The Role of Pathology in the Diagnosis of Swine Respiratory Disease

Abstract

The definition “porcine respiratory disease complex” (PRDC) is used to indicate the current approach for presenting respiratory pathology in modern pig farming. PRDC includes pneumonias with variable pictures, mixed with both aerogenous and hematogenous forms with variable etiology, often multimicrobial, and influenced by environmental and management factors. The notion that many etiological agents of swine respiratory pathology are ubiquitous in the airways is commonly understood; however, their isolation or identification is not always associable with the current pathology. In this complex context, lung lesions registered at slaughterhouse or during necropsy, and supplemented by histological investigations, must be considered as powerful tools for assigning a prominent role to etiologic agents. In recent years, the goal of colocalizing causative agents with the lesions they produce has been frequently applied, and valid examples in routine diagnostics are those that indicate pulmonary involvement during porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) infections.

A New Sampling Approach for the Detection of Swine Influenza a Virus on European Sow Farms

“…The results of our study suggest that the approach of focusing on clinically diseased animals must be scrutinized critically as, despite the highest number of animals showing clinical signs being in the nursery, the weaners were significantly more often swIAV-positive, compared to the nursery pigs. The high percentage of nursery pigs with clinical signs may be explained by the fact that swIAV, as part of the PRDC complex [ 31 ], predisposes the animals to co-infections. However, as coinfections were not investigated within the scope of our study, the role of coinfections in the evolution of clinical signs in the study farms can only be speculated.…”

Extracellular Vesicles in Veterinary Medicine

“…Considering pork industries, one of the main threats is the Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) caused by an enveloped RNA virus of the Arterivirus genus, first described in the US in 1987–1988 and referred to as mystery pig disease [ 140 ]. Since then, it has become one of the most important swine diseases of the last half-century causing reproductive impairment and pneumonia with no single successful strategy for control [ 141 , 142 ]. As for other diseases, vaccine development has therefore received wide attention.…”

Novel Multiplex PCR Assay and Its Application in Detecting Prevalence and Antibiotic Susceptibility of Porcine Respiratory Bacterial Pathogens in Guangxi, China

“…Viral pathogens are frequently considered the main factors which cause PRDC, but numerous bacteria also play important roles in the development of PRDC ( 9 – 14 ). Porcine respiratory bacterial pathogen (PRBP) infection can decrease the resistance of swine, aggravating the progression of disease or even causing sudden death ( 10 , 15 , 16 ). In addition, S. suis and P. multocida have the potential to infect humans and threaten human health.…”

“…Due to the droplet transmission of PRBPs and the similar clinical signs of different pathogen infections, most pig farms struggle to identify and control PRBPs ( 15 , 18 , 20 , 22 ). In pig farms where PRBPs are epidemic, broad-spectrum antibiotics are frequently employed as the only treatment; however, this untargeted blind medication may increase costs and cause a vicious circle of antibiotics and resistant pathogens, dramatically damaging the economic benefits of pig farms ( 5 , 18 , 22 ).…”