Respiratory Coinfections and the Impact on Herd Productivity
Respiratory coinfections are a combination of significant infectious agents, environmental stressors, and challenges affecting the health of the pig, resulting in reduced performance, increased medication costs, and increased mortality.1 Such infectious agents include influenza A virus in swine (IAV-S), porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome (PRRS), and Mycoplasma hyopneumoniae (Mhp).
Affecting approximately 70% of growing pigs, IAV-S is a viral infection of the cells lining the bronchi and bronchioles resulting in the breakdown of the mucosal barrier.2,3 In breeding herds, IAV-S is more frequently detected in replacement gilts and suckling pigs of breeding herds compared with sows. On farrow‐to‐finish farms, the virus may persist in the population due to the continuous in introduction of susceptible young pigs.4
The most economically significant disease affecting US swine production, affecting 92% of pigs, PRRS is a viral disease that impairs the immune system and causes a decrease in reproductive performance in breeding animals and respiratory disease in pigs of any age.5
PCV is a virus that induces a multisystemic disease and impairs the immune system, leaving pigs susceptible to other diseases, including pneumonia.5 Today, 95% of herds continue to be positive for PCV2 and 100% of infected pigs are susceptible to developing porcine circovirus associated disease (PCVAD), usually between 2 and 4 months of age.6,7
Mhp is a bacterium that attaches to the epithelial cells of the upper respiratory tract causing cilial damage.8 With an estimated prevalence of 70% in the United States (Maria Pieters, personal communication 2020), Mhp primarily affects grower-finisher pigs in age-segregated production systems but younger nursery‐age pigs in continuous‐flow systems are also at risk.8 In fact, the Swine Disease Reporting System recently reported 15% to 20% of respiratory cases submitted to the participating veterinary diagnostic laboratories show positive results for Mhp by polymerase chain reaction.9
When a respiratory infection occurs, it potentially affects the entire pig population, serving to “fuel the fire” of coinfection. Damage to the respiratory mucosa caused by one infection creates an opportunity for coinfection by other organisms.3 Once the immune system is compromised, pigs are more susceptible to coinfection from other circulating respiratory pathogens, such as Glaesserella parasuis and Streptococcus suis, creating a “knock-on” effect of disease.3
The true cost of respiratory coinfections
As a result of respiratory coinfection, producers may observe decreased nursery performance and greater total mortality and significantly lower average daily gain at closeout, all of which contribute to higher losses in net profitability. Recent data even suggest respiratory coinfections can contribute to economic losses up to $21 per pig.10
Manage respiratory health with a whole-herd approach
The goal of a whole-herd approach is to minimize exposure and maximize immunity of susceptible pigs.11 This strategy has been used recently to successfully control PRRS and IAV-S infections within populations and is equally appropriate for all respiratory infections, potentially leading to the reduction of disease endemicity, and the impact of coinfections on the herd.12
To learn more about the impact of respiratory coinfections on the herd and how solutions
from Boehringer Ingelheim can help, contact your representative.
To learn more about the impact of respiratory coinfections on the herd and how solutions from Boehringer Ingelheim can help, contact your representative.