Although not a natural segway for most non-veterinary people, Fall makes me think of the state of the world with antibiotics. We see many animals in Fall and Spring with allergy and secondary bacterial infections of the skin and ears. I am faced with the dilemma of responsible prescribing numerous times a day.
My grandfather was a human physician when antibiotics, first Sulfa drugs then Penicillin, came on the market. His stories of saving lives using these new drugs brought tears to my eyes. What has changed? Why? What can we do about it? Why can’t we just make “stronger” antibiotics? Why does the WHO regard this issue as a major threat to world health, food security, and world development?
For an antibiotic to be effective, the unique bacteria in a single individual must be sensitive to the drug. My dog’s staphylococcal skin infection may resolve using Cephalexin, while your dog’s staph may be completely resistant. Using more of an ineffective drug does not change this. Every bacteria every time you treat an infection is different. Even if the same organism is cultured from the same site of the same individual at two separate times, the susceptibility to different drugs may be vastly different. Antibiotics only treat bacteria, they do not do anything to treat viral infections or other non-bacterial diseases. When given in non-bacterial disease, they only ensure that if a secondary bacterial infection does occur, it will likely be resistant to the drug used.
In response to being exposed to antibiotics, especially when improperly used, bacteria fight back and develop resistance to drugs. When you or your pet are exposed to an antibiotic, either purposely or through environmental contamination with drugs, every bacterium in the body is affected. Sources of inadvertent antibiotic exposure include antibiotic residues in meat or those excreted in animal wastes. Animals and people have billions of bacteria on skin, in upper airways, and especially in the gut. Frighteningly, once a bacteria develops resistance, this resistance can be transmitted to other species of bacteria. Often resistance to a single antibiotic confers resistance to multiple classes of antibiotics. The result is the alarming and rapid development of multiple antibiotic resistant strains.
So what can be done to curb this frightening trend toward superbugs and untreatable disease? The first is to evaluate the risk of antibiotic exposure related to non-illness use of drugs in agriculture. In the European Union all antibiotic use for growth promotion in animals was banned in 2006. Similar controls were instituted in 2017 in the U.S. Antibiotics used for disease treatment and prevention, although still used, must be prescribed by a veterinarian. The second critical step is judicious prescribing of antibiotics when treating illness. Non-bacterial diseases, like bloody urine in non-geriatric cats, most upper respiratory infections in cats, and many cases of kennel cough in dogs should not be treated with antibiotics. We have been conditioned to believe we must take home an antibiotic, but in many cases, this is detrimental to both you and your pet. I often have clients who are troubled by my not dispensing antibiotics for non-bacterial infections, even after a thorough explanation of why they are not indicated. Antibiotics should be taken as dispensed and treatment should extend slightly past the resolution of clinical signs. A test, called a culture and sensitivity, can tell us what drugs are effective for an individual bacterial infection. Whenever possible this test should be performed. Antibiotic resistance is a complex issue which will require much intervention to solve. I challenge us all as pet parents to be part of the solution.