Sowman H R, Cave N J, Dunowska M
a School of Veterinary Science , Massey University , Palmerston North , New Zealand.
b Current address: Ministry for Primary Industries , Wallaceville , New Zealand.
N Z Vet J. 2018 Sep;66(5):236-242. doi: 10.1080/00480169.2018.1490214. Epub 2018 Jul 18.
AIMS To determine which of the common canine respiratory pathogens circulate among selected populations of healthy and diseased dogs in New Zealand. METHODS Coagulated blood samples for serology and oropharyngeal swabs for virology were collected from healthy dogs (n=47) and from dogs with acute respiratory disease (n=49). For diseased dogs a convalescent blood sample was also collected 3-4 weeks later. Oropharyngeal swabs were subjected to virus isolation and tested for canine parainfluenza virus (CPIV), canine adenovirus (CAdV) 2, canine herpesvirus (CHV), canine respiratory coronavirus (CRCoV), canine influenza virus (CIV), canine distemper virus (CDV), Bordetella bronchiseptica, Streptococcus equi subsp. zooepidemicus, and Mycoplasma cynos nucleic acids by quantitative PCR (qPCR). Sera were tested for CRCoV antibody using competitive ELISA and results expressed as percent of inhibition (POI). RESULTS The mean age of diseased dogs (2.7, min <0.5, max 8.5 years) was lower than the mean age of healthy dogs (5.3, min <0.5, max 17 years) (p<0.001). In total, 20/94 (21%) dogs were positive for at least one agent by qPCR. Diseased dogs were most commonly positive for M. cynos (8/47, 17%), followed by CPIV (3/47, 6%) and B. bronchiseptica (3/47, 6%), while healthy dogs were most commonly positive for CAdV-2 (6/47, 13%), followed by M. cynos (2/47, 4%). All samples were negative for CIV, CRCoV, CDV and S. equi subsp. zooepidemicus. Viruses were not isolated from any of the samples tested. In total, 47/93 (50%) dogs were seropositive for CRCoV on at least one sampling occasion. Samples from diseased dogs were more frequently seropositive for CRCoV, with higher POI, than samples from healthy dogs. CONCLUSIONS AND CLINICAL RELEVANCE We showed that CAdV-2, CPIV, CHV, CRCoV, B. bronchiseptica and M. cynos circulated among sampled dogs. The convenience sampling methodology, with a poor match between the populations of diseased and healthy dogs in terms of age, breed and use, together with the relatively small sample size precluded inference of any causal relationships between infection with a given pathogen and development of disease. None-the-less, our data suggest that further investigation into epidemiology and disease association of CRCoV and M. cynos is warranted. In addition, circulation of novel respiratory pathogens among dogs in New Zealand should be considered in future studies, as 70/94 (74%) diseased dogs were negative for all the pathogens tested.
目的 确定新西兰选定的健康犬和患病犬群体中流行的常见犬类呼吸道病原体。方法 从健康犬（n = 47）和患有急性呼吸道疾病的犬（n = 49）采集用于血清学检测的凝血血样和用于病毒学检测的口咽拭子。对于患病犬，在3 - 4周后还采集了恢复期血样。对口咽拭子进行病毒分离，并通过定量PCR（qPCR）检测犬副流感病毒（CPIV）、犬腺病毒（CAdV）2型、犬疱疹病毒（CHV）、犬呼吸道冠状病毒（CRCoV）、犬流感病毒（CIV）、犬瘟热病毒（CDV）、支气管败血波氏杆菌、马链球菌兽疫亚种和犬支原体核酸。使用竞争ELISA检测血清中的CRCoV抗体，结果以抑制百分比（POI）表示。结果 患病犬的平均年龄（2.7岁，最小<0.5岁，最大8.5岁）低于健康犬的平均年龄（5.3岁，最小<0.5岁，最大17岁）（p<0.001）。总共，94只犬中有20只（21%）通过qPCR检测至少对一种病原体呈阳性。患病犬最常见的阳性病原体是犬支原体（8/47，17%），其次是CPIV（3/47，6%）和支气管败血波氏杆菌（3/47，6%），而健康犬最常见的阳性病原体是CAdV - 2（6/47，13%），其次是犬支原体（2/47，4%）。所有样本对CIV、CRCoV、CDV和马链球菌兽疫亚种均为阴性。在所检测的任何样本中均未分离到病毒。总共，93只犬中有47只（50%）在至少一次采样时CRCoV血清学检测呈阳性。患病犬的样本比健康犬的样本更频繁地CRCoV血清学检测呈阳性，且POI更高。结论与临床意义 我们发现CAdV - 2、CPIV、CHV、CRCoV、支气管败血波氏杆菌和犬支原体在采样犬中流行。便利抽样方法中，患病犬和健康犬群体在年龄、品种和用途方面匹配不佳，且样本量相对较小，排除了推断特定病原体感染与疾病发生之间任何因果关系的可能性。尽管如此，我们的数据表明有必要进一步调查CRCoV和犬支原体的流行病学及疾病关联。此外，未来研究应考虑新西兰犬中新型呼吸道病原体的流行情况，因为94只患病犬中有70只（74%）对所有检测病原体均为阴性。
