Lesson 12
Administration of Medication to the
horse
Oral
administration
1.
Drenching – administering liquid
medication by mouth. This is not a preferred method usually because horses will
often refuse to swallow many liquids, and in attempting to give it, it could go
down the trachea. Never squirt or
forcefully administer a liquid substance orally with the horse’s head up. Most medications are now formulated to
pleasant tasting or in paste form.
2.
Stomach
tube –
Frequently used on the horse. The
stomach tube is passed up the nostril.
The horse must swallow the tube for it to travel down the esophagus on
the left side of the neck and into the stomach.
This method is used when it is vital that the horse receive an oral
medication or nutrition and he refuses to swallow voluntarily.
3.
Balling
gun – Care and
experience are required for this procedure.
It is usually easier for the horse to swallow pills that have been
coated with something such as corn oil.
4.
Feed
additives – Very
common practice with many products, but remember the horse can be very
picky.
5.
Pastes
& Gels –
These formulations are becoming the most widely used means of administering
medications and supplements to horses.
They are formulated in such a way that horses accept them readily.
Parenteral
administration –
medication administered by injection.
1.
Intramuscular
A. Lateral neck muscles. (Above the spine, below
the nuchal ligament and in front of the scapula, in a triangular area. Best
for vaccines and smaller doses of medication (less than 20cc.)
B.
Heavy muscles of the buttocks (semitendinosis & semimembranosis)
–This area is good for larger volumes of medication, however, it takes more
practice to get efficient.
C. Muscular part of the rump (gluteal region) as
it slopes slightly downward – horse usually
tolerates this area of injection very well. The only negative, it is a bad area for an
abscess to form from a contaminated injection.
Often it is easiest, after first using
an alcohol or other disinfectant swab to prepare the area of injection, to
place the needle into the muscle, and then attach the syringe and complete the
injection. In this way, you can make
sure blood does not flow from the needle.
If blood does flow, you must pull the needle out and reinsert.
Medications
intended for intramuscular use that are inadvertently injected into the venous
or arterial circulation can cause a severe reaction and sometimes-even death.
Needle
size is usually 1-½ inches long and 18 to 20 gauge.
2.
Intravenous – I.V. injections are given in the Jugular vein. Intravenous injections in the horse are a
common way of administering injectable medication, but must be done by someone
who is well trained in the technique and familiar with the medication being
used. Beware of the “know it all” around
the barn area who wants to give your horse a “bute”
shot. Bute and many other I.V.
injectables can be very caustic if not given correctly into the vein, and can
cause long term and serious problems if not done properly.
Improper technique can sometimes cause a
medication to be injected into the carotid artery causing immediate death to
the horse.
A 1 ½ inch 18 gauge needle is usually used for
I.V. injections.
Technique: hold off jugular vein in lower part
of jugular furrow in order to distend the vein with blood so you can identify
it. Insert needle into vein so it is
well placed and blood is flowing, then attach syringe. Pull back on syringe to be sure you are still
in the vein, then administer the medication slowly. Draw back on syringe when you are finished
administering medication to recheck placement and flush needle of medication.
3.
Intravenous catheters – Used when large volumes of fluids are to be
given intravenously. Routinely done on very ill horses. As an owner you may be called upon to monitor
intravenous fluid administration.
Important points in monitoring I.V. fluid administration once a catheter
has been placed are:
D. Usually the catheter is
positioned in a downward direction.
E. Fluids should be flowing at an
even rate, which you can determine by making sure the air bubbles are flowing
up in the fluid bottle.
F. If smooth flow is interrupted (no
air bubbles) immediately close off valve to prevent further flow of medication.
If you note a swelling beginning to appear around the entrance of the catheter
(the catheter has moved out of the vein) immediately close off flow of
medication.
G. The horse is okay if he is hooked
up to an I.V. and the lines are filled with fluid, but it has been closed off.
H. If you are using an air pump or
other positive flow device and the fluids are either accumulating under the
skin or are running out, immediately close off the flow or at last resort
rapidly pull out I.V. catheter. It can
always be replaced. The idea is to
prevent the horse from having air injected into his vein, or a large
accumulation of fluid out of the vein.
I. If you have given a horse a large
volume of medication I.V. that took more than 30 seconds to give, it is always
a good idea to keep the horse’s head up for 4 or 5 minutes and keep slight
pressure on the injection site to prevent the horse from bleeding back. Even a
10cc shot in the vein can bleed back if the horse lowers his head to graze or
eat right after the shot.
4. Intra-articular injections – The
injection of a medication directly into a joint. This is a commonly done
procedure in horses to treat a joint directly.
This is a technique which would unlikely be performed by anyone other
than your veterinarian. It must be done
with the utmost attention to sterility, because a joint infection from improper
technique could have devastating affects on the horse. The injection site is
usually scrupulously prepared and a needle is place into the joint without the
syringe. Excess synovial fluid is allowed to flow out of the joint where it can
be visually examined for abnormalities, then a syringe is attached to the
needle and the medication is injected directly into the joint. A sterile gauze pad or disinfectant pad are
placed over the area of injection and is secured by a temporary bandage.
Oftentimes an injection of Bute or Banamine is also given I.V. to prevent a
possible joint flare up.
5. Subcutaneous (under the skin), and
intradermal (between the epidermis and dermis) injections in the horse are
rare.