Mesenteric Abscess Complicated by Septic Peritonitis in a Dog: Multimodal Diagnosis, Surgical Management, and Serial Quantitative Bacterial Load Monitoring

Abstract

Simple Summary Mesenteric abscesses are rare in dogs and can lead to a life-threatening infection of the abdominal cavity called septic peritonitis. This report describes the case of a young dog that developed such an abscess after treatment for a blood parasite infection. The veterinary team used a combination of tools to diagnose and monitor the condition: X-rays, repeated ultrasound scans, laboratory blood tests, bacterial cultures with antibiotic sensitivity testing, and microscopic examination of the removed tissue. A distinctive feature of this report is that the bacteria in the abdominal fluid were counted three times after surgery, showing a steady decline that matched the dog’s clinical improvement. The abscess was surgically removed, the abdomen was washed, and antibiotics were chosen based on laboratory results. The dog recovered fully and was healthy at the one-month check-up. This case illustrates that combining imaging, bacterial counting, and tissue examination can support accurate diagnosis, treatment selection, and confirmation of recovery. As serial bacterial counting is rarely documented in veterinary medicine, it may complement clinical judgment in monitoring treatment response, though its ability to guide antimicrobial duration and drain removal requires further study.