Serum antibody response to canine parvovirus, canine adenovirus-1, and canine distemper virus in dogs with known status of immunization: study of dogs in Sweden

Serum antibody titers to canine parvovirus (CPV), canine adenovirus-1 (CAV-1), and canine distemper virus (CDV) were measured in dogs with known immunization status. The dogs represented 3 groups: nonvaccinated dogs less than 12 months old; vaccinated dogs less than 12 months old; and adult dogs greater than 12 months old. For practical reasons, the population from which the specimens were obtained could be considered as free from natural infection with CAV-1 and CDV. In nonvaccinated dogs less than 12 months old, antibodies against all 3 viruses were measured at the time the dogs were given their first vaccination. Altogether, 50.7% of the dogs had titer greater than or equal to 1:10 to CPV, and 26.1 and 46.2% had titer greater than or equal to 1:8 to CAV-1 and CDV, respectively. The concentration of maternal antibody seemed to be of major importance for failure of immunization with use of inactivated CPV vaccine, but not with CAV-1 and CDV vaccination. In dogs less than 12 months old and vaccinated against CPV infection with inactivated virus, only 11.5% had titer greater than or equal to 1:80. In dogs vaccinated against infectious canine hepatitis and canine distemper, 63.2 and 78.3%, respectively, had titer greater than or equal to 1:16. In adult dogs greater than 2 months old and vaccinated against CPV infection, less than 50% had titer greater than or equal to 1:80, regardless of time after vaccination. There was no significant difference in titer between vaccinated and nonvaccinated dogs.(ABSTRACT TRUNCATED AT 250 WORDS)     

Three-year duration of immunity in dogs following vaccination against canine adenovirus type-1, canine parvovirus, and canine distemper virus

A challenge-of-immunity study was conducted to demonstrate immunity in dogs 3 years after their second vaccination with a new multivalent, modified-live vaccine containing canine adenovirus type 2 (CAV-2), canine parvovirus (CPV), and canine distemper virus (CDV). Twenty-three seronegative pups were vaccinated at 7 and 11 weeks of age. Eighteen seronegative pups, randomized into groups of six dogs, served as challenge controls. Dogs were kept in strict isolation for 3 years following the vaccination and then challenged sequentially with virulent canine adenovirus type 1 (CAV-1), CPV, and CDV. For each viral challenge, a separate group of six control dogs was also challenged. Clinical signs of CAV-1, CPV, and CDV infections were prevented in 100% of vaccinated dogs, demonstrating that the multivalent, modified-live test vaccine provided protection against virulent CAV-1, CPV, and CDV challenge in dogs 7 weeks of age or older for a minimum of 3 years following second vaccination.     

Assessment of serum antibody titers against canine distemper virus, canine adenovirus type II, and canine parvovirus in Alaskan sled dogs before and after a long-distance race

OBJECTIVE: To determine serum antibody titers against canine distemper virus (CDV), canine adenovirus type II (CAV-2), and canine parvovirus (CPV) in trained sled dogs prior to and after completion of a long-distance race. DESIGN: Prospective cohort study. ANIMALS: 195 Alaskan sled dogs (from 18 kennels) that participated in the 2006 Iditarod Trail Race. PROCEDURES: All 1,323 dogs participating in the race had been vaccinated against the 3 viruses at 19 to 286 days prior to initial blood sample collection (obtained within the month preceding the race). Within 12 hours of race completion, blood samples were collected from 195 dogs (convenience sample) and matched with each dog's prerace sample. Serum antibody titers (90% confidence intervals [CIs]) were determined via serum neutralization assays. RESULTS: After racing, geometric mean titers against CDV and CPV were significantly higher (2,495 [90% CI, 321 to 16,384] and 6,323 [90% CI, 512 to 32,768], respectively) than prerace values (82 [90% CI, 11 to 362] and 166 [90% CI, 32 to 1,024], respectively). Sixty-one of 194 (31.4%) dogs had > or = 4-fold increases in anti-CPV antibody titers after racing. Prerace serum antibody titers against CDV, CPV, and CAV-2 varied significantly by sled team but were not associated with time since vaccination. CONCLUSIONS AND CLINICAL RELEVANCE: Postrace increases in serum anti-CDV and anti-CPV antibody titer might reflect exposure of dogs to these agents immediately before or during racing. Dogs had no clinical signs of CDV-, CAV-2-, or CPV-associated disease; therefore, the clinical importance of these titer changes is uncertain.     

Association between cancer chemotherapy and canine distemper virus, canine parvovirus, and rabies virus antibody titers in tumor-bearing dogs.

OBJECTIVE: To determine the association between cancer chemotherapy and serum canine distemper virus (CDV), canine parvovirus (CPV), and rabies virus antibody titers in tumor-bearing dogs. DESIGN: Prospective study. ANIMALS: 21 client-owned dogs with various malignancies and 16 client-owned dogs with lymphoma. PROCEDURE: In study A, serum antibody titers were measured by use of hemagglutination inhibition (CPV titers) or serum neutralization (CDV titers) before and at least 1 month after initiation of chemotherapy. Baseline values were compared with values obtained from a control population of 122 healthy dogs seen for routine revaccination. Titers were considered protective at > or = 1:96 for CDV and > or = 1:80 for CPV. In study B, serum IgG titers were measured by use of immunofluorescent assay (CDV and CPV titers) and rapid fluorescent focus inhibition test (RFFIT, rabies titers) at baseline and again at weeks 5, 8, and 24 of a standard chemotherapy protocol for treatment of lymphoma. An IgG titer of > or = 1:50 was considered protective for CPV and CDV. An RFFIT titer of > or = 0.5 U/ml was considered protective for rabies virus. RESULTS: Significant changes were not detected in CDV, CPV, and rabies virus titers following chemotherapy in tumor-bearing dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that established immunity to CDV, CPV, and rabies virus from previous vaccination is not significantly compromised by standard chemotherapy used to treat tumor-bearing dogs.     

Prevalence of positive antibody test results for canine parvovirus (CPV) and canine distemper virus (CDV) and response to modified live vaccination against CPV and CDV in dogs entering animal shelters

Canine parvovirus (CPV) and canine distemper virus (CDV) infections are relatively common in animal shelters and are important population management issues since the immune status of incoming dogs is usually unknown. This study aimed to determine the prevalence of positive antibody test results for CPV and CDV in incoming dogs aged ≥ 4 months and to measure antibody response over 2 weeks following vaccination with a modified live vaccine (MLV). Dogs aged 4-24 months entering an adoption-guarantee shelter (Shelter 1, n=51) and aged ≥ 4 months entering a limited admission shelter (Shelter 2; n=51) were enrolled. Dogs from Shelter 1 had been vaccinated with MLV at a municipal shelter 5 days before enrollment, whereas dogs from Shelter 2 had no known history of vaccination at enrollment. Sera were obtained on day 1, immediately prior to CPV/CDV MLV, and tested using an in-clinic ELISA kit to detect CPV/CDV antibodies. Dogs negative for CPV and/or CDV were retested at day 6-8 and those dogs still negative at day 6-8 were retested at day 13-15. Prior to CPV/CDV MLV on day 1, more dogs tested positive for CPV (Shelter 1 - 68.6%; Shelter 2 - 84.3%) than for CDV (Shelter 1 - 37.3%; Shelter 2 - 41.2%). On day 1, prior to MLV, all spayed/neutered animals tested CPV antibody-positive (n=17/102) and CPV antibody-positive dogs were older than serologically negative dogs (Shelter 1, P=0.0029; Shelter 2, P=0.0042). By day 13-15, almost all dogs were CPV antibody-positive (Shelter 1 - 97.9%; Shelter 2 - 100.0%) and CDV antibody-positive (Shelter 1 - 93.8%; Shelter 2 - 97.8%). MLV induces protective antibody titers against CPV/CDV in almost all dogs after 13-15 days.     

Clinical use of serum parvovirus and distemper virus antibody titers for determining revaccination strategies in healthy dogs

OBJECTIVE: To assess whether serum canine parvovirus (CPV) and canine distemper virus (CDV) antibody titers can be used to determine revaccination protocols in healthy dogs. DESIGN: Case series. ANIMALS: 1,441 dogs between 6 weeks and 17 years old. PROCEDURE: CPV and CDV antibody titers in serum samples submitted to a commercial diagnostic laboratory were measured by use of indirect fluorescent antibody (IFA) tests. On the basis of parallel measurements of CPV and CDV serum antibody titers in 61 paired serum samples determined by use of hemagglutination inhibition and serum neutralization methods, respectively, we considered titers > or = 1:5 (IFA test) indicative of an adequate antibody response. RESULTS: Age, breed, and sex were not significantly associated with adequate CPV- or CDV-specific antibody responses. Of 1,441 dogs, 1,370 (95.1%) had adequate and 71 (4.9%) had inadequate antibody responses to CPV, whereas 1,346 of 1,379 (97.6%) dogs had adequate and 33 (2.4%) had inadequate responses to CDV. Vaccination histories were available for 468 dogs (468 for CPV, 457 for CDV). Interval between last vaccination and antibody measurement was 1 to 2 years for the majority (281/468; 60.0%) of dogs and 2 to 7 years for 142 of 468 (30.3%) dogs. Interval was < 1 year in only 45 of 468 (9.6%) dogs. CONCLUSIONS AND CLINICAL RELEVANCE: The high prevalence of adequate antibody responses (CPV, 95.1%; CDV, 97.6%) in this large population of dogs suggests that annual revaccination against CPV and CDV may not be necessary.     

5种常见犬腹泻病毒基因芯片检测方法的建立

为建立一种简便、快速、高效的可同时区分犬腺病毒1型（canine adenovirus type 1,CAV-1）、犬腺病毒2型（canine adenovirus type 2,CAV-2）、犬冠状病毒（canine coronavirus,CCV）、犬瘟热病毒（canine distemper virus,CDV）、犬细小病毒（canine parvovirus,CPV） 5种常见犬腹泻病毒的基因芯片诊断方法,本研究以CAV-1、CAV-2、CCV、CDV、CPV 5种犬腹泻病毒为靶病毒,根据NCBI上收录的病毒基因序列在其保守区域内设计引物,在此基础上根据变异区域设计针对每种病毒的探针2~3条,优化检测体系的各反应条件,确定该检测方法的特异性与敏感性,建立可同时区分5种病毒的基因芯片检测方法。结果显示,建立的基因芯片检测方法可同时检测以上述5种犬腹泻病毒,其中PCR的退火温度为55℃、延伸时间为1 min 15 s;探针与PCR产物的杂交温度40℃、杂交时间2.5 h时,该方法对CAV-1、CAV-2、CCV、CDV和CPV 5种病毒标准品的检测限分别为0.2 fg/μL、2 fg/μL、2 fg/μL、20 pg/μL和0.02 fg/μL,具有较高的灵敏性;同时对犬副流感病毒进行特异性试验,发现无阳性信号出现,具有较强的特异性;对14份临床腹泻样品检测结果显示,基因芯片方法对CAV-1、CAV-2、CCV、CDV和CPV 5种病毒的阳性检出率分别为28.57%、50.00%、64.28%、14.28%和85.71%,并且基因芯片检测方法的敏感性较PCR要高10~100倍。以上结果表明,本研究建立的基因芯片检测方法具有特异、敏感等特点,对临床中犬类混合感染病毒检测具有一定的诊断意义。     

北京地区犬呼吸道冠状病毒感染状况的监测与分析

本研究旨在分析犬呼吸道冠状病毒（canine respiratory coronavirus,CRCoV）的感染情况和在北京地区的流行病学状况。采用RT-PCR方法,对自2015年12月—2017年3月于中国农业大学动物医院采集的487份犬咽鼻拭子进行了CRCoV检测,同时,对部分样本进行了犬副流感病毒（canine parainfluenza virus,CPIV）、犬腺病毒II型（canine adenovirus type 2,CAV-2）、犬瘟热病毒（canine distemper virus,CDV）等病毒的混合感染情况调查。结果表明：CRCoV的阳性率为21.36%（104/487）;CRCoV与CPIV、CAV-2、CDV的混合感染率分别为3.43%（11/321）,0%（0/156）和3.85%（6/156）。在所有呼吸道症状记录完整的455例样本中,无呼吸道症状的犬CRCoV携带率为27.19%（31/114）;呈轻度呼吸道症状（鼻液、咳嗽）的犬CRCoV感染率为19.73%（59/299）;呈中至重度呼吸道症状（肺炎）的犬CRCoV感染率为14.28%（6/42）。对2016年11月―2017年3月采集的146例样本进行CRCoV与CPIV、CAV-2、CDV混合感染情况调查,CRCoV带毒犬混合感染率为12.50%（1/8）;呈轻度呼吸道症状的CRCoV感染犬混合感染率为41.18%（7/17）;呈中至重度呼吸道症状的CRCoV感染犬混合感染率为100.00%（2/2）。454例不同年龄段犬的CRCoV阳性率为15.56%~22.97%;除7月份CRCoV检出率高外,较冷的冬春季节检出率高于夏秋季节。结果提示：CRCoV的致病力较弱,单一感染犬常表现为无或轻度呼吸道症状,与其他呼吸道病毒（CPIV、CAV-2、CDV）混合感染时多出现轻度或中至重度呼吸道症状。该病毒在冬春季节更易流行;其感染率和年龄无显著关系。     

Three-year rabies duration of immunity in dogs following vaccination with a core combination vaccine against canine distemper virus, canine adenovirus type-1, canine parvovirus, and rabies virus

Thirty-two seronegative pups were vaccinated at 8 weeks of age with modified-live canine distemper virus (CDV), canine adenovirus type-2 (CAV-2), and canine parvovirus (CPV) vaccine and at 12 weeks with a modified-live CDV, CAV-2, CPV, and killed rabies virus vaccine. An additional 31 seronegative pups served as age-matched, nonvaccinated controls. All test dogs were strictly isolated for 3 years after receiving the second vaccination and then were challenged with virulent rabies virus. Clinical signs of rabies were prevented in 28 (88%) of the 32 vaccinated dogs. In contrast, 97% (30 of 31) of the control dogs died of rabies infection. These study results indicated that no immunogenic interference occurred between the modified-live vaccine components and the killed rabies virus component. Furthermore, these results indicated that the rabies component in the test vaccine provided protection against virulent rabies challenge in dogs 12 weeks of age or older for a minimum of 3 years following vaccination.     

Duration of serologic response to three viral antigens in cats

OBJECTIVE: To determine whether vaccinated cats either remained seropositive or responded serologically to revaccination against 3 key viral antigens after extended periods since their last vaccination. DESIGN: Serologic survey. ANIMALS: 272 healthy client-owned cats. PROCEDURE: Cats were > or = 2 years old and vaccinated for feline panleukopenia virus (FPV), feline calicivirus (FCV), and feline herpesvirus (FHV). On day 0, cats were revaccinated with a vaccine from the same line of vaccines as they had historically received. Antibody titers were measured in sera collected on day 0 (prevaccination titer) and 5 to 7 days later (postvaccination titer). Cats were considered to have responded serologically if they had a day-0 hemagglutination inhibition titer to FPV > or = 1:40, serum neutralization (SN) titer to FCV > or = 1:32, SN titer to FHV > or = 1:16, or > or = 4-fold increase in antibody titer after revaccination. RESULTS: The percentage of cats that had titers at or above the threshold values or responded to revaccination with a > or = 4-fold increase in titer was 96.7% for FPV, 97.8% for FCV, and 88.2% for FHV. CONCLUSIONS AND CLINICAL RELEVANCE: In most cats, vaccination induced a response that lasted up to and beyond 48 months for all 3 antigens. Although not equivalent to challenge-of-immunity studies as a demonstration of efficacy, results suggest that revaccination with the vaccine used in our study provides adequate protection even when given less frequently than the traditional 1-year interval. The study provides valuable information for clinicians to determine appropriate revaccination intervals.     

Serum antibody responses to vaccinal antigens in lean and obese geriatric dogs

The immune responses in control dogs [1 to 4 years of age, body condition score (BCS): 4 to 5 out of 9] were compared to those of aging dogs (based on breed and body size) either categorized as lean (BCS: 4 to 5 out of 9) or obese (BCS: 8 to 9 out of 9). Of interest were the serum titers to the following common agents found in vaccines, canine parainfluenza virus (CPIV), canine parvovirus (CPV), canine distemper virus (CDV), canine respiratory coronavirus (CRCoV), and Bordetella bronchiseptica. There were no statistical differences in the antibodies to CPIV, B. bronchispetica, and CRCoV, among the age/weight categories, nor among the age/weight categories and the time, in days, between the date of sample collection and the date of the last recorded vaccination for CPIV, B. bronchiseptica, CPV, and CDV. For CPV, the control dogs had significantly (P < 0.002) higher serum neutralization (SN) titers than the lean geriatric dogs and the obese geriatric dogs. For CDV SN titers, the only statistically significant (P = 0.01) difference was that the control dogs had higher SN titers than the lean geriatric dogs.     

Duration of immunity for canine and feline vaccines: a review

In our studies aimed at assessing the minimum duration of vaccinal immunity (DOI), approximately 1000 dogs have been vaccinated with products from all the major US veterinary biological companies. The DOI for the various products is determined by antibody titers for all dogs and, by challenge studies in selected groups of dogs. Recently, all major companies that make canine vaccines for the U.S. market have completed their own studies; published data show a 3 years or longer minimum DOI for the canine core products, canine distemper virus (CDV), canine parvovirus type 2 (CPV-2), and canine adenovirus-2 (CAV-2). Studies with feline core vaccines - feline parvovirus (FPV), calicivirus (FCV) and herpes virus type I (FHV-1) have shown a minimum DOI of greater than 3 years. Based on these results, the current canine and feline guidelines (which recommend that the last dose of core vaccines be given to puppies and kittens > or =12 weeks of age or older, then revaccination again at 1 year, then not more often than every 3 years) should provide a level of protection equal to that achieved by annual revaccination. In contrast, the non-core canine and feline vaccines, perhaps with the exception of feline leukaemia vaccines, provide immunity for < or =1 year. In general the effectiveness of the non-core products is less than the core products. Thus, when required, non-core vaccines should be administered yearly, or even more frequently.     

A modified live canine parvovirus vaccine. II. Immune response

The safety and efficacy of an attenuated canine parvovirus (A-CPV) vaccine was evaluated in both experimental and in field dogs. After parenteral vaccination, seronegative dogs developed hemagglutination-inhibition (HI) antibody titers as early as postvaccination (PV) day 2. Maximal titers occurred within 1 week. Immunity was associated with the persistence of HI antibody titers (titers greater than 80) that endured at least 2 years. Immune dogs challenged with virulent CPV did not shed virus in their feces. The A-CPV vaccine did not cause illness alone or in combination with living canine distemper (CD) and canine adenovirus type-2 (CAV-2) vaccines, nor did it interfere with the immune response to the other viruses. A high rate (greater than 98%) of immunity was engendered in seronegative pups. In contrast, maternal antibody interfered with the active immune response to the A-CPV. More than 95% of the dogs with HI titers less than 10 responded to the vaccine, but only 50% responded when titers were approximately 20. No animal with a titer greater than 80 at the time of vaccination became actively immunized. Susceptibility to virulent CPV during that period when maternal antibody no longer protects against infection, but still prevents active immunization, is the principal cause of vaccinal failure in breeding kennels where CPV is present. Reduction, but not complete elimination, of CPV disease in large breeding kennels occurred within 1-2 months of instituting an A-CPV vaccination program.     

Antibody titers for canine parvovirus type-2, canine distemper virus, and canine adenovirus type-1 in adult household dogs

Serum antibody titers for canine parvovirus type-2 (CPV-2), canine distemper virus (CDV) and canine adenovirus type-1 (CAV-1) were investigated in 1031 healthy adult household dogs (2 to 18 years old) given an annual inoculation in the previous 11 to 13 months. The number of dogs retaining significant titers of antibodies against CPV-2, CDV, and CAV-1 were 888 (86%), 744 (72%), and 732 (71%), respectively. There were no differences between males and females in antibody titers against the 3 viruses. Antibody titer for CPV-2 was significantly higher in younger dogs than in older dogs, CDV antibody was significantly higher in older dogs than in younger dogs, and CAV titer was not associated with age.     

Three-year serologic immunity against canine parvovirus type 2 and canine adenovirus type 2 in dogs vaccinated with a canine combination vaccine

A group of client-owned dogs and a group of dogs at a commercial kennel were evaluated for duration of antibody responses against canine parvovirus type 2 (CPV-2) and canine adenovirus type 1 (CAV-1) after receiving a combination vaccine containing recombinant canarypox-vectored canine distemper virus (CDV) and modified-live CPV-2, CAV-2, and canine parainfluenza virus, with (C6) or without (C4) two serovars of Leptospira (Recombitek C4 or C6, Merial). Duration of antibody, which correlates with protective immunity, was found to be at least 36 months in both groups. Recombitek combination vaccines can confidently be given every 3 years with assurance of protection in immunocompetent dogs against CPV-2 and CAV-1 as well as CDV. This allows this combination vaccine, like other, similar modified- live virus combination products containing CDV, CAV-2, and CPV-2, to be administered in accordance with the recommendations of the American Animal Hospital Association Canine Vaccine Task Force.     

Application of a dot enzyme-linked immunosorbent assay for evaluation of the immune status to canine parvovirus and distemper virus in adult dogs before revaccination.

A growing body of literature has been published indicating that the current practice of annual vaccination of dogs may not be beneficial and in some cases may even be harmful. A number of publications have proposed assessing the immune status of dogs before annual revaccination. In this study the usefulness of a commercially available dot-ELISA kit was evaluated to determine the duration IgG antibody titers to canine parvovirus (CPV) and canine distemper virus (CDV) in 158 dogs vaccinated at least one year ago. Overall, the percentage of dogs with protective antibody titers to both CPV and CDV was 84%. The percentage of dogs with borderline antibody titers was 11% for CPV and 10% for CDV. Four percent of the dogs had no detectable antibody to CPV and 6% had no antibody to CDV. The results reported here are in good agreement with other studies measuring IgG antibody levels. It is concluded that the kit offers veterinarians the opportunity of determining antibody titers and revaccinating only those pets whose antibody titers to specific diseases have waned.     

Serosurvey of ex situ giant pandas (Ailuropoda melanoleuca) and red pandas (Ailurus fulgens) in China with implications for species conservation.

Conservation strategies for the giant panda (Ailuropoda melanoleuca) include the development of a self-sustaining ex situ population. This study examined the potential significance of infectious pathogens in giant pandas ex situ. Serologic antibody titers against canine distemper virus (CDV), canine parvovirus (CPV), canine adenovirus (CAV), canine coronavirus (CCV), canine herpesvirus, canine parainfluenza virus (CPIV), Toxoplasma gondii, Neospora caninum, and Leptospira interrogans were measured in 44 samples taken from 19 giant pandas between 1998 and 2003 at the Chengdu Research Base of Giant Panda Breeding in Sichuan, China. Seroassays also included samples obtained in 2003 from eight red pandas (Ailurus fulgens) housed at the same institution. All individuals had been vaccinated with a Chinese canine vaccine that included modified live CDV, CPV, CAV, CCV, and CPIV. Positive antibody titers were found only against CDV, CPV, and T. gondii. Sera were negative for antibodies against the other six pathogens. Results indicate that the quality of the vaccine may not be reliable and that it should not be considered protective or safe in giant pandas and red pandas. Positive antibody titers against T. gondii were found in seven of the 19 giant pandas. The clinical, subclinical, or epidemiologic significance of infection with these pathogens via natural exposure or from modified live vaccines in giant pandas is unknown. Research in this area is imperative to sustaining a viable population of giant pandas and other endangered species.     

Presence of antibodies to canine distemper virus, canine parvovirus and canine adenovirus type 1 in free-ranging jackals (Canis adustus and Canis mesomelas) in Zimbabwe

A survey of free-ranging jackals (Canis adustus and Canis mesomelas) in Zimbabwe was conducted to determine the prevalence of serum antibodies to canine distemper virus (CDV), canine parvovirus (CPV) and canine adenovirus type 1 (CAV-1). Sera from 16 Canis adustus and 22 Canis mesomelas were collected from 1990 to 1993 from various regions of Zimbabwe and assayed by means of immunofluorescent techniques. Seroprevalence in C. adustus and C. mesomelas respectively were 50% and 63.6% for CDV, 12.5% and 18.2% for CPV and 37.5 and 9.1 for CAV-1. These results demonstrate that jackals are infected with these viruses and may act as reservoirs of them, although their susceptibility to the viruses is not known.     

Serosurvey of infectious disease agents of carnivores in captive red pandas (Ailurus fulgens) in China.

The future of the endangered red panda (Ailurusfulgens) depends in part on the development of protective measures against infectious diseases. The present study is a first step toward improved understanding of infectious diseases in the species' home regions. Serum samples obtained from 73 red pandas in 10 captive facilities in southwest, east, and northeast China from October to December 2004 were tested for antibodies against nine common infectious pathogens of carnivores. Antibody titers against canine distemper virus (CDV), canine parvovirus (CPV), and canine adenovirus (CAV) in the three facilities in which red pandas were vaccinated were highly variable. The CAV titer in one vaccinated red panda was high enough to suggest infection with the field virus following vaccination. Together with anecdotal reports of vaccine-associated morbidity and mortality, our results suggest that the Chinese vaccine is not suitable for this species. In the seven unvaccinated groups, CDV titers were low and occurred in 20-100% of the animals; antibody titers against CPV were found in seven of eight areas. Only one of 61 and two of 61 unvaccinated red pandas had CAV and canine coronavirus titers, respectively, and these titers were all low. Positive titers to Toxoplasma gondii were found in four locations (33-94% seropositive); the titers in 52% of seropositive individuals were of a magnitude consistent with active disease in other species (1:1,024 to > or = 1:4,096). One red panda in each of three locations was seropositive for Neospora caninum. Antibodies against canine herpesvirus and Brucella canis were not detected in any of the samples. Only one of the 73 red pandas had a weak positive influenza A titer. The results of this study emphasize the need for research on and protection against infectious diseases of red pandas and other endangered species in China.     

Effect of vaccination with recombinant canine distemper virus vaccine immediately before exposure under shelter-like conditions

Vaccination with modified-live virus (MLV) canine distemper virus (CDV) vaccine has historically been recommended for animals in high-risk environments because of the rapid onset of immunity following vaccination. Recombinant CDV (rCDV) vaccine was deemed a suitable alternative to MLV-CDV vaccination in pet dogs, but insufficient data precluded its use where CDV was a serious threat to puppies, such as in shelters, kennels, and pet stores. In this study, dogs experimentally challenged hours after a single dose of rCDV or MLV vaccine became sick but recovered, whereas unvaccinated dogs became sick and died. Dogs vaccinated with a single dose of rCDV or MLV vaccine 1 week before being experimentally challenged remained healthy and showed no clinical signs. Dogs given one dose of rCDV vaccine hours before being placed in a CDV-contaminated environment did not become sick. These findings support the hypothesis that rCDV vaccine has a similar time-to-immunity as MLV-CDV vaccines and can likewise protect dogs in high-risk environments after one dose.