Animal Health Matters: An antibiotic shortage affects humans and animals alike

In this space, I frequently write about things shared between animals and people. Most often, those things are the bacteria or viruses that animals spread to people to make us sick. We often also share environments and surroundings with our animals, especially our pets. Both of these are the underpinnings of “One Health”: the concept that animals, people and the environments in which we live are all interconnected. The health (or unhealthiness) of one affects the other.

Lately, news reports have reminded me that we share something else with animals: medications. One of those medicines, amoxicillin, which is used in animals as well as people, has been the subject of quite a bit of press in recent weeks.

For a variety of proposed reasons, there is an ongoing shortage of amoxicillin for use in human patients. Since this is a medication often prescribed to infants and young children, many parents as well as their healthcare providers are very troubled about its unavailability. Whether it’s excessive demand or – you guessed it – “supply chain” issues, all of a sudden it’s hard to get supplies of amoxicillin when it never was a problem in the past. This is forcing healthcare providers to look for alternatives.

Amoxicillin has been a go-to tool for healthcare providers. It is an antibiotic, prescribed to treat bacterial infections in various parts of the body. The molecule, closely related to penicillin, kills bacteria by interfering with one of their essential functions: reproducing. It prevents the bacterial cell’s progeny from forming cell walls. Without this structure these bacteria quickly die. Amoxicillin and its close relatives work well on gram-positive bacteria such as Staph and Strep, which rely on their cell walls more than gram-negative bacteria do.

Common infections treated with amoxicillin include those of the ears, nose, throat, urinary tract, and skin. It’s also used for lung and airway infections such as pneumonia and bronchitis. Parents are perhaps most familiar with amoxicillin as the pink liquid prescribed for their little ones’ ear infections.

Many of these infections, particularly those of the respiratory tract, could be caused by viruses as well. Of course, antibiotics are ineffective against viral infections. Yet they are sometimes prescribed when any possibility of a bacterial infection exists, to cover the bases. Treating respiratory infections, even viral ones, with antibiotics is proposed as one reason for the current high demand for amoxicillin. The recent upsurge in Respiratory Syncytial Virus (RSV) cases in young kids means more respiratory cases are coming into doctor’s offices, many of which are being treated – rightly or wrongly – with antibiotics.

Amoxicillin is also a valuable tool in veterinary medicine. It’s used in pill or liquid form in dogs and cats for respiratory problems similar to those found in people, and it’s also very useful to treat wounds, abscesses and skin infections. For dairy cattle, there is an intramammary version of the antibiotic that can be used to treat mastitis cases.

So far, there are no reports of shortages of the animal-labeled forms of amoxicillin as there have been with the human formulations. It’s something that veterinarians are watching closely, though. If manufacturers concentrate more on producing human drug forms, it’s possible some of the veterinary products could find themselves in short supply.

Interestingly, veterinarians can use human-formulated medications, including amoxicillin, for their clients’ animals when no appropriately labeled animal medication is available. For example, there is no drinking water amoxicillin formulation for young pigs. Veterinarians can purchase bottles of the human medication to dilute out in drinking water for animal groups. It’s these uses that could be limited due to the shortage of human-labeled amoxicillin.

The amoxicillin shortage – and how it is coinciding with the surge in RSV cases in children – has also shone a light on responsible use of antibiotics in general. Using these antibacterial drugs for infections where only viruses are present doesn’t do the patient (human or animal) any good, yet it promotes the possibility that the bacteria we’re trying to kill will become resistant to these drugs. So - in addition to germs, medications, and drug shortages, people and animals share something else: the need for their healthcare providers to be responsible about how they use these valuable antibiotics.

Russ Daly, DVM, is the Extension Veterinarian at South Dakota State University.  He can be reached via e-mail at russell.daly@sdstate.edu or at 605-688-5171.