Gastrointestinal Disorders

Antibiotic-Responsive Enteropathy: Does It Exist?

Julien Dandrieux

BSc, Dr. med. vet., PhD, DACVIM (SAIM), MRCVS

University of Edinburgh, Easter Bush Campus

Midlothian, Scotland, United Kingdom

Q. What diagnostic and management tools are helpful for cases of chronic enteropathy (CE)?

A. Chronic enteropathy (CE) is defined as primary gastrointestinal disease of three weeks’ or more duration. Investigation is required to rule out extra-intestinal disease and parasitic disease, followed by sequential treatment trials. Although endoscopic biopsies were historically obtained during initial investigation, this is now reserved for cases not responding to treatment or those with severe clinical signs or protein-losing enteropathy (often more severe disease). Many animals respond to dietary change and, for this reason, the first treatment trial is typically a food trial with a hydrolyzed or novel protein diet.¹

Q. What issues arise when antibiotics are used as the next step?

A. Antibiotics, such as metronidazole, tylosin, or oxytetracycline, were previously often used in cases unresponsive to a food trial. However, there are several arguments to discourage the use of antibiotics overall for CE:

• Intestinal dysbiosis is a hallmark of CE and antibiotics are a cause of further intestinal dysbiosis that can take months to resolve.
• Long-term follow-up has shown that most dogs treated with antibiotics for CE will relapse and require ongoing or recurrent antibiotic treatment.
• There is rising concern for development of bacterial resistance with inappropriate antimicrobial use. In view of the short-term response, if any, and requirements for repeat use of antibiotics, CE should not be considered as a disease justifying antibiotic use, especially in the early stages of treatment trials.

Antibiotics should be considered in animals presenting with signs suggestive of systemic inflammation, such as pyrexia, neutrophilia with left shift or neutropenia, especially if a bacterial infection has been documented. In addition, antibiotics are indicated in dogs with granulomatous colitis and invasive E. coli.

Q. What should we consider instead of antibiotics?

A. Nutrition is a first-choice strategy and multiple diet trials might be required before patients are determined to be non-food responsive or partially food responsive. Different strategies, such as providing fiber, prebiotics, or probiotics, can be considered instead of antibiotics in dogs that don’t respond to a diet trial or that have recurrence of their gastrointestinal signs despite initial response.

If the episodes are infrequent and mild, supportive care at home, such as antiemetics and/or appetite stimulants, is an option. For dogs with more pronounced signs, different strategies are being actively researched and the use of fecal microbiota transplantation (FMT) is of particular interest as CE is characterized by a bacterial dysbiosis.

1. Makielski, K., Cullen, J., O’Connor, A., & Jergens, A. E. (2019). Narrative review of therapies for chronic enteropathies in dogs and cats. Journal of Veterinary Internal Medicine, 33(1), 11-22. doi: 10.1111/jvim.15345