Vaccination of pigs
Attaining the maximum protecton from a vaccine depends on the timing, frequency and administration route of the vaccine.
The right route
When using a vaccine, it is essential to follow the manufacturer's or veterinarian's recommendations. Some vaccines for diseases such as leptospirosis, porcine parvovirus and erysipelas should be administered under the skin, preferably behind the ear, to reduce carcase blemishes. Therefore, a short 12 mm, 18-gauge needle is used. E. coli vaccines must be injected into muscle, and a 38 mm, 18-gauge needle is required for sows and gilts. For sucker pigs, a short 12 mm needle is adequate for injecting into muscle. The neck is the preferred site for injections into muscle.
Some vaccines that are not injectable are given orally (by mouth) or nasally.
The injection site
Injectable vaccines stimulate a tissue reaction at the site of injection; consequently, carcase blemishes can occur at the injection site. Therefore, the neck is the recommended injection site. Additionally, hypodermic needles can break during vaccination if the pig is not restrained properly, so the pig must be restrained for effective vaccination.
Different vaccines can be given on the same day but the injections should be given at different sites. The syringe must be calibrated to ensure the correct dose.
Syringes or vaccinators must be clean and maintained to ensure good hygeine. Clean off any organic matter or dirt with warm soapy water and rinse thoroughly. Sterilise by either boiling for 15 minutes or immersing in an approved disinfectant. Then rinse with sterile water.
Hygiene is also important during vaccination. If using a bottled vaccine, use a sterilised needle to withdraw the vaccine into the syringe and use another needle to inject the pig.
Commonly used vaccines for diseases
Pork producers should adopt technology that prevents production-limiting diseases in their pig herds. Several of these diseases can be controlled by vaccination. Vaccines for many diseases are available off the shelf (commercial vaccines). Alternatively, vaccines can also be made to suit specific herd health situations (autogenous vaccines). Prevention of disease requires veterinary diagnosis. It is essential to follow any specific veterinary recommendations for controlling disease.
Vaccines are available for leptospirosis, erysipelas, porcine parvovirus, E.coli scours, mycoplasma pneumonia (also known as enzootic pneumonia), actinobacillosis pleuropneumonia (APP), Glässer's disease (Haemophilus parasuis), and ileitis (Lawsonia intracellularis).
The vaccination program adopted by the pork producer may in some cases depend on the vaccines used, as multivalent (more than one disease covered by the vaccine) vaccines are available in Australia.
Leptospirosis causes stillbirths, high piglet mortality rates and abortions, and can cause non-reproductive illness in humans.
Initially, vaccinate all breeding stock (boars included) twice at four to six weeks apart, and then every six months. Ensure that gilts and boars entering the breeding herd are similarly dosed. Vaccination of sows about to farrow or with very young litters should be delayed a week. Otherwise, it is safe to vaccinate pregnant gilts and sows.
Alternatively, each sow can be vaccinated as she reaches a particular stage of her reproductive cycle, such as prior to farrowing or at weaning/re-mating. Both systems work well as long as every breeder is vaccinated. Don´t forget to vaccinate boars every six months. A single unvaccinated breeder in an intensive piggery can become infected and spread enough leptospira organisms to infect vaccinated animals.
The vaccine should be refrigerated and used promptly once opened. For this reason, in smaller pig herds, many pork producers vaccinate the whole breeding herd every six months.
A combined parvovirus, leptospirosis and erysipelas vaccine is now commercially available in Australia.
This virus causes reproductive failure in breeding pigs throughout Australia (it is different to the parvovirus in dogs).
The vaccination routine is exactly the same as for leptospirosis and the comments on storage, timing and the necessity for two initial doses also apply. Vaccination for both diseases can be performed at the same time but the vaccines must not be mixed in the same syringe and the injections should be given in different sites. A combined parvovirus, leptospirosis and erysipelas vaccine is now commercially available in Australia.
E. coli scours (Colibacillosis)
Escherichia coli (a bacteria) causes scouring in the suckling pig and in pigs after weaning. Vaccines are available in Australia for preventing this disease. However, attention must be paid to the environment and management of the sow and baby pig.
Sucker scours (Neonatal scours)
To prevent scours in the newborn pig, the vaccine is given to the gilts and sows so that immunity is passed through the first milk to the baby pig. In an unvaccinated herd, vaccinate all gilts and sows twice initially - 7-8 weeks before farrowing and then three weeks before farrowing. In subsequent pregnancies, a single dose should be given three weeks before farrowing. All gilts entering the herd require the one initial dose of vaccine at selection.
This vaccine should be given into the muscle, such as in the neck. It is recommended that a 38 mm (l.5 in.), 18-gauge needle be used for vaccination to ensure the vaccine is injected into muscle and not the fat under the skin.
E.coli can cause scouring, a reduction in growth rate and sudden death in pigs after weaning. The vaccine to prevent this disease is given to sucker pigs one week before weaning. The vaccine is injected into the muscle in the neck to avoid carcase blemishes.
Actinobacillus pleuropneumonia (APP)
There is an inactivated vaccine that will aid in the control of APP serovars 1 and 15 in growing pigs. The serovar of the strain present on a farm should be identified by culture or serology to ensure that the appropriate vaccine is being used. Pigs are vaccinated with a 2 mL intramuscular injection at weaning and again three weeks later.
An intranasal vaccine for APP is now available in Australia. It is recommended that producers discuss the use of this vaccine with their herd veterinarian.
Glässer´s disease (Haemophilus parasuis)
There is an inactivated vaccine that will aid in the prevention of disease due to Haemophilus parasuis serovars 4, 5 and 13. The serovar of the strain present on a farm should be identified by culture to ensure that the appropriate vaccine is being used. A 2 mL dose should be administered by intramuscular injection. The minimum age at first vaccination is one week, with the second dose given 2-3 weeks after the first. The second injection should be administered at least three weeks before the expected field challenge occurs.
A combined Glässer´s disease and Mycoplasma pneumonia vaccine is also commercially available.
Erysipelas causes fever, diamond skin disease, arthritis, abortion, heart disease and death. The vaccination routine has two alternatives: use the vaccine routine as for leptospirosis and porcine parvovirus or give the booster dose three weeks before farrowing in gilts and sows. This increases the level of protection against erysipelas passed onto the piglet through the sow's first milk (colostrum). Routine vaccination of growing pigs is not usually recommended but may be necessary in some pig herds.
A combined parvovirus, leptospirosis and erysipelas vaccine is commercially available in Australia.
Enzootic pneumonia (also known as mycoplasma pneumonia)
Enzootic pneumonia (Mycoplasma hyopneumoniae) reduces growth rates and can kill pigs. It also predisposes pigs to other respiratory infections, such as porcine pleuropneumonia. The vaccine is administered to piglets but can also be used for introduced growers and breeders. It is essential to follow the manufacturer´s recommendations for use. Shake the vaccine well before use. A 2 mL dose should be administered by intramuscular injection. For the two-shot vaccine, the minimum age at first inoculation is one week, with the second dose given 2-3 weeks after the first. Administer the second injection at least three weeks before the expected field challenge occurs. For the one-shot vaccine, give the 2 mL dose at approximately three weeks of age.
Ileitis (Lawsonia inracellularis)
Clinically, the manifestation of ileitis can be acute or chronic. The acute form of the disease presents as a bloody diarrhoea and death. Acute ileitis mainly occurs in gilts and older finisher pigs of 3-12 months of age. In contrast, in the chronic form, onset occurs more gradually and symptoms last for up to several weeks. The chronic form is usually seen in weaner and grower pigs.
The ileitis vaccine available in Australia is an attenuated live vaccine, which is given orally. The vaccine is a prescription animal remedy, which means it is only available from registered veterinarians who will outline the vaccination program for the pork producer prior to the use of the vaccine.
- Follow the manufacturer's recommendations, read the label and check the expiry date.
- Store vaccines in a refrigerator and use promptly once opened if required by the instructions. Never use an inactivated vaccine that has been frozen.
- Always observe the withholding period instructions when using chemical treatments.