56 • Alternatives to Animal Use in Research, Testing, and Education 
produced domestically in the United States in 1975, 
and that 20,000 monkeys were imported from 
India. The report’s authors could not be located 
and the methodology is unclear, thus making it 
impossible to validate. It appears that the data are 
based on interviews with personnel at two ani- 
mal breeding facilities (Charles River Breeding 
Labs, Inc., and White Eagle Farms) and perhaps 
a few other people in industry, academia, and gov- 
ernment. As it is difficult to give any credibility 
to such data, the source was assigned a confidence 
rating of “indeterminate.” 
Alex Brown & Sons 
An Alex Brown &, Sons (2) report on Charles River 
Breeding Labs, Inc., stated that the company pro- 
duces 22 million animals annually worldwide, spe- 
cializing in mice, rats, guinea pigs, hamsters, and 
primates. It did not give any breakdown by spe- 
cies, nor do any other analyses of Charles River. 
The number was primarily a guess based on a few 
interviews and so its value must be questioned. 
The confidence rating of this source was "poor.” 
Andrew N. Rowan 
In a 1984 book, Of Mice, Models, & Men: A Criti- 
cal Evaluation of Animal Research, Andrew N. 
Rowan estimated that approximately 71 million 
laboratory animals are used each year, including 
45 million mice and 15 million rats (39). These 
figures were obtained by looking at all the availa- 
ble data sources for animal use in the United States, 
especially information on Charles River breeding 
production. In 1985, Rowan revised these estimates 
to distinguish between production, acquisition, and 
actual use. The new estimates on animals used sug- 
gest that between 25 and 35 million animals are 
used per year (40). As these are based on a very 
broad analysis with many assumptions, they have 
been given a confidence rating of "poor.” 
Surveys and Estimates on Amphibians; 
Fish, and Birds 
There is little good survey information on labora- 
tory use of amphibians, fish, or birds. Use of these 
animals is not required to be reported on the USD A/ 
APHIS annual reports. Therefore, the only sources 
of estimates are personal communications with 
experts in these fields. 
The most recent assessments of amphibian use 
were the ILAR surveys of 1965-71, which indicated 
the use of 3.37 million amphibians in 1971. As men- 
tioned earlier, however, it is not known how to 
normalize for institutions that did not report, so 
the usefulness of these data are questionable and 
the confidence rating is “indeterminate.” 
Several individuals who use or produce amphib- 
ians were surveyed, yielding a wide range of esti- 
mates. A former general manager of a major sup- 
plier of amphibians estimated that approximately 
9 million frogs were shipped by suppliers in 1969 
for educational and teaching purposes (13). This 
is a global estimate and so its confidence rating 
was considered "indeterminate.” An amphibian 
researcher at Louisiana State University did a sur- 
vey of the use of bullfrogs that estimated that 
150,000 bullfrogs and 200,000 tadpoles could have 
been used in 1981 (a decrease since 1971, he found). 
He then assumed that bullfrogs represent roughly 
10 percent of amphibian use and estimated that 
about 1 million frogs and 2 million tadpoles were 
used in the United States for teaching and research 
in 1981 (8). The assumptions in this method are 
very general and so the value of this estimate is 
questionable; an “indeterminate” rating was as- 
signed . F inally , George Nace (34, 3 5) estimated that 
about 9 million frogs were shipped by suppliers 
in 1971, but that this dropped to roughly 4.5 mil- 
lion in 1981 and stabilized at that level in 1984, 
with 90 percent of the usage educational and 10 
percent research. There is fairly good detail for 
the basis of the estimates, but it is difficult to con- 
firm the totals due to the large number of users. 
This source was given a confidence rating of "fair.” 
Reliable data on fish used in laboratories were 
particularly difficult to obtain. Estimates were 
received from commercial and institutional (includ- 
ing Government) users in the field. For fish over 
half an inch long, the yearly use appears to range 
between 500,000 and 1 million. For smaller fish, 
the best estimate is that 2 million to 3 million are 
used yearly . Most are used for toxicological studies . 
Although the numbers are fairly consistent from 
source to source, they are only global estimates 
and so were given a confidence rating of “fair.” 
These numbers apply only to laboratory use. They 
do not include fish that are used in the wild in 
propagation, contamination, feeding, and other 
ecological studies. 
