Lecture 20: BRD Therapeutics & Antimicrobial Stewardship

What is the difference between prophylaxis, metaphylaxis, and treatment?

• Prophylaxis—action taken to prevent disease such as vaccination and health/herd screening for disease; goal is to stop a disease from happening in healthy animals

• Metaphylaxis—use of an antimicrobial (usually an antibiotic) in a group of animals that are at a high risk of developing a disease

• Treatment—medical or therapeutic care given to an animal with an illness or injury

What is the difference between antimicrobials and antibiotics?

• Antimicrobials—any substance given to kill or inhibit the growth of a microorganism (including bacteria, fungi, viruses, or parasites)

• Antibiotics—a medication that kills, inhibits, or stops the growth of a bacteria; used to treat a bacterial infection

What is antimicrobial stewardship?

the optimal selection, dosing, and duration of antimicrobial treatment resulting in the best clinical outcome with minimal side effects to the patients and minimal impact on subsequent resistance

What is resistance?

the ability of a pathogen or organism to withstand a drug or other treatment; treatment is no longer effective against the pathogen

What did AMDUCA do?

Extra-label of drug use in food animals if:

• There is no approved drug labeled for such use and that contains the same active drug in required dosage form and concentration

• The approved drug is clinically ineffective

• That the proposed drug is not on the prohibited list

What is FARAD?

Database of drugs and research of extra-label drugs with established withdrawal times

What are the considerations before making a drug choice to treat BRD?

• How sick is the animal?

• Be straight with the owner

• How many animals in the herd are affected?

• What is the owner’s plan for the individual or herd?

• Remember withdrawal times

What are mainstays and optionals of BRD treatment?

Mainstays of treatment:

• Antibiotics

• Fluids

• Anti-inflammatories

• Nutritional support

Optional treatments:

• Immune stimulant

• Vitamin and mineral supplement

What are the important considerations when prescribing beta-lactams for BRD?

• 0 days milk withdrawal for ceftiofur (Naxcel, Excenel, and Excede)

• Most of the drugs that are labeled for lactating dairy cattle are beta-lactams

• These drugs attack the cell wall of the bacteria

What tetracycline must have a VFD?

chlortetracycline (Aureomycin)

What macrolide is cardiotoxic to humans and other species?

tilmicosin (micotil)

What beta-lactams are commonly prescribed to treat BRD?

• penicillins

• cephalosporins

What macrolides are commonly prescribed to treat BRD?

• tulathromycin (Draxxin)

• gamithromycin (Zactran)

• tilmicosin (Micotil)

What tetracyclines are commonly prescribed to treat BRD?

• oxytetracycline (LA 300)

• chlortetracycline (Auremycin)

Which therapeutic of BRD has an 18-month meat withdrawal time?

aminoglycosides: gentamicin and amikacin

What antibiotics used to treat BRD cannot be used off label in food producing animals?

• fluorquinolones: enrofloxacin (Baytril)

• sulfonamides: sulfadimethoxine (Albon, Sustain bolus, SMZ, Sulmet)

What therapeutic of BRD requires 2 doses with different withdrawal times?

florfenicol (Nuflor)

What fluids are involved in BRD therapy?

• Intravenous: Sodium chloride, Lactated ringers, Hypertonic saline

• Oral: Water, Water with electrolytes

What anti-inflammatories/anti-pyretics are used in BRD therapy?

• Flunixin meglumine (Banamine): Injectable or Trans-dermal solution

• Dexamethasone??: “no animal should die without steroids”, Careful in pregnant animals***

• Meloxicam??: Mixed reviews, Depends on age of animal, Probably not for fever, but may help with inflammation

What are products like Resflor or Draxxin KP an example of?

combo product with an antibiotic and anti-inflammatory drug (usually not full anti-inflammatory dose)

What nutritional support is provided for BRD therapy?

• milk replacer/tube feeding

• providing grain or concentrates

• hay and/or grass

• immune stimulant

• vitamins and minerals