The vaccines pigs need depend on whether they’re raised for production or kept as pets, but nearly all pigs require protection against three core diseases: porcine circovirus type 2 (PCV2), mycoplasma pneumonia, and erysipelas. Breeding animals need additional vaccines, and pet pigs have their own unique requirements, including rabies. Here’s a breakdown of what’s recommended and when.
Core Vaccines for All Pigs
Three vaccines form the foundation of any swine health program, whether you’re running a commercial operation or raising a few pigs on a small farm.
Porcine circovirus type 2 (PCV2) typically causes disease in pigs between 6 and 12 weeks of age. It leads to wasting, poor growth, and increased susceptibility to other infections. In unvaccinated herds, the impact is dramatic: vaccination reduces overall mortality by 50% and improves daily weight gain during finishing by over 9%. Piglets are usually vaccinated at 3 weeks of age with a booster at 6 weeks, though some producers start as early as 1 week. Over a dozen commercial vaccines are available in the United States, including options designed for sows and gilts as well as piglet-specific formulations.
Mycoplasma hyopneumoniae causes enzootic pneumonia, a chronic respiratory disease responsible for enormous economic losses worldwide. Infected pigs develop a persistent dry cough, reduced feed efficiency, and slower growth. Healthy piglets can be vaccinated starting at 3 weeks of age, with a booster 2 to 3 weeks later. A single-dose vaccine is also available. Research shows that the immune response from vaccination, including the cell-level immunity that actually fights the infection, persists through the end of the fattening period.
Erysipelas is caused by a bacterium that triggers the classic “diamond skin disease,” along with joint inflammation, heart damage, and abortion in pregnant sows. Piglets receive two doses starting at 8 to 12 weeks of age, spaced 3 to 4 weeks apart. An oral vaccine option exists for piglets over 8 weeks old.
Extra Vaccines for Breeding Stock
Sows, gilts, and boars need a broader vaccine program because reproductive diseases can devastate an entire herd’s output. Two vaccines are especially important for breeding animals on top of the core three.
Parvovirus is a leading cause of reproductive failure in swine. Infection during pregnancy can cause mummified fetuses, stillbirths, and small litters. Gilts should receive their first dose at 5 to 6 months of age, with a booster 3 to 4 weeks later. Sows are revaccinated 3 to 8 weeks before each breeding. Boars need a booster every 6 months.
Leptospirosis can cause abortion, stillbirth, and weak piglets, and some strains also pose a risk to humans handling infected animals. A 6-valent vaccine (covering six bacterial strains) is given starting at 8 to 12 weeks of age with a booster 3 to 4 weeks later. Breeding animals are revaccinated either 3 weeks before breeding or every 6 months.
Sows should also receive an erysipelas booster on the day of weaning before rebreeding, since the disease can cause abortion and is easily spread in farrowing environments.
Porcine Reproductive and Respiratory Syndrome
PRRS is one of the costliest diseases in the swine industry. Modeling on a 1,000-sow farrow-to-finish operation in Europe estimated annual losses from PRRS at roughly €400,000 to €443,000. Vaccination of sows alone returned an estimated €148 to €270 per sow per year in financial benefit; adding piglet vaccination pushed that figure to €170 to €340 per sow.
Whether to vaccinate for PRRS depends on your herd’s status. Farms that are PRRS-negative generally avoid the vaccine to maintain their clean status. Farms dealing with active circulation or repeated outbreaks typically vaccinate both sows and piglets. Your veterinarian can help determine your herd’s PRRS status through blood testing and guide the decision.
Vaccines for Pet and Mini Pigs
Pet pigs face a different risk profile than production animals. The Merck Veterinary Manual recommends four vaccines for pet pigs:
- Erysipelas: first dose at 8 to 12 weeks, booster 3 to 4 weeks later, then semiannually or annually.
- Leptospirosis (6-valent): same initial schedule, boosted semiannually or annually.
- Pneumonia (Actinobacillus pleuropneumoniae): same initial schedule, boosted semiannually or annually.
- Rabies: first dose at 14 to 16 weeks, boosted annually.
Rabies vaccination is particularly important for pet pigs. No rabies vaccine is currently licensed specifically for pigs, so it’s used off-label, but it’s strongly recommended based on exposure risk. Some municipalities require proof of rabies vaccination for pet pigs, so check your local regulations.
Why Timing Matters for Piglets
Piglets receive antibodies from their mother’s colostrum in the first hours of life. These maternal antibodies protect newborns, but they also interfere with vaccines. If you vaccinate too early, the mother’s antibodies neutralize the vaccine before the piglet’s own immune system can respond. If you wait too long, there’s a gap where the piglet has no protection at all.
The sweet spot is when maternal antibody levels are still high enough to offer some passive protection but low enough to let the vaccine work. For most diseases, that window falls around 3 to 4 weeks of age or later. PCV2 vaccination at 1 week of age, for instance, can result in lower growth performance compared to vaccinating at 3 weeks. Vaccines against pleuropneumonia aren’t recommended before 6 weeks because earlier doses simply don’t take hold well. For PRRS, piglets with high maternal antibodies at the time of vaccination show a suppressed immune response for at least 4 weeks afterward.
How to Give Vaccines Properly
Most swine vaccines are given as intramuscular injections in the neck, just behind the ear and in front of the shoulder. Never inject into the ham or loin, as this can cause tissue damage in meat cuts and lead to carcass trim losses.
Needle size should match the pig’s age and size:
- Baby pigs: 18- to 20-gauge needle, 1/2 inch long.
- Nursery pigs: 18- to 20-gauge, 3/4 inch for intramuscular or 5/8 inch for subcutaneous.
- Finishers: 16-gauge, 1 inch for intramuscular or 3/4 inch for subcutaneous.
- Breeding stock: 16- or 14-gauge, 1 1/2 inches.
For subcutaneous injections in small pigs, the flank works well. For larger pigs, inject into the loose skin behind the ear. The goal is to place the vaccine just under the skin without penetrating into muscle.
Building a Vaccination Schedule
A practical schedule for a farrow-to-finish operation looks roughly like this: piglets receive their first PCV2 and mycoplasma vaccines around 3 weeks of age, with boosters 2 to 3 weeks later. Erysipelas vaccination starts at 8 to 12 weeks. Gilts entering the breeding herd get parvovirus at 5 to 6 months, along with leptospirosis and erysipelas boosters before their first breeding. Sows are revaccinated for leptospirosis and erysipelas before each breeding cycle or every 6 months.
Every farm’s disease pressure is different. Operations in areas with high PRRS prevalence or those dealing with influenza outbreaks may need additional vaccines beyond this core program. A herd-specific plan developed with a veterinarian, ideally based on diagnostic testing and mortality records, will always outperform a one-size-fits-all approach.