Plague

flea

Plague is a highly infectious disease caused by bacteria carried by rodents such as ground squirrels, chipmunks, wood rats, and mice. A few ways plague can be transmitted to humans or pet include:

  • Bites from infected fleas
    • Hungry fleas will leave a sick or dead rodent to find new blood meals from humans
  • Direct contact with sick or dead animals
    • Plague bacteria in the blood, urine, or saliva of an infected animal can enter cuts and abrasions on humans
  • Pet involvement
    • Infected rodents fleas can be brought into a home or campsite by a dog or cat
    • Plague pneumonia can be transmitted by a sick cat that is coughing and sneezing

The Vector Control Program routinely collects and tests fleas and blood samples from squirrels in our local mountains and campgrounds. If tests come back positive for plague, park rangers are notified, squirrel burrows may be treated for fleas, and warning signs are posted to inform the public on how to avoid fleas and protect themselves and their pets from this serious disease.

symptoms of plague

 

 

Symptoms

Symptoms include chills, fever, headache, muscle aches, weakness, and most commonly swollen and tender lymph nodes (called buboes). This stage is called the bubonic plague. Plague symptoms usually appear 2 to 6 days after infection. Plague is treatable when found early.

An animal with plague will become very ill, may stop eating and will have a fever. Swollen lymph glands may occur, generally in the neck area.

Inform your veterinarian if a pet becomes sick following a visit to a plague area. 

Prevention

  • Avoid known plague areas.
  • Use flea control products on pets.
  • Avoid contact with wild animals and their fleas, especially sick or dead rodents.
  • Use caution when handling a sick pet that has been in a plague area.
  • Avoid face-to-face contact with sick pets or sick humans.
  • Report sick or dead animals to park rangers or the Vector Control Program.
  • Contact a physician immediately if you become ill within 7 days of being in a plague area.
plague warning at trailhead

Control

  • State and local vector control programs monitor plague activity. Rangers and park employees are trained to watch for sick or dead rodents. 
  • The Vector Control Program routinely collects and tests fleas and blood samples from squirrels in our local mountains and campgrounds.
  • Warnings will be posted by park rangers or health officials in areas where plague is found. Use caution when entering these areas.
  • Flea powder put into rodent burrows may be used to control fleas carrying plague. The powder gets in the rodents' fur after they enter, killing fleas inside the burrow. This is very effective and does not harm rodents.

 

Plague Positives
 

2020 Plague Positve Rodents 

No plague potitives have been detected to date in 2020

2019 Plague Positive Rodents

No plague positives were detected in 2019.

2018 Plague Positive Rodents

Date Community Area Location Species
10/10/2018 Tecate Border Area  Big-eared woodrat

2017 Plague Positive Rodents

Date Community Area Location Species
09/27/2017 Palomar Doane Campground California Ground Squirrel
08/24/2017 Palomar Cedar Grove Campground California Ground Squirrel

2016 Plague Positive Rodents

No plague positives were detected in 2016

2015 Plague Positive Rodents

Date

Community Area

Location

Species

06/24/2015* Palomar Cedar Grove Campground California Ground Squirrel

*Denotes the re-capture of a previously tested positive squirrel.

Squirrel On Palomar Mountain Tests Positive for Plague

2014 Plague Positive Rodents

Date Community Area Location Species
09/14/2014 Palomar Doane Valley Campground California Ground Squirrel
09/14/2014* Palomar Doane Valley Campground California Ground Squirrel
07/15/2014 Palomar Camp Palomar California Ground Squirrel
07/15/2014 Palomar Camp Palomar California Ground Squirrel
07/15/2014* Palomar Camp Palomar California Ground Squirrel
07/15/2014* Palomar Camp Palomar California Ground Squirrel
07/15/2014 Palomar Cedar Grove Campground California Ground Squirrel
07/15/2014* Palomar Cedar Grove Campground California Ground Squirrel
07/15/2014 Palomar Fry Creek Campground California Ground Squirrel
07/15/2014 Palomar Doane Valley Campground California Ground Squirrel
07/15/2014 Palomar Doane Valley Campground California Ground Squirrel
06/30/2014 Palomar Camp Palomar California Ground Squirrel
06/30/2014 Palomar Camp Palomar California Ground Squirrel

*Denotes the re-capture of a previously tested positive squirrel.

Squirrels Test Positive for Plague in 2014

2013 Plague Positive Rodents

Date

Community Area

Location

Species

09/17/2013*

Palomar

Cedar Grove Campground

California Ground Squirrel

09/17/2013

Palomar

Cedar Grove Campground

California Ground Squirrel

09/17/2013

Palomar

Cedar Grove Campground

California Ground Squirrel

06/13/2013

Palomar

Fry Creek

California Ground Squirrel

06/12/2013

Palomar

Doane Campground

California Ground Squirrel

06/12/2013

Palomar

Cedar Grove Campground

California Ground Squirrel

06/12/2013

Palomar

Cedar Grove Campground

California Ground Squirrel

05/09/2013

Palomar

Cedar Grove Campground

California Ground Squirrel

*Denotes the re-capture of a previously tested positive squirrel.

2012 Plague Positive Rodents

Date

Community Area

Location

Species

07/26/2012

Palomar

Doane Campground

California Ground Squirrel

07/25/2012

Palomar

Cedar Grove Campground

California Ground Squirrel

07/25/2012

Palomar

Cedar Grove Campground

California Ground Squirrel

04/12/2012

Palomar

Cedar Grove Campground

California Ground Squirrel

2011 Plague Activity - none to report

2010 Plague Positive Rodents

Date

Community Area

Location

Species

05/06/2010

Palomar

Doane Campground

California Ground Squirrel

2009 Plague Positive Rodents

Date

Community Area

Location

Species

06/11/2009

Palomar

Doane Campground

California Ground Squirrel

06/11/2009

Palomar

Doane Campground

California Ground Squirrel

04/02/2009

Palomar

Doane Campground

California Ground Squirrel

2008 Plague Positive Rodents

Date

Community Area

Location

Species

10/22/2008

Palomar

Doane Campground

California Ground Squirrel

10/22/2008

Palomar

Doane Campground

California Ground Squirrel

09/24/2008

Palomar

Doane Campground

California Ground Squirrel

08/04/2008

Palomar

Cedar Grove Campground

California Ground Squirrel

07/18/2008

Palomar

Doane Campground

California Ground Squirrel

07/15/2008

Palomar

Doane School Camp / Palomar Mtn.

California Ground Squirrel

06/26/2008

Palomar

Doane Campground

California Ground Squirrel

06/05/2008

Palomar

Doane Campground

California Ground Squirrel

06/05/2008

Palomar

Doane Campground

California Ground Squirrel

Plague Activity Map (2008 through 2011)


Questions?

  (858) 694-2888

  vector@sdcounty.ca.gov

Flea by Andrei Savitsky
Plague symptoms by Mikael Häggström