Compatibility of a bivalent modified-live vaccine against Bordetella bronchiseptica and CPiV, and a trivalent modified-live vaccine against CPV, CDV and CAV-2.

Eight puppies (group 1) were vaccinated once with a bivalent modified-live vaccine against infectious tracheobronchitis by the intranasal route and at the same time with an injectable trivalent vaccine against canine parvovirus, canine distemper virus and canine adenovirus; a second group of eight puppies (group 2) was vaccinated only with the intranasal bivalent vaccine, and a further eight puppies (group 3) were vaccinated only with the injectable trivalent vaccine. Three weeks later they were all challenged with wildtype Bordetella bronchiseptica and canine parainfluenza virus by the aerosol route, and their antibody responses to the five vaccine organisms were determined. Oronasal swabs were taken regularly before and after the challenge for the isolation of bacteria and viruses, and the puppies were observed for clinical signs for three weeks after the challenge. There were no significant differences in the puppies' titres against canine parvovirus, canine distemper virus and canine adenovirus type 2 between the groups vaccinated with or without the bivalent intranasal vaccine. After the challenge the mean clinical scores of the two groups vaccinated with the intranasal vaccine were nearly 90 per cent lower (P=0.001) than the mean score of the group vaccinated with only the trivalent injectable vaccine, and the puppies in this group all became culture-positive for B bronchiseptica and canine parainfluenza virus. There were only small differences between the rates of isolation of B bronchiseptica from groups 1, 2 and 3, but significantly lower yields of canine parainfluenza virus were isolated from groups 1 and 2 than from group 3.

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.

Protection of dogs for 13 months against Bordetella bronchiseptica and canine parainfluenza virus with a modified live vaccine.

Twelve specific pathogen-free (spf) puppies were vaccinated intranasally with a bivalent, modified live vaccine against infectious tracheobronchitis (group 1) and six puppies of the same age and from the same source served as unvaccinated controls (group 2). Both groups were challenged with wild-type Bordetella bronchiseptica and canine parainfluenza virus by the aerosol route 56 weeks after group 1 had been vaccinated, and at the same time six 10-week-old spf puppies from the same source (group 3) were also challenged. Oronasal swabs were taken regularly before and after the challenge, for the isolation of bacteria and viruses, and the dogs were observed for clinical signs for three weeks after the challenge. The control dogs became culture-positive for B bronchiseptica and canine parainfluenza virus, but the isolation yields from the vaccinated group were significantly lower (P<0.05). The mean clinical scores of the vaccinated group were 61 per cent lower than the scores of group 2 (P=0.009), and 90 per cent lower than the scores of group 3 (P=0.001).