New insights into the trillions of microbes that make up the gut microbiome call into question, among other things, the use of antibiotics to treat diarrhea in canine and feline patients.
Dr. Jennifer Granick, associate professor of small animal internal medicine at the University of Minnesota’s College of Veterinary Medicine, suggested that treatment should instead focus on restoring health to the complex system of bacteria and other microbes. in the gastrointestinal tract.
“When I went to vet school, we were taught to use metronidazole for diarrhea, and what I hope to convince you is that maybe we should think about rethinking our approach,” said Dr. Granick during his presentation, “First Do No Harm: A New Approach to Diarrhea in the Dog and Cat,” July 30 at the 2022 AVMA Convention in Philadelphia.
The gut microbiota has been shown to be an essential component of host health. As Dr. Granick explained, these microbes create defensive barriers against potential pathogenic organisms, aid in the breakdown of nutrients and the release of energy from ingested foods, supply nutritional metabolites to enterocytes, help regulate the immunity and metabolize substances that the host cannot, such as drugs.
The gut microbiota in dogs and cats consists primarily of the genus Firmacutes, Bacteroides species and fusobacteria, Dr. Granick said. The canine gastrointestinal tract contains large amounts of Enterococcus and lactic acid-producing species, while Lactobacillus, Enterococcusand Bifidobacterium species are found in the feline gastrointestinal tract.
Gut health is not a new idea in veterinary medicine, Dr. Granick said, noting how withholding food was considered beneficial in cases of parvovirus infection and pancreatitis.
“We don’t do that anymore because there are many studies indicating that early enteral feeding is more helpful in rehabilitating these animals earlier,” she said. “The key to this is feeding the gut because the gut needs bacteria to eat to stay healthy.”
A growing body of research shows that antibiotics have little or no impact in cases of acute diarrhea and hemorrhagic diarrhea syndrome. In fact, evidence suggests that anti-infective drugs can worsen the microbiome, such as infections, inflammatory diseases, and poor diet.
What are the alternatives to antibiotics? Prebiotics, i.e. substances introduced into the microbiome to get it back on track. High-fiber pet food diets and eyelash additives fall into this category. There are also probiotics, or “good bacteria,” Dr. Granick explained. The result of these two elements is the post-biotic, which includes metabolites, short-chain fatty acids and functional proteins.
Fecal microbiome transplantation is another potential option, but it’s a relatively new procedure with a lot to learn, according to Dr. Granick. “Screening your donors is so important,” she cautioned, “not just for fecal pathogens, but also to make sure they don’t have a long history of antimicrobial use. “
What does Dr. Granick do when confronted with a case of acute diarrhoea? She prescribes a highly digestible diet, probiotics, more or less prebiotics, and deworming, depending on the patient’s history.
In chronic cases, his initial approach is to follow either a highly digestible diet or a high fiber diet. “My decision-making really depends on what has already been tried,” Dr. Granick said. “Often when I see patients with chronic diarrhea, they’ve gone through a few different treatment trials first. And I will make my diet decision based on what has already happened.
Additionally, Dr. Granick prescribes both prebiotics and probiotics, performs a blood test to determine if a B12 supplement is needed, and deworms the patient. If the patient is hypoalbuminemic and Dr. Granick thinks the animal has protein-losing enteropathy, she begins immunosuppressive therapy. If the patient does not respond to treatment, Dr. Granick performs additional diagnostic tests.
The last thing Dr. Granick tries is antibiotics. “That doesn’t mean there aren’t antibiotic-responsive diarrhoea. There absolutely are,” she said. “But antibiotics are the last thing I do, which is really different from when I started practicing because that was the first thing I did.”