How Much Penicillin Can You Give a Horse?

Last Updated on December 26, 2022

Have you ever used Penicillin for an infection or on a cut? Did you know that you can also use Penicillin for your horse? As with all veterinary matters, always defer to your vet’s judgment, but it is safe to use Penicillin on horses, as long as it is done in the right ways and the right amounts! How much penicillin can you give a horse?

Penicillin can be used on many animals to help with many different things.  In this article, I’ll be discussing what Penicillin does, who can use it, how you give a horse Penicillin, and most importantly, how much Penicillin it is safe to give a horse.

What is the Purpose of Penicillin?

Maybe you’ve heard the word Penicillin before; perhaps you have some sitting in your medicine cabinet at home.  But do you know what Penicillin does, or what it is?

Penicillin is a bactericide that is used to treat infections.  Its primary function is to enter into infected areas of skin and flesh and to kill bacteria in these areas.  These infected areas should be observed by a vet before Penicillin is used, but frequently vets will recommend its use.


Who is Penicillin for?

Penicillin is can be used for many animals and even people.  But there are different types of Penicillin for different types of organisms.  In this case, Penicillin G Procaine is intended to be used to treat horses, cows, pigs, and sheep.

There are also different types of Penicillin, administered in different ways, that are suitable for people, cats, dogs, and other animals.  Penicillin is used to treat different types of infections in all branches of life that it extends to.

As stated, different types of Penicillin are appropriate for different kinds of animals.  Similarly, different types of Penicillin have different forms of consumption. For example, for humans, Penicillin can take the form of a tablet or liquid medicine.

For horses, Penicillin is an injectable form administered with a syringe.  If you are not familiar with using a syringe, and your vet has determined that Penicillin is needed to treat your horse, please have it demonstrated before trying it on your own.  Incorrect use of a syringe can severely injure yourself or the horse.

How Do You Give A Horse Penicillin?

The syringe should have a 16 or 18-gauge needle, at approximately 1.5 inches long.  It should be disinfected and cleaned before use to prevent further infection. They should also be sterilized before use.

The syringe should be injected into the muscular areas of the horse near his hips, hind end, upper legs, or neck.  A syringe should NOT be injected into a blood vessel or near a major nerve or nerve area. If the injected area begins bleeding while the syringe is inserted, remove and restart immediately.

If your horse is being treated with Penicillin for multiple days, each injection should be done in a different location or his body; injections should never be done in the same place during the same injection period.

If you are unsure of how your horse will react to injections, or you know for a fact your horse misbehaves when injected, have someone present to help prevent your horse from moving, which could cause injury both to himself and those present.

How Much Penicillin Should You Give a Horse?

Finally, how much Penicillin is it safe to give your horse? Assume your vet prescribes your horse Penicillin for an infected area, and you safely know how to administer an injection via syringe.  Now what?

Horses can get 1.0 mL of Penicillin for every 100 pounds of body weight, once a day.  So, if your horse weighs approximately 1,000 pounds, he could get 10.0mL of Penicillin daily.  Typically, the exact dosage will be disclosed to you by your vet, because it will depend on the circumstances.

If your vet does recommend the 1.0mL for every 100 pounds method for determining a  correct dosage, then the dosage will depend on how large and heavy your horse is! For example, you wouldn’t be using the same dosage on a mini horse as you would on a Clydesdale.  

How Much Penicillin Should You Give a Horse?

Your vet should be able to make a safe guess as to how much your horse weighs by simply looking at him, but it never hurts to have your horse professionally weighed from time to time, for scenarios just like this.

Duration of the dosages will also depend on the circumstances; how severe the infection is, how long it has been around, the horse’s overall health, etc.  

Penicillin For Horse

Sometimes horses only need to be injected with Penicillin one time, sometimes they need to be injected with Penicillin every day for a week, and sometimes they need to be injected with Penicillin every day for a month- it all depends on each horse’s situation.

Your vet will be able to recommend what the correct duration for your horse’s treatment will be.  In some cases, there will be a prescribed duration before a revisit; the revisit will tell whether that duration needs to be extended, or whether the horse has healed enough to be taken off the Penicillin.

When to Give a Horse Penicillin?

Penicillin is an antibiotic used to treat various infections in horses. Several different types of penicillin can be effective against a range of common infectious diseases in horses.

Penicillin should only ever be given to horses when it has been prescribed by a veterinarian, and there are several reasons for this. Firstly, your veterinarian will be able to identify the correct form of penicillin to use and the most effective dose for your horse. Secondly, responsible antibiotic use is vital in the medical world to prevent the increase of bacteria that are resistant to antibiotics.

This means that they are only ever prescribed when absolutely necessary, and you should never be tempted to give your horse a course of penicillin without the go-ahead from your veterinarian.

Is Penicillin Made Out of Horse Urine?

Penicillin is a naturally derived antibiotic, but it is not made from horse urine. Penicillin comes from a specific mold, Penicillium, which was first identified nearly 100 years ago as having antibacterial properties.

Penicillin is commonly confused with Premarin, a human hormonal treatment that is extracted from horse urine. But you can rest assured that your antibiotic penicillin treatment is cultivated in a laboratory, not from horse urine!

Can You Overdose a Horse on Penicillin?

Penicillin in horses has a relatively large safety margin, but overdoses can occur. One of the main issues comes from errors during the administration of this medicine, which should only ever be given to horses by intramuscular injection. If injected into a vein, penicillin will cause extreme excitement and uncontrollable behavior. This is not fatal and the symptoms will gradually subside, but the horse can injure itself in the meantime.

Some horses are also allergic to penicillin and will have a reaction when injected with this medication. The symptoms range from mild hives to breathing difficulties and collapse. A horse that has had an allergic response to penicillin should never be given another dose, as a second allergic reaction may prove fatal.

What happens if you give a horse too much penicillin?

The dose range of penicillin in horses has a large safety margin, but care must be taken not to exceed the prescribed dose. Penicillin overdose in horses can lead to neurological problems, particularly in those with reduced kidney function. If you suspect that you have accidentally given your horse too much penicillin, contact your veterinarian immediately for advice.

Injecting a large dose of penicillin into one site can also lead to injection site abscesses. If you are injecting a larger horse that needs more than 10ml of penicillin, split the dose over two injection sites. Remember to use a clean, sterile needle for each injection.

Can You Give a Horse Penicillin For a Cold?

Penicillin is an antibiotic that is used to treat bacterial infections. Most infectious respiratory diseases of horses are viral, and antibiotics will not affect a horse that has a cold. Horses with respiratory viruses are normally treated symptomatically, with medication to ease breathing and supportive nursing care.

The only situation where a horse with respiratory disease may be given penicillin is if it develops a secondary bacterial infection. Your veterinarian will most likely take samples of any respiratory secretions and culture them to determine the best type of antibiotic to use. Never be tempted to give penicillin to a horse without veterinary advice, as you may cause more harm than good in the long run.

Conclusion – How Much Penicillin Can You Give a Horse

Penicillin has many uses for many different creatures, both human and animal! It is extremely effective in treating bacterial infections in horses, though one must be careful and seek out veterinary advice before using it on horses.

Penicillin on horses can be given up to 1.0mL per every 100 pounds a horse weighs. This will depend on the size and density of each horse! Make sure you know how to safely administer and use Penicillin before using it on your horse.

I hope this article helped you better understand how Penicillin can be safely used to treat horses and how much Penicillin is safe to use on a horse! If so, please share this article, and share with us your stories of using Penicillin on horses!