First, when we do a diagnostic investigation for porcine circovirus 2 (PCV2) and people are suggesting a PCV2 infection, even in vaccinated populations, we need to take samples to be sure that PCV2 is involved in that clinical case," Dr. Fano said. "We use PCR and tissue homogenate from the diseased animal, and we take tissue and run a histopath."

The objective is to gain information about microscopic lesions and the presence and identification of the pathogen. To do this, PCR or, in some cases, immunohistochemistry is used.

"When we identify that PCV2 is an important part of the clinical case, that triggers the next step which is a root cause analysis - we need to see why we are having this problem. In most of the cases, we go down what we call the porcine circovirus associated disease (PCVAD), Decision Tree," he said.

In most of the cases, the decision tree leads to the sow herd.

"We need to identify if there is a problem - what we call Sow Herd Instability," he said. "In that case, again, we use PCR in order to assess the transplacental transmission rate."

Because PCV2 is a very complex, multifactorial disease, diagnostic tools help provide valuable information for an investigation.

"At the end of the day, we are trying to minimize infection pressure in the whole system in order to have a better performance of the vaccine in the pig herd," he said. "We use diagnostics in order to identify the infection status of the pathogen in the system. Also, we use diagnostics to see if the vaccination program is working well, and we are doing a good job preventing PCV2 disease and PCVAD."

Fano recommends conducting diagnostic investigations every month or every other month in dead or euthanized animals. Routine herd health monitoring is a dynamic ongoing process that benefits the entire operation, he said.

For more information about swine diagnostics, click here or connect to the Thermo Fisher Scientific Swine Resource Center.