Frostbite in Chickens

Every owner thinks about winter and all the risks that come with it if you own chickens. Other articles review winterizing well and I urge you to go read those in order to adequately prepare for winter. Winter does take preparation to protect your animals from the wet and bitter cold. Frostbite becomes a risk when below 32 °F or 0 °C (freezing temperatures). It’s important to know the risks, in order to prevent. If you live in a cold area, then purchasing a cold hardy breed of chicken is essential to their survival and longevity. The cushion-combed Chantecler origin Canada is a cold hardy breed as is the rose-combed Wyandotte and walnut-combed Yokohama (Damerow, 2017). The larger single combs on chickens tend to be at more risk for frostbite. The Ancona Mediterranean breed is an example of a chicken breed at risk for frostbite. Also ducks or birds that lack feathering on the face such as Muscovy ducks are as well.

All breeds of chickens are at risk for frostbite, even cold hardy breeds if the conditions are right. Areas of the body most at risk are combs, wattles, legs, feet, and toes due to lack of feathering.

Freezing of the skin and underlying tissues potentially causing also long term nerve damage is referred to as Frostbite (Poultry DVM, 2019). As a chickens core temperature decreases, blood is shunted to vital organs for oxygenation thereby decreasing blood flow and circulation to extremities or the peripheral regions of the body leaving it at risk for frostbite. Decreased blood flow and oxygen to a tissue may lead to tissue death and gangrene evidenced by hard black tissue. This can be seen as early as a few days following injury. The severity of tissue death depends on degree of frostbite and length of exposure to freezing temperatures (Poultry DVM, 2019).

Stages of frostbite are mild, moderate, and severe.




Frostbite can resolve without sequelae or end in gangrene with tissue loss and amputation. Severity of frostbite depends on temperature, wind chill, length of exposure, wet/dry cold, immersion, age, and overall health of a chicken (Poultry DVM, 2019). There are four degrees of frostbite as described here (Laskowksi-Jones & Jones, 2018; Poultry DVM, 2019).

• First degree: This is freezing of the surface layer of skin. Combs and wattles will appear white or pale in color. The feet or legs will appear slightly reddened.

• Second degree: The skin will completely freeze and harden but not the underlying tissue.

• Third or Fourth degree: The skin and underlying tissue is affected. This is severe and tissue will appear black from gangrene. You will begin to see a line of demarcation between healthy and unhealthy tissue. The severity of the injury usually can be appreciated by 3-6 weeks.

The long term effects of frostbite in surviving tissue include: increased susceptibility to cold re-injury, sensory loss, decreased circulation, and osteoarthritis (Poultry DVM, 2019). Combs and wattles may appear bluish or purplish in color. Fertility and egg productivity can be affected by low temperatures with or without frostbite (Jacquie, 2015). These issues resolve on own when temperatures warm up.

Clinical Signs
Discoloration or blackening tips of combs, wattles, legs, feet, or toes
Reddened feet or toes
Cold or hard skin
Swelling of combs, wattles, or toes
Blood filled blisters
Limping on feet when temperatures are low

Diagnosis
See vet
Treatment

• If tissue still frozen: Rewarm in a warm water bath (body temperature 104-108°F or 40-42°C)
• Do not use direct heat (e.g. heat lamps, hair dryer, or heating pads) to rewarm.
• Do not massage affected area
• Do not touch blisters
• Do not let chickens walk on legs, feet, or toes affected by frostbite (use a sling type restraint, splinting or wrapping)
• Do not attempt to remove affected tissue to prevent exposure of healthy tissue to infection
• Do not put chicken outside again if risk of refreezing
• Place chicken in warm environment with supportive care
• Do not medicate for pain unless directed by a veterinarian as this may be harmful

* "Do not" advice cautions against the item in question due to causing more tissue damage when frostbite injury is likely.

Supportive care: Once affected tissue rewarmed, wrap and dress area. Wrap each toe separately if toes involved. Keep in warm quiet environment for rest and recovery. Do not return to cold environment. Make an appointment to see your local veterinarian. Depending on severity, the bird may require hospitalization or medication since frostbite can be painful and permanently damaging. Prophylactic antibiotics may be necessary to prevent a secondary infection. Surgical amputation may be required and performed by a veterinarian only.

Some evidence has shown that streptokinase treatment and rapid rewarming resulted in reduced tissue damage with greatest benefit seen at 12 hours of freezing and still effective up to 48 hours following injury (Poultry DVM, 2019).

Risk Factors
Adult roosters with large combs/wattles
Hens with large combs/wattles
Dehydration (use water heaters to prevent freezing water or provide fresh water 3 x day)
Poor ventilation or airflow
Condensation on coop or windows
Dripping water from beaks or water spillage (may be minimized by cup or nipple water systems)
Living in high altitudes as reduced oxygenation to capillaries
Pre-existing health conditions
(those with metabolic disorders, cardiovascular disease, or atherosclerosis are more at risk due to decreased circulation)
No access to shelter or insufficient shelter
Wind, rain, and snow (feather legged breeds more susceptible)

Prevention

• Provide protection from cold temperatures and drafts (winterize and insulate coop)
• Keep bedding dry (add straw as warmest)
• Provide adequate roosting bars in which the chicken can cover feet with feathered breast when asleep (2-4 inches wide)
• Provide windbreak free of ice and snow with a covered coop/run
• Use proper ventilation to prevent moisture build up
• Cover combs and wattles with petroleum jelly
• Check for signs of frostbite after each night of freezing temperatures
• In colder climates pick breeds that are more cold hardy and at less risk for frostbite
• Monitor temperature and humidity levels in coop (can use wireless weather station sensors)

* Chickens that are housed in uninsulated, unheated, poorly ventilated coops are more at risk for frostbite (Poultry DVM, 2019). Chickens generate moisture through breathing, droppings, and water spillage thus increasing the humidity level of the coop. When temperatures drop below freezing with increased humidity, those moisture areas freeze. Moisture from humidity tends to rest on combs, wattles, and toes also areas with the least amount of circulation resulting in frostbite. Keep clean dry top dressing of straw in coop/run during winter months as straw holds heat the best (Jacquie, 2015). Do not attempt to heat the entire coop as this may be detrimental to the health of the flock. See support measures below.

*Petroleum Jelly works by conserving heat, insulates tissue from moisture, and freezes at a lower temperature than cell fluid in combs and wattles (Damerow, 2017).

Support

Photos Courtesy of Poultry DVM

References
Andrews, C. (2012-2019). Backyard chickens and frostbite. Retrieved from https://www.raising-happy-chickens.com/backyard-chickens-frostbite.html

Calle, P.P., Montali, R.J., Janssen, D.L., Stoskopf, M.K., & Strandberg, J.D. (1982). Distal extremity necrosis in captive birds. Journal of Wildlife Diseases 18(4), 473-479.

Damerow, G. (2017). How to protect your chickens from frostbite. Retrieved from https://blog.cacklehatchery.com/how-to-protect-your-chickens-from-frostbite/

Jacquie, J. (2015). Frostbite in chickens. Retrieved from https://articles.extension.org/pages/70255/frostbite-in-chickens

Journal of American Medical Association (JAMA) (1944). High altitude frostbite. Retrieved from https://jamanetwork.com/journals/jama/article-abstract/265832

Laskowksi-Jones, L. & Jones, L.J. (2018). Frostbite: Don't be left out in the cold. Nursing 48(2), 26-33.

Poultry DVM.(2019). Frostbite. Retrieved from http://www.poultrydvm.com/condition/frostbite