From the Research
For imaging to evaluate a potential abscess after a dog bite, I recommend starting with ultrasound as the first-line imaging modality. This approach is based on the principle of using the least invasive and most effective method to assess the presence of an abscess, given the potential for rapid progression of infections due to the polymicrobial nature of dog bite wounds, as noted in studies such as 1. Ultrasound can effectively identify fluid collections, assess their size and depth, and determine if an abscess has formed.
If ultrasound results are inconclusive or if there's concern about deeper tissue involvement, a CT scan with contrast would be the next appropriate step, as it provides detailed visualization of soft tissues and can better delineate the extent of infection. MRI may be considered in cases where there's concern for osteomyelitis or joint involvement, though it's typically not the initial imaging choice. X-rays have limited value for soft tissue abscesses but may be useful if there's concern for foreign bodies or underlying bone involvement.
When scheduling imaging, it's crucial not to delay appropriate treatment, including wound cleaning, antibiotics (such as amoxicillin-clavulanate 875/125 mg twice daily for 5-7 days, as suggested by 2 and 3), and tetanus prophylaxis if needed. The choice of antibiotic should be guided by the most recent and relevant evidence, with amoxicillin-clavulanic acid being a commonly recommended option for its broad-spectrum coverage, including against Pasteurella, Staphylococcus, and anaerobes, which are commonly found in dog bite infections 3. Imaging helps guide management decisions, particularly regarding the need for surgical drainage, which is often necessary for established abscesses. Early imaging is important because dog bite infections can progress rapidly, emphasizing the need for prompt and effective treatment strategies.