Comparative trial of the canine parvovirus, canine distemper virus and canine adenovirus type 2 fractions of two commercially available modified live vaccines

The results of vaccinating two groups of puppies with commercial vaccines, both of which claimed to provide adequate protection with a final vaccination at 10 weeks of age, were compared. Groups of 19 and 20 puppies with similar titres of maternally derived antibodies against canine parvovirus (cpv), canine distemper virus (cdv) and canine adenovirus type 2 (cav-2) at four weeks of age were vaccinated at six and 10 weeks of age and their responses to each vaccination were measured by comparing the titres against cpv, cdv and cav-2 in the serum samples taken immediately before the vaccination and four weeks later. After the vaccination at six weeks of age, all 19 of the puppies in group 1 had responded to cpv and cdv, and 14 had responded to cav-2; in group 2, 17 of the 20 had responded to cpv, 19 to cdv and 15 to cav-2. In both groups the puppies that did not respond to the first vaccination had responded serologically to cpv, cdv and cav-2 at 10 weeks of age.     

Response of puppies to canine-origin parvovirus vaccines

Pups 9-18 1/2 weeks old were given a single dose of 1 of 4 commercial, live, canine-origin parvovirus vaccines. All 4 vaccines evoked high levels of antibody in seronegative pups, but variable response in those with low levels of maternally derived antibodies. Vaccinal virus spread to unvaccinated contact controls and elicited essentially equivalent titers. No clinical signs of parvovirus infection were observed in vaccinates or controls.     

Antibodies to parvovirus, distemper virus and adenovirus conferred to household dogs using commercial combination vaccines containing Leptospira bacterin

To examine how the inclusion (+) or exclusion (-) of inactivated Leptospira antigens in a vaccine for canine parvovirus type 2 (CPV-2), canine distemper virus (CDV) and canine adenovirus type 2 (CAdV-2) affects antibody titres to CPV-2, CDV and CAdV-1 antigens, household dogs were vaccinated with commercially available vaccines from one of three manufacturers. CPV-2, CDV and CAdV-1 antibody titres were measured 11 to 13 months later and compared within three different age groups and three different bodyweight groups. There were significant differences between CPV-2 antibody titres in dogs vaccinated with (+) vaccine and those vaccinated with (-) vaccine for two products in the two-year-old group and for one product in the greater than seven-year-old group; no significant differences were seen that could be attributed to bodyweight. No differences in CDV antibody titres were observed within age groups, but a significant difference was seen in the 11 to 20 kg weight group for one product. Significant differences in CAdV-1 antibody titres were seen for one product in both the two-year-old group and the ≤10 kg weight group.     

犬瘟热与犬细小病毒混合感染的诊断与治疗

犬瘟热病毒与犬细小病毒分别引致犬瘟热和犬细小病毒病。这两种病毒对犬科动物危害大,发病率和死亡率都较高,且混合感染较为常见。通过临床诊断、血清学检测、血常规检测、影像学检查等方法,分析一例犬瘟热和犬细小病毒混合感染病例,并采用特异性血清与支持对症治疗相结合方法,提出综合防治措施。通过对该典型案例的深入分析,可为临床同类疾病诊断和治疗提供参考。     

Dog response to inactivated canine parvovirus and feline panleukopenia virus vaccines

Inactivated canine parvovirus (CPV) and inactivated feline panleukopenia virus (FPV) vaccines were evaluated in dogs. Maximal serologic response occurred within 1-2 weeks after vaccination. Antibody titers then declined rapidly to low levels that persisted at least 20 weeks. Immunity to CPV, defined as complete resistance to infection, was correlated with serum antibody titer and did not persist longer than 6 weeks after vaccination with inactivated virus. However, protection against generalized infection was demonstrated 20 weeks after vaccination. In unvaccinated dogs, viremia and generalized infection occurred after oronasal challenge with virulent CPV. In contrast, viral replication was restricted to the intestinal tract and gut-associated lymphoid tissue of vaccinated dogs. Canine parvovirus was inactivated by formalin, beta-propiolactone (BPL), and binary ethylenimine (BEI) in serum-free media; inactivation kinetics were determined. Formalin resulted in a greater loss of viral HA than either BEI of BPL, and antigenicity was correspondingly reduced.     

同时检测犬瘟热病毒和犬细小病毒双重PCR方法的建立

为建立可以同时检测犬瘟热病毒(CDV)和犬细小病毒(CPV)的双重PCR方法,本研究根据GenBank登录的CDV N蛋白序列和CPV NS基因保守序列,设计合成2对特异性引物。通过优化反应条件,对CDV阳性病毒株反转录后的cDNA模板和CPV的DNA模板进行双重PCR扩增,同时得到2条与试验设计相符的669 bp(CDV)和392 bp(CPV)特异性条带,建立了同时检测CDV和CPV的双重PCR方法。实验结果表明:在同一PCR反应体系中可以同时检测这2种病毒,而对犬腺病毒Ⅰ型、犬腺病毒Ⅱ型、狂犬病毒检测均为阴性;CDV和CPV的最低检出限分别为101.8TCID50和101.4TCID50。采用该方法对在黑龙江省不同地区所采集的30份犬病料样品进行检测,CDV阳性率为30%;CPV阳性率为23.33%,表明建立的PCR方法可以用于临床诊断。     

Evaluation of the efficacy and duration of immunity of a canine combination vaccine against virulent parvovirus, infectious canine hepatitis virus, and distemper virus experimental challenges

The results of this study confirmed that dogs vaccinated subcutaneously with a commercially available multivalent vaccine containing modified-live canine distemper virus, canine adenovirus type 2, canine parvovirus type 2b, and canine parainfluenza virus antigens were protected against sequential experimental challenge 55 to 57 months after initial vaccination given at 7 to 8 weeks of age. All 10 vaccinates were protected against clinical diseases and mortality following parvovirus and infectious canine hepatitis experimental infections. All vaccinates were protected against mortality and 90% against clinical disease following distemper challenge. These data support at least a 4-year duration of immunity for these three "core" fractions in the combination vaccine.     

Utility of two modified-live virus canine distemper vaccines in wild-caught fishers (Martes pennanti)

Background: Canine distemper virus (CDV) infects families in the order Carnivora. As a preventive measure, vaccinations against CDV are frequently given to mustelids in captive environments.

Objectives: Our objectives were to compare the utility between two modified-live virus canine distemper vaccines (MLV CDV's), Fervac-D® (no longer manufactured) and Galaxy-D® (now manufactured by MSD Animal Health as part of a multivalent vaccine), in developing an immune response in wild-caught fishers.

Animals and methods: The Pennsylvania Fisher Reintroduction Project (PFRP) used 14 wild-caught fishers during one year of the project to evaluate the utility of vaccinations against CDV as part of any reintroduction project. Fishers were injected subcutaneously in the nape of the neck with their designated vaccine.

Results: Fervac-D® did not effectively stimulate development of a serologic antibody response, whereas Galaxy-D® had adequate seroconversion or rise of titer levels to suggest that the general use of MLV CDV may be suitable in fishers pending further studies.

Conclusion: We recommend that future studies be conducted, evaluating the use of currently produced vaccines in fishers. Future research should also focus on the length of days required between administration of primary and booster vaccines to achieve sufficient immune response.

Clinical importance: If only primary doses are required, then hard-release reintroduction projects for fishers could be recommended. If primary and booster vaccines are required then soft-release reintroduction projects should be recommended that include captive management periods, allowing for appropriate vaccination intervals needed to maximize the probability of protection against CDV.     

Evaluation of a dot ELISA kit for measuring immunoglobulin M antibodies to canine parvovirus and distemper virus

A dot ELISA for the detection of immunoglobulin M (IgM) antibodies to canine distemper virus (CDC) and canine parvovirus (CPV) was assessed. The titres of IgM antibodies to CDV and CPV in 100 dogs were measured by the Immunocomb ELISA kit and compared with the results derived from the immunofluorescence assay (IFA). There was a strong correlation between the results of the dot ELISA technique and the IFA (P < 0.001). The dot ELISA kit was also used to assess the changes in the levels of immunoglobulin G (IgG) and IgM antibodies to CPV and CDV in 10 puppies vaccinated with a polyvalent vaccine. High levels of IgM antibodies to CPV were first detected seven days after they were vaccinated, and after nine days all the pups had high titres of IgG antibodies to CPV. High levels of IgM antibodies to CDV were detected after nine days and the highest average titres were recorded after 12 days. IgG antibodies to CDV were present from nine days after vaccination.     

Serologic response of maned wolves (Chrysocyon brachyurus) to canine and canine parvovirus vaccination distemper virus.

This study evaluated the immune response of 47 (22 males, 25 females) captive maned wolves (Chrysocyon brachyurus) to modified-live canine parvovirus and canine distemper virus (Onderstepoort and Rockborn strains) vaccines. Sera were collected from 33 adults and 14 pups, including five free-ranging pups captured at 1 yr of age or younger. All the adults and four captive-born pups had been vaccinated prior to this first blood collection. Virus neutralization and hemagglutination-inhibition assays were performed for quantitating antibodies against canine distemper and canine parvovirus, respectively. Distemper antibody titers > or = 100 were present in 57% of adults and 14% of pups. All adults and 29% of pups had parvovirus antibody titers > or = 80. After vaccination, 72% of the wolves developed antibody titers > or = 100 against distemper and 98% developed titers > or = 80 against parvovirus. Both vaccines used were safe and immunogenic to juvenile and adult maned wolves, regardless of prior vaccination history.     

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.     

Prevalence of antibodies against canine distemper virus and canine parvovirus among foxes and wolves from Spain

Viral diseases can influence the population dynamics of wild carnivores and can have effects on carnivore conservation. Hence, a serologic survey was conducted in an opportunistic sample of 137 foxes (Vulpes vulpes) and 37 wolves (Canis lupus) in Spain for 1997-2007 to detect antibodies against canine distemper virus (CDV) and against canine parvovirus (CPV) by indirect ELISA. Antibodies against CDV were detected in 18.7% of the analyzed animals and antibodies against CPV in 17.2%. There was no difference in antibody prevalence to CDV between both species, even in the same region (P>0.05), but there was a significant difference in antibody prevalence to CPV between foxes (5.1%) and wolves (62.2%) (P<0.05). In fox populations there was a significant difference in antibody prevalence to CDV between geographic areas (Aragón 26.4%, La Mancha 7.8%, P<0.05). In wolf populations there was significantly higher antibody prevalence against CPV (P<0.05) in Castilla y León (100%) than in the Cantabric region (53.3%). There was no significant sex or age-related difference in the antibody prevalence against CDV or CPV in foxes. These results indicate that contact with CDV is widespread among wild canid populations in Spain and that CPV is endemic in the Iberian wolf population. The implications of these results are briefly discussed.     

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.