A recent study comparing the microbiomes of people and their pets revealed some interesting findings. It seems that when we share a dwelling with a dog, we are also sharing the microorganisms that live on, and in, our bodies, also known as our microbiome.
Reading this article coincided with a recent discussion I (Henri Bianucci) had with an office colleague, Dr. Aubrey Hirsch, about the appropriate way to manage a couple of cases that were before me.
One instance was an older male cat with a sudden onset of blood in his urine and what appeared to be extreme pain associated with urination. I examined the urine and found only red blood cells. None of the white blood cells, commonly associated with infections, were present. Despite this, part of my treatment plan included a course of antibiotics. Dr. Hirsch disagreed. She said this condition is likely brought on by stress, and has nothing to do with an infection.
I knew she was right, but every other time I had treated this condition with antibiotics, it had gone away, and knowing that the owners wanted a quick resolution, I was inclined to include antibiotics “just in case.”
I decided to let reason and science prevail. I treated the cat's stress with an antidepressant, Amitriptyline, and administered a pain killer as well as an anti-inflammatory. The problem resolved within 48 hours, just like the other ones that had received antibiotics.
The next case was a 4-year-old Yorkshire terrier with diarrhea of a few days' duration. The dog was otherwise fine. She was not vomiting, had no fever and was continuing to eat and drink. There was a small amount of blood in the stool. I was preparing to reach for the magic bullet, which in the veterinary profession is an antibiotic called Metronidazole. This is the most commonly prescribed antibiotic for treating bloody diarrhea in the veterinary profession. It is very effective against the common bacterial culprits, and it also has a soothing effect on the gut lining.
The bottom line is that it works, and works fast. But this, too, ran counter to the recommendations of Dr. Hirsch. Her recommendation was to begin with a highly digestible diet for three to seven days, give an anti-diarrheal, and administer a probiotic. I followed her advice, and the diarrhea resolved within a short time.
The importance of these cases is that they illustrate a tendency to turn to antibiotics due to a desire to quickly resolve a problem rather than out of a rational, evidence-based approach. These patients could have been administered antibiotics unnecessarily. Both cases would have resolved, and our belief in the need for antibiotics would be sustained.
This shotgun approach may have serious implications for people and pets, that goes way beyond administering unneeded drugs.
In his 1945 Nobel lecture, Sir Alexander Fleming, the discoverer of penicillin, recognized the potential for antibiotic resistance. “It is not difficult to make microbes resistant to penicillin in the laboratory by exposing them to quantities not sufficient to kill them, and the same thing has occasionally happened in the body.”
Since then many new antibiotics have been developed, and have seen the rapid development of resistant strains of bacteria. We are rapidly entering into what has come to be called the post-antibiotic age. In other words we are quickly finding ourselves surrounded by bacterial strains for which we have no effective antibiotics due to resistance.
The Danish Small Animal Veterinary Association (DSAVA) has an antibiotic guideline pyramid that ranks the importance of various classes of antibiotics. Those with a high risk of antibiotic resistance, and with few therapeutic alternatives, are ranked from the top to bottom. In the second tier from the top is Metronidazole, the magic bullet I mentioned earlier. A life-threatening cause of diarrhea in humans is a bacteria known as Clostridium difficile, (C-diff), and the treatment of choice is Metronidazole. This is one of the few drugs that is effective against this deadly bug, so if resistance were to develop, the consequences could be dire.
There are more single-celled organisms (bacteria, fungi and viruses) in our microbiome than the number of our own cells. The average adult has two to three pounds of microorganisms inhabiting places like the skin, and digestive tract. The complex relationship between our health and these organisms is just beginning to be understood. Gastrointestinal health, normal brain function, a healthy immune system and cancer resistance all seem to be influenced by the microbiome.
It is clear that we have to take a much more considered approach to treating common conditions in both the human and veterinary medical arenas. When we use antibiotics, we indiscriminately wipe out large populations of bacteria that we actually rely upon for disease resistance. This disruption in normal flora can persist for months. Furthermore, antibiotic use drives the development of resistant strains of bacteria, so if one of these organisms does produce an infection, we may have limited our ability to treat it.
Given the fact that we share much of this microbial population with our own pets, treatments that affect their flora may also affect our own, and therefore impact our health. So, the next time you, or your veterinarian reach for the antibiotics, pause and consider if there is an alternative, rational approach.