Transmissible Viral Proventriculitis in Broiler Chickens from Bosnia and Herzegovina

The etiology of transmissible viral proventriculitis (TVP) of broiler chickens has been discussed since its initial recognition 40 years ago. Regardless of its low direct impact on mortality rate, it leads to high economic losses in the broiler industry through reduction of food conversion, weakening of birds, and their increased susceptibility to pathogens. The aim of the present study was to examine the potential presence of TVP on the broiler chicken farms in Bosnia and Herzegovina, to characterize microscopic lesions, and to investigate the viruses implicated in etiology of TVP by PCR-based methods. In total, 143 diseased broiler chickens from 16 farms in Bosnia and Herzegovina were euthanized and subjected to necropsy and subsequent histopathology of proventriculi. A representative number of proventriculi samples (n = 50) that exhibited histopathologic changes were processed for molecular detection of chicken proventricular necrosis virus (CPNV), girovirus (GyV3), chicken anemia virus (CAV), and infectious bursal disease virus (IBDV) by PCR-based methods. In addition, samples of bursa of Fabricius (n = 39) and spleen (n = 50) were tested for IBDV. Histopathology revealed changes consistent with TVP in 39.8% (57/143) and LP (lymphocytic proventriculitis) in 2.1% (3/143) of samples. All 50 proventricular samples showed positivity to CPNV with Ct values ranging between 18 and 26. GyV3 was detected in eight samples (16%), with Ct values ranging from 11.1 to 27.5. The presence of CAV was more prominent (38%), with 19 positive broiler chickens (Ct ranging from 9.6 to 35.6). Pooled samples of spleen, bursa, and proventriculi from three farms were positive for IBDV. The obtained results represent the first documented data on TVP and the first record of CPNV and GyV3 presence in broiler farms from Bosnia and Herzegovina.