Respiratory diseases constitute a major health problem in small ruminant herds around the world, and parainfluenza virus type 3 (PIV-3) has been shown to play a vital role in their etiology. This cross-sectional study describes the serological status of the non-vaccinated dairy goat popu- lation in Poland with respect to PIV-3 infection and investigates the relationship between the presence of antibodies to PIV-3 and some basic herd-level and animal-level factors, including small ruminant lentivirus (SRLV) infection. Serum samples from 1188 goats from 48 herds were tested for the concentration of antibodies to PIV-3 using a quantitative immunoenzymatic assay. Specific antibodies were detected in all tested goats from all herds. The concentration of PIV-3 antibodies varied from 8.4 to >240 ng/ml (median 95.9 ng/ml) and was significantly higher in goats from larger herds and from these herds in which cough was often observed by farmers. Moreover, it was noted that female goats had higher antibody concentrations than males. On the other hand, the concentration of PIV-3 antibodies did not prove to be significantly linked to the presence of SRLV infection. This study shows that PIV-3 infection in the Polish goat population is widespread and appears to contribute to the occurrence of respiratory diseases in goat herds.

Bovine parvovirus (BPV), bovine coronavirus (BCoV) and bovine parainfluenza virus (BPIV) are common etiologies causing gastrointestinal and respiratory diseases in dairy herds. However, there are few reports on the synchronous detection of BPV, BCoV and BPIV. The present article aimed to develop a quick and accurate RT-PCR assay to synchronously detect BPV, BCoV and BPIV based on their specific probes. One pair universal primers, one pair specific primers and one specific probe was designed and synthesized. After the concentrations of primer and probe and annealing temperature were strictly optimized, the specificity, sensitivity and repeatability of the established triplex probe qRT-PCR were evaluated, respectively. The results showed the recombinant plasmids of pMD18-T-BPV, pMD18-T-BCoV and pMD18-T-BPIV were 554bp, 699bp and 704bp, respectively. The optimal annealing temperature was set at 45.0°C for triplex qRT-PCR. The triplex probe qRT-PCR can only synchronously detect BPV, BCoV and BPIV. Detection sensitivities were 2.0×102, 2.0×102 and 2.0×101 copies/μL for BPV, BCoV and BPIV, being 1000-fold greater than that in the conventional PCR. Detection of clinical samples demon- strated that triplex probe qRT-PCR had a higher sensitivity and specificity. The intra-assay and inter-assay coefficient of variation were lower than 2.0%. Clinical specimens verified that the triplex qRT-PCR had a higher sensitivity and specificity than universal PCR. In conclusion, this triplex probe qRT-PCR could detect only BPV, BCoV and BPIV. Minimum detection limits were 2.0×102 copies/μL for BPV and BCoV, and 2.0×101 copies/μL for BPIV. The sensitivity of this triplex probe qRT-PCR was 1000-fold greater than that in the conventional PCR. The newly qRT-PCR could be used to monitor or differentially diagnose virus infection.