• Disease Prevention: Can prevent severe, irreversible organ damage such as acute kidney failure, liver failure, and pulmonary hemorrhage.
• Public Health (Zoonosis): Because the disease can spread from animals to humans, vaccinating dogs helps reduce environmental shedding and protects owners.
• Facility Requirements: Many boarding facilities, dog daycares, and shelters now require proof of annual leptospirosis vaccination for entry.
• Import/Export Regulations: Vaccination may be necessary to meet state or international requirements for transporting or importing dogs. 

ADMINISTRATION

• Injection Site: Usually given under the skin (subcutaneously), often in the rear leg (left rear is common for lifestyle vaccines).
• Initial Series: Young dogs and unvaccinated adults need two shots, spaced 2 to 4 weeks apart, to build immunity.
• Boosters: Annual boosters are usually recommended to maintain protection, though the exact schedule can vary, so ask your vet.
• Type: Most are killed (inactivated) vaccines, protecting against specific bacterial serovars, reducing severity, but not always preventing infection entirely.