Cryptosporidium is commonly associated with

neonatal diarrhea in calves. Giardia has been

reported to cause diarrhea among humans, dogs,

cats, calves, and horses. Little information has been

available on fecal shedding patterns of

Cryptosporidium and Giardia among beef calves.

As part of a 1992-93 study of cattle health and

management on the nations cow/calf operations,

beef cow/calf producers were offered the

opportunity to submit fecal samples from scouring

beef calves less than 3 months of age. The samples

were tested for the presence of Cryptosporidium and

Giardia. In addition, fecal pats from nonscouring

calves less than 6 months of age were collected and

evaluated similarly.

The USDAs National Animal Health Monitoring

System (NAHMS) collected the samples and other

data during the Beef Cow/Calf Health and

Productivity Audit (CHAPA). The National

Veterinary Services Laboratories (also

of the USDA) performed the tests. An

objective of the CHAPA was to describe

health and management for 70 percent

of U.S. beef cow inventory.

Producers from a total of 69

operations submitted 391 samples from

diarrheic calves for Cryptosporidium

and Giardia evaluation. A total of

1,053 samples were submitted from

nondiarrheic calves from 141 operations.

Percentages of calves positive for

each evaluation are shown in Figure 1.

Just over 20 percent of the samples from

diarrheic calves submitted for

Cryptosporidium evaluation were

positive, as were 11.2 percent of those submitted

from nondiarrheic calves. Giardia was more

common than Cryptosporidium in diarrheic calves

and nondiarrheic calves. Just over one-quarter (26.9

percent) of samples from diarrheic calves submitted

for Giardia evaluation were positive, as were 45.9

percent of those from nondiarrheic calves.

Differences in prevalences between diarrheic and

nondiarrheic calves are probably at least partly due

to an older average age of calves in the nondiarrheic

group.

Figure 1 also shows that Cryptosporidium and

Giardia commonly exist on beef operations. Nearly

40 percent of operations submitting samples from

diarrheic calves had at least one positive for

Cryptosporidium. Also, 41.8 percent of operations

submitting samples from nondiarrheic calves had at

least one positive. Nearly two-thirds of the

operations for which diarrheic samples were tested

for Giardia had at least one positive result, and 90.8

Cryptosporidium and Giardia

in Beef Calves

National Animal Health Monitoring System

United States

Department of

Agriculture

Animal and

Plant Health

Inspection

Service

Veterinary

Services

Figure 1

January 1994
percent of the operations with nondiarrheic

calf samples tested had at least one positive.

Some of the test results were related to

calf age. Among diarrheic calves, those

positive for Giardia tended to be older than

those that were negative, 47.1 days for

positive and 35.3 days for negative

(Figure 2).

Figures 3 and 4 show the results of

testing for both organisms by age group.

The percentage of diarrheic calves positive

for Giardia was highest for those in the 31-

to 60-day age group (37.1 percent, Figure

3). More than one-half of the nondiarrheic

calves from 61 to 90 days of age tested

positive for Giardia (Figure 4).

Overall, there was a trend to decreasing

prevalence of positive samples among

nondiarrheic calves as the average age of the

calves increased.

In summary, Cryptosporidium and

Giardia appear to be common in beef calves

whether they have diarrhea or not and are

common in beef herds. Fecal shedding of

both organisms is related to calf age with

oldest calves being much less likely to shed

than young calves.

Other NAHMS collaborators included the

National Agricultural Statistics Service (USDA)

and State and Federal Veterinary Medical

Officers.

Centers for Epidemiology & Animal Health

USDA:APHIS:VS, Attn. NAHMS

2150 Centre Ave., Bldg. B, MS 2E7 

Fort Collins, Colorado 80526-8117

(970) 494-7000

N137.0194

Figure 2

Figure 4

Figure 3