews at eggs hatch in colon & rectum
Tapeworms require intermediate host and affects all age groups. This has been shown to cause certain types of colic in horses.
Oribatid mites exist as free living mites in pastures – the mites eat tapeworm eggs & once the egg is eaten by the mite, it develops into an intermediate infective stage – horse ingests the infected mite – about 2-4 months after ingestion the tapeworm reaches maturity and cause ulcerations of large intestine & cecum, colic, & severe intestinal blockage.
Most of these species of horse parasites don’t seem to create as serious of a health threat due to the lower incidence of infestation or there lifecycle is not as harmful. And both of them, the tapeworms and the pinworms are killed by Ablerquant.
Anthelmintics to treat equine parasites
Ablerquant by Abler is an Ivermectin broad spectrum dewormer equine medication, which means this chemical dewormer can completely eradicate the internal horse parasites, worm infestation and most especially when combined with Praziquantrel. The administration of the Invermectin-Praziquantel paste dewormer appears to be very safe in pregnant mares and their foals.