Most of the common antibiotics prescribed for humans are exactly the same as the ones used for dogs, and the pill, capsule and gel-caps versions of these antibiotics are good for many years past their expiration date.
The fact that expiration dates on pill antibiotics are a marketing fraud has been widely know for years. In an article entitled "Drug Expiration Dates - Do They Mean Anything?", The Harvard Heath Letter summarizes a 20-year study done by the FDA for the U.S. military:
It turns out that the expiration date on a drug does stand for something, but probably not what you think it does. Since a law was passed in 1979, drug manufacturers are required to stamp an expiration date on their products. This is the date at which the manufacturer can still guarantee the full potency and safety of the drug.
Most of what is known about drug expiration dates comes from a study conducted by the Food and Drug Administration at the request of the military. With a large and expensive stockpile of drugs, the military faced tossing out and replacing its drugs every few years. What they found from the study is 90% of more than 100 drugs, both prescription and over-the-counter, were perfectly good to use even 15 years after the expiration date.... So the expiration date doesn't really indicate a point at which the medication is no longer effective or has become unsafe to use.... Is the expiration date a marketing ploy by drug manufacturers, to keep you restocking your medicine cabinet and their pockets regularly? You can look at it that way.
The Wall Street Journal put this story on their front page a few years back. But don't take my word for it: You can read the article, in its entirety, right here.
Do drugs really stop working after the date stamped on the bottle? Fifteen years ago, the U.S. military decided to find out. Sitting on a $1 billion stockpile of drugs and facing the daunting process of destroying and replacing its supply every two to three years, the military began a testing program to see if it could extend the life of its inventory. The testing, conducted by the U.S. Food and Drug Administration, ultimately covered more than 100 drugs, prescription and over-the-counter. The results, never before reported, show that about 90% of them were safe and effective far past their original expiration date, at least one for 15 years past it.
In light of these results, a former director of the testing program, Francis Flaherty, says he has concluded that expiration dates put on by manufacturers typically have no bearing on whether a drug is usable for longer. Mr. Flaherty notes that a drug maker is required to prove only that a drug is still good on whatever expiration date the company chooses to set. The expiration date doesn't mean, or even suggest, that the drug will stop being effective after that, nor that it will become harmful.
Medscape has posts here and here (PDF).
The U.S. Department of Defense has a post here.
The AMA has noted that antibiotics are good for years past their shelf life and has raised questions about how much medicine is being tossed down the sink.
So how come so few veterinarians seem to know this?
The answer, I think, is illuminating.
You see, on some important issues, veterinarians are often taught very little. The entire "course" given on canine nutrition, for example, may be a single lecture from a dog food salesman. The lecture on flea and tick remedies may be a lecture from a Merial salesperson who will detail "the spread" to be made from selling non-prescription Frontline as if it were a prescription drug (hint: it's not).
As for antibiotics, vets will learn by heart the branded and generic names of various drugs, and what they treat, but they may not learn other essential information.
And, as alarming as it may sound, that's true for many human doctors too.
Pharmacist and U.S. Army Colonel George Crawford, who used to be in charge of the Department of Defense's pharmaceutical Shelf Life Extension Program (SLEP) notes :
"Nobody tells you in pharmacy school that shelf life is about marketing, turnover and profits."
Right. Apparently no one does in veterinary school either.
You would think veterinarians and doctors might learn about this stuff in a Continuing Medical Education (CME) course, right?
Except there is a little joker in the deck.
You see, those CME courses are heavily subsidized by drug and vaccine makers, who help pay the speaker fees and travel costs for many of the lecturers.
Drug and vaccine makers make money when people throw good medicine down the drain, and they make money when dogs are over-vaccinated.
The business of canine health care is business, and good health and integrity often take the hind post.
Everyone in the system -- vets, pharmacies, and manufacturers -- profit when dogs are over-vaccinated and non-expired medicines are thrown down the drain.
Billions of dollars are wasted every year as a consequence.
The problem with over-vaccination and flushing good medicines down the drain is more than money, of course.
Throwing good antibiotics down the drain unnecessarily adds to the antibiotic load in our sewers, streams and rivers -- the very kind of thing that can help establish a beach head for real pathology in our own communities.
For those looking for information on antibiotic type and dosage to treat simple flesh wounds, urinary tract infections, and ear infection on your dogs, see this link on the main web site. Please note my advice to NOT use tetracycline on dogs
For those looking to obtain antibiotics without prescription, simply look in almost any dog supply catalogue in the country (see here, here, here, here for example) or simply go to Amazon.com (see here) and order.
Antibiotics without prescription have been sold to treat common farm and kennel ailments for years, and they work fine with a few caveats: know what you are dosing for, know how what you should be dosing with, know how much to dose, and know how long to maintain the dosing regime. A barbed-wire flesh wound or cut foot is a pretty simple thing to diagnose, but some others are not. If you are in doubt about what is going on with your dog, go to a vet.
For those looking for a low-cost source of generic doxycycline (used to treat Lyme, heartworm, and malaria), see this blog post to save thousands.