Elimination of guttural pouch infection and inflammation in asymptomatic carriers of Streptococcus equi.

The research article mainly focuses on the treatment of asymptomatic carriers of Streptococcus equi, a bacterium that causes strangles in horses. The treatments were targeted towards the elimination of the bacterium’s colonization in the guttural pouch of the horses, considering the infectious risk posed by the carriers to susceptible horses.

Research Context

• The analysis was conducted amid three prolonged outbreaks of strangles, a highly contagious disease that affects horses’ respiratory system.
• Fourteen silent (asymptomatic) carriers were revealed through endoscopic examination. Thirteen out of the fourteen showed presence of the bacterium in their guttural pouch, a part of the horse’s respiratory tract.
• Additionally, two more horses were studied that exhibited a severe guttural pouch pathology and were confirmed carriers of S. equi.

Intervention Strategy

• Initially, the treatment focused on eliminating the gross changes in the guttural pouch as viewed through endoscopy. The technique used for this included flushing (irrigation) of pouches with saline, suction of fluid, and endoscopic handling of chondroids (accumulated pus nodules).
• Subsequently, antibiotic treatment was applied to eradicate S. equi infection.

Treatment Outcomes

• All the horses received systemic antibiotics, with some receiving topical antimicrobial treatment in conjunction.
• Treatment was deemed successful when the guttural pouches returned to normal as viewed on endoscopy, and S. equi was not detected through nasopharyngeal swabs (throat swabs) and pouch rinses on three consecutive occasions.
• One carrier having blocked guttural pouch openings had to undergo a surgery, but all other horses were treated effectively with non-surgical methods.
• Five carriers who received potentiated sulphonamide as initial therapy required further treatment using penicillin or ceftiofur, applied both systematically and topically.

Conclusions

• The treatment regime successfully eliminated S. equi infection and related inflammation from the guttural pouches for fourteen out of fifteen carriers.
• The study demonstrates that a treatment protocol involving endoscopic manipulation and appropriate antibiotic intervention can manage asymptomatic carriers effectively, preventing the transmission risk to other healthy horses.