Administering treatments to livestock via injection can be a hairy business, in more than one respect. It is therefore essential to take the necessary steps to safeguard your animals against injury, infection and even death, while procedures must be in place to protect the handler and workers.
Stockfarm asked veterinarians Drs Danie Odendaal and Riaan Mulder to shed some light on how a livestock producer should differentiate between the various injection sites (subcutaneous, intramuscular and intravenous) and the procedures that must be followed when injecting an animal.
Preparation for injection
The specific product and route of application must first be decided before selecting and preparing the equipment needed to apply the product. “This is on authority of animal health and safety procedures, and usually involves higher management in large-scale farming operations,” says Dr Odendaal. “In small-scale farming operations the livestock owner, in consultation with an animal health professional, is responsible for selecting a product.”
The first factor to consider is for which type of animal the product will be used, as well as the stage of the animal’s production cycle. The following pertains to cattle:
- Bull: Before and during breeding.
- Cow: During gestation and after calving.
- Heifer: One year old and two years old.
- Calf: Newborn and at weaning.
- Feedlot calf: Shortly after arrival and before slaughter.
According to Dr Odendaal, all products are registered and tested for use in specific species and the information will always be indicated on the product label and insert. “It shows which disease-causing organisms the product is effective against, or for which health-enhancing purposes it can be used.”
Main categories of indications
The following categories of vaccines to protect against preventable infectious diseases caused by bacteria and viruses – most of these products are registered under the Fertilizers, Farm Feeds, Seeds and Remedies Act, 1947 (Act 36 of 1947) – are available:
- Ectoparasite control (ticks, lice, mites, flies).
- Endoparasite control (roundworm, tapeworm, flukes).
- Antibiotics (bacteria, protozoa).
- Minerals (supplement shortages).
- Vitamins (supplement shortages).
Keep in mind that there are several other types of medicine registered under the Medicines and Related Substances Act, 1965 (Act 101 of 1965) for which a veterinary prescription is required, such as antibiotics, anti-inflammatory products, and hormones.
Various physical injuries can arise when handling livestock, especially when they are kept in a crush pen. Under these circumstances the animals will always exhibit defensive behaviour, including fight or flight behaviour. The crush must be inspected and prepared beforehand to make sure it is on par and that there is nothing that can cause injury to animals.
Preventing injury to the operator
A particular hazard associated with injecting animals is a needlestick injury. Procedures such as careful positioning of the hands and appropriate restraint of the animal should be applied to minimise the risk of a needlestick injury.
Dr Odendaal cautions that care should always be taken when using hypodermic needles. “When using disposable needles, make sure the needle is capped until immediately before it is inserted into the animal. After use, all needles should be re-sheathed while ensuring that the needle does not puncture any fingers.”
All used sharps and hypodermic needles must be discarded in a ‘sharps’ container. Sharps and needles should be discarded immediately to avoid the risk of injury.
Directions for application
There are various application methods, and each must be considered in terms of ease of application (Table 1), number of animals to be treated, and facilities available. Dr Odendaal states that this also has a direct impact on the skills needed to prepare and apply the individual product correctly.
Table 1: Methods of application.
|Application||Skill level needed|
|Oral application (dose)||Medium|
Injection method: Intramuscular
Some products must be injected into the muscle for better absorption or because it can cause substantial swelling if administered under the skin.
There are a few considerations when injecting into the muscle:
- The product must not be directly injected into a blood vessel.
- The product must preferably be injected into a lower value muscle (meat cut), as it can cause muscle damage that may lead to connective tissue growth or even an abscess if hygiene was substandard during injection.
- Damage to other underlying structures such as the nerves or bone.
Administering an intramuscular injection containing a tetracycline antibiotic is used here as an example of the equipment needed, the preparation and application – remember, all products must be used according to animal health and safety procedures.
Selection of equipment
- Choose a disposable syringe: Acquire the size that will be needed to apply the specific product according to the weight of the animal.
- Choose a disposable needle: Acquire the size that will be needed to apply the specific product according to the thickness (viscosity) of the product to be applied.
Preparation of equipment
- Prepare the work surface next to the crush pen: A table or other clean surface is needed for the equipment. In addition, open or unwrap the disposable syringe and disposable needles.
- Calibration of the equipment: When using a disposable syringe, no calibration is needed.
- Drawing up the product into the syringe: Use a sterile needle and insert it into the bottle; draw up the right amount of product according to the dose calculated for the specific animal.
Application of product
- Treatments are applied to the correct site as per prescription (injecting into the rump or injecting into the neck).
- Disinfect the injection site with methylated spirits.
- Insert the needle.
- Attach the syringe and pull back the plunger (aspirate).
- Inject the product.
- Remove the syringe and needle.
Figure 1: Correct site when giving an intramuscular injection in the rump.
Figure 2: Correct site when giving an intramuscular injection in the neck.
Injection method: Subcutaneous
According to Dr Odendaal, most injections are administered this way. “Some injections must only be administered subcutaneously, otherwise it will have severe negative effects.” This also applies to injectable broad-spectrum mineral or vitamin combinations that are registered for use below the skin only. “If this injection is administered into the muscle, it can increase the chances of toxicity.”
The best method to administer a subcutaneous injection is to lift the skinfold and insert the needle under the tented skin.
The correct method when injecting subcutaneously.
Injection method: Intravenous
Intravenous (IV) injections are administered into the vein and it is best to let a veterinarian handle this. According to Dr Mulder, these injections are usually administered into the jugular vein in the neck of larger animals. This vein can be tricky to find, so the animal must be well-restrained while administering the injection.
To find the vein, press your thumb into the jugular groove near the juncture of the animal’s neck and shoulder. “This is just below the location where you want to inject,” says Dr Mulder. “The vein will usually distend along the length of the groove. It can be lethal to rapidly inject medication into an animal’s vein, so these injections must be administered very slowly.”
In terms of ‘downer’ cows “one can also inject her in the protruding milk vein situated just in front of the udder. The trouble is that the vein, which is usually easy to find, can be covered in dirt and if you miss the vein, it can cause serious bleeding under the skin and possibly thrombosis.”
The correct way to administer heartwater blood.
Injection method: Intramammary
Dr Mulder also refers to intramammary injections, where antibiotics are injected into the udder to treat mastitis infections. “A distinction must be made between ‘lactating’ and ‘dry cow’ antibiotics, the latter being longer-acting than lactational antibiotics.” He notes that producers must also be on the lookout for withdrawal symptoms.
Injection method: Intraperitoneal
When a sick animal requires large amounts of fluid, it is usually administered intraperitoneally (IP). “The fluid is injected into the abdominal cavity where the peritoneum lining absorbs it,” explains Dr Mulder.
“The injection site is located on the right paralumbar fossa. Facing the cow from behind, on the right-hand side, in the hollow area formed by the ribs in the front, is the lumbar vertebra dorsally and the hip bone at the back. The needle is directed at a right angle to the skin to penetrate the muscle layer.”
Injecting into the abdominal cavity is easier than via the jugular or subcutaneously for ‘downer’ cows with milk fever. It is key to only use medicine or vaccines specifically manufactured for IP use in animals, as some medication can cause peritonitis (inflammation of the membrane lining of the abdominal wall that covers the abdominal organs). (Image supplied by Dr Riaan Mulder)
Oral application (dosing): This is mostly applicable to remedies against internal parasites and for mineral/vitamin supplementation. The product will work directly inside the intestinal tract, or can be taken up into the bloodstream by absorption in the gut.
Pour-on: This is a relatively easy application method. Take note, though, that the full dose must be applied and if the operator is not skilled, part of the application can be wasted (it can end up on the ground instead of on the animal).
Pour-on between the ears.
Hand spraying or dipping: Hand spraying is a very cost-effective way of treating external parasites, but it takes time and dedication to do it effectively. The product strength must be correct, and it is therefore essential to follow the mixing instructions meticulously.
Spot treatment: Some products, such as tick grease or an antibiotic spray, are formulated specifically for application on a small area of the animal.
Application in water or feed: This application is mostly used for mineral or vitamin supplements. However, this method can also be used for antibiotics under intensive farming conditions such as in a feedlot. – Carin Venter, Stockfarm