United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture 

Veterinary Services 

Centers for Epidemiology and Animal Health April 2011 

_________________________________________________________________________________________________________________________ 

Biosecurity of Urban Chicken 

Flocks in Four U.S. Cities 

Biosecurity involves the use of management 

practices designed to prevent the introduction of 

disease. Some basic biosecurity guidelines for urban 

chicken flocks include1

: 

 Keep your distance. Isolate new birds and birds 

returning from places where they were exposed 

to other birds (such as fairs or shows) for 30 

days. 

 Keep it clean. Prevent germs from spreading by 

washing hands, and cleaning shoes, tools, and 

equipment. 

 Keep visitors out of the chicken area whenever 

possible. 

 Limit contact with wildlife and rodents. If 

chickens are kept outdoors, they should be in an 

enclosed area covered with a solid roof and wire 

mesh or netted sides. 

 Know the warning signs of infectious bird 

diseases. Watch for early signs to prevent the 

spread of disease. 

 Report sick birds. Report unusual signs of 

disease or unexpected deaths. 

 Consider vaccination to protect your birds from 

diseases. 

The U.S. Department of Agriculture’s (USDA) 

National Animal Health Monitoring System conducted 

the Poultry 2010 study. One objective of the study was

to characterize biosecurity practices in urban chicken 

flocks in four major U.S. cities: Denver, Los Angeles, 

Miami, and New York City. 

To collect data in Denver, Los Angeles, and Miami, 

feed stores were visited and a questionnaire was 

administered to customers who owned chickens, lived 

on less than 1 acre of land, and lived within the 

respective city’s defined boundaries. The questionnaire 

was available in English and Spanish, and only one 

questionnaire per household was administered. In New 

York City, data were collected from members of a 

chicken-related club, rather than from feed store 

customers. The study questionnaire was available for 

completion on the club’s Web site and also administered 

at a presentation to club members. A total of 147, 189, 

56, and 33 questionnaires were completed in Denver, 

Los Angeles, Miami, and New York City, respectively. 

 

Biosecurity practices 

 Approximately two-thirds of flocks (65.7 percent) 

always or sometimes required hand washing before

handling chickens, and almost 9 of 10 flocks 

(88.3 percent) always or sometimes required hand 

washing after handling chickens. 

 One-third of flocks (33.3 percent) always or 

sometimes required people (including family) to wear 

dedicated clothing or change clothing before 

entering the chicken area. 

 Approximately one-half of flocks (51.5 percent) 

always or sometimes required at least one of the 

following footwear practices before entering the 

chicken area: 

o Use of footbath 

o Scrub boots/shoes 

o Wear shoe covers, dedicated shoes, or change 

shoes 

 A higher percentage of flocks in Los Angeles always 

or sometimes required at least one footwear practice 

compared with flocks in Denver and New York City 

(figure 1). 

0 20 40 60 80 100

All

New York

Miami

Los Angeles

Denver

City

Percent

Any footwear

requirement

Wear

dedicated

clothing or change

clothing

before

entering

Wash hands

before

handling

chickens

Wash hands

after

handling

chickens

Practice

Figure 1. Percentage of Flocks that Always or Sometimes 

Required the Following Practices for People (Including Family)

Entering the Chicken Area, by City

40.4

65.2

51.8

21.9

51.5

25.3

43.5

33.9

9.4

33.3

63.0

71.5

69.6

37.5

65.7

93.8

85.5

82.1

90.6

88.3
United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture 

Flock additions 

New birds can be a source of disease introduction. 

Flock owners were asked if they acquired any new 

chickens (excluding those hatched on site) during the 

previous 12 months. 

More than two-thirds of flocks in Denver and New 

York City had acquired new chickens during the previous 

12 months (figure 2). However, many of these 

acquisitions were actually initial flock startups, rather 

than new additions to existing flocks. About one-third of 

all flocks in Denver and New York City (32.9 and 35.5 

percent, respectively) had acquired their first chickens in 

the previous 12 months. 

Flock owners should acquire new birds from healthy 

flocks known to be free of disease. Before purchasing 

new birds, ask the seller about his/her bird health 

program, including vaccinations given, and whether or 

not the flock has been tested for diseases or recently 

examined by a veterinarian. Also, observe the source 

flock for signs of illness, such as eye or nasal discharge, 

diarrhea, or excessively underweight birds. New birds 

should be quarantined for a minimum of 30 days and 

tested for relevant diseases before introduction to the 

flock.1

 Quarantined birds should be kept where they 

cannot have contact with the existing flock, and separate 

feeding equipment, clothing, and footwear should be 

used when caring for quarantined birds. Alternatively, 

flocks could be managed all-in/all-out (no new additions 

until previous flock is removed). 

0

20

40

60

80

Denver Los Angeles All

City

Percent

Figure 2. Percentage of Flocks that Acquired New Chickens

(Excluding Those Hatched On Site) During the Previous

12 Months, by City

Miami New York

76.2

40.8

53.7

66.7

56.8

Chickens that leave the flock and then return 

 

Chickens that leave the flock to attend an event and 

return represent another avenue for introducing disease 

agents. Only 6.9 percent of flocks took chickens to a 

location, such as a fair or show, where other birds were 

present and then returned them to the flock during the 

previous 12 months (table 1). 

Table 1. Percentage of flocks that took chickens to a 

location such as a fair or show where other birds 

were present and then returned them to the flock 

during the previous 12 months, by city 

Percent Flocks 

City 

Denver 

Los 

Angeles Miami New York All 

7.9 5.7 12.8 0.0 6.9 

Visitors 

Visitors can carry disease agents from one flock to 

another. Flock owners were asked about business 

visitors and nonbusiness visitors. Business visitors 

included veterinarians, extension agents, customers 

purchasing chicken products, bird dealers/buyers, meter 

readers, other service persons, etc. Nonbusiness visitors 

included school groups, friends, neighbors, etc. 

 Only 14.1 percent of flocks had any business visitors 

enter the chicken area during the previous 12 

months. 

 About one-half of flocks had nonbusiness visitors 

enter the chicken area during the previous 12 

months. About 4 of 10 flocks in Denver (39.6 

percent) and 6 of 10 flocks in New York City (59.4 

percent) had nonbusiness visitors enter the chicken 

area 10 or more times (figure 3). 

Flock owners can take precautions to reduce the risk 

of visitors introducing disease to their flock. For example, 

visitors who own birds or have been in contact with birds 

should not be allowed in the chicken area. All visitors 

should be asked to change into clean boots and wash 

their hands before entering the chicken area. 

0

20

40

60

80

100

10 or more

1 to 9

0

Number Times

Percent

Denver Los Angeles Miami New York

City

30.9

29.5

39.6

72.3

20.6

7.1

68.1

21.3

10.6

9.4

31.2

59.4

Figure 3. Percentage of Flocks by Number of Times Nonbusiness Visitors* 

Entered the Chicken Area During the Previous 12 Months, and By City

*School groups, friends, neighbors, etc.
United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture 

Contact with other animals 

Contact with domestic poultry, wild birds, rodents, 

and insects can spread infectious agents; therefore, it is 

important to ensure that wildlife does not have access to 

poultry housing. As mentioned before, if chickens are 

kept outdoors, they should be in an enclosed area 

covered with a solid roof and wire mesh or netted sides. 

Providing food and water only in the covered area will 

discourage migratory birds from mingling with the flock. 

 About 3 of 10 flocks (29.0 percent) had a wild-bird 

feeder at the location where the chickens were kept. 

 Wild birds other than waterfowl were seen daily in 

the chicken area in 39.5 percent of flocks, and 

neighbors’ chickens/birds were seen daily in 14.3 

percent of flocks. 

 Pet dogs or cats were seen daily in the chicken area 

in 62.6 percent of flocks. 

Biosecurity for Birds educational campaign 

Overall, 29.4 percent of urban chicken owners had 

heard of the Biosecurity for Birds educational campaign, 

a USDA–Animal and Plant Health Inspection Service 

initiative designed to help poultry owners keep their birds 

healthy. 

Summary 

Biosecurity involves management practices that 

reduce the risk of introducing disease to a flock. Each 

flock owner should develop a biosecurity plan based on 

the specific risks of the flock and on the diseases 

targeted for control. The biosecurity plan may include 

some combination of management practices and the use 

of vaccines.2

 Everyone in the family, including children, 

should be aware of biosecurity protocols. 

References 

1. Bird owners can find additional information on 

backyard biosecurity practices at: 

http://www.aphis.usda.gov/animal_health/birdbio

security/

2. For more information about vaccinations: 

http://www.poultry.uga.edu/extension/tips/docum

ents/07%2005%20BY%20tip%20J%20M%20M

%20(web).pdf

__________________ 

For more information, contact: 

USDA:APHIS:VS:CEAH 

NRRC Building B, M.S. 2E7 

2150 Centre Avenue 

Fort Collins, CO 80526-8117 

970.494.7000 

Email: NAHMS@aphis.usda.gov 

http://nahms.aphis.usda.gov 

#603.0411 

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