Reams of information and accusations have pointed toward the cattle industry re-garding its contribution to the de-velopment of microbes resistant to antibiotics used in humans, pets and livestock.
Are farmers, ranchers and feedlot operators doing their best to improve this situation?
I believe the quick answer is yes and will give examples of how I think we lead the field, even if there is always room for improvement.
There will no doubt be advancements in the future, such as quicker detection of disease, non-antibiotic antimicrobials, different and broader vaccination programs and better ways to reduce stress, which leads ultimately to less disease and less reliance on antibiotics.
The cattle industry stands almost alone in the number of new antimicrobial products developed, far more than in human medicine.
This is because it takes many millions of dollars to develop, test and receive approval for a new antibiotic. It is costly to do all the safety, residue and efficacy work.
The economics don’t encourage new products in human medicine because treatments last only a few days and safety studies are all encompassing and extremely expensive.
This is why a new major antibiotic hasn’t been developed for about 20 years.
More antibiotics developed for cattle means more choice.
This allows producers to use, on the advice of their veterinarian, the product that is specifically suited to the infection at hand.
That is wise, and so is using only one antibiotic rather than several in combination.
We have also found that if the product is going to work, it will work quickly, which means there is rarely a need to carry on treatment regimens for weeks on end.
This makes medical and economic sense for the producer because antibiotics have a cost. Producers seldom treat too long or with too much product.
Also, dosing is more accurate thanks to more accurate scales.
The convenience of long acting products combined with the effort required to bring cattle for treatment ensure that most cattle are not over-treated.
Farmers have bought into the concept of beef quality assurance and are almost without exception giving the right amount in the right location for the right disease condition.
Here are a few suggestions to maintain this good record.
- Always keep dose charts around. Almost every antibiotic has a different dose.
- Write down protocols to train new employees.
- Follow drug withdrawals.
The old days of “if some is good, more is better” are gone, and we know that if the proper dose is given, in time it should work.
If not, we need to re-examine the situation.
Beef and dairy producers almost always use products approved for their class of livestock.
Chronic diseases are not over-treated, and cattle are either shipped once drugs are withdrawn or humanely put down. Both are positive steps to preventing resistance from developing.
Producers have likely heard about the amount of drugs used in cattle production compared to human medicine.
What they are not told is that most of these products are additives and ionophores put in feed and have nothing to do with antibiotics.
As Tim McAllister of Agriculture Canada says, antibiotics don’t directly promote growth but reduce illness so cattle keep eating and hence gain weight.
As for the amount used, it makes sense that treating a 2,000 pound bull or a 1,500 lb. cow will require more medication than a 200 lb. human.
Keep these rebuttals in mind next time the allegation is brought up that “farmers are causing antibiotic resistance.”
Vaccination is still the best biosecurity program. Fewer calves get sick and those that do will respond to treatment quicker and are less likely to relapse.
Vaccination programs and better response that comes from using newer long-acting products have also cut down on the use of feed additive antibiotics.
Many feedlots are using less of the feed additive antibiotics that are designed to reduce incidences of liver abscesses and pneumonia. These antibiotics are also in a class of drugs that are seldom, if ever, used by medical doctors.
It’s also important to follow label directions.
The labels of some antibiotics clearly state when the product should not be used, such as fluoroquinolones (Baytril or A-180) in diarrhea cases.
This is because the medical sector wants to save this family of drugs for use in human medicine and not develop resistance to enteric (diarrhea) organisms.
Likewise, cephalosporins are used only for treatment and not for preventive or prophylaxis treatment in the face of an outbreak.
Roy Lewis is a technical services veterinarian with Merck Animal Health in Alberta.