ECC Suggested Readings
January 2025
Yu Ueda DVM, PhD, DACVECC
I’m originally from Japan and currently work as a clinical assistant professor in the small animal emergency and critical care service and as the director of the extracorporeal therapy service at North Carolina State University. I also serve as the vice president of the Japanese Veterinary Emergency and Critical Care Society (JaVECCS), collaborating with veterinarians and veterinary nurses in Japan and across various Asian countries.
A paper that I recently liked…
Clinical course and radiographic resolution of pneumonia in dogs treated with a shorter versus longer course of antimicrobials: a randomized, double-masked, placebo-controlled study.
Reineke EL, McClosky ME, ... Redding LE. J Am Vet Med Assoc. 2025 Jan 1 (Epub 2024 Sep 20)
Paper Commentary
The study design
The study I selected is a prospective, randomized, double-masked, placebo-controlled study.
A knowledge gap of the study was an appropriate duration of antimicrobial treatment for dogs with uncomplicated pneumonia.
The primary objective of the study was to compare clinical and radiographic outcomes in dogs treated with either a shorter (2-week) or longer (4-week) course of antimicrobials.
The study background
Pneumonia is a common condition diagnosed in dogs in ER and ICU settings. Historically, these patients have been treated with 4-6 weeks of antimicrobial therapy, extending at least 1 to 2 weeks beyond the resolution of clinical and/or radiographic signs of disease, despite limited evidence to support this practice. Recent studies in veterinary medicine, however, suggest that a shorter course of antimicrobials (less than 14 days) may be sufficient for uncomplicated pneumonia. In fact, this approach aligns with human guidelines, some of which recommend even a shorter duration of therapy (<7 days). The study I chose adds valuable data to the growing body of literature, demonstrating that a long course of antimicrobial therapy (like 4-6 weeks) is likely unnecessary for dogs with uncomplicated pneumonia that show clinical and radiographic improvement when reevaluated within 10 to 14 days of starting treatment.
Study considerations
I like this paper since it is a randomized placebo-controlled study. This study design minimizes biases and provides a high level of evidence. This study also included both clinical signs and radiographic changes to evaluate treatment outcome and achieved excellent follow-up rates with all enrolled dogs completing the trial, which further strengthen the reliability of the findings. I also like this study since it reflects clinical practice, where most dogs with radiographic patterns and a clinical history consistent with pneumonia are treated empirically with antimicrobials, enhancing its applicability to typical clinical settings.
This study also highlights challenges in conducting randomized controlled trials in veterinary medicine. Despite an initial target of 70 dogs based on sample size calculations, the study enrolled only 30 dogs over 3 years. This limited the ability to detect differences in relapse rates or other outcomes between the shorter and longer treatment groups. As such, further research with a larger sample size is necessary to confirm that a shorter duration of antimicrobial therapy does not increase the frequency of pneumonia relapse compared to a longer duration of antimicrobial therapy.
This study also suggested that clinical improvement precedes radiographic resolution, consistent with findings in human medicine. As a result, clinical signs, rather than radiographic findings, are suggested as a more practical (and cost-effective) guide for determining the duration of antimicrobial therapy.
What I take home
In my practice, we treat uncomplicated pneumonia with antimicrobials within 7-14 days, especially when dogs show significant clinical improvement or resolution at the end of the treatment period, and the findings of this study support our practice. However, it remains a common practice in many settings to treat uncomplicated pneumonia with a longer duration. I believe this study supports the idea of trying a shorter course of antimicrobials (< 14 days) and discontinuing treatment if clinical signs resolve at reevaluation within 10-14 days.
