Pet Corner

Antibiotics: Are They Really Necessary for Your Pet?


Antibiotics can be harmful for pets. Gentle herbs with antibiotic activity include garlic, goldenseal and thyme.

Content Tools

I’ve been on a rant against synthetic antibiotics for several years now, and I haven’t softened my stance one iota. In fact, if anything I’ve become even more adamantly anti-antibiotic, for a host of reasons.

All About Antibiotics

You probably have heard that the use of antibiotics leads to bacterial strains that have adapted to become resistant to the antibiotics. But how big is the problem? Turns out it is HUGE.

By one account in 1946, just a few years after the introduction of penicillin, 14 percent of the strains isolated from sick patients were already resistant. By the end of that decade, the frequency had jumped to 59 percent in the same hospital. Today, almost all species of bacteria have developed resistant strains; many species have strains that are at least 70 to 80 percent resistant to one or more antibiotics; and some bacterial strains are almost 100 percent resistant to nearly all the antibiotics currently available.

Bacteria, with their extremely rapid reproduction rate, are uniquely adapted to use evolution as a survival mechanism. No synthetic antibiotic yet produced has been able to kill 100 percent of the pathogenic bacteria it is meant to kill (without also killing the patient), and so, no matter how “effective” the antibiotic, there will always be a few resistant bugs left over to regenerate a new subspecies of resistant bacteria.

With bacteria, however, the scenario goes beyond simple evolution: Bacteria’s plasmids (mini-chromosomes that carry genetic information) can transfer antibiotic resistance information from one species to another (say from Streptococcus to Staphylococcus), and the plasmid can transfer resistance information to more than one antibiotic at a time. So, if one Streptococcal strain survives an antibiotic insult from several different antibiotics and thereby “learns” how to resist each of these antibiotics, this strain can transfer this multiple-antibiotic resistance “know-how” to its offspring and to other, entirely different, species of bacteria.

In 1942, the total amount of antibiotic available in the entire world amounted to about 32 liters of penicillin. Today, some 20 million pounds of antibiotics are used annually in this country alone.

Much of the total quantity of antibiotics produced in this country (some estimates indicate more than 80 percent of total production) is fed to food animals at sub-therapeutic levels—levels that promote animal growth (and allow for cheaper meat for the consumer), but that allow for a faster production of resistant bacterial strains. Add to this the fact that several million pets are being treated with antibiotics each year, and it is easy to see how resistant strains are being passed on to farmers, pet-owning families and people living nearby.

More Dangers of Antibiotics

Billions of bacteria live on our pets’ skin and in their digestive tracts. Almost none of these bacteria ever cause harm, and many of them are not just beneficial, they are absolutely necessary to maintain a healthy inner and outer environment. For example, a healthy gut actually requires that certain bacterial species be present in adequate numbers, and many of the bacteria normally found on the skin help provide a healthy protective activity against outside invaders.

Only a very small percentage of bacteria ever become pathogenic (causing harm), and the body has many mechanisms to keep these pathogens from gaining a foothold. It almost always takes some change in the body’s homeostatic mechanisms to allow these species to revert to unhealthy ones.

Use an antibiotic that is effective enough to kill most of the pathogenic bacteria, and you have not only instigated the process of creating resistant bugs, but you’ve also set off a chain reaction that can kill many of the beneficial bugs in and on the body. The most common symptom you’ll see from the kill-off of the beneficial bacterial species is diarrhea, the result of destroying the normally protective flora of the gut. However, many medical scientists are now speculating that a loss of the normal flora of the body could lead to chronic conditions, such as immune-mediated diseases and cancers.

Whenever your pet is on antibiotics, including herbal antibiotics, add a supplement to the diet to repopulate your pet’s gut with normal, beneficial bugs, known as probiotics.

Herbs to the Rescue

Fortunately, herbal remedies offer some respite from the unhealthy morass antibiotics have gotten us into, and there are several mechanisms whereby herbs are effectively antibiotic: Many of the most commonly used herbs have direct antibiotic activity (i.e., they kill germs); several herbs enhance the immune system, thus helping the body eliminate unwanted pathogens; and antioxidant activity is present in many herbs, thus helping the body rid itself of the toxic byproducts of infection.

Within many herbs lies an almost complete medicine chest of substances that are active against a wide variety of microorganisms. There are two keys here. First, a typical herb contains dozens of bioactive ingredients, and second, these bioactive ingredients have activity against many different microorganisms, including the viruses where synthetic antibiotics are ineffective.

What this means is that it is extremely difficult for any one bacterial species to develop resistance to all the different bioactive mechanisms contained in a single plant, and it means that the herb will likely be effective against a wide variety of microorganisms.

On the other hand, herbal medicines do not contain gargantuan amounts of any one bioactive substance, so their effects are often mild and relatively slow-acting.

Some herbs with active antibiotic activity include calendula (Calendula officinalis), echinacea (Echinacea spp.), garlic (Allium sativum), goldenseal (Hydrastis canadensis), lavender (Lavandula angustifolia), peppermint (Mentha ×piperita), sage (Salvia officinalis) and thyme (Thymus vulgaris).

As the body defends itself against bacteria and the polluting toxins from the environment, cells form oxidative products (free radicals) that are toxic to inner tissues. Antioxidants counter these toxic byproducts and in turn enhance the ability of the immune system to function properly. Several nutritional supplements, including vitamins A, C and E and the minerals selenium and zinc act as antioxidants.

Herbal antioxidants include almost all the spice herbs, such as basil (Ocimum basilicum), oregano (Origanum vulgare spp. hirtum), thyme and cayenne (Capsicum annuum). Herbs that have a direct effect on the immune system include astragalus (Astragalus membranaceus), echinacea, calendula and thuja (Thuja occidentalis).

Using Herbal Antibiotics

You can provide any of these herbs as a supplement to the diet on a daily or weekly basis, and the beautiful aspect of herbs is that they often can simply be added to the diet as a tasty sprinkle atop your pet’s food. Do a taste test to see which herbs your pet likes the best; it is these herbs that are likely to be the ones he needs the most. Herbs also can be given at therapeutic levels whenever an infection arises; check with your holistic vet for therapeutic dosages. I like to add probiotics to the diet whenever I’ve prescribed antibiotics, herbal or otherwise. •

Randy Kidd holds doctorates in veterinary medicine and clinical pathology. After practicing traditional veterinary medicine for 10 years, he opened Honoring the Animals, a holistic practice in Kansas City, Missouri. Visit our website,, to order Dr. Kidd’s pet-care books.

Information provided in “Pet Corner” is not intended to replace the advice of a qualified veterinarian.