Safe Use of Animal Medicines
Arden Wohlers, Extension Veterinarian
David R. Smith, Extension Veterinarian
Dee Griffin, Extension Veterinarian
Veterinary drugs, including
antibiotics, antiparasite medications and vaccines, play an important
role in the control and prevention of disease in all livestock. However,
there is risk when working with animals and animal medicines. The United
States Department of Agriculture (USDA), Food and Drug Administration
(FDA) and the Environmental Protection Agency (EPA) have strict rules
regulating the prescription, distribution and use of animal medications
and chemicals. Regulations on how a drug is stored, administered, and
disposed of ensure product safety to the producer, the animal, the consumer
and the environment.
The medications approved for
use in animals today are safer and more effective than ever before. Many
products, such as arsenic and strychnine that were used as common treatment
medications decades ago are no longer available because of their danger
to people. Older products, such as chloramphenicol and some organophosphates
that were used more recently have been removed from the marketplace because
of human safety issues. The medicines and chemicals used today are safer,
but only if the label instructions and manufacturer recommended safety
precautions are followed.
Safe use of any product is
contingent on the ability to properly restrain the animal and the training
and competency of the individual administering the medication. A concern
of the FDA is that products are labeled properly so that medicines can
be used by livestock producers with reasonable safety. To receive FDA
approval veterinary drugs must be reasonably safe for the animal, the
person who administers the drug, for humans who consume products from
the animal, and for the environment. In addition, they must be effective
for the condition being treated. FDA regulations also require that the
label contains adequate directions for the safe administration of the
product. FDA recognizes that for some medications the label is not sufficient
to assure adequate training for the safe and appropriate use of the product.
In these cases the product requires a prescription with directions for
use provided by a veterinarian, a veterinarian/client/patient relationship
is needed to supplement the label of prescription drugs.
Contact with Medication
May Be a Risk
People with known allergies
to specific antibiotics should not use those products to treat animals
or work where those products are being used to treat animals. Additionally
those antibiotics should be removed from the treatment protocol and the
treatment area should be thoroughly cleaned to remove remaining traces
of that antibiotic before the person works in the area. A person exposed
to antibiotics or other medications which cause them allergies should
see a physician as soon as possible. The most common hazard from animal
medications (including antibiotics) is a local reaction at the skin surface
from chemical irritation or inflammation from accidental injection. Needle
penetration presents a risk of a localized infection that could eventually
spread to other parts of the body. When exposure occurs immediately wash
the exposed or injected area and treat with a topical antibiotic ointment.
The recommended precaution when working around any drug or chemical is
to wear long sleeves, rubber gloves and protective eye wear. If drugs
or antibiotics are splattered into the eye, the eye should be flushed
immediately with water. The individual should see a physician if swelling
or pain develops after skin contact or accidental injection.
Some Drugs are Toxic
to Humans
Some drugs can be extremely
dangerous if an inadvertent exposure has occurred. An example is the prescription
antibiotic tilmicosin phosphate, sold under the label Micotil. Micotil
is a very effective drug for respiratory infections in cattle and sheep.
However, Micotil is very toxic to the cardiovascular system of humans
and swine. The accidental injection of Micotil into humans has caused
death and there is no antidote. The manufacturer of Micotil has made a
considerable effort to inform the users of their product of the danger
involved. They recommend having the animal properly restrained, handling
loaded syringes with care, never carrying a loaded syringe in your pocket
and keeping needles properly covered until used. Because this is a prescription
medication and because the product is dangerous if mishandled, the cattle
producer should use this antibiotic only after detailed label review and
discussing its use with a veterinarian. If a person does receive an accidental
injection he should immediately call a physician, apply ice to the injection
site and go to a hospital. For further emergency information call 1-800-722-0987
or 1-317-276-2000.
Prostaglandins (examples:
Lutalyse, Estrumate) and cortical steroids (example: dexamethasone) can
potentially cause pregnant women to go into labor or abort if exposed
to this medication by injection or absorbed through the skin from a spill.
Pregnant women should not handle a prostaglandin or dexamethasone bottle
or work in an area or touch equipment where these drugs are used. If accidental
exposure occurs they should wash the exposed area and contact a physician
immediately. People with asthma, bronchial or other respiratory problems
should handle prostaglandins with extreme caution as they can cause bronchial
spasms that may result in death.
Drugs May be Poisons
The organophosphates and the
pyrethroids are the most common pesticides used on cattle in treating
for lice, cattle grubs and intestinal parasites. These chemicals are designed
to kill pests but are also dangerous to people. However, in most cases
the amount of chemical that people are exposed to is too small to cause
harm. Exposure may be by skin contact or by inhaling vapors. This group
of drugs interferes with the normal way that nerves and the brain function.
Symptoms include dizziness, headache, tremors, convulsions and loss of
consciousness. If symptoms occur, get immediate medical help. Exposure
can be avoided by wearing protective clothing and eyewear. Whenever there
is an accidental spill clothes should be changed and the skin washed with
soap and water immediately. Exposed clothing should be laundered separately
and extra rinse cycles run through the washing machine after removal of
the clothing.
Dirty Needles can be a Source of Infection
The most probable danger to
humans from vaccines is from accidental infection from an unclean needle.
Anyone routinely giving injections should have a current tetanus immunization.
Some individuals may have a (localized) reaction to the carriers within
the vaccine. The exposed area should be washed immediately and observed
for an inflammatory reaction. A physician should be contacted if pain
or swelling develops.
Live Vaccines May Infect
People
Vaccines that include live
bacterial components have the potential to cause disease in humans. The
most notorious example of this is brucellosis vaccine that can cause undulant
fever. When exposure occurs a physician needs to be consulted for appropriate
treatment.
Proper Animal Restraint
is Critical
Appropriate facilities are
vital for the success of any cattle operation to provide quick, safe and
easy handling of livestock and animal medicine. Many injuries are the
result of inadequate design of the structures used to confine and restrain
the animals rather than by the animals themselves. Operating and maintaining
facilities that are designed with worker safety in mind can greatly reduce
the danger associated with working with livestock.
Key Points for the Safe Use
of Animal Medicines are:
• Develop a herd health
plan to minimize disease problems.
• Use only licensed products.
• Administer medicines only if you are competent to do so.
• Read the label or the Material Safety Data Sheet (MSDS) carefully.
• Note the manufacturer recommendations and warnings.
• Use the product according to the directions on the label.
• Adopt good hygiene practices when injecting animals.
• Wash your hands thoroughly after handling any medication or vaccine.
• Note the withdrawal period for the medicine and do not market
the animal until after the withdrawal period.
• Provide good handling facilities to properly restrain the animal
for safe administration of livestock medicines.
• Be aware of your surroundings; look for slip, trip, and fall hazards.
• Store medicines in a secure place.
• Dispose of unused medicines and used needles in a safe manner.
• Protect skin and eyes with appropriate clothing and eye wear.
• If you are using a medication that has a potential for “human
toxicity”, talk with your veterinarian to see if a different medication
can be used or ask for advice on safe handling of the medication.
• Ask your veterinarian about the technique for one-handed subcutaneous
injection.
• If you do accidentally inject yourself, wash the affected area
well with clean water and soap, inform your co-worker, and if it is a
drug of known “human toxicity” call your local poison control
center IMMEDIATELY. The phone number for the Nebraska Regional Poison
Center is 800-222-1222.
It is important that all people
involved in medicating cattle have the proper training and supervision
to make the workplace safe for both man and beast.
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