Illnesses and deaths from the West Nile Virus are again on the rise.
Officials have noted another increase in the disease among California horses.
After a drop in late September, disease reports accelerated last week.
Another 25 horses died from West Nile, including eight in Sacramento County alone.
The disease has now killed more than 200 California horses this year and sickened nearly 300 more.
Unlike humans, however, horses can be vaccinated against the virus.
Meanwhile, health officials in Calaveras County are reporting another three birds that have tested positive for the West Nile Virus.
That makes the total seven for infected dead birds in Calaveras County, and eight in Tuolumne County.
The finding is significant, according to public health director Colleen Tracy, because of the number of birds found in a short period of time.
The virus has still not been found in horses or humans so far in Calaveras County or Tuolumne County.
Officials still say it´s a good idea to use mosquito repellant until the end of mosquito season, at the end of October.