Think of trillions of bacteria holding up little "Resist!" signs and chanting "Say it loud! Say it clear! Bacteria are welcome here!"
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Antibiotics are used to treat bacterial infections. Each antibiotic only works on certain types of bacterial infections, so the selection of which one to use and at what dosage depends on the type of infection and how bad it is.
Antibiotics are useless against viruses and will not cure viral infections.
Let's say that again. They're useless against viruses. When we say useless, we mean "It will not cure your common cold nor your grievously unhappy norovirus." In the Dark Ages, like about 20 years ago, people and pets with yucky viruses were often given antibiotics to prevent secondary infections such as pneumonia, but this approach is not favored anymore because of the bacteria’s ability to develop antibiotic resistance. The bacteria are forming groups and creating terrorist-like cells; they are dug in deep. This is war!
But here's the deal, and I want you to totally take this to heart as though your pet's life depended on it, because - and I don't mean to sound overly dramatic, but you know, it's true - your pet's life could depend on it. Maybe not your current pet, but one you have yet to meet and love.
Let's start here.
Each antibiotic uses a different mechanism with which to kill bacteria, and thus the class of antibiotics has many approaches to death and destruction. Some work by preventing a bacterium from building a cell wall (that's cool), some by dissolving bacteria’s membranes (icky), and some affect the way the bacteria build protein or copy DNA (that's innovative; I don't think I would have thought of that). These different methods tell us why it’s most effective to culture the infection and know exactly what type you're dealing with so you can clear it out quickly. It's far better than using a generic broad-spectrum antibiotic because that's like a shot in dark; however, often a pet must be started on a broad-spectrum antibiotic because there's this raging infection and you won't get the culture results for a few days, and you need to jump on this now, now, now. The earlier you start to kill off an infection, the easier it is for antibiotics to treat it; less bacteria needing to be killed means it's simpler to conquer.
Think of trillions of bacteria holding up little "Resist!" signs and chanting “Say it loud! Say it clear! Bacteria are welcome here!” as they march towards the capitol. Antibiotic resistance occurs when bacteria develop the ability to survive the drugs designed to kill them, resulting in failure to cure infections. This is an important reason not use antibiotics unless your pet truly needs them.
A major contributor to antibiotic resistance is not finishing the entire prescription, which allows surviving bacteria to grow in number and in strength. Antibiotics first wipe out bacteria that are easiest to kill - who wouldn't go after them first? - like soldiers taking out the weakest opponents first, but there will always be some bacteria that are able to survive the initial blast of an antibiotic. If you stop giving the antibiotic before these stronger, more resistant bacteria - let's call them soldiers - have been killed, the soldiers will reproduce and create a generation of bacteria that is more resistant than the previous generation. Think of 1960s Baby Boomer protesters compared to their parents. This process is sometimes repeated to the point where we accidentally create bacteria that are so strong that they no longer respond to that antibiotic, and just push the antibiotic out of its way. At this point, the formerly kind and gentle bacteria who were just dropping in for a beer are now more than a bit intimidating, like combat grunts with clenched jaws who won't give up their bar seat.
This is the best time ever to say "They needed killin'."
To make things even worse, some bacteria can pass their resistance directly to other bacteria. Sign up here, fellow protestors, as we sprinkle resistance dust throughout your neighborhood.
Let’s say your pet has an infection. You give him an antibiotic that kills 99.999% of the bacteria, which is generally good because killing off that many allows your pet's own immune system come in and take care of the rest. Zap! But your pet seems fine and you forget and skip the last few pills. Oops. It happens, right? Unfortunately, killing 99.999% of bacteria isn’t enough because if the infection started with several trillion bacterial organisms, the remaining 0.001% can still number in the millions. Without any antibiotic on board, those remaining bacteria can flourish, and by the time you notice signs of an infection – which you may think is new, although it isn’t necessarily - it will be a lot harder to get rid of it. It's angrier, organized, and even weaponized: a sniper's gun is being aimed. Any time you give antibiotics to your pet or a human family member, be absolutely certain to finish all the pills provided when you are supposed to give them, even when the patient feels better. Drug-resistant infections, such as methicillin-resistant Staphylococcus aureus (MRSA), are more difficult to treat but these mercenaries often can still be successfully resolved if treated promptly.
Just because both antibiotics and bacteria want to win this battle of wills doesn't mean we should give up. The antibiotics are resisting the growth of bacteria that isn't affected by the drugs, and the bacteria do their best to resist getting killed.
Not all bacteria cause infections; many of them are considered friendly. Not friendly like the booze hound hanging out every night at the VFW who never leaves a tip, but beneficial. Friendly bacteria help keep us healthy in many ways, so when antibiotics kill friendly bacteria in a friendly fire kind of event, we can lose these benefits. For instance, friendly bacteria in the digestive tract aid in digestion and help synthesize essential compounds necessary for health; antibiotic therapy may kill off some of these friendly bacteria, causing diarrhea and a clean up on Aisle Four. Probiotics are mixtures of microbes that are thought to contribute to digestive health and that may be helpful for pets taking antibiotics. Talk to your veterinarian about whether probiotics are useful for your pet’s situation and which ones are best for your pet. Handing your dog a bottle of kombucha is not helpful - he's already nauseous.
Used correctly, antibiotics are the big gun in medicine’s ability to heal infections. Used incautiously and when not necessary, antibiotics can cause some difficult problems, such as bacterial resistance ("Overthrow the gut! Overthrow the gut!"). Give the entire number of pills provided to your pet to avoid creating bacterial resistance, for everyone’s sake. Resist, resist, resist creating resistant bacteria and pop those pills!
VIN News Service commentaries are opinion pieces presenting insights, personal experiences and/or perspectives on topical issues by members of the veterinary community. To submit a commentary for consideration, email email@example.com.