INTRODUCTION
Most commercially available canine leptospira vaccines are effective at controlling
clinical disease and preventing mortality. Only a few claim to control infection or
renal excretion; important parameters in limiting the spread of this zoonotic disease.
Additionally, there are concerns about whether vaccine immunity persists for a full 12
months. The following studies investigate the ability of a new European tetravalent
vaccine (Nobivac® L4 – MSD Animal Health) to control infection in dogs following
challenge with strains from serogroups Canicola, Icterohaemorrhagiae,
Grippotyphosa and Australis at 12 months post-vaccination.

MATERIALS AND METHODS
For each study two groups of conventional beagle dogs,were used. One group was
subcutaneously vaccinated with Nobivac DHPPi reconstituted in Nobivac L4 at 6 and
10 weeks. The second (control) group was vaccinated with just Nobivac DHPPi. In
each study dogs were challenged with a pathogenic strain from one of the four
serogroups, 12 months after the second vaccination. Samples of blood, serum and
urine were collected at intervals during the four weeks following challenge and were
evaluated for the presence of challenge organisms or leptospiral antigen by culture
and PCR.

CONCLUSION
Vaccination of dogs with Nobivac L4 is effective at reducing infection post-challenge
for at least 12 months.