Basics

An introduction to Organization, Safety, Handling, the Physical Exam, Medications, and the Intramuscular (IM) Injection

Just as you are a product of your experiences, so is every horse you will ever meet. Patience, respect, and understanding will get you further much faster than bullying your patient. Our job is to teach by example. If we choose to use derogatory terms to refer to our patients, we not only demonstrate a lack of understanding of equine behavior, but we give our clients license to treat their animals poorly. Our patients are not crazy, they simply act like horses.  

Horses are by nature, flight animals, and our patients frequently have minimal experience with people. Many have been labeled “broncs” after being manhandled. People are watching us work. When you choose to finesse a patient rather than bully it, you make an investment. The payoff occurs the next time you (or some other veterinary professional) work with that patient.   

Learn to watch (and listen)  every chance you get. So much of what there is to be learned comes from watching others work. Don’t cheat yourself out of these opportunities.   

STAYING ORGANIZED

The most important thing that you can do to keep things moving smoothly and safely is to stay organized. We have caddies and bucket organizers designed to keep the supplies that you need readily available. Do not carry armloads of supplies to your patient or to the area in which you will be working. Every time you use something, put it back where it belongs. Keep caddies and buckets clean and stocked. If everyone completes each task that they start, this is not an issue. Every chance you get, clean the clutter, empty the sharps, empty the trash, put the records away. This will make everything run smoother.

SAFETY

The safety of the patient, volunteers, and any observers is always of primary concern. Each situation must be evaluated and a common sense decision made as to the whether the procedure should be done. The ground covering and slope, location of fences and buildings, availability of skilled personnel, and presence of distractions that may frighten the horse must all be considered. These are elective procedures, which should only be done when it is safe. 

  • The safest place to stand when handling a horse is at the shoulder.  
  • Do not stand behind horses.  
  • Do not kneel or sit on the ground when working with or around horses, always remain on the ball of one or both feet.
  • Do not stand directly in front of horses, except during dental procedures.  
  • When you are the handler, stay on the same side of the horse as the examiner. 
  • Never wrap the lead rope around your hand. 
  • Do not do anything you are uncomfortable with.   
  • Stay off of the “leg side” of any anesthetized patient. If you cannot do so, maintain a distance of at least six feet between you and the hooves of the patient unless you are trimming the feet.
  • Never let a horse out of your field of vision unless you are at least 40 feet away.
  • If a patient is wearing a speculum, always keep a hand on the nose.
  • Do not hold anything under your arm or between your legs when you are handling or working on a horse.

THE MOST BASIC OF NOTES ON HANDLING.

The single most important thing that you can do to learn about being a horseman is to watch every interaction between a horse and a person that happens around you.

  • Watch how the horse responds to the person.
  • Watch how the person responds to the horse.
  • Watch how the horses response differs from person to person, as this will lead you to the people you can learn the most from.

You cannot learn to read/handle a horse by reading a few paragraphs in this document. It takes years of experience, and many people, perhaps the majority of them, lack the basic observational traits necessary to see what is in front of them, and learn from it. Start by looking at yourself.

  • Think about how you move and speak. This is all that the horse sees and hears. People who move and speak in fits and starts do not instill confidence in their patient.  
  • Every interaction that you have with a horse is a training interaction. You either train the horse that you are partners, but you are in charge, or you train the horse that it is in charge and some would say, in this case, that the horse trains you.
  • Learn your limits- don’t start something if you don think you can complete it. Every time you don’t finish what you started you tell the horse you really don’t mean what you say.
  • Mean what you say.  Ask for what you want/expect firmly and clearly, but without bullying. You cannot expect a horse to do what you ask if you are unclear or unsure when you ask. 
  • Approach every horse with the belief that everything is going to go well, and that you will be able to complete the task at hand. If you don’t think that you can complete the task at hand, do not approach the horse.  
  • Horses follow your lead. If your body, voice, or manner says that something may go wrong, the horse will sense it and things may indeed go wrong. Horses read anxiety or tentativeness in humans as “this is a bad situation: run for your life, we are going to die.”  Self preservation is the horse’s primary goal and if you, as the “herd leader” are worried about the outcome, why should they go along with you?
  • This is not to say that you should move quickly or always assume that the best will happen. It is just that you should plan ahead so that everything is in your favor and not attempt procedures for which you are unprepared. Moving quietly, but confidently, in the knowledge that you have prepared for all eventualities, will improve the outcome every time.    

PHYSICAL EXAMS

At times we are unable to perform a physical exam on our patients. They often lack the training necessary to facilitate examination. As a patient becomes excited, sedatives become less effective, making it more difficult to achieve sedation in the patient. Then if the patient is a surgical case, anesthesia and recovery are compromised. Do not compromise the patient’s anesthesia and recovery as well as your safety by trying to take an obviously healthy horse’s temperature.   

Normal physical exam parameters: (these parameters are relatively unchanged by anesthesia) 

  • Temperature:  99.0 to 101.5  
  • Heart beat:  24 to 44 bpm                             
  • Respiration:  8 to 24 bpm

The heart beat should be regular. An irregular beat should be evaluated prior to anesthesia or sedation. A regularly irregular beat (i.e., 3 beats, a dropped beat, 3 beats, a dropped beat) usually indicates a 2nd degree AV block. This is a relatively common arrhythmia in the horse. In most cases this will not affect anesthesia. An irregularly irregular heart beat may be indicative of atrial fibrillation. This is a more uncommon arrhythmia, and requires further evaluation.  

The nose should be free of discharge and the patient’s eyes and coat should be bright. The patients should be alert and should have an energy level appropriate to its age.

A Body Condition Score or BCS will be recorded on every patient. Note cards are attached to every caddy and clipboard. Refer to these cards, touch your patient, and assign an appropriate number.

VACCINES, ANTHELMINTIC AND OTHER MEDICATIONS

All medications should be given for a reason and a cost/benefit ratio should be considered. There is no medication that cannot cause an adverse reaction. Some examples:

  • TMS can give the patient a life threatening antibiotic induced colitis.
  • Adverse reactions to vaccines may include high fever in the day or days following the injection, swelling at the injection site, abscess formation, and anaphylaxis.
  • Penicillin can cause anaphylaxis, or an excitatory response, either of which can result in serious injury.  
  • Intramuscular injections of non-antibiotics such as vitamins or flunixin can cause Clostridial myositis, which is life threatening (rarely even standard vaccines can do this: always take post vaccination lethargy and swelling seriously).

Our antihilmintic of choice is Ivermectin. We use 1% injectable solution for cattle, however we ALWAYS administer this orally. It is dosed at 200 mcg/kg or 1 ml/100 lbs of body weight. 

The frequency with which a patient needs treatment for intestinal worms varies greatly.   

  • For a horse living on thousands of acres on the plains, twice a year (once after the first freeze in the fall and once when things start to thaw out in the spring) is entirely appropriate.  
  • For horses living in irrigated fenced pastures, once a month may be necessary.
  • If a patient appears particularly “poor” we send a dose of ivermectin home with the patient to be administered a month later.
  • Actual fecal egg count analysis of a representative number of horses from a population is ideal for formulating an effective parasite control program.

Vaccines

  • All vaccines require refrigeration.  
  • One multi dose vial will be carried in the cooler in each caddy.  
  • Check the icepacks every time you reach into the cooler for a vaccine. During summer clinics they will need to be changed mid day.  
  • You can draw up several doses at the start of the day. 
  • The syringes must be clearly labeled.  

Tetanus Toxoid:  

  • One ml of tetanus toxoid is administered IM to patients over the age of 8 weeks.
  • Tetanus toxoid should be administered annually, as well as when a patient is injured or is undergoing a surgical procedure.  
  • To attain initial immunity tetanus toxoid must be boosted 3-4 weeks after the first vaccination.  
  • Until this booster is given, each tetanus toxoid vaccine is considered to be the patient’s first.

Rabies

  • Rabies vaccines should be administered annually to equine patients. The dose is 2 ml given IM.  

Tetanus Antitoxin

  • Tetanus Antitoxin is not a vaccine.  
  • It is a prophylactic treatment administered to prevent tetanus. Rather than providing stimulation to the immune system, to produce antibodies against the tetanus organism’s toxin, antitoxin provides those antibodies directly. These antibodies are proteins with a limited lifespan, approximately 6 weeks. Tetanus protection is therefore immediate, but short lived. 
  • It is administered only to surgical or injured patients who have not been previously or consistently vaccinated for tetanus.  
  • Tetanus antitoxin is administered IM at a dose of 1500 units. Packaging must be consulted to determine what volume is necessary to administer 1500 units.
  • There is a small risk of acute liver failure in patients who receive a tetanus antitoxin. There is a higher risk of tetanus infection without the antitoxin. We feel that the risk is outweighed by the benefits.  

Injectable flunixin meglumine (Banamine) 

  • It is dosed at 1.1 mg/kg and administered IV to surgery patients, patients undergoing significant dentistry, or other patients in which pain and inflammation are deemed necessary for treatment and an NSAID is an appropriate choice. 
  • This is a Non Steroidal Anti Inflammatory Drug (NSAID) and is administered to provide analgesia.  
  • All NSAIDs are nephrotoxic (hard on the kidney) and ulcerogenic (hard on the stomach and GI tract) to varying degrees. 

Procaine Penicillin G 300,000 U/ml

  • Must be mixed thoroughly – some brands take longer than others to mix. Turn the bottle upside down and look at the base to ensure that it has been properly mixed prior to drawing PPG into a syringe. Failure to mix thoroughly results in administration of the procaine portion of the drug to the patient, while the antibiotic remains in the bottle.
  • Should be drawn from the bottle at room temperature.
  • Must be refrigerated after opening.
  • Is administered IM or SQ only. IV administration can cause severe adverse reactions such as seizure.
  • May be administered at doses ranging from 20,000 to 40,000 IU/kg.  
  • We use PPG to protect against clostridial growth (tetanus and gangrene) while the wound or surgical site is healing.  
  • When discussing penicillin with the client we must be clear. Many of our clients use the slow release, long acting penicillin benzathine (150,000 U/ml) in their horses. This drug is not effective in the horse as it is not possible to administer it in high enough volume 

The Pharmacy:

  • Trimethoprimsulfamethoxazole tablets 
  • Phenylbutazone tablets 
  • Metronidazole tablets
  • Procaine Penicillin G injectable 
  • Excede injectable
  • Flunixin meglumine injectable
  • Carbocaine, Injectable
  • Lidocaine Injectable
  • Assorted topical and eye ointments

ADMINISTRATION OF INJECTABLE DRUGS: INTRAMUSCULAR (IM) INJECTIONS

Most injections given to horses will be Intravenous (IV) or Intramuscular (IM) injections. Students will generally not be asked to give IV injections to patients who are conscious, and will only give IV injections under direct supervision. Mistakenly injecting any drug into the artery will cause your patient to seizure and fall down or flip over backwards. This places the patient, yourself and the client at risk of serious injury and reduces the client’s faith in your ability and in the clinic. There is no excuse for an intra-arterial injection. Learn good technique and USE IT!

Syringes must be clearly labeled. Unlabelled syringes are garbage.

Syringes of lidocaine, vaccines, and PPG may be used for more than one patient as long as they have not been contaminated. The needle must be changed after each injection. If the syringe is immediately reloaded, then all clinic participants can tell that the needle has been replaced, as you must do so prior to reloading the syringe. Do not remove a dirty needle and set the syringe down prior to needle replacement as doing so results in contamination of the syringe. All syringes used for IV injections are discarded after a single use.

Intramuscular injections may be given in the neck, semimembrinosus/semitendinosus (“semis”), or pectoral muscles. Some clinicians also use the muscles of the forearms as well as the gluteal muscles. Use of the pectoral muscles is associated with a short lived edema. Use of the gluteal muscles is generally limited, as drainage of an abscess is difficult to achieve. The neck and “semis” are the two most common sites for IM injections in the horse.

Intramuscular injections in the adult horse should be given using a 1 ½” needle. Less viscous products such as vaccines, or gentamicin should be administered with a 19 ga or 20 ga needle while more viscous solutions, such as procaine penicillin should be given through an 18 ga or 16 ga needle. 

The area of the neck used for injections is bordered by the scapula, the nuchal ligament, and the spine.  Prior to giving an IM injection, feel the neck. You can be certain you are above the vertebrae if you feel where they are prior to choosing an injection site. Avoid use of the neck for IM injections in foals. They lack large neck muscles and it is possible to inject into the spine. Avoid the use of the neck for viscous solutions such as procaine penicillin if the patient is very thin and lacks adequate muscle