Disease is an interaction between the pig, a disease agent and the environment. That “disease triad” is the key to determining what’s happening in any given operation, says C. Scanlon Daniels, owner of Circle H Veterinary Service, LLC, in Dalhart, Texas.
Daniels spoke at a seminar during the American Association of Swine Veterinarians annual meeting last weekend. His practice is primarily focused on swine, dairy and beef, and laboratory services are a significant component of the business.
Daniels explains the process as follows: Pigs are susceptible to disease agents and if exposed, can become infectious. If pigs are continually exposed, they can become resistant.
“The key is figuring out when the non-infectious cause is primary and infectious agents are opportunistic, or secondary,” says Scanlon. “There are several non-infectious causes of disease that should be considered when infectious disease interventions do not have the desired effect.”
Biosecurity measures can minimize contact with suspect pigs from infectious disease. But how do you know if non-infectious disease is your problem? Scanlon gave these examples of potential non-infectious causes of disease:
- Water with high total dissolved solids – “High total dissolved solids create an osmotic draw that doesn’t allow normal water absorption to occur,” says Scanlon. “Since many pigs experience a period of mild post-weaning diarrhea as they transition from sow milk to solid feed, diarrhea caused by poor water quality can go undiagnosed. Change your water supply, if possible, and if you can’t, transition the building to house older pigs.”
- Insufficient water availability – In recently weaned pigs, the main clinical sign is failure to thrive. It can be caused by changes in water pressure, overstocking or poor water height adjustment, explains Scanlon.
- Feed palatability – Producers should provide an alternative diet from a mill or farm that is not observing decreases in feed intake, suggests Scanlon.
- Feed availability – “Feeders with small feed reservoirs have long been known to cause poor feed conversion,” says Scanlon. “In addition, the periodic lack of feed availability with these types of feeders can result in high numbers of deaths due to intestinal torsion.
- Mulberry Heart – Scanlon notes the gross signs of Mulberry Heart are frequently mistaken for Haemophilus parasuis and/or Streptococcus suis.
- Ventilation – Environmental temperature can have a significant impact on pigs, says Scanlon. Pigs that are cold expend more energy to keep warm. Alternatively, pigs that are cold don’t want to leave their resting spot so they consume less feed. It’s a double-edged sword.
Scanlon reiterates the importance of considering non-infectious causes of disease if traditional approaches and interventions aren’t working. “Look for other factors that could be causing the disease.” In addition, he suggests producers frequently evaluate their operations to make sure “bad” situations don’t start being considered “normal.”
“It’s important to look for other factors that may be at play,” he says.