Are Antibiotics Always Useful for Intestinal Diseases in Dogs or Cats, and What Does the Gut Microbiome Do?

New findings about the trillions of microbes that make up the gut microbiome are, among other things, calling into question the use of antibiotics to treat Diarrhea in dogs and cats.

Instead, the focus should be on restoring the normal environment of bacteria and other microorganisms in the intestine.
The gut microbiome has been shown to be an essential component of the host’s health.

What does the gut microbiome do?
It forms:

• Defense barriers against potentially pathogenic organisms,
• support the breakdown of nutrients and the release of energy from ingested food or feed,
• provides nutrients for the intestinal cells,
• helps regulate the body’s defenses (immunity),
• and metabolizes substances that the host cannot process, such as medications.

What are the consequences of food withdrawal (nutritional abstinence) in Diarrhea?

Even suspending food intake in Diarrhea must be critically questioned. The sooner nutrition (or partial nutrition) is provided via the intestine, the faster the animals recover and the better the chances of survival for severely ill animals. The reason for this is the resulting possible nutrition of the intestinal cells and the maintenance or restoration of an optimal gut microbiome. Many studies now prove this.

A growing body of research shows that antibiotics have little or no effect on acute Diarrhea and hemorrhagic Diarrhea syndrome. In fact, there is evidence that antibiotics to combat intestinal infections can damage the microbiome, much like a poor diet can delay the healing process in infections and inflammatory diseases.

What alternatives are there to antibiotics?

• Prebiotics – are non-digestible plant-based feed or food components that serve as a food source for the microbiome, thereby promoting the growth and activity of the microbiome. These include, for example, fiber-rich pet food and psyllium seed supplements.
• Postbiotics – are not living bacteria, but merely components thereof. They contain metabolic components (metabolites), short-chain fatty acids and functional proteins. They are able to break down harmful bacteria and have an anti-inflammatory effect.
• Fecal microbiome transplantation is another option, in which feces from healthy donors is transferred to the diseased animal using probes or in the form of capsules. The donor animals must be free of pathogens and must not have received antibiotics for an extended period themselves.

In acute Diarrhea, therefore, a

• highly digestible diet,
• Probiotics (viable microorganisms such as certain bacteria or yeasts)
• possibly prebiotics as well as
• deworming are useful.

In chronic Diarrhea, a

• highly digestible or fiber-rich diet, supplemented by
• prebiotics and
• postbiotics are useful.

Especially in chronic Diarrhea, the history (anamnesis) is particularly important. Furthermore, an initial deworming and laboratory diagnostic tests are essential. It needs to be clarified whether there is already a protein deficiency, whether the B12 content in the blood is reduced, etc. If there is a protein deficiency, there is a suspicion of an intestinal disease associated with protein loss (protein-losing enteropathy). In such a case, an immunosuppressive treatment would be necessary. Sometimes further tests are necessary.

Of course, antibiotics may also be necessary for specific bacterial infections. Your veterinarian will decide that. But they are rather no longer at the beginning of a treatment or are even the sole therapeutic measure for diseases associated with Diarrhea in dogs and cats.

Source: Dr. Granick: A New Approach to Diarrhea in the Dog and Cat. AVMA Convention 2022, Philadelphia. New findings about the trillions of microbes that make up the gut microbiome are, among other things, calling into question the use of antibiotics to treat Diarrhea in dogs and cats.