Mojave River Hatchery raceway

Bacterial Outbreak at CDFW Hatcheries Temporarily Halts Fish Stocking in Southern California

Several California Department of Fish and Wildlife (CDFW) fish hatchery facilities in the eastern Sierra and Southern California are battling a bacterial outbreak that has the potential to cause significant losses to both hatchery and wild fish populations. The outbreak of Lactococcus garvieae, which is similar to streptococcus, has sickened fish at the Mojave River Hatchery and has been detected at both the Black Rock and Fish Springs hatcheries. A fourth CDFW hatchery, Hot Creek Hatchery, was originally quarantined out of caution but after testing that quarantine has been lifted.

The L. garvieae bacteria has never before been detected in fish in California, and CDFW must take a cautious and careful approach to ensure the protection of the state’s aquatic resources – fish, hatchery facilities and public waterways. Infected fish can show symptoms including bulging eyes, lethargic or erratic swimming and increased mortality, or be asymptomatic and show no signs of infection depending on a several factors including water temperature and stress. Fish-to-human transmission of this bacteria is rare and unlikely.

Fish stocking has temporarily been halted from the facilities under quarantine while hatchery staff treats the affected fish populations and takes measures to prevent the spread of the bacteria. Planting will resume when fish have recovered from the infections and fisheries pathologists have determined that they no longer present a threat to the environment.

“This is a challenge for our hatcheries because the bacteria is previously unknown in California, and we don’t have tried-and-true strategies on hand to combat it,” said Jay Rowan, environmental program manager for CDFW’s Hatchery Production and Fish Health Laboratory. “A successful approach will have three components: Treating the affected fish at the hatcheries, finding the origin of the outbreak, and planning ahead to contain and prevent the spread of the bacteria. Unfortunately, we may be in for a long battle here, which means there will not be a lot of fish plants in the near future in the eastern Sierra and Southern California. I wish we could give anglers a target date for when we think we can start planting again, but it’s all up to how fast and how well the fish respond to the treatments.”

Current treatment measures at the hatcheries include keeping water temperatures low, reducing stress due to crowding and other factors, introducing antibiotic medication and special diet in order to assist the fish in fighting off the infection. CDFW is currently investigating the source of the outbreak. For additional information, please see CDFW’s frequently asked questions about the L. garvieae outbreak.

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Media Contacts:
Jay Rowan, CDFW Hatchery Program, (916) 212-3164
Harry Morse, CDFW Communications, (208) 220-1169

riparian brush rabbit

Deadly Disease Detected in California Wild Rabbits for the First Time

The California Department of Fish and Wildlife (CDFW), in conjunction with the California Animal Health and Food Safety Lab, San Bernardino has diagnosed Rabbit Hemorrhagic Disease (RHD) in a black-tailed jackrabbit carcass submitted from private property near Palm Springs in early May. Samples submitted to the National Veterinary Services Laboratory in Plum Island, New York, confirmed the presence of the RHD virus type 2 (RHDV2) in California for the first time. This disease is highly contagious and often lethal to both wild and domestic rabbits. The carcass that was tested was one of about 10 dead jackrabbits observed on the Palm Springs property.

RHDV2 is not related to coronavirus; it is a calicivirus that does not affect humans or domestic animals other than rabbits. At this time, no other California rabbit populations are known to be infected, but the disease has spread quickly in other states, prompting CDFW biologists to prepare for more reports in the coming months. A “quick facts” reference guide can be found on CDFW’s website.

Since March 2020, RHDV2 has caused mortalities of both wild and domestic rabbits in New Mexico, Colorado, Arizona, Texas and Mexico. Deaths of both wild rabbits and jackrabbits have occurred. Infected rabbits and jackrabbits may exhibit no symptoms leading up to their sudden death, or may suffer from fever, swelling, internal bleeding and liver necrosis. The range of susceptible species in North America is currently unknown, but all rabbit, jackrabbit, hare and pika species are likely susceptible.

CDFW Senior Wildlife Veterinarian Deana Clifford noted the introduction of RHDV2 to California could significantly impact wild rabbit populations, particularly those already at risk, such as the endangered riparian brush rabbit (Sylvilagus bachmani riparius) and those with limited distribution in the state, such as the pygmy rabbit (Brachylagus idahoensis).

“Unfortunately, we may also see impacts to species that depend on rabbits for food, as rabbits are a common prey species for many predators,” noted Dr. Clifford.

CDFW will carefully monitor the progression of RHDV2 in California, including investigating and testing rabbits found dead, monitoring populations of endangered rabbits and working with partners, including the U.S. Fish and Wildlife Service, the California Department of Food and Agriculture (CDFA) and the U.S. Department of Agriculture.

Public reports are an extremely helpful tool as wildlife veterinarians monitor the situation. CDFW is asking anyone who lives, works or recreates in wild rabbit habitat to report any sightings of sick or dead rabbits to CDFW’s Wildlife Investigations Laboratory. To report sightings of sick or dead wild rabbits, hares or pikas contact the CDFW Wildlife Investigations Lab at (916) 358-2790 or file an online mortality report through CDFW’s website.

Outdoor recreationists should take precaution when hiking, camping or backpacking and not handle or disturb carcasses to minimize the potential spread of RHDV2. Additionally, hunters should take precautions to prevent spreading the virus, such as wearing gloves when field dressing rabbits, washing hands and burying remains onsite so that scavengers cannot spread the virus. The virus is hardy and can remain viable on meat, fur, clothing and equipment for a very long time, making it easily transmissible to other areas.

In California, hunting season for brush rabbits and cottontails opens July 1 and runs through the last Sunday in January. The season is open statewide, except for a closed area in the Central Valley near the riparian brush rabbit range. Hunting season for jackrabbits is year-round and statewide.

A vaccine for RHDV2 is not currently available in the U.S., thus domestic rabbit owners should practice good biosecurity measures to protect their animals from this disease, such as washing hands before and after working with rabbits, not sharing equipment with other owners and keeping their rabbits isolated from wild or feral rabbits.

Domestic rabbit owners who have a sick rabbit should contact their veterinarian. If domestic rabbits are found dead, please contact the local CDFA Animal Health Branch or call (916) 900-5002.

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Media Contacts:
Dr. Deana Clifford, CDFW Wildlife Investigations Laboratory, (916) 358-2378
Kirsten Macintyre, CDFW Communications, (916) 804-1714

Riparian brush rabbit photo courtesy of Moose Peterson. All rights reserved.

raccoon eating from a dog bowl

Distemper Cases Rise Among California’s Foxes, Raccoons, Skunks

Residents Reminded to Vaccinate Pets, Remove Wildlife Attractants

The California Department of Fish and Wildlife (CDFW) is reporting an unusually high number of canine distemper virus (CDV) cases in wildlife populations throughout the state. CDV can infect a wide range of domestic and wild carnivores, including some non-canids. Gray foxes, raccoons and skunks are the most commonly affected species.

Unvaccinated domestic dogs can potentially contract the disease through contact with food or water bowls that are “shared” with infected wild carnivores. Pet owners should be particularly vigilant in their efforts to keep their domestic animals from coming into contact with wildlife. CDV is not transmissible to humans.

“Keeping dogs up to date on vaccinations not only protects pets, it protects wildlife,” said CDFW Senior Wildlife Veterinarian Deana Clifford. “Wild animals can spread distemper to domestic dogs, but unvaccinated domestic dogs can also spread the disease to wild animals.”

Dr. Clifford noted that distemper is the most common disease CDFW finds as the cause of death in California’s carnivores. Large outbreaks of distemper may temporarily reduce some local carnivore populations, thus wildlife biologists and veterinarians monitor reports of sick animals and confirm disease cases when possible to track potential impacts.

Transmission of CDV typically occurs similar to the common cold, via inhalation of infected respiratory droplets or direct contact with saliva, nasal discharge and tears. Occasionally other body fluids (feces and urine) contain the virus. Environmental transmission of canine distemper is rare because the virus does not survive long in the environment. For this reason, CDV presents more of a problem for dense wild carnivore populations as close contact between animals is necessary to spread the disease. While distemper may occur at any time of year, CDV is more common in adult animals during the winter and is thought to be more common in juvenile animals in the spring and summer.

Distemper can cause respiratory, neurologic and gastrointestinal illness. Clinical signs may vary depending on the strain of the virus, the environment, the host species and the age of the infected animal. Signs include (but are not limited to) depression, fever, labored breathing, diarrhea, anorexia, incoordination, moving in small circles, yellow to clear discharge from the nose and eyes, and crusting on the nose, eyes, mouth or footpads. There is no treatment for sick animals except supportive care. Infected animals may or may not survive the illness. Animals with the virus may not show clinical signs but can still spread the virus for up to 90 days.

In addition to removing food and other attractants, CDFW urges the public to keep a safe distance from sick or injured wild animals, as animals that are ill or feel threatened may act aggressively. Please report the sick animal’s behavior and location to the closest CDFW office and/or to a local animal control agency, as soon as possible.

Any wildlife encounter that is an emergency should be reported to 9-1-1. For non-urgent questions concerning wildlife, please contact your local CDFW Regional Office or your local animal control service. Additional information about living with wildlife can be found on CDFW’s website.  If you are bitten or scratched by a wild animal, please wash the wound vigorously with soap and water and consult a physician and/or contact your County Public Health Department. Neurologic signs of CDV may not be distinguishable from rabies virus infection, which is a public health risk.

Do not handle carcasses of wild animals with bare hands. CDFW’s has protocol for safe handling and disposal of carcasses on its website.

For questions regarding distemper in wildlife or concerns about sick animals, contact CDFW’s Wildlife Investigations Laboratory at (916) 358-2790.

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Media Contact: 
Kirsten Macintyre, CDFW Communications, (916) 322-8988

California kingsnake infected with Snake Fungal Disease

Snake Fungal Disease Detected in California

The California Department of Fish and Wildlife (CDFW) has confirmed the state’s first case of Snake Fungal Disease (SFD) in a California kingsnake (Lampropeltis californiae) from Plymouth, Amador County. The snake, which was emaciated and suffering from severe skin disease, was found by a member of the public on the side of the road and submitted for rehabilitation to Tri County Wildlife Care. Given its poor prognosis and the potential presence of SFD, the snake was humanely euthanized by CDFW’s Wildlife Investigations Laboratory and sent to the University of Illinois, where post-mortem examination and testing confirmed it was infected with the Ophidiomyces ophiodiicola fungus that causes SFD. In addition, this week the fungus was detected on the skin and in tissues from a Florida watersnake (Nerodia fasciata pictiventris) found deceased and collected by CDFW from Folsom, Sacramento County, suggesting the original case was not isolated.

SFD is a newly emerging disease in snakes. Cases may be mild to life-threating. Visible signs may include scabs, skin ulcers or nodules, crusted scales, discolored scales, cloudy eyes and a swollen or disfigured face. The infection may cause the upper layer of infected skin to shed repeatedly. Affected snakes are often emaciated, possibly due to decreased ability to capture prey, and often rest in open, unprotected areas where they are exposed to adverse weather and predators.

The Ophidiomyces ophiodiicola fungus lives in soil and can be transmitted to snakes through skin abrasions or through direct contact with other infected snakes. SFD can also be passed from mother to offspring at birth in some species. Snake species that share dens may be at higher risk than solitary species.

First characterized in 2008, SFD has been detected in more than 30 snake species in the U.S. and Europe. The fungus is present in at least 23 states, primarily in eastern states and the Midwest, although in 2018 it was also detected in Idaho and in southern Ontario, Canada. This detection in California is the furthest west the disease has been confirmed.

Although SFD has caused significant mortalities in species of conservation concern, such as the Timber Rattlesnake (Crotalus horridus) and federally threatened Eastern Massasauga (Sistrurus catenatus), other species may only exhibit mild infections.

It is unknown if SFD will impact snake populations in California. CDFW will be working with wildlife rehabilitators, academic and agency partners, and others who work with snakes to increase surveillance for SFD in California and implement appropriate precautions to minimize risk for human-caused spread among snakes. There is no evidence that SFD is transmittable from snakes to humans.

Although members of the public should avoid directly handling or disturbing snakes, they can assist CDFW’s efforts by reporting sightings of snakes with skin sores or unusual behavior.

As a reminder, releasing any animals that have been in captivity, even temporarily, requires prior written approval by CDFW.

More information on SFD is available at:

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Media Contacts:
Laura Patterson, CDFW Nongame Wildlife Program, (916) 341-6981

Dr. Deana Clifford, CDFW Wildlife Investigations Lab, (916) 358-2378
Kirsten Macintyre, CDFW Communications, (916) 322-8988

CDFW Expands Statewide Sampling for Chronic Wasting Disease

The California Department of Fish and Wildlife (CDFW) is increasing the scope of its monitoring and testing efforts for Chronic Wasting Disease (CWD) in California’s deer and elk herds.

“While California has never had a report of CWD, increased testing is needed to establish with a high degree of certainty that there are no deer with CWD in California,” said CDFW Wildlife Veterinarian Brandon Munk. “Keeping this disease out of our state is a top priority, both for wildlife managers and for hunters.”

CWD is always fatal to deer and elk, and is an ongoing concern for hunters and managers throughout the country. Once CWD enters a herd, it is nearly impossible to eradicate. Although there are no known cases of CWD being transferred to humans, the Centers for Disease Control and Prevention (CDC) recommends not consuming meat or organs from any animal that tests positive for CWD.

CDFW’s Wildlife Investigations Laboratory has set an ambitious goal to test 600 deer statewide during this year’s hunting seasons and increasing that number to 2,000 statewide in the upcoming years.

Continued hunter cooperation will be key to achieving the CWD deer testing goals. CDFW will set up check stations during the various deer seasons, and hunters will be asked to bring their deer in for the quick removal of a lymph node for testing. CWD testing of hunter-taken deer is voluntary, and no meat is taken.

Information about specific locations and times of operation of CWD check stations in each of the state’s deer zones and control hunt areas will appear on CDFW’s website. Hunters can also contact regional CDFW offices to get check station schedules. Some offices may also offer onsite deer testing.

Some professional meat processors and butchers throughout the state are also partnering with CDFW to take samples from deer at the hunter’s request. Hunters who may be unable to visit a check station or CDFW regional office for sampling are encouraged to ask their butcher ahead of time if sampling is available at the time of processing.

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Media Contacts:
Brandon Munk, CDFW Wildlife Investigations Lab, (916) 358-1194
Nathan Graveline, CDFW Big Game Program, (916) 445-3652
Kirsten Macintyre, CDFW Communications, (916) 322-8988