Equine Strongyles

Equine strongyles are parasitic worms found primarily in horses, mules, and donkeys.
They are distinguished into two types based on size: large and small strongyles.

Large strongyles are considerably more pathogenic compared to small strongyles.
Not zoonotic: Although there are species affecting humans and other animals, equine strongyles do not pose a risk to humans.

Commonly known as the equine bloodworm.
Life Cycle:
- Specific life cycle characteristics can be found in literature.
- Larvae prefer to inhabit the cranial mesenteric artery.
- Adults usually reside in the cecum and large intestines.
Damage Mechanism:
- These parasites inflict significant damage by migrating through the gut; this can result in complications such as:
- Thromboembolic colic: a serious condition resulting from blood clots obstructing blood flow.
- Potentially fatal if untreated.
Clinical Signs:
- Commonly referred to as colic, which indicates abdominal pain, but is not a specific diagnosis since many conditions can cause colic.
Diagnosis:
- Through identification of eggs in fecal samples alongside clinical signs.
Treatment:
- Can be treated using Ivermectin or Amoxidectin (brand name: Quest).
- Quest Plus: combines Amoxidectin and Probenecid.
Thromboembolic colic occurs through:
- Blood clots disrupting blood supply to the intestines, leading to torsion.
- Surgical intervention is required as medication will not suffice.
- Intussusception: intestines rolling onto themselves (similar to rolled-up socks).
- Also requires surgical treatment.
- Rupture: intestinal rupture can occur if untreated for too long, making surgical repair potentially futile depending on the damage extent.

Preventative Measures:
- Regular deworming schedules are crucial to control strongyles and prevent their proliferation.
- There has been a noted reduction in large strongyles with increased deworming but a rise in other parasite types.

Observational Evidence of Strongyles:
- Presence of bloodworms leads to significant damage in the mesenteric lining, particularly around the mesenteric artery.
- Observed damage includes darkened areas indicative of parasitic activity, indicating unhealthy intestines.

Increasing recognition as a problem due to neglect in treatment compared to larger variants.
Over 40 species exist, with 15-20 capable of cohabitation within a single host.
Infection Preference:
- Prefer the cecum and colon.
- They do not migrate as extensively as large strongyles, which makes them harder to detect.
Clinical Signs:
- Typical symptom is watery diarrhea, especially during summer.
- Presence easily observed, with fecal exams often revealing high egg counts.
Treatment:
- Moxidectin is effective but can be harsh on horses; observing for side effects is necessary.
- Steroids may be given to manage inflammation.
- Emphasis on maintaining a strict deworming schedule to avoid complications from growing populations of small strongyles.

Significant infections may require multiple treatments due to the maturity stages of the parasites and their resistance.
Importance of regular fecal exams to adjust deworming strategies.

Strongyloides exhibit two life cycles: one parasitic within horses and one in the environment.
Infective Stage:
- Larval stage 3 can be ingested or penetrate the skin.
- Transmammary transmission is notable as mares can pass the larvae to their foals during nursing.
Clinical Significance:
- Symptoms notably observed shortly after foaling, where foals might suffer from severe diarrhea due to maternal transmission.
Diagnosis:
- Detection of larvae in fecal samples; eggs may also be identified, especially of species like Strongyloides westerii.
Treatment Protocols:
- Deworming mares (with Ivermectin or Oxibendazole) post-foaling can reduce larval transmission to foals.
Common Species:
- Includes S. stercoralis, S. papillosus, and S. westerii, with varying detection methods for eggs and larvae.

Continued study on equine strongyles and improvement in treatment regimens are critical for maintaining horse health. Further discussion will follow on related parasites, such as pinworms.