bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of intratesticular injection of glycerol for nonsurgical sterilization of dogs
Authors: Immegart Heidi M. , Threlfall Walter R.
Published: December 2005

Objective—To determine efficacy of intratesticular
injection of glycerol as a means to sterilize dogs.

Animals—Six 2- to 4-year-old sexually intact male dogs.

Procedure—Testicular volume, serum testosterone
concentration, and number of sperm in ejaculate
were determined before and at weekly intervals for
12 weeks following intratesticular injection of a 70%
glycerol solution (1 ml/testis). Testicular tissue specimens
for histologic evaluation were obtained 4, 8,
and 12 weeks following injection.

Results—Number of sperm in ejaculate following glycerol
injection was not significantly different from number
before injection. Compared with preinjection values,
serum testosterone concentrations were significantly
less 5, 9, and 10 weeks following injection,
although libido and ejaculate characteristics were
unchanged. Testicular swelling was evident 24 to 48
hours following injection, and testicular volume
decreased starting on week 5 following treatment.
Seminiferous tubules and evidence of normal spermatogenesis
were detected in testicular biopsy specimens
obtained from all dogs 12 weeks following injection.

Conclusions and Clinical Relevance—Intratesticular
injection of a 70% glycerol solution did not result
in azoospermia and sterility in dogs. ( Am J Vet Res
2000;61:544–549)
Complex segregation analysis of deafness in Dalmatians
Authors: Famula Thomas R. , Oberbauer Anita M. , Sousa Candace A.
Published: December 2005

Objective—To use pedigree analysis to evaluate the
feasibility of a major locus model for deafness in
Dalmatians.

Animals—605 purebred Dalmatians from 42 families.

Procedure—Hearing loss was evaluated through the
brainstem auditory-evoked response. Dogs were
classified into mutually exclusive categories: normal
hearing, unilaterally deaf, or bilaterally deaf.
Information was collected on sex, coat color, presence
or absence of a color patch at birth, and eye
color. Statistical analyses were performed by use of
regressive logistic models designed for complex segregation
analysis. Genetic correlations among eye
color, deafness, and color patch were estimated.

Results—Prevalence of hearing loss was 11% for
dogs classified as unilaterally deaf and 5% for dogs
that were bilaterally deaf. Complex segregation analysis
detected statistical evidence of a single allele with
an expected frequency of 0.21 that had an effect on
the prevalence of deafness. Results of analyses suggested
that this locus cannot completely explain the
inheritance and incidence of deafness in Dalmatians.
Genetic correlation estimates among deafness, eye
color, and color patch revealed strong interrelationships
among these characteristics.

Conclusions and Clinical Relevance—To reduce the
incidence of hearing loss in Dalmatians, unilaterally
deaf, blue-eyed dogs should not be considered as
potential parents. ( Am J Vet Res 2000;61:550–553)
Influence of dietary protein and lipid on weight loss in obese ovariohysterectomized cats
Authors: Szabo Joseph , Ibrahim Wissam H. , Sunvold Gregory D. , Dickey Kenneth M. , Rodgers Janet B. , Toth Ida E. , Boissonneault Gilbert A. , Bruckner Geza G.
Published: December 2005

Objective—To determine effects of dietary lipid and protein on development of hepatic lipidosis (HL) and on physical and biochemical indices following rapid weight loss in cats.

Animals—24 ovariohysterectomized cats.

Procedure—Cats were fed a high energy diet until they gained 30% of their ideal body weight and then randomly assigned to receive 1 of 4 weight-reduction diets (6 cats/diet) at 25% of maintenance energy requirements per day. Diets contained a low or high quality protein source and a lipid source deficient or sufficient in long chain essential fatty acids (LCEFA). Serum and plasma samples and liver biopsy specimens were obtained for biochemical analyses and determination of hepatic lipid content before and after weight gain and during and after weight loss.

Results—Irrespective of weight-reduction diet fed, all cats lost weight at a comparable rate (4.51 to 5.00 g/d/kg of obese body weight). Three cats developed hepatic lipidosis. Significant changes in plasma insulin, cholesterol, triglyceride, and serum glucose concentrations were detected after weight gain and weight loss in all diet groups, but values for these variables did not differ among groups.

Conclusions and Clinical Relevance—Cats can lose 25 to 30% of their obese body weight over 7 to 9 weeks without developing overt clinical signs of HL, provided that weight-reduction diets are highly palatable, contain a high quality protein, have a source of LCEFA, and are fortified with vitamins and microminerals. However, rapid weight loss may increase risk factors associated with development of diabetes mellitus. (Am J Vet Res2000;61:559–565)
Acute cardiovascular effects and pharmacokinetics of carvedilol in healthy dogs
Authors: Sawangkoon Suwanakiet , Miyamoto Mutsumi , Nakayama Tomohiro , Hamlin Robert L.
Published: December 2005

Objective—To determine acute cardiovascular effects
and pharmacokinetics of carvedilol in healthy dogs.

Animals—14 mature healthy Beagles.

Procedure—12 dogs were anesthetized with morphine
and α-chloralose. Catheters were placed in the
aorta, left ventricle, and right atrium to record systemic
and pulmonary pressures and determine vascular
resistance and cardiac output. Electrocardiograms
(leads I, aVF, and V3) were recorded to
determine electrocardiographic changes. Variables
were measured before and after IV injection of incremental
doses of carvedilol (cumulative doses, 10, 30,
70, 150, 310, and 630 μg/kg of body weight;
n = 6) or vehicle alone (6). Pharmacokinetic analysis
was performed, using 2 conscious dogs given 160 mg
of carvedilol/kg as a single IV injection.

Results—Heart rate and velocity of fiber shortening at
zero load (Vmax) increased slightly but significantly from
baseline values at doses of carvedilol ≥ 310 μg/kg and
10 μg/kg, respectively. Carvedilol did not affect systemic
and pulmonary pressures or vascular resistances.
Intravenous administration of approximately 150 μg of
carvedilol/kg resulted in a plasma carvedilol concentration
of approximately 100 ng/ml. Mean elimination halflife
was 54 minutes, half-life of distribution was 3.5
minutes, and volume of distribution was 2,038 ml/kg.

Conclusions and Clinical Relevance—The therapeutic
plasma concentration of carvedilol in humans
is 100 ng/ml. At that plasma concentration in dogs,
the reduction in afterload and positive inotropic effect
that we observed would be beneficial for treating
heart failure and minimizing the cardiotoxic effects of
doxorubicin. (Am J Vet Res 2000;61:57–60)
Pharmacokinetics of fenbendazole following intravenous and oral administration to pigs
Authors: Petersen Mads Bjelke , Friis Christian
Published: December 2005

Objective—To determine pharmacokinetics and
metabolic patterns of fenbendazole after IV and oral
administration to pigs.

Animals—4 mixed-breed female pigs weighing 32 to
45 kg.

Procedure—Fenbendazole was administered IV at a
dose of 1 mg/kg. One week later, it was administered
orally at a dose of 5 mg/kg. Blood samples were collected
for up to 72 hours after administration, and plasma
concentrations of fenbendazole, oxfendazole, and
fenbendazole sulfone were determined by use of
high-pressure liquid chromatography. Plasma pharmacokinetics
were determined by use of noncompartmental
methods.

Results—Body clearance of fenbendazole after IV
administration was 1.36 L/h/kg, volume of distribution
at steady state was 3.35 L/kg, and mean residence
time was 2.63 hours. After oral administration, peak
plasma concentration of fenbendazole was 0.07 µg/ml,
time to peak plasma concentration was 3.75
hours, and mean residence time was
15.15 hours. Bioavailability of fenbendazole was
27.1%. Oxfendazole was the major plasma metabolite,
accounting for two-thirds of the total area under the
plasma concentration versus time curve after IV and
oral administration. Fenbendazole accounted for 8.4%
of the total AUC after IV administration and 4.5% after
oral administration.

Conclusions and Clinical Relevance—Results indicate
that fenbendazole was rapidly eliminated from
plasma of pigs. The drug was rapidly absorbed after oral
administration, but systemic bioavailability was low.
( Am J Vet Res 2000;61:573–576)
Effects of endurance training on standard and signal-averaged electrocardiograms of sled dogs
Authors: Constable Peter D. , Hinchcliff Kenneth W. , Olson Jeanne L. , Stepien Rebecca L.
Published: December 2005

Objective—To determine the effect of endurance training on QRS duration, QRS-wave amplitude, and QT interval.

Animals—100 sled dogs in Alaska.

Procedure—Dogs were examined in early September (before training) and late March (after training). During the interim, dogs trained by pulling a sled with a musher (mean, 20 km/d). Standard and signal-averaged ECG were obtained before and after training.

Results—Endurance training significantly increased mean QRS duration by 4.4 milliseconds for standard ECG (mean ± SEM; 62.3 ± 0.7 to 66.7 ± 0.6 milliseconds) and 4.3 milliseconds for signal-averaged ECG (51.5 ± 0.7 to 55.8 ± 0.6 milliseconds) without changing body weight. Increase in QRS duration corresponded to a calculated increase in heart weight (standard ECG, 23%; signal-averaged ECG, 27%). Signal-averaged QRS duration was correlated with echocardiographically determined left ventricular diastolic diameter for the X orthogonal lead (r= +0.41), Y orthogonal lead (r= +0.33), and vector (r= +0.35). Training also increased QT interval (234 ± 2 to 249 ± 2 milliseconds) and R-wave amplitude in leads II and rV2, increased peak-to-peak voltage and S-wave amplitude in the Y orthogonal lead, and decreased Q-wave amplitude in the Y orthogonal lead.

Conclusions and Clinical Relevance—Electrocardiographic changes reflected physiologic cardiac hypertrophy in these canine athletes in response to repetitive endurance exercise. The QRS duration increases in response to endurance exercise training and, therefore, may be of use in predicting performance in endurance activities. (Am J Vet Res2000;61:582–588)
Concentrations of trace minerals in the spinal cord of horses with equine motor neuron disease
Authors: Polack Evelyne W. , King John M. , Cummings John F. , Mohammed Hussni O. , Birch Milton , Cronin Thomas
Published: December 2005

Objective—To compare concentrations of trace minerals in the spinal cord of horses with equine motor neuron disease (EMND) with those of horses without neurologic disease (control horses).

Animals—24 horses with EMND and 22 control horses.

Procedure—Spinal cord trace mineral concentrations in horses with EMND and control horses were analyzed by use of inductively coupled plasma atomic emission spectroscopy (calcium, phosphorus, sodium, potassium, magnesium, copper, iron, manganese, nickel, zinc, aluminum, cobalt, and chromium), atomic absorption spectrophotometry (lead and cadmium), flameless atomic absorption (mercury), and fluorometry (selenium).

Results—Copper concentration was significantly higher in the spinal cord of horses with EMND, compared with control horses; spinal cord concentrations of all other trace minerals were similar between groups.

Conclusion and Clinical Relevance—Among spinal cord trace minerals investigated in the study, only copper concentrations were significantly different between horses with EMND and horses without neurologic disease, which suggests that copper may be involved in the pathogenesis of EMND. An hypothesis of oxidative injury in this disease is supported by the finding of increased copper concentrations in the spinal cord and by low vitamin E concentrations reported by other researchers. (Am J Vet Res2000; 61:609–611)
Effects of interleukin-1β and tumor necrosis factor-α on expression of matrix-related genes by cultured equine articular chondrocytes
Authors: Richardson Dean W. , Dodge George R.
Published: December 2005

Objective—To determine the effects of interleukin- 1β (IL-1β) and tumor necrosis factor-α (TNF-α) on expression and regulation of several matrix-related genes by equine articular chondrocytes.

Sample Population—Articular cartilage harvested from grossly normal joints of 8 foals, 6 yearling horses, and 8 adult horses.

Procedure—Chondrocytes maintained in suspension cultures were treated with various doses of human recombinant IL-1β or TNF-α. Northern blots of total RNA from untreated and treated chondrocytes were probed with equine complementary DNA (cDNA) probes for cartilage matrix-related genes. Incorporation of35S-sulfate, fluorography of14C-proline labeled medium, zymography, and western blotting were used to confirm effects on protein synthesis.

Results—IL-1β and TNF-α increased steady-state amounts of mRNA of matrix metalloproteinases 1, 3, and 13 by up to 100-fold. Amount of mRNA of tissue inhibitor of metalloproteinase-1 also increased but to a lesser extent (1.5- to 2-fold). Amounts of mRNA of type-II collagen and link protein were consistently decreased in a dose-dependent manner. Amount of aggrecan mRNA was decreased slightly; amounts of biglycan and decorin mRNA were minimally affected.

Conclusions and Clinical Relevance—Treatment of cultured equine chondrocytes with IL-1β or TNF-α resulted in marked alterations in expression of various matrix and matrix-related genes consistent with the implicated involvement of these genes in arthritis. Expression of matrix metalloproteinases was increased far more than expression of their putative endogenous inhibitor. Results support the suggestion that IL-1β and TNF-α play a role in the degradation of articular cartilage in arthritis. (Am J Vet Res2000;61: 624–630)
Evaluation of nitric oxide as an inhibitory neurotransmitter in the equine ventral colon
Authors: Hoogmoed Linda M. Van , Rakestraw Peter C. , Snyder Jack R. , Harmon Faye A.
Published: December 2005

Objective—To determine the role of nitric oxide and an apamin-sensitive nonadrenergic noncholingeric inhibitory transmitter on contractility of the ventral colon of horses.

Sample population—Strips of the circular and longitudinal muscle layers and taenia of the ventral colon from 14 horses.

Procedure—Muscle strips were suspended in tissue baths and attached to force transducers. Contractile activity of circular, longitudinal, and taenia muscle strips in response to electrical field stimulation was measured after addition of apamin and a nitric oxide inhibitor, N-nitro-L-arginine methyl ester (L-NAME).

Results—Electrical field stimulation reduced contractile activity in the circular muscle layer and taenia but not the longitudinal muscle layer. Addition of L-NAME significantly reduced inhibitory contractile activity at all frequencies for the circular muscle layer, whereas a significant effect was evident for the taenia only at the highest frequency. The combination of L-NAME and apamin resulted in a significant reduction in inhibition of the taenia at all frequencies but for circular muscle only at lower frequencies.

Conclusions and Clinical Relevance—Nitric oxide and an apamin-sensitive neurotransmitter appear to mediate a component of inhibitory transmission in the circular muscle and taenia, but not the longitudinal muscle layer, of the equine ventral colon. Nitric oxide has a role in regulating contractile activity of the equine ventral colon, and nitric oxide synthase inhibitors may be useful in horses with ileus of the large colon. (Am J Vet Res2000;61:64–68)
Effects of a 98% solution of glycerol or sterilization with ethylene oxide on FeLV in bone allografts and effects on bone incorporation of allografts in cats
Authors: Coronado George S. , Swenson Cheryl L. , Martinez Steven A. , Burkhardt Kim S. , Arnoczky Steven P.
Published: December 2005

Objectives—To compare virucidal effects and bone
incorporation properties of cortical bone allografts transplanted
into specific-pathogen-free (SPF) cats.
Allografts consisted of untreated bone from a SPF cat
(negative-control group) and bone from 5 FeLV-infected
cats that was subjected to sterilization with ethylene
oxide (ETO), preservation with glycerol, or no treatment
(positive-control group).

Sample Population—Bones from the aforementioned
groups and twenty 8-week-old SPF cats (5
cats/group) implanted with an allograft from 1 of the
aforementioned groups.

Procedure—After implantation, blood samples were
collected weekly to monitor FeLV p27 antigen and antibody
titers. Quantification of FeLV provirus was performed
on blood samples at weeks 0, 4, and 8 and
donor bone samples at time of implantation. Cats were
euthanatized 8 weeks after transplantation, and graft
sites were evaluated.

Results—All results for negative-control cats were negative.
All ETO group cats had negative results for antigen
and provirus in blood, whereas 1 cat had a low antibody
titer. Although 3 ETO-treated allografts were positive for
provirus, the DNA appeared denatured. One cat in the
glycerol group had positive results for all tests in blood
samples. All glycerol-preserved allografts were positive
when tested for provirus. All results for positive-control
group cats were positive. Differences in incorporation of
bone grafts were not observed.

Conclusions and Clinical Relevance—Glycerol
preservation of FeLV-infected bone allografts did not
eliminate transmission of retrovirus to recipients. In
contrast, ETO sterilization appeared to denature DNA
and prevent infection. Treatments did not affect incorporation
of bone grafts in young cats. (Am J Vet Res 2000;61:665–671)
Comparison of pharmacokinetics of fentanyl after intravenous and transdermal administration in cats
Authors: Lee D. David , Papich Mark G. , Hardie Elizabeth M.
Published: December 2005

Objective—To compare pharmacokinetic and pharmacodynamic characteristics of fentanyl citrate after IV or transdermal administration in cats.

Animals—6 healthy adult cats with a mean weight of 3.78 kg.

Procedure—Each cat was given fentanyl IV (25 mg/cat; mean ± SD dosage, 7.19 ± 1.17 mg/kg of body weight) and via a transdermal patch (25 µg of fentanyl/h). Plasma concentrations of fentanyl were measured by use of radioimmunoassay. Pharmacokinetic analyses of plasma drug concentrations were conducted, using an automated curvestripping process followed by nonlinear, leastsquares regression. Transdermal delivery of drug was calculated by use of IV pharmacokinetic data.

Results—Plasma concentrations of fentanyl given IV decreased rapidly (mean elimination half-life, 2.35 ± 0.57 hours). Mean ± SEM calculated rate of transdermal delivery of fentanyl was 8.48 ± 1.7 mg/h (< 36% of the theoretical 25 mg/h). Median steadystate concentration of fentanyl 12 to 100 hours after application of the transdermal patch was 1.58 ng/ml. Plasma concentrations of fentanyl < 1.0 ng/ml were detected in 4 of 6 cats 12 hours after patch application, 5 of 6 cats 18 and 24 hours after application, and 6 of 6 cats 36 hours after application.

Conclusions and Clinical Relevance—In cats, transdermal administration provides sustained plasma concentrations of fentanyl citrate throughout a 5- day period. Variation of plasma drug concentrations with transdermal absorption for each cat was pronounced. Transdermal administration of fentanyl has potential for use in cats for long-term control of pain after surgery or chronic pain associated with cancer. (Am J Vet Res2000;61:672–677)
In vitro retinoid-induced growth inhibition and morphologic differentiation of canine osteosarcoma cells
Authors: Hong Sung-Hyeok , Kadosawa Tsuyoshi , Nozaki Kazutoshi , Mochizuki Manabu , Matsunaga Satoru , Nishimura Ryohei , Sasaki Nobuo
Published: December 2005

Objective—To determine differentiation and
growth inhibition effects of retinoids on canine
osteosarcoma cells.

Sample Population—3 osteosarcoma cell lines established
from osteosarcomas in dogs.

Procedure—Osteosarcoma cells were incubated
with various concentrations of all-trans-retinoic acid
and 9-cis-retinoic acid or control medium, counted
daily for 10 days, and evaluated for morphologic
changes. Synthesis of DNA was measured by use of
a cell proliferation ELISA. To analyze effect of
retinoids on colony formation on plastic dishes, cells
were cultured for 14 days, fixed, and stained; number
of colonies was counted.

Results—In a dose-dependent manner, both
retinoids induced morphologic differentiation and
growth inhibition in the 3 osteosarcoma cell lines and
inhibited each cell's ability to form anchorage-dependent
colonies.

Conclusion and Clinical Relevance—Retinoids
induced differentiation of osteosarcoma cells of dogs,
resulting in altered expression of their malignant phenotype.
Induction of differentiation by retinoids may
have potential as an adjunctive treatment for
osteosarcoma in dogs. (Am J Vet Res 2000;61:69–73)
Pharmacokinetics of enrofloxacin administered intravenously and orally to foals
Authors: Bermingham Eden C. , Papich Mark G. , Vivrette Sally L.
Published: December 2005

Objective—To determine the pharmacokinetics of enrofloxacin administered IV and orally to foals.

Animals—5 clinically normal foals.

Procedure—A 2-dose cross-over trial with IV and oral administration was performed. Enrofloxacin was administered once IV (5 mg/kg of body weight) to 1-week-old foals, followed by 1 oral administration (10 mg/kg) after a 7-day washout period. Blood samples were collected for 48 hours after the single dose IV and oral administrations and analyzed for plasma enrofloxacin and ciprofloxacin concentrations by use of high-performance liquid chromatography.

Results—For IV administration, mean ± SD total area under the curve (AUC0-∞) was 48.54 ± 10.46 µg · h/ml, clearance was 103.72 ± 0.06 ml/kg/h, halflife (t1/2β) was 17.10 ± 0.09 hours, and apparent volume of distribution was 2.49 ± 0.43 L/kg. For oral administration, AUC0-∞was 58.47 ± 16.37 µg · h/ml, t1/2βwas 18.39 ± 0.06 hours, maximum concentration (Cmax) was 2.12 ± 00.51 µg/ml, time to Cmaxwas 2.20 ± 2.17 hours, mean absorption time was 2.09 ± 0.51 hours, and bioavailability was 42 ± 0.42%.

Conclusions and Clinical Relevance—Compared with adult horses given 5 mg of enrofloxacin/kg IV, foals have higher AUC0-∞, longer t1/2β, and lower clearance. Concentration of ciprofloxacin was negligible. Using a target Cmaxto minimum inhibitory concentration ratio of 1:8 to 1:10, computer modeling suggests that 2.5 to 10 mg of enrofloxacin/kg administered every 24 hours would be effective in foals, depending on minimum inhibitory concentration of the pathogen. (Am J Vet Res2000;61: 706–709)
Efficacy of difloxacin in calves experimentally infected with Mannheimia haemolytica
Authors: Olchowy Timothy W. J. , TerHune Terry N. , Herrick Robert L.
Published: December 2005

Objective—To determine the efficacy of difloxacin, a novel fluoroquinolone antibiotic, in calves experimentally infected withMannheimia haemolytica(formerlyPasteurella haemolytica).

Animals—Seventy-two 3-month-old Holstein calves.

Procedures—Calves were inoculated withM haemolyticaintratracheally; after they developed clinical signs of pneumonic pasteurellosis, they were randomly assigned to 1 of 6 groups (n = 12/group). Calves in each group were treated with 10% difloxacin (2.5 or 5 mg/kg of body weight), 5% difloxacin (2.5 or 5 mg/kg), enrofloxacin (5 mg/kg), or saline (0.9% NaCl) solution (control group), once daily for 5 days, and clinical signs were scored daily. On day 15, calves were euthanatized, and the percentage of diseased lung tissue was calculated. Swab specimens of the lungs were submitted for bacterial culture.

Results—Mortality rate and percentage of diseased lung tissue were significantly higher and cure rate and average daily gain were significantly lower for control calves, compared with calves in the treatment groups; however, no significant differences were found among treatment groups.Mannheimia haemolyticawas isolated from the lungs of 10 control calves and from at least 2 calves in each of the treatment groups.

Conclusions and Clinical Relevance—Results suggest that difloxacin and enrofloxacin were equally effective for treatment of calves with experimentally induced pneumonic pasteurellosis. However, treatment of infected calves with difloxacin or enrofloxacin may not eliminate the organism. (Am J Vet Res2000;61:710–713)
Pharmacokinetics of clomipramine in dogs following single-dose intravenous and oral administration
Authors: King Jonathan N. , Maurer Max P. , Hotz Rolf P. , Fisch Roland D.
Published: December 2005

Objective—To determine pharmacokinetics of
clomipramine and its principle metabolite (desmethylclomipramine)
in the plasma of dogs after IV or oral
administration of a single dose.

Animals—6 male and 6 female Beagles.

Procedures—Clomipramine was administered IV
(2 mg/kg), PO (4 mg/kg) after food was withheld for 15
hours, and PO (4 mg/kg) within 25 minutes after dogs
were fed. Plasma clomipramine and desmethylclomipramine
concentrations were measured by use
of a gas chromatography with mass-selection method.

Results—Time to peak plasma concentrations of
clomipramine and desmethylclomipramine following
oral administration was 1.2 hours. For clomipramine,
after IV administration, elimination half-life was 5 hours,
mean residence time was 3 hours, and plasma clearance
was 1.4 L/h/kg. Values for mean residence time
and terminal half-life following oral administration were
similar to values obtained following IV administration,
and systemic bioavailability was approximately 20% for
clomipramine and 140% for desmethylclomipramine,
indicating fast absorption of clomipramine from the gastrointestinal
tract and extensive first-pass metabolism.
Administration of clomipramine with food did not alter
the area under the concentration versus time curve for
desmethylclomipramine but resulted in a 25% increase
for clomipramine. Clomipramine and desmethylclomipramine
were extensively bound (> 96%) to
serum proteins. There were no significant differences
in area under the concentration versus time curve
between male and female dogs.

Conclusions and Clinical Relevance—Results indicate
that there should not be any clinically important
differences in efficacy regardless of whether
clomipramine is administered with or without food.
(Am J Vet Res 2000;61:74–79)
Effect of age on immunocytochemical staining characteristics of adenohypophyseal cells in Mongolian pony mares and stallions
Authors: Tan Jian-Hua , Sasaki Fumihiko
Published: December 2005

Objective—To determine the effect of age on immunocytochemical staining characteristics of adenohypophyseal cells of Mongolian pony mares and stallions.

Animals—35 Mongolian ponies.

Procedure—Pituitary glands from 1- to 22-year-old horses of both sexes were collected at a commercial slaughterhouse in China and allocated into 7 groups according to age and sex: prepubertal stallions (n = 5; 1 to 2 years old), young stallions (6; 3 to 7 years old), middle-aged stallions (4; 10 to 12 years old), old stallions (5; 15 to 22 years old), young mares (3; 3 to 7 years old), middle-aged mares (5; 10 to 12 years old), and old mares (7; 15 to 22 years old). Pituitary glands were processed for microscopy, and sections were immunocytochemically stained for various pituitary hormones. The percentages and cell areas of 6 types of adenohypophyseal cells were determined by use of morphometry.

Results—Age-related alterations in adenohypophyseal cells were detected in horses > 15 years old. Percentage of somatotrophs decreased with age regardless of sex, and percentage of lactotrophs increased with age in stallions. In old mares, percentage of follicle-stimulating hormone cells increased, whereas cell area of follicle-stimulating hormone and luteinizing hormone cells decreased. Differences between sexes for percentage of somatotrophs and lactotrophs, and cell area of follicle-stimulating hormone and luteinizing hormone cells were not evident in old horses.

Conclusions and Clinical Relevance—Differences among percentages and cell areas of pituitary cell types in old horses may be associated with degeneration of the sex organs. (Am J Vet Res2000;61: 826–831)
Effect of hemodialysis on plasma amino acid concentrations in healthy dogs
Authors: Elliott Denise A. , Marks Stanley L. , Cowgill Larry D. , Kass Philip H. , Rogers Quinton R.
Published: December 2005

Objective—To characterize the effect of maintenance hemodialysis on plasma amino acid concentrations and to quantitate free amino acid losses into the dialysate during hemodialysis in healthy dogs.

Animals—8 healthy adult dogs.

Procedure—Five dogs received hemodialysis treatments 3 times per week for 4 weeks. Plasma amino acid concentrations were evaluated once per week for 4 weeks in each of the 5 dogs prior to hemodialysis (time 0), 90 minutes during hemodialysis, and immediately after hemodialysis (180 minutes). Total free amino acid concentrations and plasma amino acid concentrations (time 0, 90 minutes, and 180 minutes) in the dialysate were evaluated in 3 dogs that received 1 hemodialysis treatment.

Results—Significant time versus week interactions with any plasma amino acid were not detected; however, significant decreases in all plasma amino acid concentrations measured were detected at the midpoint of dialysis (46 ± 2%) and at the end of each dialysis session (38 ± 2%). Mean (± SEM) total free amino acid loss into the dialysate was 2.7 ± 0.2 g or 0.12 g/kg of body weight.

Conclusions and Clinical Relevance—Hemodialysis is associated with significant alterations in plasma amino acid concentrations and loss of free amino acids into the dialysate. Loss of amino acids into the dialysate, coupled with protein calorie malnutrition in uremic patients, may contribute to depletion of amino acid stores.(Am J Vet Res2000;61:869–873)
Effect of daily floor treatment with sodium bisulfate on the fly population of horse stalls
Authors: Sweeney Corinne R. , Scanlon Tiffany , Russell Gail E. , Smith Gary , Boston Raymond C.
Published: December 2005

Objective—To determine application rate and effectiveness of sodium bisulfate to decrease the fly population in a horse barn environment.

Sample Population—12 privately owned farms in southeastern Pennsylvania.

Procedure—Application rates of sodium bisulfate were approximately 2.3 kg/stall, 1.1 kg/stall, and 0.5 kg/stall. Two or 3 stalls were treated, and 1 or 2 stalls were not treated (control stalls) at each farm. Farm personnel applied sodium bisulfate in treated stalls daily for 7 days. Fly tapes were hung from the same site in treated and control stalls. After 24 hours, the fly tape was removed, flies adhering to the sticky surface were counted and recorded, and a new fly tape was hung. This procedure was repeated daily during each of the testing periods.

Results—Following the application of 2.3 kg of sodium bisulfate/stall, the numbers of flies collected on the fly tape were significantly decreased in treated stalls, compared with control stalls during the same time periods on 9 of the 12 farms evaluated. Following the application of 1.1 kg of sodium bisulfate/ stall, fly numbers were significantly decreased in treated stalls on 6 of the 9 farms evaluated. Following the application of 0.5 kg of sodium bisulfate/stall, fly numbers were significantly decreased in the treated stalls on 3 of the 4 farms evaluated.

Conclusions and Clinical Relevance—Our findings suggest that sodium bisulfate would be effective for fly control in horse barns. (Am J Vet Res2000; 61:910–913)
Determination of the cDNA sequence and mRNA expression of interleukin-1 receptor antagonist in horses
Authors: Dhar Arun K. , Thompson Margret S. , Paradis Mary Rose , Alcivar-Warren Acacia
Published: December 2005

Objective—To determine the complementary DNA (cDNA) sequence of interleukin-1 receptor antagonist (IL-1ra) in horses and compare messenger RNA (mRNA) expression of IL-1ra among horses of various breeds.

Sample Population—Blood samples from neonatal and adult horses examined for a variety of diseases.

Procedure—A polymerase chain reaction procedure was used to amplify a 220 base pair (bp) portion of the genomic DNA. The upstream and downstream regions of the cDNA sequence were determined by means of 5' and 3' rapid amplification of cDNA ends (RACE) procedures. Northern blot hybridization was used to examine steady-state mRNA expression of IL- 1ra.

Results—The consensus sequence of the cDNA obtained with the 5'-RACE procedure and the sequence for the 220 bp portion of the genomic DNA represented the putative sequence for secreted IL- 1ra. The predicted secreted IL-1ra amino acid sequence contained 176 residues with an in-frame stop codon; the N-terminal 25 amino acid residues resembled the signal peptide reported for human secreted IL-1ra. An approximately 1.3 kilobase pair (kb) band that represented a portion of the 3' end of the coding region and the 3' untranslated region was obtained by use of the 3' -RACE procedure. Northern blot hybridization detected a 1.6 kb transcript in blood RNA from adult Arabian, Belgian, Thoroughbred, and Standardbred horses.

Conclusions—Results suggest that the DNA for equine secreted IL-1ra has a short (29 bp) 5' untranslated region, a 534 bp coding region, and a long (approximately 1,080 bp) untranslated region. (Am J Vet Res2000;61:920–924)
Pharmacokinetics of acetazolamide after intravenous and oral administration in horses
Authors: Alberts Michael K. , Clarke Cyril R. , MacAllister Charles G. , Homer Lynne M.
Published: December 2005

Objective—To determine the pharmacokinetics of acetazolamide administered IV and orally to horses.

Animals—6 clinically normal adult horses.

Procedure—Horses received 2 doses of acetazolamide (4 mg/kg of body weight, IV; 8 mg/kg, PO), and blood samples were collected at regular intervals before and after administration. Samples were assayed for acetazolamide concentration by high-performance liquid chromatography, and concentrationtime data were analyzed.

Results—After IV administration of acetazolamide, data analysis revealed a median mean residence time of 1.71 ± 0.90 hours and median total body clearance of 263 ± 38 ml/kg/h. Median steady-state volume of distribution was 433 ± 218 ml/kg. After oral administration, mean peak plasma concentration was 1.90 ± 1.09 µg/ml. Mean time to peak plasma concentration was 1.61 ± 1.24 hours. Median oral bioavailability was 25 ± 6%.

Conclusions and Clinical Relevance—Oral pharmacokinetic disposition of acetazolamide in horses was characterized by rapid absorption, low bioavailability, and slower elimination than observed initially after IV administration. Pharmacokinetic data generated by this study should facilitate estimation of appropriate dosages for acetazolamide use in horses with hyperkalemic periodic paralysis. (Am J Vet Res2000;61:965–968)
Effects of training on maximum oxygen consumption of ponies
Authors: Katz Lisa M. , Bayly Warwick M. , Roeder Mikel J. , Kingston Janene K. , Hines Melissa T.
Published: December 2005

Objectives—To establish maximum oxygen consumption (O2max) in ponies of different body weights, characterize the effects of training of short duration onO2max, and compare these effects to those of similarly trained Thoroughbreds.

Animals—5 small ponies, 4 mid-sized ponies, and 6 Thoroughbreds.

Procedure—All horses were trained for 4 weeks. Horses were trained every other day for 10 minutes on a 10% incline at a combination of speeds equated with 40, 60, 80, and 100% ofO2max. At the beginning and end of the training program, each horse performed a standard incremental exercise test in whichO2max was determined. Cardiac output (), stroke volume (SV), and arteriovenous oxygen content difference (C [a-v] O2) were measured in the 2 groups of ponies but not in the Thoroughbreds.

Results—Prior to training, meanO2max for each group was 82.6 ± 2.9, 97.4 ± 13.2, and 130.6 ± 10.4 ml/kg/min, respectively. Following training, meanO2max increased to 92.3 ± 6.0, 107.8 ± 12.8, and 142.9 ± 10.7 ml/kg/min. Improvement inO2max was significant in all 3 groups. For the 2 groups of ponies, this improvement was mediated by an increase in; this variable was not measured in the Thoroughbreds. Body weight decreased significantly in the Thoroughbreds but not in the ponies.

Conclusions and Clinical Relevance—Ponies have a lowerO2max than Thoroughbreds, and larger ponies have a greaterO2max than smaller ponies. Although mass-specificO2max changed similarly in all groups, response to training may have differed between Thoroughbreds and ponies, because there were different effects on body weight. (Am J Vet Res2000; 61:986–991)
Development of a technique for the in vivo assessment of flatulence in dogs
Authors: Collins Stella B. , Perez-Camargo Gerardo , Gettinby George , Butterwick Richard F. , Batt Roger M. , Giffard Catriona J.
Published: December 2005

Objective—To develop a noninvasive method for the
in vivo assessment of flatulence in dogs.

Animals—8 adult dogs.

Procedure—Rectal gases were collected via a perforated
tube held close to each dog's anus and attached
to a monitoring pump fitted with a sensor that recorded
hydrogen sulfide concentrations every 20 seconds.
Patterns of flatulence were monitored for 14
hours after feeding on 4 days, and within- and
between-dog variation was assessed over 4 hours on
4 consecutive days. Rate of hydrogen sulfide production
(flatulence index) and frequency and number of
emissions were evaluated as potential indicators of
flatus characteristics. An odor judge assigned an odor
rating to each flatulence episode, and the relationship
between that rating and hydrogen sulfide concentration
was determined.

Results—Flatulence patterns varied within and
between dogs. Variation was most pronounced for flatulence
index; mean coefficients of variance within
dogs over time and between dogs on each day were
75 and 103%, respectively. Flatus with hydrogen sulfide
concentrations > 1 parts per million could be
detected by the odor judge, and severity of malodor
was highly correlated with hydrogen sulfide concentration.
Odor ratings were accurately predicted by use of
the equation 1.51 × hydrogen sulfide concentration0.28.

Conclusions and Clinical Relevance—The technique
described in this report appears to provide sensitive,
reliable, and relevant data and will enable further
studies of the factors that influence flatulence in
dogs. Use of this technique also has the potential to
aid in investigations of colonic physiology and pathology.
(Am J Vet Res 2001;62:1014–1019).
Soluble scute proteins of healthy and ill desert tortoises (Gopherus agassizii)
Authors: Homer Bruce L. , Li Chen , Berry Kristin H. , Denslow Nancy D. , Jacobson Elliott R. , Sawyer Roger H. , Williams J. Elliot
Published: December 2005

Objectives—To characterize protein composition of shell scute of desert tortoises and to determine whether detectable differences could be used to identify healthy tortoises from tortoises with certain illnesses.

Animals—20 desert tortoises.

Procedures—Complete postmortem examinations were performed on all tortoises. Plastron scute proteins were solubilized, scute proteins were separated by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and proteins were analyzed, using densitometry. Two-dimensional immobilized pH gradient-PAGE (2D IPG-PAGE) and immunoblot analysis, using polyclonal antisera to chicken-feather β keratin and to alligator-scale β keratin, were conducted on representative samples. The 14-kd proteins were analyzed for amino acid composition.

Results—The SDS-PAGE and densitometry revealed 7 distinct bands, each with a mean relative protein concentration of > 1%, ranging from 8 to 47 kd, and a major protein component of approximately 14 kd that constituted up to 75% of the scute protein. The 2D IPG-PAGE revealed additional distinct 62- and 68- kd protein bands. On immunoblot analysis, the 14-, 32-, and 45-kd proteins reacted with both antisera. The 14-kd proteins had an amino acid composition similar to that of chicken β keratins. There was a substantial difference in the percentage of the major 14- kd proteins from scute of ill tortoises with normal appearing shells, compared with 14-kd proteins of healthy tortoises.

Conclusions and Clinical Relevance—The major protein components of shell scute of desert tortoises have amino acid composition and antigenic features of β keratins. Scute protein composition may be altered in tortoises with certain systemic illnesses. (Am J Vet Res2001;62:104–110)
Results of intradermal tests in horses without atopy and horses with atopic dermatitis or recurrent urticaria
Authors: Lorch Gwendolen , Hillier Andrew , Kwochka Kenneth W. , Saville William A. , LeRoy Bruce E.
Published: December 2005

Objective—To compare results of intradermal tests (IDT) for environmental allergens at 30 minutes and 4, 6, and 24 hours after injection in horses without atopy and horses with atopic dermatitis (AD) or recurrent urticaria (RU).

Animals—22 horses without atopy, 10 horses with RU, and 7 horses with AD.

Procedure—In all horses, medical history was obtained, and results of physical examination, hematologic examination, serum biochemical analyses, examination of bronchoalveolar lavage fluid, and IDT with 73 allergens were examined.

Results—Horses with AD or RU had a significantly greater mean number of positive reactions for IDT, compared with horses without atopy. Horses with AD had a significantly greater number of positive reactions than horses without atopy in every allergen group at all time periods, except for molds at 4 and 24 hours. Horses with RU had a significantly greater number of positive reactions than horses without atopy in every allergen group, except for molds at 30 minutes and 4 and 6 hours, trees at 4 and 6 hours, and grasses at 4 hours.

Conclusions and Clinical Relevance—A significantly greater number of positive reactions for IDT in horses with AD or RU, compared with horses without atopy, provides evidence of type-I IgE-mediated hypersensitivity for these diseases. Evaluation of results of IDT performed in horses with AD or RU is useful in determining specific allergens for the formulation of immunotherapy along with providing identification of allergens that could be useful when creating avoidance strategies. (Am J Vet Res2001;62:1051–1059)
Changes in molecular expression of aggrecan and collagen types I, II, and X, insulin-like growth factor-I, and transforming growth factor-β1 in articular cartilage obtained from horses with naturally acquired osteochondrosis
Authors: Semevolos Stacy A. , Nixon Alan J. , Brower-Toland Brent D.
Published: December 2005

Objective—To determine molecular changes in the expression of insulin-like growth factor-I (IGF-I) and transforming growth factor-β1 (TGF-β1) in horses with osteochondrosis, and to characterize expression of matrix aggrecan and collagen types I, II, and X in articular cartilage of affected joints.

Sample Population—Articular cartilage from affected stifle or shoulder joints of 11 horses with naturally acquired osteochondrosis and corresponding joints of 11 clinically normal horses.

Procedure—Harvested specimens were snap frozen in liquid nitrogen, and total RNA was isolated. Specimens were fixed in 4% paraformaldehyde for histologic examinations. Expression of matrix molecules was assessed by analysis of northern blots and in situ hybridization, using equine-specific cDNA probes and riboprobes, respectively. Expression of IGF-I and TGF-β1 was assessed by use of noncompetitive quantitative polymerase chain reaction, in situ hybridization, and immunohistochemical analysis.

Results—Cartilage obtained from osteochondrosis lesions had significantly greater expression of IGF-I, compared with normal cartilage. Expression of TGF- β1 and collagen type I were higher, but not significantly so, in affected tissues. Expression of aggrecan or collagen types II and X did not differ between affected and clinically normal cartilage.

Conclusions and Clinical Relevance—Increased expression of growth factors and collagen type I was found in cartilage from osteochondrosis lesions. However, this probably reflects a healing response to injured tissue rather than a primary alteration. Therefore, methods aimed at altering concentrations of growth factors in cartilage of growing horses would be unlikely to alter the incidence or progress of the disease. (Am J Vet Res2001;62:1088–1094)
Experimental induction of chronic borreliosis in adult dogs exposed to Borrelia burgdorferi–infected ticks and treated with dexamethasone
Authors: Chang Yung-Fu , Novosel Vesna , Chang Chao-Fu , Summers Brian A. , Ma Din-Pow , Chiang Yu-Wei , Acree William M. , Chu Hsien-Jue , Shin Sang , Lein Donald H.
Published: December 2005

Objective—To develop a method to experimentally induceBorrelia burgdorferiinfection in young adult dogs.

Animals—22 healthy Beagles.

Procedure—All dogs were verified to be free of borreliosis. Twenty 6-month-old dogs were exposed toBorrelia burgdorferi-infected adult ticks and treated with dexamethasone for 5 consecutive days. Two dogs not exposed to ticks were treated with dexamethasone and served as negative-control dogs. Clinical signs, results of microbial culture and polymerase chain reaction (PCR) testing, immunologic responses, and gross and histologic lesions were evaluated 9 months after tick exposure.

Results—Predominant clinical signs were episodic pyrexia and lameness in 12 of 20 dogs. Infection withB burgdorferiwas detected in microbial cultures of skin biopsy specimens and various tissues obtained during necropsy in 19 of 20 dogs and in all 20 dogs by use of a PCR assay. All 20 exposed dogs seroconverted and developed chronic nonsuppurative arthritis. Three dogs also developed mild focal meningitis, 1 dog developed mild focal encephalitis, and 18 dogs developed perineuritis or rare neuritis. Control dogs were seronegative, had negative results for microbial culture and PCR testing, and did not develop lesions.

Conclusions and Clinical Relevance—Use of this technique successfully induced borreliosis in young dogs. Dogs with experimentally induced borreliosis may be useful in evaluating vaccines, chemotherapeutic agents, and the pathogenesis of borreliosisinduced arthritis. (Am J Vet Res2001;62:1104–1112)
Radiometric assessment of hexose monophosphate shunt capacity in erythrocytes of rhinoceroses
Authors: Paglia Donald E. , Weber Brandon , Baumgarten Ingrid , Harley Eric H.
Published: December 2005

Objectives—To measure metabolic rates of the hexose monophosphate shunt (HMPS) in erythrocytes of rhinoceroses, and to test the hypothesis that low concentrations of endogenous ATP in erythrocytes impair HMPS capacity, thereby increasing susceptibility to oxidant-induced hemolysis.

Animals—13 black and 3 white rhinoceroses, freeranging in several regions of southern Africa, and 1 Sumatran rhinoceros in US captivity.

Procedure—HMPS fluxes were measured in rhinoceros erythrocytes with carbon-labeled glucose in the presence and absence of known HMPS activators.

Results—Compared with values for human erythrocytes, mean basal state HMPS fluxes were appreciably lower (22 to 46%) in all 3 rhinoceros species studied. Shunt activators increased HMPS rates approximately 5-fold over basal rates in rhinoceros erythrocytes, compared with increases in humans of 10-fold with ascorbate and 15-fold with methylene blue. Stimulated HMPS rates in human erythrocytes were quantitatively 5- to 10-times greater than those observed in rhinoceros erythrocytes. Overall HMPS catabolic rates were completely independent of intracellular ATP concentrations.

Conclusions and Clinical Relevance—HMPS glycolytic and recycling rates and responses to activators are inherently low in erythrocytes from 3 species of rhinoceros, likely contributing to (but not solely responsible for) the high susceptibility of black rhinoceroses to oxidant-induced hemolysis. Slow erythrocyte HMPS capacities were independent of intracellular ATP concentrations, invalidating a current hypothesis regarding the pathogenesis of hemolytic anemia in captive black rhinoceroses. Limitations in HMPS capacities emphasize the importance of protecting rhinoceroses from exposure to drugs, chemicals, toxins, foodstuffs, and other conditions known to increase production of oxidizing metabolites, reactive oxygen species, and free radicals.(Am J Vet Res2001;62:1113–1117)