Successful medical treatment of splenic abscesses in a horse.

The research discusses a successful case of medical treatment for splenic abscesses in a horse. Previously, there were no successful treatments reported for this rare condition in horses.

Case Description

• A 6-year-old Quarterhorse mare presented with signs of sickness including lethargy, weight loss, and intermittent fever for 6 weeks.
• Initial treatments with a mix of trimethoprim, sulfadimidine, and phenylbutazone showed minimal improvement.
• Upon examination, the mare was found to be weakened, anorexic, and in poor body condition.
• Initial tests revealed higher than normal levels of mature neutrophils and hyperfibrinogenaemia, indicating inflammation or infection.
• Palpation revealed an enlarged, firm and nodular spleen, suggestive of splenic abscesses.
• Ultrasonography was used as a diagnostic tool, which confirmed the presence of multifocal, hypoechoic, nodular masses in the spleen, suggestive of either splenic abscesses, lymphosarcoma, or granuloma.

Diagnostic Process

• Ultrasound-guided aspiration and tissue biopsy confirmed the presence of degenerate neutrophils and bacteria, confirming the diagnosis of splenic abscessation.
• The biopsied spleen tissue revealed infiltration by neutrophils and areas of necrosis, indicative of an active inflammation and tissue death, and further confirming the abscessation.
• Despite the clear presence of bacteria in the spleen aspirate and biopsy, bacterial cultures did not identify a specific causative organism.

Treatment Method and Outcome

• Upon diagnosis, the mare was treated with procaine penicillin and gentamicin for 10 days.
• The mare’s condition improved over treatment, with gain in weight and demeanor.
• Follow-up ultrasound of the spleen showed a significant reduction in the abscesses, resulting in a mildly mottled appearance in the spleen parenchyma.
• The owner decided to end treatment against the recommendation of continuing the antimicrobial therapy for another 1 to 2 weeks.
• However, 6 months post-treatment, the mare remained in good health and resumed normal activity.

Discussion and Implications

• The study suggested that infections spread from the respiratory tract or lymphatic spread from abdominal lymph nodes could potentially cause splenic abscesses in horses.
• As a rarity in horses, splenic abscesses have previously been associated with penetrating abdominal traumas, but no such history was recorded for this mare.
• The successful treatment of the splenic abscesses highlights the potential for medical management of this rare condition, diverging from past reports where affected horses had to be euthanized.
• Despite the inability to isolate a causative organism from the bacterial cultures, the antibiotic treatment was successful, indicating a high likelihood that bacteria were at the root of the abscesses.