Objective—To evaluate the cytopathic effects of
Tritrichomonas foetus and a purified cysteine protease
(ie, CP30) of T foetus on cultured bovine uterine
epithelial cells (BUECs) in vitro.
Sample Population—10 reproductive tracts were
obtained from late-term bovine fetuses at a commercial
Procedure—An in vitro culture system of BUECs was
developed to study the cytopathic effects of T foetus
and purified CP30 of T foetus on host cells.
Cytotoxicity of T foetus or CP30 on exposed BUECs
was determined. Fluorescence microscopy and flow
cytometry analyses were used to detect apoptosis. A
fluorometric assay was used to detect BUEC caspase
3 activation. The CP inhibitor E-64 and a caspase
inhibitor were used to inhibit apoptosis.
Results—Cytopathic effects were observed in
BUECs treated with parasites or CP30 and were concentration
and time dependent. The BUECs underwent
apoptosis in the presence of parasites or CP30.
The specific CP inhibitor E-64 abolished the induction
of apoptosis in BUECs by CP30. The caspase inhibitor
reduced the amount of apoptosis in BUECs.
Conclusions and Clinical Relevance—T foetus and
its CP30 induce apoptosis in cultured BUECs in vitro.
Induction of apoptosis by CP30 is correlated with protease
activity. Endometrial cell death as a result of a
T foetus infection is likely to be more important in
mediating infertility than a direct effect on the conceptus.
Provoking an apoptotic reaction in the host may
mitigate an inflammatory reaction or immune
response and therefore favor survival of the parasite in
a chronic infection. (Am J Vet Res 2005;66:1181–1186)
Objective—To evaluate the efficacy of ceftiofur crystalline-
free acid (CCFA) administered into the posterior
aspect of an ear for treatment of corneal ulceration
associated with naturally occurring infectious bovine
Animals—78 beef calves located at Sierra Foothills
Field Station (SFS) and 52 calves located at a commercial
dairy (CD). All calves were from 3 to 9
Procedure—At each site, calves were randomly allocated
to 1 of 2 treatment groups by use of a block
design determined by corneal ulcer size. A single
dose of CCFA (6.6 mg of ceftiofur equivalents/kg, SC)
was administered into the posterior aspect of a pinna.
A second group of calves received a single dose of
vehicle (0.03 mL/kg, SC; controls). Corneal ulcers
were photographed, and clinical signs were assessed
in calves every 3 to 4 days for 21 days.
Results—A positive treatment effect was detected
at SFS. Results at the CD were inconclusive
because ulcer healing occurred rapidly in control and
CCFA-treated calves. At SFS, treatment with CCFA
resulted in shorter mean healing times, smaller
corneal ulcer surface area measurements, amelioration
of ocular discharge and photophobia, and a 50%
increase in the percentage of calves healed by day
14. After adjustment for initial corneal ulcer size,
treatment with CCFA resulted in a 4-fold increase in
the odds of corneal ulcer healing by day 14, compared
Conclusions and Clinical Relevance—A single dose
of CCFA administered into the posterior aspect of a
pinna had a positive treatment effect against naturally
occurring IBK in calves with corneal ulcerations . (Am J Vet Res 2004;65:1185–1188)