Veterinarians across the Bay Area are warning dog owners about a sharp rise in serious contagious illnesses, with leptospirosis and canine influenza at the center of their concern. Clinics from Santa Clara County to Berkeley are treating more sick dogs, and local health departments are stepping in as these infections threaten both pets and, in some cases, people. I see a pattern that links crowded dog spaces, shifting weather and gaps in vaccination, and it is putting Bay Area dogs at real risk.
The surge is not limited to one neighborhood or one disease. Reports from In Santa Clara County, In Berkeley and other parts of California point to bacterial and viral threats that spread quickly when dogs share water bowls, sniff the same grass or spend time in kennels. For owners who think of the dog park as a harmless daily routine, the new warnings suggest it is time to look more closely at vaccines, hygiene and early signs of illness.
Leptospirosis moves from background threat to front-page problem
Leptospirosis has long been a quiet worry for veterinarians, but I now see it moving into the spotlight as more Bay Area dogs fall ill. In Santa Clara County, at least one dog contracted lepto last year, and in Berkeley at least two dogs have already been infected in 2026, a pattern that signals wider spread in everyday environments rather than in rare, isolated clusters. Local clinicians describe a highly contagious bacterial disease that thrives in wet soil and puddles, which are common across the Bay Area’s mix of urban parks and hiking trails, and those conditions give the bacteria many chances to reach curious dogs that drink from or walk through contaminated water.
The concern is not limited to pets because leptospirosis can also infect people who come into contact with contaminated urine or water. Health departments across California are now sounding the alarm about this risk, warning that the same bacteria that attacks dogs can, in rare cases, cause serious illness in humans who share those spaces. When I look at the warnings tied to In Santa Clara County, In Berkeley and the broader Bay Area, the message is clear: lepto is no longer a distant problem, it is a present one that crosses the usual line between animal and human health, and it demands more attention from both veterinarians and families.
A spike in cases has Bay Area veterinarians on edge
Clinics across the Bay Area are not just seeing a few unlucky cases; they are reporting a spike in serious, contagious disease in their exam rooms. Veterinarians describe a steady flow of dogs with vomiting, fever and kidney trouble that match leptospirosis, and they link the trend to more time in shared spaces like dog parks, day care centers and boarding kennels. I hear the same worry repeated: the region’s social dog culture, which many people love, is now helping bacteria move faster from one animal to the next…