How To Administer Farm Animal Medications Yourself

When your vet is not available, you can take over certain health-care tasks and administer animal medications. Here is advice from two experts.

by Sharon Biggs Waller
PHOTO: Jenoche/Shutterstock

A veterinarian is the first person you consult when an animal needs medical care, but if your vet is unavailable or can’t get to your farm in time, the care of the animal falls to you. As daunting as it might seem, it’s perfectly fine to administer animal medications yourself. Doing so can even save you money on vet visits.

We talked to a couple of experts to get some advice on:

  • what’s available over the counter
  • how to give an injection
  • withholding time for meat, milk and eggs
  • what to do if your farm is organic

Jonathan Townsend, D.V.M., Ph.D., is the director of extension programs at Purdue University College of Veterinary Medicine, and Matt Shane is the district extension director at Michigan State University.

Over-the-Counter Treatment

It’s crucial to consult your veterinarian before administering medication. Townsend says it’s important to establish a veterinary-client-patient relationship because your vet knows you and your farm well enough to give simple advice over the phone. Some vets might charge a fee for this service.

“The importance of having a working relationship with a veterinarian is that it establishes a valid [veterinary-client-patient relationship] and allows for the purchase of prescription products and the use of drugs in a prescribed extra-label fashion,” he says.

While most medications are available only through a veterinarian, some are available over the counter, generally antibiotics. Livestock medication is sold at feed and farm-supply stores. You’ll find them kept in a small refrigerator or locked in a cabinet with syringes and needles.

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It’s good to have some of these medications on hand in case of an emergency.

Don’t, however, grab a bottle and leave without reading the label. The medication might not treat the problem or be appropriate for your animal. For example, Shane advises to be careful with penicillin because there are long-acting and short-acting types.

“The dosages are calculated for cattle, and you can’t really dose a small amount of long lasting penicillin for a small animal like a lamb,” he says.

pig animal medication animals medications



Penicillin is widely found in stores. Common uses for this antibiotic include treating pneumonia and shipping fever in cattle and sheep; strangles in horses; and erysipelas in swine.

However, Townsend adds that penicillin is less effective now, and the recommendation for dosing is three to 10 times more than the dosage on the label. This larger dosage requires a longer withdrawal interval (see “Withdrawal Interval” at the end) and multiple shots at once. Penicillin is thick and not easy to administer.

“Here is where a vet’s advice would be important,” he says. “Another antibiotic might be a better choice.”


The second most common antibiotic found over the counter is oxytetracycline, which is a longer-acting antibiotic labeled for beef cattle, dairy cattle, calves and swine. It’s commonly used to treat pink eye, hoof rot, scours, pneumonia, infections and wooden tongue.

That said, not all forms are long acting, Townsend says. Some are 100 mg/ml preparations with more frequent dosing—another example of the need to read the label closely.

Product names for antibiotics differ by manufacturer. They include Duramycin 72-200 for oxytetracycline and Pro-Pen-G for penicillin. Look for the chemical name underneath the brand name.

Read more: Here are some tips for properly managing your livestock medications.

Administration Notes

Most of these drugs are administered via injection. Some are administered through water, such as the anticoccidial drug amprolium, and you might be tempted to go with these, especially if you’re squeamish about giving a shot.

There are downsides. Townsend points out that it’s difficult to gauge the right medication dosage and to be sure that the animal has drunk enough (or any) of the medicated water.

Additionally, you might not find your animal’s species listed on the bottle at all. Can you still use it for your goats or sheep? Maybe.

Animals such as goats and sheep are considered minor livestock, and as a result, very little research as been done for them. So it’s important to consult your vet for advice on extra-label usage for an over-the-counter medication that does not include your animal.

Commonly used pain medications are phenylbutazone (also called bute) and flunixin (also called banamine). They are available only through a veterinarian. It’s good to have these in your first aid kit to treat pain, such as colic in horses.

Both are available in oral paste and tablets as well as injectable. Note: It can be illegal to use bute for some animals, such as for dairy cows older than 20 months of age.

How to Give a Shot

There are three ways to give your animal an injection of medication: subcutaneous, intramuscular and intravenous. The one you choose depends on the medication and, to some extent, your experience.

Townsend says the administration of medication depends on manufacturer recommendations and usage approval, such as absorption through specific routes. “For instance, some carriers are very irritating and some are tissue damaging, so those are going to direct how the medication is administered,” he says.

Subcutaneous Injection (SUBCU)

A subcutaneous injection is administered under the skin and used when medication can be released slowly or when an animal has little muscle, such as with a young lamb. Most medication can be given subcutaneously.

Method: Tent the skin and insert the needle at a 45-degree angle pointing downward. Be careful not to “buttonhole” your injection by poking the needle through the opposite side.

Intramuscular Injection (IM)

An intramuscular injection is administered into the muscle and can be tricky if you have little experience pushing a needle through hide. Medications given IM spreads through the fat layer.

Method: Insert the needle straight in at a 90-degree angle in one smooth dart-like motion.

Intravenous Injection (IV)

An intravenous injection is administered into the vein, which allows rapid transfer of the medication. This is not for the novice. Only a veterinarian or a highly knowledgeable person should give IV injections.

Needle Gauge and Length

Needles come in various diameters and lengths. Which one you choose depends upon the animal, what medication you inject and how you inject it.

“You want to make the smallest hole in the animal to make the right dose,” Shane says. “Some antibiotics are really thick and syrupy. So you’ll need to go with the bigger gauge.”

The general range of needles for livestock species is 14 to 20 gauge—the smaller the number, the bigger the diameter. The most common for young stock and small species are 18 to 20 gauge needles. 18 is the smallest you’d use for cattle or larger species.

Note: Be very careful with choosing the gauge for your animal. A too-thin needle can bend or break off inside the animal. Always restrain your animal when giving a shot.

The correct needle length depends on the animal’s size and how you use the needle. Shorter needles, such as a 1/2-inch, are best for subcutaneous shots to help with the 45-degree angle needed. They are also appropriate for IM shots for young animals.

If you vaccinate a steer IM, for example, choose a 1 1/2-inch needle. This length will get the medication through the hide and into the muscle.

horse animal medication animals medications

Injection Sites

The triangular area on the neck is the most common place to give a shot. Animals have a triangular pattern on the side of the neck behind the shoulder and in front of the ear where there is a lot of dense tissue.

The skin is also loose there, especially when you turn the neck toward you, which makes it a good place for a subcu injection.

It’s also good for IM, but be careful to avoid the jugular vein and the ligaments along the crest of the neck. Young animals, such as goats and kids, don’t have enough muscle in the neck for an IM shot, so subcu is appropriate if the medication allows.

The second most common site is in the side, just behind the shoulder and right under the elbow. It has plenty of loose skin for a subcu injection. There’s also a large muscle appropriate for an IM injection.

The animal’s use also factors in on choosing a site. “Tissue damage on a valuable cut of meat [such as the loin, top, rump or leg] can be an expensive loss,” Townsend says. “So the neck is a good place for an injection for cattle as it’s a low-quality cut.”

Try to avoid giving shots in the rear flank because an animal won’t be able to walk if it’s sore. Equally, IM shots in a young animal’s neck might prevent it from nursing.

“Gravity also plays a part,” Shane says. “You want to choose a place where a [possible] abscess will be able to drain down [from the injection site].”

Read more: When is the best time to vaccinate a calf? Here are some pointers.

Step-by-step Instructions

Step 1

Fit your needle onto the syringe, remove the cap and draw the syringe back to bring in some air.

Step 2

Shake the vial then turn it upside down. Insert the needle. Press the air into the bottle to break the vacuum and slowly pull the syringe back until you reach the right dose. Make sure your needle is below the liquid.

Note: Cubic centimeter (cc) and milliliter (ml) is the same amount of volume.

Step 3

Gently tap the syringe to bring any air bubbles to the top. Push the bubbles back into the bottle, check the dosage once more, and remove the needle.

Note: Air bubbles won’t harm the animal but they take up space and can cause an incorrect medication dose.

Step 4

Don’t rely on eye-hand coordination when recapping the needle. Avoid finger sticks by laying the cap down a surface and sliding the needle inside.

Step 5

Clean the hide with alcohol, remove the needle cap and administer the shot. Pull the plunger back slightly to check for blood. If you see blood, you’ve hit a vein. Remove the needle and try again in a different spot. Recap as in Step 4.

Note: ask your veterinarian or pharmacist for assistance with discarding needles safely.

Tips: Never use a bent or damaged needle; throw it away and use another one. Damaged or weakened needles can break off inside an animal. If you need to inject multiple animals, don’t pull more medication into a single syringe and go from one animal to another.

“It’s very easy to push the plunger too far and overload the medication,” Shane says. “Instead use a dosing syringe made for this purpose.”

If you’re nervous about giving a shot, practice on an orange or banana. This mimics the feeling of injecting through skin.

Even armed with information, administering medication to an animal can be daunting, so ask your vet or a knowledgeable person for advice if you need it.

Administering medication is a crucial skill for every hobby farmer.

Sidebar:Educational Resources

The Food Animal Residue Avoidance Databank, commonly called FARAD, is a component of the Food Animal Residue Avoidance and Depletion program. It’s a university-based scientific program that lists recommendations for safe withdrawal intervals. The site also includes recommendations for extra-label withdrawal. If you have a more detailed question, you can contact FARAD for help.

Food Animal Residue Avoidance and Depletion Species Page is FARAD’s species-specific sister site with in-depth information about each species, including honeybees and wildlife. It also has information on treatment and withdrawal intervals for organic farms.

Youth Quality Care of Animals is a national multispecies educational and certification program for ages 8 to 21 that focuses on food safety, animal well-being and character awareness.

Sidebar: Organic Animals

Animal welfare is part of organic livestock farming, so you must must treat animals when they are ill or injured. The USDA has certain standards for treatment, but beyond that, your organic certifier might have additional requirements.

“For the most part, when you use medications not on the certified list, that animal is no longer organic, and that goes for a milk cow as well; its milk will never be able to be sold as organic again,” says Jonathan Townsend, D.V.M., Ph.D., the director of extension programs at Purdue University College of Veterinary Medicine.

“There is a requirement that an animal be treated humanely, and if it needs to go to non-organic therapy then it needs to be done. The animal comes first.”

Sidebar: Withdrawal Interval

It’s important to avoid eating food from treated animals before the withdrawal interval ends. Otherwise, there is a good chance you’ll consume the medication, which can be unhealthy and even dangerous.

As per a study published by the American Journal of Medicine in 2009, 10 percent of the human population is allergic to penicillin.

Consuming antibiotics you don’t need can lead to drug resistance. Some drugs might even be toxic. And if you sell meat, milk and eggs, you can be held liable if inspectors find drug residue in your products.

There is a broad spectrum of withdrawal intervals for medication in all livestock species. For instance, as per the Food Animal Residue Avoidance Databank, all FDA-approved, correctly administered medications for laying hens have a 0 day egg withdrawal. Penicillin has a 24-hour milk withdrawal after the final treatment, while oxytetracycline’s milk withdrawal is 96 hours after the final treatment.

(You have to discard milk for all medication during treatment.)

Extra-label withdrawal intervals can be difficult to ascertain, so visit the Food Animal Residue Avoidance Databank to find the withdrawal interval for information or ask your veterinarian for guidance.

This article originally appeared in the July/August 2019 issue of Hobby Farms magazine.

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