Nut more than 8 or 10 died after all the sheep were 
'pravi-d Deaths among the ewes were few, but the 
herder thought that 2 or 3 had died during the outbreak. 
On June 13, this band was examined in the 
hills south of Oakley, Idaho, where it had been 
grazing for some time. Ticks were scarce in 
this area, and only a few ticks were found on 
l ho animals, although they showed evidence 
of previous heavy tick infestations by encrusted 
ureas along the chin, throat, chest, and belly. 
Forty-one ticks collected at this time were 
l (>st ml for infection, with negative results. 
Many of the lambs had badly broken fleeces 
and a few had shed almost completely. Re- 
tarded growth and underweight were evident 
in some animals. Stiffness was noticed in a 
few of the lambs but otherwise all of the sheep 
appeared to be healthy. 
Agglutination tests were made on blood 
samples from 71 lambs selected at random. 
( 'omplete agglutination was observed at the 
following titers: 1:20, 33 samples; 1:40, 32; 
1:80, 30; 1:160, 20; and at 1:320, 7 samples. 
('omplete agglutination of P. tularensis 
antigen at a serum dilution of 1:20 is accepted 
as diagnostic when many of the animals show 
much higher titers. Presence of the disease 
had been confirmed by isolation of P. tularensis 
from one sick animal. On the basis of these 
samples, about 46 percent of the lambs ex- 
perienced an infection with tularemia during 
the epizootic. 
When the sheep in flock A were bled in 
June 1952, there were two sheep dogs in camp 
which the herder said had been ill about the 
same time as the sheep. Both dogs were bled 
and both were positive for P. tularensis by 
agglutination tests at titers of 1:20 and 1:80, 
respectively. 
When Dr. R. M. Thornburg of Burley, 
Idaho, made a diagnosis of tularemia in this 
band of sheep he supplied the owner with 
streptomycin for treatment of some of the 
sick animals. The owner reported the follow- 
ing results: 
In one instance, 9 sick lambs were brought in from 
the range in a truck. These were not treated and only 
one or two survived. A few days later 30 sick lambs 
were treated by injection with a single dose of strepto- 
mycin, about Yi gram each. Most of these animals 
showed marked improvement the following day and 
only two died. 
Public Health Monograph No. 28, 1955 
Although this is not a well-controlled ex- 
periment, the results are encouraging in view 
of the well-known effectiveness of streptomycin 
in therapy of human tularemia. We have no 
information that any other antibiotics have been 
tried on sheep affected with tularemia. 
Flock B 
The flock B sheep were divided into two bands 
for summer grazing. The immediate history 
of these prior to the outbreak as related to us 
by the owner, was as follows: 
The bands were turned out on the Arco Desert about 
April 9. The first sick animals were noticed 2 weeks 
later (April 23), when the sheep were west of Paul 
and north of the prominent hill on the desert known 
locally as the butte. Wood ticks were abundant in the 
sagebrush where the sheep were grazing and on the 
sheep. [This is the same location where sheep became 
sick in 1949 as reported by Jellison and Kohls (f£).] 
About 60 sick lambs from a band of 1,250 ewes and 
lambs and 30 sick yearlings from a band of 1,800 
yearlings and dry ewes were trucked to the home 
ranch for care and observation. An estimated 50 lambs 
and 15 yearlings died on the range or among these 
brought to the home ranch. 
On June 14, the small band of sheep at the home 
ranch was examined. This band included the animals 
brought in from the desert when ill and a number of 
orphan iambs which had never been on the range. 
All of the animals appeared well and active. Some 
showed evidence of having had heavy tick infestations 
earlier in the season but no ticks remained on them. 
Many of the lambs had badly broken fleeces. 
Agglutination tests for P. tularensis on serum 
samples from this group gave the following 
results: Complete agglutination at a titer of 
1:40 was observed in 25 of 61 samples from 
lambs and in 3 of '4 samples from ewes, or a 
total of 28 out of 65 samples. Thus, serums 
from 43 percent of these animals gave a positive 
agglutination test for tularemia at diagnostic 
titers. These results from a selected group are 
comparable to the random sample from flock 
A in which 46 percent gave positive tests for 
tularemia. 
It was not practical to bleed any of the sheep 
which were out on the range at this time 
(June 13) but in late July the sheep were 
driven into stockyards at Ketchum, Idaho, 
for separation and shipment of lambs. On 
July 20, 13 lambs and 13 ewes were selected 
from the flock and bled. These animal- had 
broken fleeces or were conspicuously thin or 
undersized. Six lambs and 6 ewes gave positive 
