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

Veterinary Services 

Centers for Epidemiology and Animal Health August 2012 

_________________________________________________________________________________________________________________________ 

Role of Intestinal Pathology and 

Clostridial Species in Clostridial 

Dermatitis on U.S. TurkeyGrower Farms 

Introduction

A disease of turkeys and broilers, clostridial dermatitis 

(cellulitis/gangrenous dermatitis) has become an issue of 

concern in recent years. In 2010, the U.S. Animal Health 

Association (USAHA) ranked clostridial dermatitis 

among the top three disease issues in turkeys (USAHA, 

2010). The disease causes mortality with subcutaneous 

necrosis, edema, and/or emphysema, and most often 

affects toms 13 to 18 weeks old (Clark, 2010). Disease 

pathogenesis, however, is poorly understood. Clostridial 

dermatitis is believed to be caused by hematogenous 

transmission of clostridium from the gastrointestinal tract 

to muscle and skin where bacterial toxins are produced. 

There is uncertainty about whether pathology of the 

intestine is required to allow clostridial organisms or their 

toxins to enter the bloodstream. 

Methodology

 The U.S. Department of Agriculture’s National 

Animal Health Monitoring System (NAHMS) conducted a 

study to investigate intestinal pathology and the 

presence of clostridial organisms on U.S. turkey farms. 

The goal of the study was to better understand the role 

of intestinal pathology and clostridial species in the 

pathogenesis of clostridial dermatitis. 

 For the study, 15 of the Nation’s largest turkey 

companies were selected to participate. The selected 

companies represented 76.8 percent of turkeys 

slaughtered in the United States in 2009 (WATT, 2010). 

Seven of the selected companies collected biologic 

samples from 25 farms—19 case farms and 6 control 

farms. 

 Participating companies selected case and control 

farms based on the following criteria: 

 Case farm—a farm with a history of frequent 

clostridial dermatitis outbreaks and on which an 

outbreak was anticipated during the year; 

 Control farm—a farm on which a clostridial 

dermatitis outbreak was not anticipated. 

 Case farms were visited weekly during the time 

leading up to an anticipated outbreak. Control farms 

were visited weekly during the same time period. 

Anticipated timing of an outbreak was based on the 

farm’s previous history. Of the 19 case farms, 16 had an 

outbreak of clostridial dermatitis during the study. Three 

case farms and all six control farms did not have an 

outbreak during the study. 

 Samples were collected from 397 birds from May 27 

through October 16, 2010.Three birds per week were 

euthanized, and intestinal samples were collected for 

anaerobic culture and histopathology. Samples of liver, 

litter, and litter beetles (if present) were also collected 

weekly for anaerobic culture. Poultry litter samples were 

taken from three locations in the poultry barns (the 

middle of the barn, under the feeder, and away from the 

feeder/drinkers) and then pooled. On the final visit, 

additional samples collected for culture included spleen 

and muscle from three euthanized birds. 

 During clostridial dermatitis outbreaks, spleen, liver, 

and muscle/subcutaneous samples were collected from 

recent mortalities with lesions, but intestinal culture and 

histopathology were not performed on birds found dead. 

See the NAHMS report “Poultry 2010: Clostridial 

Dermatitis on U.S. Turkey-Grower Farms” for details on 

the types of samples collected (USDA, 2012). 

Histopathology was conducted at North Carolina State 

University and anaerobic culture was conducted at Iowa 

State University. 

 

The role of C. septicum in clostridial dermatitis

 Both Clostridium septicum and Clostridium 

perfringens have been suggested as causative agents 

for clostridial dermatitis, but C. septicum may be the 

principal cause (Tellez, 2009). 

 Findings from this NAHMS study support the theory 

that C. septicum is the primary clostridial organism 

involved in clostridial dermatitis outbreaks. During 

outbreaks, 42 percent of sampled birds were positive for 

C. septicum (i.e., had C. septicum cultured from one or 

more tissues). In comparison, only 1 percent of birds 

from nonoutbreak farms were positive for C. septicum. 

Similarly, in the weeks preceding an outbreak on 

outbreak farms, only 1 percent of birds were positive for 

C. septicum (figure. 1). These findings suggest that 

C. septicum prevalence increases acutely at the time of 

an outbreak, as opposed to a high percentage of birds 

chronically harboring the organism on affected farms. 

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

 

 Approximately 20 percent of birds were positive for 

C. perfringens on outbreak and nonoutbreak farms, 

regardless of the presence or absence of a clostridial 

dermatitis outbreak (figure. 1). From this study, it is 

unclear what role, if any, C. perfringens plays in 

clostridial dermatitis. 

 Positive culture results from liver and spleen 

samples also provided evidence to support the theory of 

hematogenous spread of C. septicum. In fact, 21 percent 

of the birds sampled during an outbreak of clostridial 

dermatitis had C. septicum in the liver, and 18 percent 

had it in the spleen; 48 percent of birds sampled had 

C. septicum in the muscle/subcutaneous tissue (table 1). 

Of birds euthanized for sampling during an outbreak, 29 

percent had C. septicum in the muscle/subcutaneous 

tissues (table 1), but most of these birds did not have 

gross clostridial dermatitis lesions. Interestingly, no birds 

had C. septicum cultured from the intestines during 

outbreaks (table 1). However, the presence of 

C. septicum in the liver and spleen still suggests 

intestines as a likely source of the organism. On 

outbreak farms in the weeks prior to an outbreak, 

C. septicum was found in only one intestinal sample and 

in one liver sample (data not shown). 

Table 1. Percentage of birds positive for C. septicum 

during a clostridial dermatitis outbreak, by tissue 

tested and by bird type 

Percent Birds 

Bird Type 

Tissue 

Euthanized 

birds 

Recent dead 

with lesions All birds 

n % n % n % 

GI 0/48 0 NA 0/48 0 

Liver 2/48 4 15/34 44 17/82 21 

Spleen 1/41 2 12/33 36 13/74 18 

Muscle 9/31 29 22/33 67 31/64 48 

Any 12/48 25 24/37 65 36/85 42 

NA= intestine not cultured in birds found dead. 

C. septicum in poultry litter and litter beetles 

 Very few litter or litter beetle samples were positive 

for C. septicum or C. perfringens; in fact, only one litter 

sample from an outbreak farm was positive for 

C. septicum (table 2). This finding was surprising, since 

litter from flocks with clostridial dermatitis is theorized to 

contain high numbers of clostridial organisms (Clark, 

2010). While litter may contain other species of 

Clostridium, it does not appear that C. septicum is 

present in high numbers in litter, although it might be that 

C. septicum is difficult to recover from litter. This study 

did not purposefully collect samples from areas where 

mortalities were removed or where litter was wet, when 

collecting samples. Litter from these areas might contain 

higher numbers of clostridial organisms. 

Table 2. Number of litter and litter beetle samples 

positive for C. septicum and C. perfringens, by farm 

type 

 Number Samples Positive 

Farm Type 

Sample type Nonoutbreak Outbreak 

Litter 

C. septicum 0/46 1/71 

C. perfringens 0/46 1/71 

Litter beetles 

C. septicum 0/22 0/24 

C. perfringens 2/22 0/24 

 

0

20

40

60

Outbreak farm—

outbreak week

Outbreak farm—

not outbreak week

Nonoutbreak farm

C. septicum C. perfringens

Species

Percent

Figure 1. Percentage of birds positive for C. septicum

and C. perfringens, by farm outbreak status

Farm

1 1

42

22 21

17
United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture 

The role of intestinal pathology in clostridial 

dermatitis 

 Culture results support the theory of hematogenous 

spread of clostridial organisms from the intestinal tract; 

therefore, it is important to understand why or how 

clostridia get into the bloodstream. Studying the role of 

intestinal pathology in field outbreaks of clostridial 

dermatitis is inherently challenging. Ideally, the 

researcher would collect intestinal samples from birds 

that are about to break with the disease, to see if 

intestinal pathology is present before disease onset. 

However, this is not possible, since intestinal sampling is 

invasive and the onset of disease in an individual bird 

cannot be predicted. 

 This study attempted to measure the role of 

intestinal pathology by sampling random birds in the 

weeks leading up to a clostridial dermatitis outbreak. To 

see if intestinal changes were occurring in the flock, 

intestinal pathology was assessed microscopically by 

assigning lesion scores to four areas of the duodenum, 

four areas of the ileum, and four areas of the cecum. A 

single lesion score was assigned to Meckel’s 

diverticulum. The presence of luminal bacteria, coccidia, 

and other parasites was also noted. 

 Intestinal pathology was common. Over half of all 

sampled birds had at least mild pathology in the ileum, 

and about 40 percent of birds had pathology in Meckel’s 

diverticulum. Ileal pathology was most commonly found 

in the lamina propria or muscularis. A pattern of 

increasing intestinal pathology in the weeks leading up 

to an outbreak was not identified. In addition, the 

percentages of birds with intestinal pathology were 

similar on outbreak and nonoutbreak farms (fig. 2). 

Summary

 The NAHMS study provided evidence to support two 

theories about the pathogenesis of clostridial dermatitis: 

1. C. septicum appears to be important in the 

pathogenesis of clostridial dermatitis. 

2. Hematogenous spread of C. septicum occurs 

on turkey-grower farms during clostridial 

dermatitis outbreaks. 

 C. septicum levels increased acutely at the time of 

an outbreak, as opposed to birds chronically harboring 

the organism on affected farms. Surprisingly, very few 

poultry litter or litter beetle samples were culture positive 

for C. septicum or C. perfringens.

 Over half of turkeys on grower farms had some 

degree of intestinal damage. Therefore, clostridia may 

have the opportunity to enter the bloodstream in a high 

percentage of birds. Although the study results did not 

clearly define the role of intestinal pathology, intestinal 

damage may play a role in clostridial dermatitis. 

 Further research is needed to better understand the 

complex set of circumstances that culminate in this 

disease. 

References 

Clark S, Porter R, McComb B, Lippert R, Olson S, 

Nohner S, Shivaprasad HL. 2010. Clostridial dermatitis 

and cellulitis: an emerging disease of turkeys. Avian Dis 

54(2):788–794. 

Tellez G, Pumford NR, Morgan MJ, Wolfenden AD, 

Hargis BM. 2009. Evidence for Clostridium septicum as 

a primary cause of cellulitis in commercial turkeys. J Vet 

Diagn Invest 21:374–377. 

USAHA. 2010. Transmissible diseases of poultry report. 

USDA, 2012. Poultry 2010: Clostridial dermatitis on U.S. 

turkey-grower farms. Fort Collins, CO. #645.0612. 

Available at: 

http://www.aphis.usda.gov/animal_health/nahms/poultry/

downloads/poultry10/Poultry10_dr_ClostridialDermatitis.

pdf 

WATT Poultry USA Turkey Profiles, Feb. 2010.

______________________________ 

For more information, contact: 

USDA–APHIS–VS–CEAH–NAHMS 

NRRC Building B, M.S. 2E7 

2150 Centre Avenue 

Fort Collins, CO 80526-8117 

970.494.7000 

http://nahms.aphis.usda.gov

#656.0812 

____________________________________ 

0

20

40

60

80

Cecum

Meckel's diverticulum

Ileum

Duodenum

Nonoutbreak

farm

Outbreak farm—

outbreak week

Outbreak status

Percent

Figure 2. Percentage of birds that had pathology in the 

following areas of the intestines, by farm outbreak status

Pathology in...

6

69

35

27

17

46

7

71

54

42

2

19

Outbreak farm—

not outbreak week
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