Veterinary advice should be sought from your local veterinarian before applying any treatment or vaccine. Not sure who to use? Look up veterinarians who specialize in poultry using our directory listing. Find me a Vet

Ammonia Toxicity

Other Names: Ammonia Blindness, Ammonia-induced Conjunctivitis, Keratoconjunctivitis, Ammonia Burn

Ammonia toxicity is an inflammatory eye condition in chickens. It is caused by exposure to prolonged or high amounts of ammonia fumes. Ammonia concentrations above 25 ppm are toxic to chickens.

Ammonia has a distinctive, pungent smell and is known for its irritating effect on the respiratory system, eyes, and mucus membranes. Besides its incorporation into many household and industrial cleaners and window-cleaning products, ammonia is naturally produced within animal droppings.

When chickens are housed in confined, indoor spaces with accumulated manure, they are often exposed to high concentrations of ammonia, especially when the area is infrequently or inadequately cleaned out on a regular basis. There are several factors that affect the ammonia concentration in the air in chicken coops which include the type of bedding substrate used, bird activity, the frequency of manure removal, humidity level, surface area of the stored manure, ventilation rate, manure handling, the number of chickens, and the pH of the manure produced.

Ammonia toxicity usually occurs in both of the chicken's eyes. The main clinical symptom is the inflammation of the cornea and conjunctiva of the eye (conjunctivitis). Young, growing chicks are more susceptible to ammonia damage then adult chickens. Chickens are more prone to developing ammonia toxicity during the winter season, due to increased time spent indoors, with reduced ventilation and accumulated manure.

Clinical Signs

Crusty eyes

Swollen eyelids

Rubbing heads against wings

Gray cloudy-looking cornea

Reddened eyes

Sensitive to light

Blindness

Diagnosis

History
Clinical signs
Eye exam

Reported Cases

Case 1: Ammonia Toxicity in a Chickens Excess ammonia was the suspected cause of respiratory signs and increased mortality in a flock of 20-month-old layers and conjunctivitis and swollen eyes in a flock of 26-day-old broiler chickens. Ammonia damages the tracheal, sinus, nasal, conjunctiva and corneal epithelium, removes the cilia from the respiratory epithelium and causes excess mucus production which was found in both groups of birds submitted to the diagnostic lab. Ref

Case 2: Ammonia Toxicity in a Broiler chicks Ammonia toxicity was diagnosed in several 18- to 21-day-old broiler chicks. The chicks appeared sleepy and had their eyes closed. The eyelids were edematous and congested and the cornea had erosions. Reused and wet litter in combination with poor ventilation was the main contributing factors for this condition. Ref

Case 3: Ammonia Toxicity in a Chickens Corneal erosions due to increased ammonia levels in the house was diagnosed in 13 to 15-week-old breeder replacement chickens. The birds were reluctant to open their eyes, had swollen and reddened eyelids and the corneas had roughened surface. Increased ammonia in the house was attributed to increased moisture in the litter and decreased ventilation due to a cold spell experienced over a one to two week period. Ref

Treatment

Name	Summary
Supportive care	Isolate the bird from the flock and place in a safe, comfortable, warm location (your own chicken "intensive care unit") with easy access to water and food. Limit stress. Call your veterinarian.
Yucca (Yucca schidigera) extract	Add to diet at 100-200 mg/kg of feed to reduce ammonia levels released by the birds.	M Saeed et al., 2018; H Chepete et al., 2012; M Cabuk et al., 2004;
Management changes	Clean/change coop litter/bedding more often, consider switching to a different type of material. Peat works best for reduction of ammonia levels.	Mönki J, Saastamoinen M, Karikoski N, et al., 2021

Support

Prevention

Add 100 g/kg of natural zeolites (clinoptilolite) to the bedding litter to help reduce ammonia levels.
Ensure proper ventilation and provide dry, clean bedding that is regularly changed.
Do not overcrowd birds
Add yucca (Yucca schidigera) extract to diet of birds.
Use peat as a substrate material. It has a good capacity to bind ammonia, a feature based on its naturally low pH value.

Prognosis

It depends on how quickly it is discovered and treated.

Scientific References

Zhou, Ying, et al. . The alterations of tracheal microbiota and inflammation caused by different levels of ammonia exposure in broiler chickens Poultry Science (2020)
Liu Z, Liu G, Cai H, Shi P, Chang W, Zhang S, Zheng A, Xie Q, Ma J.. Paecilomyces variotii: A Fungus Capable of Removing Ammonia Nitrogen and Inhibiting Ammonia Emission from Manure. PLoS One (2016)
Schneider AF, Almeida DS, Yuri FM, Zimmermann OF, Gerber MW, Gewehr CE.. Natural zeolites in diet or litter of broilers. Br Poult Sci. (2016)
Skóra J, Matusiak K, Wojewódzki P, Nowak A, Sulyok M, Ligocka A, Okrasa M, Hermann J, Gutarowska B.. Evaluation of Microbiological and Chemical Contaminants in Poultry Farms. Int J Environ Res Public Health (2016)
Gutiérrez-Zapata DM, Galeano-Vasco LF, Cerón-Muñoz MF.. Semiparametric Modeling of Daily Ammonia Levels in Naturally Ventilated Caged-Egg Facilities. PloS One (2016)
Dunlop MW, Blackall PJ, Stuetz RM.. Water addition, evaporation and water holding capacity of poultry litter. Sci Total Environ (2015)
Ziganshina EE, Belostotskiy DE, Ilinskaya ON, Boulygina EA, Grigoryeva TV, Ziganshin AM.. Effect of the Organic Loading Rate Increase and the Presence of Zeolite on Microbial Community Composition and Process Stability During Anaerobic Digestion of Chicken Wastes. Microb Ecol. (2015)
David B, Mejdell C, Michel V, Lund V, Moe RO.. Air Quality in Alternative Housing Systems may have an Impact on Laying Hen Welfare. Part II-Ammonia. Animals (Basel). (2015)
Wei FX, Hu XF, Xu B, Zhang MH, Li SY, Sun QY, Lin P.. Ammonia concentration and relative humidity in poultry houses affect the immune response of broilers. Genet Mol Res. (2015)
Arteaga V, Mitchell D, Armitage T, Tancredi D, Schenker M, Mitloehner F.. Cage Versus Noncage Laying-Hen Housings: Respiratory Exposures. J Agromedicine. (2015)
Shao D, He J, Lu J, Wang Q, Chang L, Shi SR, Bing TH.. Effects of sawdust thickness on the growth performance, environmental condition, and welfare quality of yellow broilers. Poult Sci. (2015)
U.S. National Library of Medicine. Ammonia Tox Town (2014)
CAHFS Connection April 2013 Issue. California Animal Health & Food Safety (2013)
. Ammonia Agency for toxic substance and disease registry (2011)
Zhang, H. F., Jiao, H. C., Song, Z. G., & Hai, L. I. N. . Effect of alum-amended litter and stocking density on ammonia release and footpad and hock dermatitis of broilers. Agricultural Sciences in China (2011)
Moore, P. A., Miles, D. M., Burns, R., Pote, D., & Berg, K. Evaluation and management of ammonia emissions from poultry litter.. Proceedings of the Workshop on Agricultural Air Quality: State of the Science (2006)
Weaver, W. D., & Meijerhof, R. The effect of different levels of relative humidity and air movement on litter conditions, ammonia levels, growth, and carcass quality for broiler chickens Poultry Science (1991)

Good Overviews

http://edis.ifas.ufl.edu/ps031 Eye Disorders of Poultry. University of Florida Extension (2015)

Blogs

Ammonia Toxicity - A Silient Killer. A Gateway to Veterinary Network

Risk Factors

Build up of droppings in an enclosed, poorly ventilated area such as chicken coops
Increased moisture
Increased time spent indoors, such as during the winter season

Seasonality


Winter	Spring	Summer	Autumn