One of the most common questions Daniel Brown, DVM, hears from swine clients is what vaccinations are needed and when should they be given. “That topic seems to come up on almost every farm visit,” he said. Brown works from the Four Star Veterinary Service clinic in Holland, Michigan.
Ultimately, the goal of any vaccination strategy is to help lessen the risk of a disease challenge that will adversely affect pig production.
“The hope with any vaccine is, by exposing the pigs to a bug or even a piece of a bug, that their bodies learn how to deal with the pathogen if they come across it in the barn,” Brown explained. “Sometimes, we are trying to protect the pigs from a bug we know they will see, and other times, we are trying to give them protection from a bug they might see.”
Several factors can influence a vaccine strategy. The first and most important factor to consider is the objective of the client.
“In the Four Star group, we work with a range of clients from large commercial producers focused on producing pounds of quality pork to families focused on raising a handful of good-looking pigs for the show ring,” Brown said.
The different objectives of each client must be kept in mind when developing and implementing vaccine strategies.
Health history, pig density, logistics
It’s also important to consider other health challenges the farm has battled. Many producers build their vaccine protocols with the help of veterinarians or in response to a previous disease. But Brown maintains there are still producers who haven’t had a chance to discuss the different options and may vaccinate based on what they heard through the grapevine.
Pig density is another factor in devising a vaccine strategy. “Producers in Iowa will likely have a much different view on how likely they are to be exposed to a new bug such as influenza than a producer in the upper peninsula of Michigan,” Brown explained.
And then there is the issue of logistics on the farm. “Vaccine protocols that are developed with ‘how the pigs are going to be vaccinated’ are much more likely to be followed than those developed without those ideas,” he said. “It is imperative that everyone understands and agrees on the strategy to be implemented or else it is more likely to fail.
“It would be wonderful if we could wean a group of pigs, get them on feed, vaccinate them and follow up with a booster,” he said. “But if we run into a wall of reality, you have to be able to change the plan. As veterinarians, we need to have these conversations with producers about what is realistic for them.”
One of the most common pathogens requiring a vaccination is porcine circovirus type 2 (PCV2). Brown recommends having a vaccine strategy for PCV2 on virtually all farms “simply because it is so widespread and can have a wide range of effects from increased mortality in nurseries to reproductive failure in sows.”
While many vaccines for PCV2 can be given as a single dose, giving two doses after weaning a few weeks apart has been shown to improve a pig’s response to them.
Administering these two shots may pose a real challenge for some hog farms, especially if weaned pigs are housed in large groups. Brown asks himself, “After I’ve convinced a producer to walk through a pen of 500 pigs to vaccinate all of them, what’s the chance of getting him to do it again for the booster? In those situations, the booster will be harder to sell.”
Another set of bugs that are frequently vaccinated for in combination are parvovirus, erysipelas and several types of Leptospira. Often times, this will be seen in breeding animals to help prevent reproductive failures.
Other bugs that are vaccinated against will often be farm specific and may vary on what coverage can be achieved with a single product.
For instance, PCV2 vaccines are often combined to include coverage against Mycoplasma hyopneumoniae. This is a very common protocol for both show-pig and commercial producers but requires veterinarians to be very aware of the farm’s objectives. While many commercial producers vaccinate against Mycoplasma, there are some farms that aim to stay completely free of the disease. “Unfortunately, the use of the vaccine can sometimes complicate our efforts to confirm that a pig has not been exposed to the actual bug,” Brown explained.
Whether you need to add other vaccines such as erysipelas or influenza into your breeding and/or market-hog protocols will depend on factors such as pig density in your area and how previous groups performed.
“I’ve seen mild flare-ups of erysipelas in finishing stages and have had to add in a dose after weaning,” Brown said. “It’s definitely something that’s still out there and can be seen in groups that come from sows vaccinated against it.”
Many vaccination programs will include protection against influenza. “Flu travels around very easily, and we can often see a new strain develop like we see in humans,” Brown said. “When we vaccinate for the flu, it helps to reduce signs and symptoms. I will often lean heavily on using a flu vaccine in pig-dense areas.”
Brown’s vaccination strategy for most show pigs tends to be more proactive than in commercial settings where biosecurity is typically stronger.
“In the show world, it’s a larger challenge to have a robust biosecurity plan, as well as a successful breeding and show operation,” he said. “Quite often, clients will use gilts and boars that were successful on a show circuit to replace their breeding stock.
“At a show, they may go to a barn with 750 pigs that came from 500 different farms,” he added. “In these cases, I start talking about a robust vaccine program That includes all of the vaccines mentioned above (PCV2, Mycoplasma, influenza, erysipelas, parvovirus and Leptospira) plus more, depending on those other factors such as previous herd health.”
Brown’s goal when setting up a vaccine protocol for any client is to decide what diseases the pigs need to be protected against and what’s the best way to do it. Equally important is following up with the client to see how the strategy worked.
“It is critically important to follow up on how the strategy performed,” he said. “If you don’t talk to your clients about the outcomes driven by their protocols, then you won’t know whether or not you need to change your approach.”
“Vaccinology” is a huge topic of discussion and for good reason. Vaccines allow for sows to continue producing litters of healthy pigs, for market hogs to continue producing quality pork, and for youth to show their healthy animals in competitions.
It is also important for producers to have discussions with their veterinarians about vaccine use, according to Brown. The variety of products and strategies can at times be staggering when considering items such as autogenous vaccines that get into farm-specific bugs, killed versus live vaccines and oral versus injectables.
“As veterinarians, providing vaccine protocols is just one piece of the puzzle,” he said. “We must also strive to make sure clients understand the importance of following those protocols and why we developed them.
“We need to have a conversation on why each vaccine is important and why the timing is important. If you take the time to explain the ‘why’ to clients, then we will often be more successful in the implementation of our strategies,” he concluded.