Objective—To determine whether a polymerase
chain reaction (PCR) assay could be used to detect
Eperythrozoon wenyoniin the blood of cattle.
Animals—95 cattle from various herds in Alabama
and Georgia and 96 bulls enrolled in Auburn
University's Alabama Beef Cattle Improvement
Association Bull Test program.
Procedure—Blood samples were collected by means
of venipuncture of the median caudal vein and submitted
for a CBC and PCR assay. Blood smears were
made immediately after blood collection and examined
by means of light microscopy.
Results—Three of 95 cattle from herds in Alabama
and Georgia and 5 of 96 bulls enrolled in the Bull Test
program had positive PCR assay results. Organisms
were seen in blood smears from only 5 of these 8 animals.
Organisms were not seen in blood smears from
any animals for which results of the PCR assay were
Conclusions and Clinical Relevance—Results suggest
that a PCR assay may be an effective method for
detecting E wenyoni infection in cattle and that the
PCR assay may be a more sensitive test than evaluation
of blood smears. (J Am Vet Med Assoc 2001;
Objective—To evaluate persistence of bovine viral
diarrhea virus (BVDV) in semen after inoculation of
Animals—Three 2-year-old bulls and five 6-month-old
Procedure—3 seronegative 2-year-old bulls were
inoculated intranasally with BVDV. Serum and semen
samples were obtained at regular intervals until 7
months after inoculation. Serum samples were tested
for BVDV by use of virus isolation (VI) and reverse
transcription-nested polymerase chain reaction (RTnPCR)
tests. Semen samples were tested for virus by
use of VI and RT-nPCR tests. Testicular biopsy specimens
were obtained 7 months after inoculation and
tested for BVDV by use of immunohistochemical
analysis and VI and RT-nPCR tests. Semen samples
collected from 1 bull immediately before and 5 and 7
months after inoculation were administered IV to
seronegative calves, which were monitored for subsequent
viremia and seroconversion.
Results—Use of VI and RT-nPCR tests detected transient
virus in serum of all bulls. The VI test detected
BVDV in semen of 2 bulls for < 21 days after inoculation,
whereas RT-nPCR assay detected BVDV until 7
months after inoculation. Virus was detected in testicular
biopsy specimens of these 2 bulls by use of
immunohistochemical analysis and RT-nPCR assay
but could only be isolated from the biopsy specimen
of 1 bull. Of the calves administered semen IV to
detect infectious virus, only the recipient of semen
collected 5 months after inoculation of the adult bull
was viremic and seroconverted.
Conclusions and Clinical Relevance—Bovine viral
diarrhea virus can persist in semen of acutely infected
bulls for several months after exposure.
(Am J Vet Res 2003;64:428–434)
Objective—To determine whether testicular needle
biopsy is detrimental to testicular function in clinically
Animals—6 mixed-breed mature bulls.
Procedure—A randomly selected testicle from each
bull was biopsied with a 14-gauge needle biopsy
instrument. Bulls were then evaluated over a 90-day
period for changes in scrotal temperature and thermal
patterns, ultrasonographic appearance, and quality of
spermatozoa. At the end of the 90-day study, bulls
were castrated, and testicles were examined grossly
Results—Changes were detected in scrotal temperatures
and thermal patterns and in the breeding soundness
examination results during the first 2 weeks of
the study. However, there were no long-term
changes in semen quality over the course of the
experiment. Hyperechoic areas were detected on
ultrasonographic examination and corresponded to
the areas of penetration by the biopsy instrument.
Microscopic lesions that were indicative of testicular
dysfunction were not found.
Conclusions and Clinical Relevance—Results indicate
that testicular biopsy is a safe procedure in bulls.
Testicular biopsy could possibly be used to further
examine bulls that have less than satisfactory results
for breeding soundness examinations. (J Am Vet Med