Penn State vet urges ‘judicious’ use of animal antibiotics

By DOROTHY NOBLE
AFP Correspondent

ROCK SPRINGS, Pa. — “Keeping animals healthy lessens food safety issues,” Dr. David R. Wolfgang told his audience at a Penn State’s Ag Progress Days session Tuesday, Aug. 17.
Wolfgang, the Extension veterinarian field studies director, has researched and published extensively in the areas of animal health and disease prevention.
While many natural microorganisms that fight bacteria exist, including those found in soils, Dr. Wolfgang noted that bringing a new antibiotic to market typically takes a decade and costs an average of $12 million.
The Center for Veterinary Medicine and the Food and Drug Administration both must approve a drug. Approval for an antibiotic to be used for food animals is particularly rigorous. Tests include impact on the environment as well as on people.
Despite considerable advancements, especially in the last 20 years, residue concerns remain. To illustrate the improvements, residues now are reported in parts per billion rather than the previous parts per million. Last year, residues were found in 1,000 of 23 million cattle.
However, Dr. Wolfgang reports the industry aims for zero tolerance. Any residues tend to be promoted by the consumer press, he added.
Animal producers use antibiotics for several reasons. Usage to promote growth is less prevalent today. Disease prevention and therapeutic uses are more common and, he said, therapeutic uses can present more problems with residue.
Developing resistance is a problem. Any strain of bacteria has special properties. Bacteria can inactivate a drug, pump the drug out, or change the target of the drug.
Resistance is created by overuse and misuse, Wolfgang said.
Stopping the drug too soon leads the list of resistance causes. Other improper uses include using the antibiotic for a viral infection. Not completing the dose, giving too low a dose — perhaps because of cost — sets the stage for resistance. Dr. Wolfgang notes that giving the antibiotic to another animal is another misuse.
The concerns regarding antibiotics include greater numbers of immune-compromised individuals, increased cost of health care, and more incidents of foodborne illnesses.
Dr. Wolfgang recommended preserving the value and efficiency of antibiotics for the therapeutic reasons of infection and treating pain and suffering. Sub-therapeutic uses include preventing infection and increasing growth and production.
The European Union banned five growth-promoting antibiotics on the basis of precautionary principles, and consumer and political opinion, Dr. Wolfgang said.
The consequences of the ban created economic hardship for farmers, he said. Also, the animals suffered diarrhea and weight loss plus death in poultry. The broilers experienced leg problems and deteriorating skin health.
In addition, there was no evidence of positive effects on human health.
Blanket bans appear to not be in the best interest of animals or humans.
The challenge is to use antibiotics judiciously, Dr. Wolfgang said. The modern tertiary and secondary antibiotic products which are more in use today possess greater efficacy, but concerns need to be monitored, and antibiotics used correctly, he added.