Yesterday I started the Antibiotic Resistance series to shed some light on why antibiotics are fed to cattle. If you have not already, please take a minute to read Part 1, as it provides some great background information.

In addition to Tylan, rumensin can be fed which is used to keep the animal’s stomach healthy and to prevent coccidiosis. Coccidiosis is caused by an intracellular protozoan parasite that grows in the cells of the intestines. The protozoa are passed through the feces of cattle and are picked up through things cattle come into oral contact with: feed, water, hair coats, udders, other surfaces, etc. By time cattle reach six months of age, it is estimated that 100% are infected, but only 5% show signs of infection. Symptoms include bloody diarrhea, poor growth, severe weight loss, straining to have a bowel movement (due to inflammation), and in some cases, death. This most commonly affects young cattle, but it may also occur in adult cattle. Anticoccidial drugs are most effective very early in the onset of the disease, before symptoms are visible. Therefore, it is generally advisable to feed young or just weaned calves (who are experiencing high levels of stress) an anticoccidiostat in their feed to control this protozoa. Rumensin and other anticoccidiostats are ionophores not antibiotics, which are NOT used at all in human medicine.

Anne Burkholder has invested a lot of time investigating antibiotic resistance and the link between animals and humans. On Anne’s blog you can find a category dedicated to Antibiotics, Hormones, and other growth promotants – I encourage you to check it out.

Earlier I mentioned a withdrawal date. A withdrawal date is the amount of time that must pass after an animal has received an antibiotic to the time when that animal or the products it produces can be consumed. This is measured in days, and is taken very seriously by persons involved in food production. The livestock industry has two programs in place for livestock farmers designed to enhance and reinforce proper animal care practices, recordkeeping, and the responsible and judicious use of antibiotics. These programs are Beef Quality Assurance (BQA) and Pork Quality Assurance (PQA).

In December 2013, you may have heard about the FDA’s (Food and Drug Administration) announcement to remove “improve growth, gain, and efficiency” use of feed grade antibiotics. While this article was written for beef farmers, I think Dr. Dee Griffin does a nice job of explaining what it all means here.

Many people point the finger of blame at the agricultural industry, but there are many other factors that should be considered. First, the overuse and abuse of antibiotics by humans should be discussed. Antibiotics can be obtained over the internet and in some countries without a prescription, leaving people to self-dose and self-medicate. Additionally, persons may take antibiotics for viral infections, like the common cold, when they are not effective. People may also contribute to this problem by not completing a course of antibiotics; they may stop when they feel better or save part of the dosage to decrease expenses associated with a doctor visit and prescription. By not completing a prescribed dose of antibiotics, you are not effectively killing the bacteria that are causing the infection; the bacteria that were not killed have become stronger and in turn resistant to that antibiotic at that level and duration of dosage. Finally, we live in an antibacterial society. How many of you have hand sanitizer, antibacterial soaps and lotions, antibacterial wipes, etc. at home/work? Each time you use these they may kill some bacteria, but the bacteria that are not killed become stronger and more resistant! So take a moment to ponder how you may be contributing to the antibiotic resistance level on a personal level.

Stay tuned for Part 3 of the Antibiotic Resistance discussion…