犬流感H3N2型爆发（CIV H3N2）

小柿子

最近我们医院住院部所有狗都开始咳嗽，包括自己的狗。我自己的一只金毛，2岁多，免疫完全，咳嗽，发烧（40.6度），无食欲，精神不好，白细胞低。其他狗症状相似。怀疑病毒感染，于是采了眼鼻口分泌物送北京联宠检测中心进行PCR检测，呼吸道病原全部筛查一遍，结果显示是犬流感病毒H3N2亚型。于是便到网上收集了关于犬流感病毒的信息，看到一篇国外文章，写的很全，特翻译后贴在下面。希望其他医院如有咳嗽爆发，也送检下，确定下是否是这种病毒，可以的话，希望我们也能引进相应疫苗。

最新情况，我们医院进了CIV测试板，已经测出来两例阳性，并且门诊咳嗽的非常多，犬瘟阴性，怀疑犬流感。联宠又帮我们做了10例PCR，全部都是犬流感H3N2阳性。（7月25日）

小柿子

原文网址：https://www.avma.org/KB/Resources/Reference/Pages/Canine-Influenza-Backgrounder.aspx

Canine Influenza 犬流感

Causative agent 病原

Canine influenza (CI), or dog flu, is a highly contagious viral infection affecting dogs and also cats. Influenza viruses belong to the family Othomyxoviridae. Canine Influenza is a Type A influenza virus and is further identified based on the composition of two specific proteins in the lipid outer layer of the capsid: hemagglutinin (HA) and neuraminidase (NA). At present, two strains of canine influenza virus have been identified in the United States: H3N8 and H3N2.
犬流感（CI）是一种高传染性的病毒感染性疾病，可以感染犬和猫。流感病毒属于正粘病毒科。犬流感是甲型流感病毒，可由病毒衣壳表面2中脂蛋白进行细分：hemagglutinin(HA)和neuraminidase(NA)。目前，在美国已鉴别出犬流感病毒的2种毒株：H3N8 和 H3N2。
Influenza viruses are able to quickly change and give rise to new strains that can infect different species. Both strains of canine influenza identified in the U.S. can be traced to influenza strains known to infect species other than dogs. At some point, these viruses acquired the ability to infect dogs and be transmitted from dog to dog.
流感病毒可以快速变异，并可能形成能感染其他物种的新型毒株。在美国发现的这两种毒株都可以追溯到感染其他物种（除犬）的毒株。在某一刻，这些病毒获得了感染犬的能力并在犬中传播。

Canine H3N8 influenza was first identified in Florida in 2004 in racing greyhounds. It is thought this strain developed from an equine H3N8 influenza strain that jumped from horses to dogs. Since being detected in 2004, canine H3N8 influenza has been identified in dogs in most U.S. states and the District of Columbia.
犬H3N8型流感首先于2004年在美国弗罗里达周的灰狗身上发现。这种亚型被认为是来源于马H3N8流感，从马传染给了犬。自从2004年首次发现后，犬H3N8型流感已在美国大部分州和哥伦比亚特区发现。

Canine H3N2 influenza was first identified in the United States in March 2015 following an outbreak of respiratory illness in dogs in the Chicago area. Prior to this, reports of canine H3N2 influenza virus were restricted to South Korea, China and Thailand. It was initially identified in dogs in Asia in 2006-2007 and likely arose through the direct transfer of an avian influenza virus – possibly from among viruses circulating in live bird markets – to dogs.
在美国，犬H3N2性流感于2015年3月在芝加哥地区犬只爆发呼吸道疾病后发现。在次之前，只在朝鲜、中国和泰国有关于H3N2流感的报道。该病首先于2006-2007年在亚洲的犬只身上发现，很可能是由禽流感病毒（可能是家禽市场上活家禽携带的病毒）直接传染给犬。

Following the initial diagnosis in Chicago, additional cases of canine H3N2 influenza were reported in a number of states. In early 2016, a group of shelter cats in Indiana were diagnosed with H3N2 canine influenza. It is believed the virus was transmitted to them from infected dogs.
在芝加哥首次发现后，相继在很多其他州也发现了犬H3N2流感。2016年伊始，在印第安纳州一家救助所的猫咪中爆发了犬H3N2流感。据报道，病毒是由感染的犬只传染给猫的。

In May 2017, canine H3N2 influenza was diagnosed in dogs in Florida, Georgia, North Carolina, South Carolina, Texas, Kentucky, Tennessee, Missouri, Louisiana, and Illinois. This was the same strain of H3N2 involved in the 2015 outbreak in Chicago.  
2017年5月，犬H3N2流感在以下州的犬只中发现：Florida, Georgia, North Carolina, South Carolina, Texas, Kentucky, Tennessee, Missouri, Louisiana, and Illinois。这些病毒亚型和在2015年爆发在芝加哥的H3N2型一样。

There is no evidence that either strain of canine influenza (H3N8, H3N2) can infect humans.
现在还没有证据表明犬流感的两个亚型（H3N8和H3N2）可以感染人类。

Transmission 传播
Canine influenza is transmitted through droplets or aerosols containing respiratory secretions from coughing, barking and sneezing. Dogs in close contact with infected dogs in places such as kennels, groomers, day care facilities and shelters are at increased risk of infection. CI can be spread indirectly through objects (e.g., kennels, food and water bowls, collars and leashes) or people that have been in contact with infected dogs. It is important to clean and disinfect objects that have been in contact with an infected dog to avoid exposing other dogs to the virus. Likewise, people who have been in contact with an infected dog should wash their hands and clean their clothing to avoid spreading the virus.  
犬流感是通过咳嗽、吠叫和喷嚏发射出的含有呼吸道分泌物的小液滴或雾滴来传播的。在犬舍、美容店、白天护理场所和救助所，和感染犬接触的健康犬只有非常高的感染风险。CI可以通过物品间接传播（例如笼子、食盆和水盆、脖圈和牵引绳）或通过接触过感染犬只的人来传播。感染犬只接触过的物品都必须清洁消毒，以免将病毒传播给其他犬只。同样的，当人接触过感染犬只后，也应该清洗双手和衣服以避免传播病毒。

The virus can remain viable (alive and able to infect) on surfaces for up to 48 hours, on clothing for 24 hours, and on hands for 12 hours. It is important to implement biosecurity protocols and disinfection procedures to reduce the risk of disease transmission.
在物品表面病毒可以保持活性（活性和感染力）48小时，在衣服表面保持24小时，在手上保持12小时。实施生物安全措施和严格的消毒程序非常重要，可以降低疾病的传播。

H3N8 has an incubation period of 1 to 5 days, with clinical signs in most cases appearing 2 to 3 days after exposure. Dogs infected with H3N2 may start showing respiratory signs between 2 and 8 days after infection. Dogs are most contagious during the incubation period and shed the virus even though they are not showing clinical signs of illness. Some dogs may show no signs of illness, but have a subclinical infection and shed the virus.
H3N8潜伏期1-5天，临床症状通常在暴露后的2-3天出现。犬只通常在感染H3N2型2-8天开始出现呼吸道症状。在潜伏期时，即使还没有表现出临床症状，犬就可以排毒，可传染给其他犬只。一些感染犬只可能不表现临床症状，呈亚临床感染，但是也会排毒。

Pathology and Clinical Signs 病理学和临床症状
Canine influenza virus infects and replicates inside cells in the respiratory tract from the nasal lining to the terminal airways. The inflammatory response to the infection results in rhinitis, tracheitis, bronchitis and bronchiolitis. The pathologic process results in death of the epithelial cells lining the respiratory tract, exposing the underlying basement membrane. This predisposes the respiratory tract to secondary bacterial infections that contribute to nasal discharge and coughing.
犬流感病毒在呼吸道细胞（从鼻粘膜到最终的肺泡）里复制进行感染。病毒感染后的炎症反应可以导致鼻炎、气管炎、支气管炎和细支气管炎。病毒感染导致呼吸道上皮细胞坏死，暴露下面的基底膜。这使得呼吸道容易继发细菌感染，导致流鼻涕和咳嗽。

Virtually all dogs exposed to CIV become infected, with approximately 80% developing clinical signs of disease. The approximately 20% of infected dogs that do not exhibit clinical signs of disease can still shed the virus and spread the infection.
实际上所有暴露于CIV的犬只都会被感染，大约80%表现临床症状，20%不表现临床症状，但是仍然可以排毒传播病毒。

Like other mammalian influenza viruses, canine influenza virus causes an acute respiratory infection in dogs. There is no “season” for canine influenza, and infections can occur any time of the year. Canine influenza virus infection often resembles canine infectious tracheobronchitis ("kennel cough"), which is caused by one or more bacterial or viral infections, including Bordetella bronchiseptica and parainfluenza virus.
像其他哺乳动物流感病毒一样，犬流感病毒会引起犬急性呼吸道感染。犬流感爆发没有偏向于哪一季节，全年都可以爆发。犬流感病毒感染很像犬传染性气管支气管炎（犬窝咳），犬窝咳由一种或多种细菌或病毒感染引起，包括支气管败血性博德氏杆菌和副流感病毒。

The majority of infected dogs exhibit the mild form of canine influenza. The most common clinical sign is a cough that persists for 10 to 21 days despite treatment with antibiotics and cough suppressants. Affected dogs may have a soft, moist cough or a dry cough similar to that induced by kennel cough. Nasal and/or ocular discharge, sneezing, lethargy and anorexia may also be observed. Many dogs develop a purulent nasal discharge and fever (104-105oF). The nasal discharge is usually caused by secondary bacterial infections, including Pasteurella multocida and mycoplasma species.
大部分感染犬只会表现轻微的犬流感症状。最常见的临床症状是咳嗽，即使使用抗生素和止咳药也会持续10-21天。感染犬可能湿咳或干咳，与犬窝咳引起的咳嗽相似。也可能会出现鼻涕、眼分泌物、打喷嚏、没精神和厌食症状。许多犬会有脓性鼻涕和发烧（40-40.5 ℃）。流鼻涕通常是由继发的细菌感染引起，包括多杀性巴氏杆菌和支原体。

Some dogs are more severely affected and exhibit clinical signs of pneumonia, such as a high-grade fever (104°F to 106°F) and increased respiratory rate and effort. Thoracic radiography (chest x-rays) may reveal consolidation of lung lobes. Although most dogs recover without incident, deaths due to H3N2 have been reported.
一些犬感染比较重要，会表现出肺炎的临床症状，例如高烧（40-41℃）和呼吸频率加大加快。胸片表现肺水肿。虽然大多数的犬只会没有意外的康复，但是也有H3N2致死的报道。

Cats infected with H3N2 display signs of upper respiratory disease, including nasal discharge, congestion, malaise, lip smacking and excessive salivation.
感染H3N2的猫咪会表现上呼吸道症状，包括鼻涕、充血、乏力、舔舐和过多口水。

Diagnosis 诊断
Canine influenza cannot be diagnosed solely by clinical signs (coughing, sneezing and nasal discharge) because these clinical signs also present with other canine respiratory illnesses. Tests are available to diagnose and identify stain of canine influenza virus. Tests include: virus isolation, immunoassays to detect virus antigen, PCR to detect virus nucleic acid, and serology for antibodies specific to the virus. PCR may be the most reliable test for the diagnosis of CI. Contact your diagnostic lab for recommendations regarding tests and sample collection.
犬流感单靠临床症状（咳嗽，喷嚏和鼻涕）无法确诊，因为犬其他呼吸道疾病也会引起这些临床症状。有可以诊断和检测犬流感病毒毒株的检测，包括病毒分离，病毒抗原免疫分析，病毒核酸PCR检测，病毒抗体血清学检测。PCR检测可能是CI最靠谱的检测方法。联系你们的实验室中心，听取他们的检测建议和采样方法。

Treatment 治疗
Veterinary expertise is required to determine treatment options and the best course of treatment. Treatment for CI, as for most viral diseases, is largely supportive. Good husbandry and nutrition may help dogs mount an effective immune response. Most dogs recover from canine influenza within 2-3 weeks. Secondary bacterial infections, pneumonia, dehydration, or other health factors (e.g., pregnancy, pre-existing pulmonary disease, immunosuppression, tracheal collapse, etc.) may necessitate additional diagnostics and treatments including, but not limited to:
Antimicrobials for known or suspected secondary bacterial infections.
Nonstero
idal anti-inflammatory medications as needed to reduce fever and inflammation.
Fluids to help correct dehydration or maintain hydration.
兽医需要选择治疗手段和最好的治疗方法。针对犬流感的治疗，和多数的病毒疾病一样，是辅助性的。良好的护理和营养管理可以帮助患犬更有效的产生免疫反应。多数的感染犬流感的犬只在2-3周内会康复。继发的细菌感染、肺炎、脱水或其他健康因素（例如怀孕、原先的肺部疾病，免疫抑制、气管塌陷等）可能需要另外诊断，主要治疗包括但不限于以下方面：
针对继发细菌感染进行抗微生物治疗
不可用糖皮质激素
需要时使用抗炎药物退烧抗炎
脱水时进行输液维持体液

Treatment modifications should be made as needed, based on response to treatment, other health factors, and other factors such as compliance and animal care capabilities of the owner/caretaker.
根据治疗后病情发展和其他健康因素，例如宠主/护理者的服从性和护理水平，如有需要可以改变治疗方案。

To prevent transmission of the virus, dogs infected with canine H3N2 influenza as well as other dogs in the household should be isolated for 4 weeks.
为了防止病毒传播，感染犬H3N2流感的犬只和同一环境中的其他犬只应隔离4周。

Antiviral drugs to treat influenza are approved for use in humans only. Little is known about their use, efficacy and safety in dogs. Veterinarians who use approved drugs in a manner not in accord with approved label directions (e.g., use of an antiviral drug only approved for use in humans) must follow the federal extralabel drug use regulations of the Animal Medicinal Drug Use Clarification Act (AMDUCA).
抗病毒药物治疗流感只建议在人类使用。但是关于抗病毒药犬只的使用、效果和安全性这方面知识非常少。兽医如果不按照标签来使用药物（例如使用用于人的抗病毒药物）必须按照联邦药物标签外使用规范来使用，也就是Animal Medicinal Drug Use Clarification Act (AMDUCA )。

Morbidity and Mortality 患病率和死亡率
Canine influenza virus is not widespread in the dog population and many dogs have never been exposed to the virus. The morbidity rate (the number of exposed animals that develop disease) estimated at 80%. The mortality (death) rate is low; less than 10%. Deaths occur mainly in dogs with the severe form of disease.
犬流感在犬只中的流行率并不高，许多犬从未接触过该病毒。患病率（动物暴露后患病的概率）大约是80%。死亡率很低，不到10%。病情严重的犬只才会死亡。

To date, no fatalities in cats infected with canine influenza have been reported.
目前为止，猫感染犬流感后还没有致死的报道。

Prevention and Control 预防和控制
The canine influenza virus may persist in the environment for approximately 2 days, and be viable on hands and clothing for up to 24 hours. In veterinary, boarding, and shelter facilities, the canine influenza virus appears to be easily killed by disinfectants commonly used in those facilities, such as quaternary ammonium compounds (eg, benzalkonium chloride), aldehydes, potassium peroxymonosulfate, phenols and bleach (1:30 dilution) solutions. Cleaning and disinfection protocols should be established to ensure reduce the risk of virus transmission through indirect contact with people or other fomites (e.g. cages, bowls, exam rooms, etc.).
犬流感病毒可以在环境中存活2天左右，在手上和衣服上存活24小时。在宠物医院、寄养和救助机构，犬流感可以被常用的消毒剂杀死，例如季胺盐化合物（苯扎氯胺）、醛类、过一硫酸氢钾复合盐、酚类和漂白粉（1:30稀释）溶液。需要设定清洁和消毒准则来降低病毒通过人或其他污染物（例如笼子、碗、诊室等）的传播。

All employees should wash their hands with soap and water:
Upon arriving at the facility
Before and after handling each dog
After coming into contact with dogs' saliva, urine, feces, or blood
After cleaning cages
Before eating meals, taking breaks, or leaving the facility
Before and after using the restroom
所有员工都应该在一下情形用肥皂洗手：
在到达场所时
触摸狗之前和之后
在接触犬口水、尿液、大便或血液后
在清洁笼子之后
吃饭、休息、离开场所之后
使用休息室之前和之后

Isolation protocols should be rigorously applied for dogs showing clinical signs of respiratory disease. Dogs exposed to CI or exhibiting respiratory symptoms should not be brought to locations where other dogs are present such as training classes, shows or events, day care, and boarding and shelter facilities until the isolation period is completed.
需要严格隔离有呼吸道症状的犬只。暴露于犬流感或表现临床症状的犬只不应带至有其他犬只的地方，例如训练课堂，秀场或活动，白天护理场所，以及寄养和救助场所，直到度过隔离期。

Sick or exposed dogs should be isolated, preferably in an area with a separate air supply. An isolation period of 4 weeks is recommended. Wear personal protective equipment (gown and gloves at a minimum) when handling ill animals to avoid contaminating clothing. Clean and disinfect all clothing (including shoes), equipment, surfaces and hands after exposure to dogs showing signs of respiratory disease. Owners whose dogs are coughing or exhibiting other signs of respiratory disease should bringing their dogs should not participate in activities with other dogs or bring their dogs to facilities where other dogs are present to avoid exposing them to the virus.
患病或暴露于病毒的犬只应隔离，最好隔离在有单独空气供应系统的地方。建议隔离4周。当接触患病动物时，人员需至少穿戴外罩和手套以免污染衣服。暴露于有呼吸道症状的犬只后应清洁和消毒所有衣物（包括鞋子）、设备、表面和手。犬只如果咳嗽或表现其他呼吸道症状，主人不应该带他们到有其他狗的地方去，避免传播病毒。

Veterinary practices should implement biosecurity protocols to prevent transmission of CI between dogs at the practice. Dogs with clinical signs consistent with respiratory disease should not be allowed in the waiting room. Clients may need to wait in the car with their dog until clinic staff is ready to see the dog without risking exposure to other dogs. Dogs suspected of having CI should avoid the main entrance and enter and exit the facility through a different door. Areas where potentially infected dogs are examined and treated, as well as all instruments used, must be thoroughly cleaned disinfected after the dog is discharged. Staff members should wear personal protective equipment (gloves and a gown at minimum) when examining or caring for dogs suspected of having CI.   
宠物医院应实施严格的生物安全准则来防止犬流感在犬只当中传播。有呼吸道症状的犬只不应在等候室等待接诊。客户需要在车里等到医院员工准备好接待犬只时才带进诊所。怀疑犬流感的犬只应避免从主出入口进入，应从其他门进入。怀疑感染的犬只离开后，它检查和治疗的地方，以及使用的设备都必须测地清洁消毒。员工在检查和护理怀疑有犬流感的犬只时应穿戴个人防护设备（至少手套和外罩）。

Vaccines are available for both H3N8 and H3N2 canine influenza. A bivalent vaccine offering protection against both strains is also available. Currently, there are no canine influenza vaccines approved for use in cats. Vaccination can reduce the risk of a dog contracting canine influenza. Vaccination may not all together prevent an infection, but it may reduce the severity and duration of clinical illness.
现有预防H3N8型和H3N2型犬流感病毒的疫苗。同时预防两种毒株的两联苗也有。目前，没有用于猫的犬流感疫苗。免疫可以减少犬感染犬流感的风险。疫苗并不能完全预防感染，但是可以降低疾病的严重程度和持续时间。

The canine influenza vaccine is a "lifestyle" vaccine, and is not recommended for every dog. In general, the vaccine is intended to protect dogs at risk for exposure to the canine influenza virus, which includes those that participate in activities with many other dogs or are housed in communal facilities, particularly where the virus is prevalent. Dogs that may benefit from canine influenza vaccination include those that receive the kennel cough (Bordetella/parainfluenza) vaccine, because the risk groups are similar. Dog owners should consult with their veterinarian to determine their dog’s risk of exposure to the canine influenza virus and if vaccination is appropriate for their dog.
犬流感疫苗是根据生活习惯可选择的疫苗，并不建议用于所有犬只。一般说来，疫苗用于有暴露于犬流感病毒风险的犬只，包括和很多其他犬只一起参加活动的犬只或者养在公共设施的犬只，尤其是病毒流行的地方。接种过犬窝咳疫苗（博德氏杆菌/副流感）的犬只也会受益于犬流感疫苗，因为两者的风险因素相似。宠物主人应咨询他们的兽医，来判断犬只流感病毒暴露风险以及是否需要免疫。

何灵俊

真棒

zhangdingcong

感谢分享

刘欣

及时贴，

BrentChris

默沙东只有H3N8型的单价疫苗。

陈兴慧

谢谢分享，学习啦~~

BrentChris

补充：节选《佛罗里达地区犬甲型流感病毒报告》作者：Sunchai Payungporn,* P. Cynda Crawford,† Theodore S. Kouo et al   DOI: 10.3201/eid1406.071270

    2004年在美国格雷伊猎犬上发现了流感病毒亚型H3N8。血清学实验表明病毒在灰色猎犬之外的品种亦存在。但病毒没有从受影响动物中分离出来。2005年我们在佛罗里达因呼吸道疾病病死的7只非格雷伊猎犬（non-greyhound ）中进行病毒学研究并分离出了H3N8亚型。针对杰克逊维尔和迈阿密的两只犬的H3N8病毒抗原和遗传分析与早期灰猎犬相似，这表明该种亚型病毒感染不限于格雷伊猎犬，血凝素包含五个保守氨基酸差异以区分犬和马。犬病毒抗原同源性提示抗原漂移并没有发生。

    甲型流感病毒（正粘病毒科）已知在人、马、猪和家禽中引起急性呼吸道疾病。甲型流感病毒亚型H3N8近来已成为犬呼吸道疾病的病原体，与灰猎犬爆发急性呼吸道疾病相关。该病原是与马甲型流感病毒H3N8亚型密切相关，这些病毒>96的核苷序列具有同一性，这表明病毒从马直接传播到犬只上而不需要其他菌株参与。

在避难所受影响的58只犬中临床症状：低烧、化脓性鼻液、咳嗽10-21天。收集了五只狗的急性发病期和恢复期的血清样本进行血凝抑制试验（HI）检测CIV特异性抗体。所有的犬抗体滴度的几何平均数（GMT）有所增加，从急性期的37到恢复期达到626。

另外18只具有明显临床症状7天以上的血清样本，有17只（94%）血清样本为阳性。血凝抑制试验（HI）抗体滴度范围32-2048，GMT：533，至少有十只发展为肺炎。6例安乐死，年龄在4月-3岁，安乐死的犬在安乐前症状持续2-10天。在兽医诊所40只狗中最常见的临床症状：低烧、脓性鼻液、咳嗽10-30天。从19只急性和恢复期的犬中HI测定CIV特异性抗体，其中11只有血清转换，GMT从急性期9增加到329。

    在兽医诊所中的一只9岁的约克夏在发病后三天后因肺炎死亡。

    尸检报告：7只狗均有气管炎和支气管炎的特征表面和腺上皮坏死，淋巴细胞、嗜中性粒细胞和巨噬细胞浸润增生，没有胸腔或者肺出血。

CIV H3血凝素的氨基酸序列

识别变换以及抗原性和受体结合可能的功能意义，我们分析了6个可用的CIV分离株的H3血凝素推测氨基酸序列，所有6只犬都有5个保守氨基酸替换将他们与目前流行的马病毒区分开（table.3）。保守氨基酸替换（N54K，N83S，W222L，I328T和N483T）被认为是CIV H3血凝素循环信号。对成熟的H3蛋白系统发育比较显示：Jacksonville/2005、Miami/2005和/Iowa/2005与Texas/2004形成一个子组（Figure, panel B）。有三个氨基酸的改变（L118V, K261N, G479E）来自早期的Florida / 43/2004株和Florida/242/2003株（table.3）最后 Jacksonville / 2005和Miami / 2005只有一个氨基酸的不同（S107P）

犬流感病毒（H3N8）分离株抗原性的分析

通过早期马和同期马病毒的抗原组以及马和犬自然感染后康复血清进行HI测试。一只雪貂和Florida / 43/2004也被纳入分析，HI抗体滴度相比，现期马（1999-2003）比早期感染的马（1963-1992）抗体滴度高2-16倍。马血清与犬病毒的异源滴度通常与现代马病毒的同源值相似，犬血清未能显抑制早期马病毒（1963-1992）的血细胞凝集，但抗体滴度与现代马的分离株（1999-2003）和犬分离株相当，对感染CIV雪貂的血清也观察到类似的结果。这些都显示出马病毒和犬流感病毒的抗原性相似，与系统发育树分析一致。犬Miami/2005株在马、犬、雪貂抗体滴度与2003年和2004年分离株相似，表明氨基酸替换在分离株中没有导致可测量的抗原漂移。

【文章为截取段落，并非按照原文翻译】——Sebastian Z

BrentChris

补充其他资料2：节选《犬流感·H3N2部分》爱荷华州立大学公共卫生与食品安全中心&爱荷华州立大学兽医医学院。评论日期：2015年11月
更新日期：2016年2月


In Asia, some dogs without a history of severe respiratory disease are seropositive, suggesting that subclinical infections may also occur. There are currently no published articles describing the outbreaks in the U.S.;however, informal reports suggest that most cases have been characterized by relatively mild upper respiratory signs, with few deaths。


在亚洲一些狗没有严重的呼吸道疾病史但血清反应是阳性，这表明亚临床感染也是可能发生的。目前没有发表的文章报告美国的疫情，然而非正式的报告显示上呼吸道症状是大多数病例的特征，极少数死亡。

金桥

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