[Artificial infestation of horses with the eggs of the stomach botfly (Gastrophilidae)].

The research explores the process and impact of artificially infesting 10 foals with eggs from various species of stomach botfly (Gastrophilus). The study shows that a large percentage of first-stage larvae die soon after hatching and beginning their migration, though the majority of surviving larvae are found in the stomach, duodenum, and rectum approximately 40 to 45 years post infection.

Research Context

• The study was conducted to understand the life cycle and behavior of five species of the stomach botfly—or Gastrophilus—in horses, specifically foals. The species include Gastrophilus intestinalis, G. veterinus, G. haemorrhoidalis, G. inermis, and G. nigricornis.
• Botflies are a prominent parasite that affect horses. Their life cycle is unique, starting as eggs laid on the skin of the horse and developing into larvae that burrow into the skin and migrate to the stomach.
• The researchers wanted to track the path of these larvae from hatching to migrating into the host’s body.

Methodology

• The researchers selected 10 foals and infested each one with eggs from one of the Gastrophilus species.
• After the larvae hatched, the researchers tracked their migration and survival rates.

Findings

• The study found that a sizable portion (63 to 67%) of the first-stage larvae died soon after hatching and beginning their invasion into the horse’s body. This indicates that the initial migration phase may be the most vulnerable for the larvae of these botfly species.
• However, those larvae that survived were able to reach the horse’s stomach, duodenum, and rectum. The study showed that 73 to 82% of the larvae—depending on the species—were found in these locations in 40 to 45 years after the infestation was first initiated.

Implications

• This research helps in understanding the behaviour, life cycle, and survival rates of various botfly species once they infest a host. This knowledge can potentially aid in the development of treatments or preventative measures for horses infected with botflies.