Mesenteric lymph node abscesses due to Escherichia coli in a cat.

Area of Science:

• Veterinary Medicine
• Small Animal Internal Medicine
• Diagnostic Imaging

Background:

• Chronic gastrointestinal signs, such as loose stools, are common in cats.
• Mesenteric lymphadenopathy can be associated with various underlying conditions, including infection and inflammation.
• Abscess formation within mesenteric lymph nodes is a rare presentation in feline medicine.

Observation:

• A 3-year-old cat presented with a 2-year history of chronic loose stools.
• Radiography, ultrasound, and contrast-enhanced computed tomography (CT) revealed enlarged mesenteric lymph nodes with fluid accumulation.
• Percutaneous drainage yielded purulent material, and cytology identified neutrophils and Gram-negative rods, with culture confirming Escherichia coli.

Findings:

• A definitive diagnosis of mesenteric lymph node abscesses was made.
• Surgical excision was challenging due to adherence of the abscesses to surrounding tissues.
• Drainage and antimicrobial therapy reduced lymph node size, but diarrhea persisted.

Implications:

• Successful management involved antimicrobial therapy, surgical drainage, and dietary modification with a hydrolyzed diet, suggesting concurrent food-responsive enteropathy.
• This case highlights the importance of considering mesenteric lymph node abscesses in cats with chronic gastrointestinal disease.
• This is the first reported case of mesenteric lymph node abscesses in a cat, expanding the differential diagnosis for feline lymphadenopathy.