For dogs at high risk for leptospirosis, which has diffuse symptoms and can cause liver and kidney failure – if caught too late, Dr. Ron Schultz of University of Wisconsin recommends using the four-way vaccine (which covers the L. icterohaemorrhagiae, L. canicola, L. grippotyphosa, and L. pomona serovars). It should be given first at 14 to 15 weeks (but not before 12 weeks), and repeated three to six weeks later. If the second dose is given more than six weeks after the first one, the two-dose series needs to be repeated.
Subsequent doses are administered at one year, and then annually thereafter, as the duration of immunity is relatively short-lived.
In high risk exposure areas, the clinical incidence is about 1:1000-2500 dogs; whereas the general risk is only about 1:5000-10,000 dogs. Although positive MAT serovar titers have ascribed leptospirosis to the L. autumnalis and L. Bratislava servoars, these do not produce clinical disease.
Furthermore, true clinical cases of leptospirosis have MAT serological titers of at least 1:1600 or higher, and an 8 to16-fold rise in titer three to four weeks later is needed to confirm the disease.
Even so, Schultz notes, “I find there’s still a fairly high percentage of dogs that do not respond to the 4-way vaccine. In addition, of all the bacterin vaccines, leptospirosis causes the most adverse reactions.”
Ronald D. Schultz, Professor and Chair
Department of Pathobiological Sciences
School of Veterinary Medicine
University of Wisconsin-Madison
2015 Linden Drive West
Madison, WI 53706
Dr. Ron Schultz is a friend and colleague of Dr. Dodds. He is the Principal Investigator for The Rabies Challenge Fund and the Professor and Chair, in the Department of Pathobiological Sciences, at the University of Wisconsin-Madison School of Veterinary Medicine.