• Decrease font size
  • Return font size to normal
  • Increase font size
U.S. Department of Health and Human Services

Animal & Veterinary

  • Print
  • Share
  • E-mail

Animal Husbandry and Disease Control: Cattle

Mike Apley, DVM, PhD
Diplomate, American College of Veterinary Clinical Pharmacology
Dept of Veterinary Diagnostic and Production Animal Medicine
Iowa State University, Ames, Iowa


 
Beef Industry Model
Dairy Industry Model

Outline

  • Therapeutic labels
  • Feed antimicrobial labels
  • Antimicrobial uses banned in food animals
  • Requirements for extralabel use
  • Efforts to minimize and optimize use of antimicrobials in food animals


Therapeutic Antimicrobial
Labels For Cattle

Only a subset of these labels are approved for use in lactating dairy cows

Respiratory Disease

  • Pathogen targets
    • Mannheimia (Pasteurella) haemolytica
    • Pasteurella multocida
    • Haemophilus somnus
    • Mycoplasma bovis?

 

Respiratory Disease

  • Approved antimicrobials
    • Macrolides (all injectable):  tilmicosin, erythromycin, tylosin
    • b lactams (all injectable):  penicillin, amoxicillin, ampicillin, ceftiofur
    • Tetracyclines:  chlortetracycline (feed), oxytetracycline (feed, water, injectable)
    • Florfenicol (injectable)

 

Respiratory Disease

  • Approved antimicrobials (cont.)
    • Sulfas: sulfadimethoxine (oral bolus, water, injectable), sulfamethazine (oral bolus, feed)
    • Fluoroquinolones:  enrofloxacin
    • Aminocyclitols:  spectinomycin

 

BRD Control Claims

  • Tilmicosin: “For the control of respiratory disease in cattle at high risk of developing BRD associated with Pasteurella haemolytica.”
  • Florfenicol:  “Also, it is indicated for the control of respiratory disease in cattle at high risk of developing BRD associated with Pasteurella haemolytica, Pasteurella multocida, and Haemophilus somnus.”


Enteric Disease

  • Bacterial pathogens (in calves)
    • E. coli, Salmonella
  • Others
    • Cryptosporidium
    • Rotavirus
    • Coronavirus


Enteric Disease

  • Approved antimicrobials
    • Sulfas:  Sulfachlorpyridazine (injectable, oral bolus, powder for milk replacer) for E. coli, Sulfamethazine (oral) for colibacillosis
    • Aminoglycosides:  Neomycin (oral liquid) for colibaccilosis, (water) for bacterial enteritis


Enteric Disease

  • Approved antimicrobials (cont.)
    • Tetracyclines:  oxytetracycline (injectable, oral bolus, water, feed), chlortetracycline (oral bolus, water, feed)  all for E. coli, some for Salmonella

 

Mastitis

  • Bacterial pathogens
    • Staphylococcus aureus
    • Streptococcus agalactiae
    • Streptococcus spp. (environmental)
    • Enterobacteriaceae:  E. coli, Klebsiella
    • Pseudomonas
    • Mycoplasma bovis
    • Arcanobacterium pyogenes

 

Mastitis

  • Approved antimicrobials
    • Novobiocin:  intramammary, dry cows, Strep ag/Staph aureus
    • Penicillin/novobiocin:  intramammary, lactating and dry products, Staph. aureus/Strep.)
    • Lincosamides:  pirlimycin (Intramammary, lactating cows, Staph aureus/Strep spp.)
    • Aminoglycosides: – Streptomycin/penicillin (intramammary, dry cows, Staph aureus)

 

Mastitis

  • Approved antimicrobials (cont.)
    • Beta-lactams (all intramammary):  amoxicillin, (lactating, Strep ag/Staph aureus), cephapirin (lactating/dry products, Strep ag/Staph aureus), cloxacillin (lactating/dry products, Strep ag/Staph aureus), hetacillin (lactating, Strep/Staph aureus/E. coli), penicillin (lactating/dry products, Strep ag or Strep spp.)

Mastitis

  • Approved antimicrobials (cont.)
    • Macrolides:  erythromycin (injectable, lactating and dry cow intramammary, Strep spp/Staph aureus)

 

Footrot

  • Approved antimicrobials
    • Tetracyclines:  oxytetracycline (injectable), chlortetracycline (feed)
    • Beta-lactams: ceftiofur, amoxicillin, (injectable)
    • Macrolides:  tylosin, erythromycin (injectable)
    • Sulfas:  Sulfadimethoxine (injectable, oral bolus, water), Sulfamethazine (oral bolus, water)

 

Metritis

  • Target pathogens
    • Arcanobacterium pyogenes
    • multiple anaerobes and aerobes including Staph and Strep
  • Approved antimicrobials
    • Macrolides:  tylosin  (injectable)
    • Oxytetracycline (injectable)


Other Label Indications

  • Oxytetracycline (injectable)
    • Pinkeye (Moraxella bovis)
    • Wooden tongue (Actinobacillus lignieresii)
    • Lumpy jaw (Actinomyces bovis)
    • Anaplasmosis (Anaplasma marginale)
    • Leptospirosis

 

Antimicrobial Compounds With Approvals For Administration In Feed

Tetracyclines

  • Chlortetracycline and oxytetracycline both have feed labels in cattle.
  • We will use chlortetracycline as an example of the multiple applications


Chlortetracycline

  • Calves up to 250 lb
    • 0.1 mg/lb per day for increased rate of weight gain and improved feed efficiency
  • 10 mg/lb per day for treatment of bacterial enteritis caused by Eschericia coli susceptible to chlortetracycline  (limited to use in milk replacers or starter feeds)

 

Chlortetracycline (cont.)

  • Calves (250-400 lbs)
    • 25-70 mg/head per day for increased rate of gain and improved feed efficiency
  • Growing cattle (over 400 lbs.)
    • 350 mg/head per day for control of bacterial pneumonia associated with shipping fever complex caused by Pasteurella spp. susceptible to chlortetracycline

 

Chlortetracycline (cont.)

  • Beef cattle under 700 lb.
    • 350 mg/head per day for control of active infection of anaplasmosis caused by Anaplasma Marginale susceptible to chlortetracycline
  • Beef and nonlactating dairy cattle (over 700 lb.)
    • 0.5-2.0 mg/lb daily for control of anaplasmosis as above

 

Oxytetracycline Combinations

  • With other antimicrobial compounds
  • Oxytetracycline/Neomycin
    • Feed and milk replacer labels
    • Aid in the prevention of bacterial diarrhea (scours)
  • Oxytetracycline/Lasalocid
    • Feed
    • Reducing incidence and severity of liver abscesses, improved feed efficiency and rate of weight gain


Chlortetracycline (cont.)

  • Calves, beef and nonlactating dairy cattle
    • 10.0 mg/lb per day for treatment of bacterial enteritis caused by Escherichia coli and bacterial pneumonia caused by Pasteurella multocida organisms susceptible to chlortetracycline

 

Chlortetracycline Combinations

  • Chlortetracycline/sulfamethazine
    • 350 mg/head per day of each drug for 28 days as an aid in maintenance of weight gains in the presence of respiratory disease such as shipping fever.


Tylosin

  • Beef Cattle 8-10 g/ton of prepared feed
  • To be fed so that each animal receives not more than 90 mg per head and not less than 60 mg per head per day.
  • For reduction in the incidence of liver abscesses caused by Fusobacterium necrophorum and Actinomyces

 

Virginiamycin

  • For cattle fed in confinement for slaughter
  • Various dose levels have labels for improved feed efficiency, reduction of incidence of liver abscesses, and increased rate of weight gain


Monensin

  • Confined cattle
    • Feed efficiency and prevention and control of coccidiosis
  • Pasture cattle (Slaughter, stocker, feeder, dairy and beef replacement heifers)
    • Increased rate of gain and prevention and control of coccidiosis
  • Mature, reproducing beef cows
    • Increased feed efficiency when receiving supplemental feed and prevention and control of coccidiosis


Lasalocid

  • Cattle fed in confinement for slaughter
    • Improved feed efficiency and increased rate of weight gain
  • Pasture cattle (slaughter, stocker, feeder cattle, and dairy and beef replacement heifers).
    • Increased rate of weight gain
  • Cattle up to 800 lbs.
    • Control of coccidiosis

 

Laidlomycin

For improved feed efficiency and increased rate of weight gain in cattle fed in confinement for slaughter.

Bambermycins

Cattle fed in confinement for slaughter

For increased rate of weight gain and improved feed efficiency

Pasture cattle (slaughter, stocker and feeder cattle, and dairy and beef replacement heifers)

For increased rate of weight gain

Banned Extralabel Use
Sec. 530.41  Drugs prohibited for extralabel use in animals

The following drugs are prohibited for extralabel animal and human drug uses in food-producing animals:

Chloramphenicol;

Clenbuterol;

Diethylstilbestrol (DES);

Dimetridazole;


Extralabel prohibitions (cont.)
Ipronidazole;

Other nitroimidazoles;

Furazolidone (except for approved topical  use);

Nitrofurazone (except for approved topical  use); and

Sulfonamide drugs in lactating dairy cattle (except approved use of sulfadimethoxine, sulfabromomethazine and sulfaethoxypyridazine

Requirements for Extralabel Use of Antimicrobials in Food Animals
 
AMDUCA Regulations
The drug must have either a NADA or a NDA number

The use must be within a valid Veterinary-Client-Patient Relationship (VCPR)

The veterinarian must work through a regimented thought process prior to prescribing an extralabel use

 

What happens to this guy?
Image of a herd of dairy cows with one cow standing alone

Image


 Image of a laptop computer
Minimizing Disease Pressure 
Genetic selection

Balance disease resistance with production

Alliances and integrated systems!!!

Preconditioning programs

Optimize time of exposure to vaccines, and correct nutritional deficiencies (e.g., trace elements) prior to the stress of shipment to a feeding facility


Minimizing Disease Pressure
Biosecurity procedures

Control exposure to new pathogens by managing cattle flow

Benefits of single injection therapy

Environmental management

Rodent control, calving areas, sanitation, social stress


Minimizing Disease Pressure
Immune system management

Non-specific stimulation of the immune system is not necessarily a good thing (i.e., the immune system is credited with much of the damage in bovine respiratory disease), the need is to prepare the immune system ahead of time to perform optimally (nutrition, stress control)

Minimizing Disease Pressure
Novel approaches to vaccination

Sub-unit and gene-deleted vaccines, oral vaccines

Competitive exclusion

Promote and/or inoculate with commensal competitors to decrease pathogen proliferation

Minimizing Disease Pressure
Diagnostic methods

Pathogen identification to allow selection of pathogen-specific prevention and control methods

Alternative therapies

Ancillary therapy

Other antimicrobial agents

Optimizing Therapeutic Antimicrobial Use in Food Animals
 
There are substantial gains to be made just by making sure every veterinarian has timely access to the most current information on antimicrobial use in food animals

The Veterinary Antimicrobial Decision Support System
Mike Apley, DVM, PhD

Virginia Fajt, DVM, PhD

Cory Langston, DVM, PhD

Jeff Wilcke, DVM, PhD


What makes this different than a formulary?
 
Developing a database of dosages (amount, frequency, duration)

Correlating dosages with susceptibility information based on:

Pharmacokinetics

Pharmacodynamics

Clinical data when available

Pieces of the puzzle
What concentration of the antimicrobial does it take to inhibit bacterial growth?

How is the antimicrobial best presented to the bacteria (pharmacodynamics)?

What are the pharmacokinetics in the animal?

Do our predictions hold true in clinical trials or in practice situations?


The VADS System Goal
 
Chart showing the Potential Doses for Appropriate Antimicrobial