Health note: This guide is general information, not veterinary advice, and our writers are not veterinarians. If a bird is sick, injured or not improving, contact a poultry vet, and always follow product labels and your vet's instructions for any medication. How we write health content.
Fowl cholera is a contagious bacterial disease of chickens and other birds caused by Pasteurella multocida; it can kill birds suddenly or linger as a chronic infection, and treatment does not eliminate it from a flock. Often the first sign is finding several dead birds that showed no earlier illness. This guide explains the signs, how the disease gets into a flock, what a veterinarian can do, and how to prevent it.
Key Takeaways
- Fowl cholera is caused by the bacterium Pasteurella multocida.
- Sudden deaths without earlier signs are often the first clue in an acute outbreak.
- Chronically infected and carrier birds keep the disease in a flock.
- Sulfa drugs and tetracyclines prescribed by a vet can help, but deaths often resume when treatment stops.
- There is no proven herbal or supplement treatment, and enrofloxacin must never be used in chickens.
Correction: an earlier version of this article described enrofloxacin as an effective fowl cholera treatment (it has been banned in poultry since 2005), presented herbs, probiotics and supplements as effective treatments, cited an unsupported 50% mortality figure and described vaccine types and routes that do not match veterinary references; these errors have been removed.
What is fowl cholera?
Fowl cholera is a contagious bacterial disease of birds caused by Pasteurella multocida. It can appear as a fast-moving acute disease with sudden deaths or as a slower chronic infection with localized swellings.
Turkeys and waterfowl are more susceptible than chickens, and older chickens are more susceptible than young ones. That means a laying flock of adult hens is at more risk than a brooder of chicks.
Signs of fowl cholera
Acute fowl cholera
Finding several dead birds with no earlier signs is often the first indication. Birds that are still alive may show:
- Listlessness and depression
- Loss of appetite
- Ruffled feathers
- Mucus discharge from the mouth
- Diarrhea
- Faster breathing
Chronic fowl cholera
Birds that survive, or that are infected with a less virulent strain, can develop localized infections:
- Swollen wattles
- Lameness from infected joints
- Discharge from the eyes (conjunctivitis) and throat inflammation
- Twisted neck (torticollis) when the infection reaches the ear or skull
Sudden deaths and an increase in bird deaths are also key signs of avian influenza and virulent Newcastle disease, which must be reported. If birds are dying suddenly, call your state veterinarian or USDA at 1-866-536-7593 right away. Our overview of chicken diseases and symptoms covers other causes of illness.
How fowl cholera gets into a flock
The main sources of infection are chronically infected chickens and subclinical carriers, meaning birds that look healthy but carry the bacterium. Wild birds can bring it in, and mammals including rodents, pigs, dogs and cats can also carry it.
Pasteurella multocida survives long enough to spread on crates, feed bags, shoes and equipment, but ordinary disinfectants, sunlight, drying and heat kill it. Cleaning and drying equipment is therefore effective.
Diagnosis
Signs alone cannot confirm fowl cholera. Isolating P. multocida in a laboratory is the standard for confirmation, usually from a bird submitted for necropsy. Ask your veterinarian or state diagnostic laboratory how to submit a freshly dead bird. Culture also lets the lab check which antibiotics the strain responds to.
Treatment and its limits
Sulfa drugs (sulfamethazine, sulfadimethoxine) and tetracyclines (oxytetracycline, chlortetracycline) are effective against P. multocida. However, treatment does not eliminate the bacterium from a flock, and deaths often resume when treatment stops. Your veterinarian should choose the drug based on culture and sensitivity results.
Since June 11, 2023, medically important antibiotics for animals in the US require a veterinarian’s prescription, so treatment starts with a call to your vet. Follow the egg and meat withdrawal times on the label or set by your veterinarian.
- Never use enrofloxacin or any other fluoroquinolone in chickens. FDA withdrew enrofloxacin’s approval for poultry in 2005 and prohibits extra-label fluoroquinolone use in food animals.
- Any drug not labeled for chickens is extra-label and may be used only under a veterinarian’s direction, with a withdrawal time the vet sets.
- There is no proven non-antibiotic treatment. Herbs such as oregano and garlic, probiotics and supplements are not treatments for fowl cholera, and relying on them can delay proper care.
Carriers, relapse and eradication
This is the part many keepers are not told: birds that recover can remain carriers, and treated flocks often relapse. Eradicating fowl cholera from a property requires depopulation (removing all birds), followed by cleaning and disinfection of the coop and equipment before new birds arrive.
Discuss the options with your veterinarian. For a small flock, that may mean humane euthanasia of the affected birds by a vet, a thorough clean-out, and restocking with birds from a reliable source. Do not sell or give away birds from an infected flock.
Preventing fowl cholera
- Buy birds only from reliable sources, and keep new birds separate before mixing them with your flock.
- Keep rodents, wild birds, pets and other animals out of the coop and away from feed.
- Clean and dry crates, feeders and waterers, and use dedicated coop shoes.
- Where fowl cholera is a known problem, ask your vet about vaccination. In chickens, live vaccines are given by wing-web inoculation, and adjuvanted bacterins are also used.
See our guide to biosecurity for chickens for a full routine.
FAQs
Can chickens survive fowl cholera?
Some do, but survivors can stay chronically infected or become carriers that keep the disease in the flock.
Can I use enrofloxacin (Baytril) for fowl cholera?
No. FDA withdrew enrofloxacin’s approval for poultry in 2005 and prohibits extra-label use of fluoroquinolones in food animals, including backyard chickens.
How long does Pasteurella multocida last in a coop?
Long enough to spread on crates, feed bags, shoes and equipment, but ordinary disinfectants, sunlight, drying and heat kill it, so thorough cleaning and drying are effective.
Is there a vaccine for fowl cholera?
Yes. Live attenuated vaccines are given to chickens by wing-web inoculation, and adjuvanted bacterins are also used. Ask your veterinarian whether vaccination suits your flock.
Conclusion
Fowl cholera can wipe out birds quickly and can linger in carriers after an outbreak. Get a lab diagnosis through your vet, use only prescribed antibiotics, and plan for depopulation and a thorough clean-out if you want the disease gone for good.
Sources
- Merck Veterinary Manual: Fowl Cholera
- FDA: Withdrawal of Enrofloxacin for Poultry
- FDA: The Ins and Outs of Extra-Label Drug Use in Animals
- FDA: GFI #263 Frequently Asked Questions for Farmers and Ranchers
- USDA APHIS: How to Report Sick Birds (Defend the Flock)
Checked September 2026. Labels change, so always read the label on the product you buy. See our editorial policy for how we research health articles.
