Animal to Human Diseases

If a bird is sick or injured, please contact an animal services officer at 303-438-6400.

What is Avian Flu?

Avian flu, also known as bird flu, is a naturally occurring disease in birds caused by avian influenza Type A viruses. Highly pathogenic avian influenza (HPAI) viruses can spread very quickly and can cause severe disease and death in infected birds including aquatic birds, domestic poultry, and other bird species. Avian flu mainly affects wild birds and poultry, however, there have been cases in humans and other mammals. Human infections are most likely to happen in people directly exposed to infected birds or contaminated environments.

Avian Flu Outbreaks

The ongoing H5N1 avian flu outbreak is affecting wild birds, domestic poultry, dairy cattle, and some mammals across the U.S., including Colorado. While no active human or cattle cases  have been reported in Colorado in 2025, the virus has been detected in the state’s wild birds, especially Snow and Canadian geese, raptors, and vultures.  The current public health risk is low,  CDC is tracking the situation and working with states to monitor people with exposures. 

Keep up with the latest information through the frequently updated CDPHE HPAI Response web page and the Colorado Department of Agriculture web page on avian flu.

What to Do if You've Been Exposed

If you experience any symptoms in the 10 days after exposure to an infected bird/animal, visit your health care provider to talk about testing. Learn more about avian flu in humans on the Center for Disease Control webpage.

What Actions Should I Take?

• If a bird is sick or injured, please call Animal Service at 303-438-6400 
• Do not touch dead or diseased wild birds.
• If a dead bird is on your property and removal is necessary, wear a mask, eye protection , and gloves to pick up the bird.  Double bag the bird, and place the bags in municipal trash. Wash your hands immediately or use alcohol-based hand sanitizer.
• Keep pets away from sick or dead birds and areas contaminated with feces of infected birds.  Call your veterinarian if you think your pet was exposed and is showing symptoms.  For more guidance, refer to additional CDC resources.
• Those with domestic flocks, including backyard poultry, should increase biosecurity and report suspicious disease to the State Veterinarian’s office at 303-869-9130. Learn how to secure your flock at Defend the Flock.

Waterfowl hunters should take steps to minimize the risk of spreading the virus. 

• The U.S. Fish and Wildlife Service has recommendations for hunters to protect themselves from avian flu. 

Mental Health and HPAI

Bird owners struggling with stress or anxiety around HPAI can contact 988 Colorado Mental Health Line by calling or texting 988. Farmers and ranchers can receive a voucher for six free sessions with an ag-competent provider through the Colorado Agricultural Addiction and Mental Health Program at campforhealth.org.

Additional Resources

• Colorado Department of Agriculture’s Avian Flu web page
• Centers for Disease Control Avian Flu web page
• United States Department of Agriculture’s Avian Flu web page
• USDA’s Defend the Flock web page
• USDA: Found a Dead Wild Bird

Hantavirus pulmonary syndrome (HPS) is a rare but serious disease that occurs throughout the U.S. and is caused by a virus that individuals get through contact with an infected rodent's urine, droppings, or saliva. 

In the U.S., deer mice are the reservoir of the HPS. The virus is mainly transmitted to people when they breathe in air contaminated with the virus. Rodent infestation in and around the home remains the primary risk for hantavirus exposure.

Symptoms 

Early symptoms include fatigue, fever, and muscle aches. There may also be headache, dizziness, chills, nausea, vomiting, diarrhea, and abdominal pain. About half of all HPS patients experience these symptoms.

Late symptoms: Four to 10 days after the initial phase of illness, the late symptoms of HPS appear. These include coughing and shortness of breath, with the sensation of, as one survivor put it, a "tight band around my chest and a pillow over my face" as the lungs fill with fluid.

Precautions 

SEAL UP - TRAP UP - CLEAN UP!

• Rodent-proof buildings, by plugging holes or other mouse entryways.
• Clean up rodent food sources and nesting sites.
  • Keep indoor areas clean, especially kitchens. Dispose of garbage in sealed containers.
  • Store food in rodent-proof containers, including food for pets, livestock, and birds.
  • Remove rodent hiding places near your home, such as wood, junk, and brush piles. Store firewood at least 100 feet from your house. Keep vegetation around the house well-trimmed.
• Cleaning rodent-infested areas:
  • If you need to clean up any rodent infested areas, take precautions first - it is very important you do not stir up dust! Hantavirus can be spread by sweeping up rodent droppings, urine, or nesting materials. 
  • Step-by-step instructions for cleaning up after rodents safely. 
  • Conduct year-round rodent control, or hire a professional exterminator.

Additional Resources

• CDPHE: Hantavirus
• CDC: Hantavirus
• CDC: Take precautions to avoid hantavirus

Plague is caused by the bacteria Yersinia pestis, and occurs naturally in Colorado. When humans get plague, it is usually by getting bitten by an infected rodent flea or by handling an infected animal.  People and animals that visit places where rodents have recently died from plague risk getting the disease from flea bites. Dogs and cats are also susceptible to plague and may bring plague-infected fleas into the home.  The use of a veterinary-approved flea product is strongly advised.

If detected early, plague is treatable in both people and pets.  Modern antibiotics are very effective at treating plague.  

Plague is frequently detected in rock squirrels, woodrats, and other species of ground squirrels and chipmunks.  Prairie dogs are very susceptible to plague.  Since they are active above ground, if they suddenly disappear/die-off, they serve as a visible alert that plague may be present.  If you notice decreased rodent activity in an area where you normally see active rodents, contact Broomfield Public Health. 

Symptoms

Plague should be suspected when a person develops a swollen gland or node, sudden onset of high fever, chills, headache, and extreme exhaustion, and has a history of possible exposure to infected rodents, prairie dogs, rabbits, or fleas.

Precautions

• AVOID FLEAS by protecting pets with a flea treatment, and keeping pets on a leash and out of areas inhabited by rodents, such as prairie dogs and squirrels.
• STAY OUT of areas where rodents live, including prairie dog colonies. If you enter rodent prone areas, wear insect repellent and tuck pants cuffs into socks to prevent flea bites.
• AVOID ALL CONTACT with wild rodents, including prairie dogs and squirrels; do not feed or handle them.
• DO NOT TOUCH sick or dead animals.
• PREVENT RODENT INFESTATIONS around your house: clear plants and materials away from outside walls, reduce access to food items, and set traps.
• TREAT RODENT SITES around your home in consultation with a professional pest control company
• SEE A PHYSICIAN if you become ill with a high fever and/or a swollen lymph node. Plague is a treatable illness.
• SEE A VETERINARIAN if your pet becomes ill with a high fever and/or an abscess (e.g., open sore.) Pets with plague can transmit the illness to humans.

Resources

• CDPHE: Plague
• CDC: Plague web page
• CDC: Prevention Tips

Rabies is a preventable viral disease of mammals, most often spread through infected saliva from wild animals by a bite or scratch. The most common carriers of rabies are skunks, bats, raccoons, and coyotes, but all mammals are susceptible to infections, including both you and your pets. 

Rabies is caused by a virus that affects the nervous system of humans and other mammals, and is almost always fatal without treatment. Animals with rabies may appear disoriented, stagger, drool excessively, be aggressive, appear tamer than usual, or lose their fear of humans.  The classic sign of rabies is unusual behavior; for example, skunks that are usually only seen at night may be seen in the daytime. Humans, pets, horses, livestock, and many wild animals are susceptible to rabies from a bite, scratch, or contact with the saliva of an infected animal. If you believe that you, your pet, or your livestock have had contact with a rabid animal, contact your doctor or veterinarian for prompt medical treatment.

Protect Yourself, Your Pet, and Your Community

Prevent

• Visit your veterinarian with your pet on a regular basis and keep rabies vaccinations up-to-date for all dogs, cats, ferrets, horses, and livestock.
• Report stray or ill animals to Broomfield Animal Services by calling 303.438.6400.

Protect

• Do not touch wild animals, whether alive or dead.  Rabid animals do not always appear vicious.
• Do not pick up, relocate, or attempt to feed or handle any unfamiliar or wild animals (including baby animals), even if they appear friendly.
• Never touch a bat.  If you have contact with a bat, find a bat in a room, or wake up to a bat in your bedroom, report it to Broomfield Animal Services.  Please do not let the bat go - Public Health may need to test it for rabies.
• Maintain control of your pets by keeping cats and ferrets indoors and keeping dogs under direct supervision and on a leash.
• Avoid leaving food or garbage outside as it often attracts stray dogs, cats, and wildlife to your yard.

Report

• Report any wild animal acting strangely to Broomfield Animal Services at 303.438.6400.
• Contact your veterinarian if your dog, cat, ferret, horse, or livestock is bitten or scratched by a wild animal.
• Seek immediate medical attention if you are bitten or scratched, or have any contact with a bat or other wild animal.  Then contact Broomfield Public Health at 720.887.2220 as rabies post-exposure vaccinations may be needed immediately to prevent the development of rabies.

Resources

• CDPHE: Rabies
• CDC: Rabies
• AVMA: Rabies and Your Pet

Tick-borne diseases and conditions are transmitted through the bite of a tick infected with a bacteria, virus, or parasite. Ticks can be found in Colorado and throughout the U.S. and can cause a wide variety of illnesses, including Colorado tick fever, Rocky Mountain spotted fever, tularemia, and Lyme Disease. They tend to be most active in the spring and early summer and can attach themselves to the skin of people, pets, and some wild animals. It’s important for you and your family to take precautions before, during, and after spending time outdoors both in Colorado and traveling outside the state.

Preventing a Tick Bite

On people:

• Know where to expect ticks. Ticks live in grassy, brushy, or wooded areas, or even on animals. Spending time outside, walking your dog, camping, gardening, or hunting could bring you in close contact with ticks. Many people get ticks in their own yard or neighborhood. Ticks can be active year-round!
• Wear light colored, protective clothing like pants and long-sleeved shirts to help prevent ticks from attaching to your skin. 
• Use EPA approved insect repellents containing DEET, picaridin, IR3535, Oil of Lemon Eucalyptus (OLE), para-menthane-diol (PMD), or 2-undecanone whenever you plan to be outdoors and may be at risk. 
• Treat clothing and gear with products containing 0.5% permethrin for longer term protection. Permethrin can be used to treat boots, clothing and camping gear and remain protective through several washings. Alternatively, you can buy permethrin-treated clothing and gear. Do not apply permethrin directly on skin.

For more information, visit: CDC's ticks webpage

On pets: 

• Talk to your veterinarian about topical treatments to use for tick prevention on pets.
• Clear your yard of tall grasses, brush, and debris where ticks could hide.

For more information, visit: Preventing Ticks on Pets

Protection after Being Outdoors

Ticks can get into the home on clothing and pets. 

After being outdoors: 

• Check your clothing and your gear for ticks.
• Check your pet for ticks on a daily basis. 
• Check your body for ticks. Check these parts of your body and your child’s body for ticks:
  
  • Under the arms
  • In and around the ears
  • Inside belly button
  • Back of the knees
  • In and around the hair
  • Between the legs
  • Around the waist
• Shower soon after being outdoors. Showering may help wash off unattached ticks and it is a good opportunity to do a tick check.

Remove an Attached Tick 

If you find an attached tick on you or your pet, it is important to carefully remove it immediately, while ensuring it stays intact.  Learn more about removal from the CDC’s tick webpage.

• Use clean, fine-tipped tweezers to grasp the tick as close to the skin’s surface as possible. Try not to crush the tick as you work to remove it. 
• Pull the tick slowly and steadily, straight away from the skin with even pressure. Don’t twist or jerk the tick; this can cause the mouth-parts to break off and remain in the skin. If this happens, remove the mouth-parts with tweezers. If you cannot remove the mouth easily with tweezers, leave it alone and let the skin heal.
• After removing the tick, thoroughly clean the bite area and your hands with rubbing alcohol or soap and water.
• Never crush a tick with your fingers. Dispose of a live tick by putting it in alcohol, placing it in a sealed bag/container, wrapping it tightly in tape, or flushing it down the toilet.
• Monitor for new symptoms over the next several weeks and speak to your doctor if you have additional concerns.

Symptoms  

If you are bitten by a tick, it's important to watch for symptoms that may appear up to 30 days after being bitten. Some common symptoms of tick-borne illnesses are (but not limited to): rash, fever, fatigue, headache, muscle aches, and joint pain. If you develop these symptoms after a tick bite or after visiting a known tick habitat, contact your medical provider. Use the  CDC’s Tick Bite Bot to determine when to seek health care, if appropriate, after a tick bite.

Report

If you remove a tick from yourself or a pet, ticks can be sent to the Colorado Department of Public Health and Environment's Citizen Scientist Tick Surveillance Project: Tick Submission Form.

Additional Resources

• CDPHE Tick Borne Diseases
• CDC Tick Webpage
• What to do after a tick bite
• CSU Extensions Tick and Tick-borne Diseases

Tularemia is a disease that can infect animals and people.  Tularemia is caused by the bacteria Francisella tularensis, a bacteria which occurs naturally in Colorado. Rabbits and rodents are especially susceptible and can die in large numbers during outbreaks.  Tularemia is usually a disease that occurs in wildlife such as rabbits and rodents, and it can be present in the environment in soil and water.

People can get tularemia in many different ways, including during gardening and landscaping, contact with an infected animal or through a bite from an infected insect, consuming contaminated food or water, or breathing in the bacteria. The bacteria may cause pneumonia when it is inhaled, for example from mowing over an infected rabbit or rodent carcass. Ticks, biting flies, and mosquitoes have been shown to transmit tularemia between animals and humans. Tularemia is not known to be spread from person to person.

Symptoms 

• Symptoms of tularemia usually appear 3 to 5 days after exposure to the bacteria, but can take as long as 14 days.
• Symptoms may include sudden fever, chills, headaches, diarrhea, muscle aches, joint pain, dry cough, and progressive weakness.  People can also develop pneumonia with chest pain, cough, and difficulty breathing.  Additional symptoms can develop based on how a person was infected, including skin or mouth ulcers, swollen painful lymph glands, swollen painful eyes, or a sore throat.
• Tularemia infection can be severe, but is treatable with common antibiotics, especially if caught early.
• See your healthcare provider if you are ill with these symptoms.

Precautions 

• AVOID ALL CONTACT with wild rodents, including rabbits and squirrels; do not feed or handle them. Prevent pets from eating wildlife.
• DO NOT TOUCH sick or dead animals.
• WEAR SHOES & GLOVES when gardening or working outside. Always wash hands after outdoor activities.
• AVOID MOWING OVER animal carcasses, and consider using a dust mask when mowing or doing landscape work if you have seen rabbits or rodents in your yard.
• AVOID TICKS & FLEAS by protecting pets with a flea & tick treatment.
• WEAR AN INSECT REPELLENT effective against ticks, biting flies and mosquitoes. Please visit EPA's web page for more information.
• SEE A PHYSICIAN if you become ill with a high fever, swollen lymph nodes, chest pain & difficulty breathing, or other symptoms of tularemia. 
• SEE A VETERINARIAN if your pet becomes ill.

Resources

• CDPHE: Tularemia
• CDC: Tularemia

West Nile virus (WNV) is primarily a disease of birds, spread by infected mosquitoes to people; it is not transferred from person to person. The female Culex tarsalis mosquito, the species that transmits the virus, usually starts emerging in late April or early May and continues transmitting the virus until the first hard frost, which usually is in September along the Front Range. 

Protect yourself and your family from mosquito bites, especially from dusk (evening) to dawn (morning) when the mosquitoes that spread WNV are more active.

Symptoms

• Most people (70-80%) who become infected with WNV do not develop any symptoms.
• About 1 in 5 people who are infected will develop a fever with other symptoms such as headache, fatigue, body aches, joint pains, vomiting, diarrhea, or rash. Symptoms begin between 2 to 14 days after being bitten. People with milder symptoms typically recover on their own, although some symptoms may last for several weeks. 
• A small percentage of people (less than 1%) will develop serious neurologic illnesses such as encephalitis or meningitis (inflammation of the brain or surrounding tissues). 
  • The symptoms of neurologic illness can include headache, high fever, neck stiffness, disorientation, coma, tremors, seizures, or paralysis.
  • Serious illness can occur in people of any age. However, people over 60 years of age and/or people with certain medical conditions, such as cancer, diabetes, hypertension, kidney disease, and people who have received organ transplants, are at greater risk for serious illness.
  • Recovery from severe disease may take several weeks or months. Some of the neurologic effects can be permanent.
  • About 10% of people who develop neurologic infection due to WNV will die.

Treatment

See your healthcare provider if you think you have symptoms of WNV. There is no treatment, cure, or human vaccination for WNV, but healthcare providers can treat symptoms to help patients feel better and possibly recover more quickly. 

Prevention

1. DRAIN standing water around the house since that's where mosquitoes breed. Be sure to empty old tires, cans, flowerpots, clogged rain gutters, rain barrels, and toys where puddles can occur.
2. DUSK & DAWN are when mosquitoes that carry the virus are most active, so limit outdoor activities or take precautions to prevent mosquito bites.
3. DEET, picaridin, IR3535, and some oil of lemon eucalyptus and para-menthane-diol products provide the best protection. Follow label instructions.
4. DRESS in long sleeves and pants to keep mosquitoes from biting.

Additional Information on Mosquito Control

• Broomfield Public Health and Environment contracts with Vector Disease Control, which provides surveillance, monitoring, and control of mosquitoes. 
• Call the Vector Disease Control Mosquito at Hotline 303.428.5908 for any mosquito complaints or concerns.
• Watch the mosquito control video to learn more about how mosquito control activities are handled and how to protect you and your family from West Nile virus. 

Mosquito control in the City and County of Broomfield

 YouTube Video 

Resources

• CDPHE: West Nile virus
• CDC Fight the Bite
• CDC: West Nile virus

Resources

CDPHE: Animal Related Diseases