Cauda equina syndrome, diskospondylitis, and a paravertebral abscess caused by Rhodococcus equi in a foal.

The research article describes a case of a 4-month-old Quarter Horse that was found to have Cauda equina syndrome, diskospondylitis, and a paravertebral abscess caused by Rhodococcus equi. After treatment which included surgery, medication, and 120-day administration of antibiotics, the horse completely recovered and remained neurologically normal two years later.

Presentation of the Case

• The research revolves around a 4-month-old male Quarter Horse who was brought in for evaluation because of urinary incontinence, an unusual symptom in such a young horse.
• Upon physical examination, the symptoms lined up with Cauda equina syndrome. This condition involves the damage or inflammation of nerves in the lower back, resulting in a range of symptoms that can include urinary and fecal incontinence, sexual dysfunction, and progressive weakness and loss of sensation in the legs.
• For further clarity, radiography was performed and it revealed diskospondylitis, an inflammation of a vertebral disk, specifically between S2 through S4 vertebrae.

Surgical Intervention and Isolated Cause

• In order to alleviate the condition, surgical actions were taken. The infected bone was surgically cleaned (curetted) and drainage was established for a detected paravertebral abscess, a collection of pus near the vertebral column.
• The examination revealed Rhodococcus equi in specimens of bone and in fluid samples extracted from the paravertebral abscess. Rhodococcus equi is a soil-dwelling bacterium that is known to cause severe infections, particularly in horses. It’s known to be opportunistic, infecting the host when the immune system is compromised or if it gains access to normally sterile body regions.

Medication and Follow-up

• Bethanechol was administered to stimulate urination. This medicine is primarily used to treat urinary retention without any obstruction.
• The horse was put on a 120-day course of Erythromycin and Rifampin, both antibiotics effective against Rhodococcus equi. This antibiotic therapy aims to destroy the bacteria causing the infection.
• The comprehensive treatment led to a complete resolution of the horse’s neurological dysfunction. Two years post-discharge, the horse remained neurologically normal and showed no identifiable effects resulting from the prior disorder, demonstrating the success of the treatment strategy implemented by the researchers.