A900
Vaccines and Giving Injections

The following are general suggestions for proper use and handling of vaccines:

Preventing disease is considerably less expensive than using a veterinarian to treat individual animals with emergency problems.

It is important that horse owners establish a consistent health program to reduce the amount of infectious disease problems present on their premises. All animals are susceptible to many infectious diseases. Infectious diseases can enter a facility through purchased additions or carried onto a farm by other animal species and humans. A number of new vaccines and combination vaccines have become available in recent years. It is important to identify which diseases are a problem on the farm or in the area. With a veterinarian, create a strategy for protecting against and decreasing exposure to infectious diseases. Set up a written vaccination schedule to be followed. Modify the vaccination schedule as conditions warrant and available vaccines change. It is advisable to develop a complete program of management, sanitation, feeding, and health care to ensure a healthy and successful operation. The following are some suggestions for the effective use of vaccines:

Modified Live Vaccines:

Advantages Disadvantages
  • One dose required
  • Faster immune response
    •
  • Stronger and more durable response
  • Fewer post vaccination reactions
  • Not recommended for pregnant animals or animals in contact with pregnant animals
  • Possible viral shedding to other animals
  • Improper handling may inactivate the vaccine

 

Killed Virus Vaccines:

Advantages Disadvantages
  • Recommended for pregnant animals
  • Stable in storage
  • Multiple doses required 
  • Weaker immune response
  • Shorter duration immune response 
  • Adjuvants may cause reactions
  • Hypersensitivity reactions more common

 

The two most common routes to administer injections are intramuscular (IM) and subcutaneous (SQ or SC). A few vaccines are given intranasal (IN). Giving vaccines by the improper route can result in failure to immunize and may result in local reactions.

 

Intramuscular (IM)

Drugs given IM are picked up by the blood supply and spread very rapidly to all tissues of the body. A needle that is 1 ½ inches in length and 19 or 20 gauge

in diameter is recommended for making IM injections. The best location to give injections is in the heavy muscles of the neck. It is best to give no more than 10-20 mL at any one site. To avoid accidental intravenous (IV) administration, pull the plunger back to make sure no blood appears in the syringe. If blood appears, pull the needle completely out and re-insert the needle in a new site.

 

Subcutaneous (SQ or SC)

A 1-inch needle of 22-25 gauge diameter is the best size needle to use. The loose skin on the top of the neck is a good location for SQ injections. Substances injected SQ are not picked up by the blood supply as quickly as with IM injections.

 

Intranasal (IN)

Intranasal vaccines are packaged with special applicators that fit on the end of a syringe. Restrain the horse and squirt the contents quickly into the nasal passages. The animal may sneeze or cough, but this does not reduce the effectiveness of the vaccination. Never inject an intranasal product in the muscle or skin.

* See page B360 for the exact locations for giving injections.