bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct and indirect contact rates among beef, dairy, goat, sheep, and swine herds in three California counties, with reference to control of potential foot-and-mouth disease transmission
Authors: Bates Thomas W. , Thurmond Mark C. , Carpenter Tim E.
Published: December 2005

Objective—To estimate direct and indirect contact rates on livestock facilities and distance traveled between herd contacts.

Sample Population—320 beef, dairy, goat, sheep, and swine herds, 7 artificial insemination technicians, 6 hoof trimmers, 15 veterinarians, 4 sales yard owners, and 7 managers of livestock-related companies within a 3-county region of California.

Procedure—A questionnaire was mailed to livestock producers, and personal and telephone interviews were conducted with individuals.

Results—Mean monthly direct contact rates were 2.6, 1.6, and 2.0 for dairies with < 1,000, 1,000 to 1,999, and ≥ 2,000 cattle, respectively. Mean indirect contact rates on dairies ranged from 234 to 743 contacts/ mo and increased by 1 contact/mo as herd size increased by 4.3. Mean direct monthly contact rate for beef herds was 0.4. Distance traveled by personnel and vehicles during a 3-day period ranged from 58.4 to 210.4 km. Of livestock arriving at sales yards, 7% (500/7,072) came from ≥ 60 km away, and of those sold, 32% (1,180/3,721) were destined for a location ≥ 60 km away. Fifty-five percent (16/29) of owners of large beef herds observed deer or elk within 150 m of livestock at least once per month.

Conclusions and Clinical Relevance—Direct and indirect contacts occur on livestock facilities located over a wide geographic area and at a higher frequency on larger facilities. Knowledge of contact rates may be useful for planning biosecurity programs at the herd, state, and national levels and for modeling transmission potential for foot-and-mouth disease virus. (Am J Vet Res2001;62:1121–1129)
Effects of a bioactive glass on healing of closed skin wounds in dogs
Authors: Gillette Robert L. , Swaim Steven F. , Sartin Eva A. , Bradley Dino M. , Coolman Shindok L.
Published: December 2005

Objective—To determine effects of intraincisional bioactive glass on healing of sutured skin wounds in dogs.

Animals—9 purpose-bred mature female Beagles.

Procedure—3 small matched bilateral (treated vs control) full-thickness truncal skin incisions were made and sutured. Treated wounds received intraincisional particulate bioactive glass prior to closure. Laser Doppler perfusion imaging was used to assess percentage change in tissue perfusion 3 and 5 days after incision on 1 set of 2 matched wounds, and skin and subcutaneous tissue-cutaneous trunci breaking strength were assessed at 5 days. The other 2 sets of wounds were used for histologic evaluation at 5 and 21 days, respectively.

Results—Subjective signs of gross inflammatory reaction were not detected in treated or control wounds. At 5 days, median subcutaneous tissuecutaneous trunci breaking strength was significantly higher in treated wounds than in control wounds (188.75 vs 75.00 g). At 5 days, median scores were significantly higher for neutrophils (1 vs 0), macrophages (2 vs 1), and necrosis (1 vs 0) for treated wounds than for control wounds. At 21 days, median macrophage scores were significantly higher for treated wounds than for control wounds (2 vs1).

Conclusions and Clinical Relevance—Bioactive glass in soft tissues does not cause a gross inflammatory reaction but causes an increase in histologic signs of inflammation, which decreases with time. Bioactive glass has potential for increasing tissue strength. Increased subcutaneous breaking strength could be beneficial in treating wounds in which early healing strength is needed. (Am J Vet Res2001;62:1149–1153)
Heritability estimations for diseases, coat color, body weight, and height in a birth cohort of Boxers
Authors: Nielen Angelique L. J. , Janss Luc L. G. , Knol Bart W.
Published: December 2005

Objective—To obtain heritability estimates for diseases and characteristics in Boxers.

Animals—Birth cohort of 2,929 purebred Boxers from 414 litters.

Procedure—Heritability estimates were determined for cheiloschisis-palatoschisis, cryptorchidism, epilepsy, stifle disorders, cardiac disorders, coat color, birth weight, and adult weight, and height. Binary traits were analyzed by use of a mixed-effects probit model. Some traits also were analyzed by use of a model that postulated monogenic inheritance. Full pedigree analyses were performed. Variation in incidences of disease among clusters of related dogs was evaluated.

Results—Heritability estimates were virtually zero for cardiac disorders, medium (0.17 to 0.36) for most other traits, and high (> 0.55) for coat color, birth weight, and adult height. Litter effects and risk factors affected cheiloschisis-palatoschisis, heart murmur, coat color, broadly defined epilepsy, and adult weight. Litter effects may be attributable to common environmental effects for littermates but also may be attributable to dominance variation caused by a recessive gene. Heritability estimates increased when stricter definitions for epilepsy and stifle disorders were used. The monogenic model did not reveal higher heritability estimates for 6 traits analyzed. Incidences for white coat differed significantly for 10 familial clusters, confirming high heritability and effects of familial lineage.

Conclusions and Clinical Relevance—Results indicate that genetic improvement of most traits should be feasible, except for cardiac disorders. However, because most traits are influenced by environmental effects as well as genetic effects, genetic counseling based on polygenic inheritance and use of familial information rather than strict exclusion of parents is preferred. (Am J Vet Res2001;62:1198–1206)
Alterations in systemic and local colonic hemodynamic variables associated with intravenous infusion of ATP-MgCl2 in healthy anesthetized horses
Authors: Tetens Joanne , Eades Susan C. , Hosgood Giselle , Koch Catherine E. , Moore Rustin M.
Published: December 2005

Objective—To characterize alterations in systemic and local colonic hemodynamic variables associated with IV infusion of ATP-MgCl2in healthy anesthetized horses.

Animals—12 adult horses.

Procedure—Six horses were given ATP-MgCl2, IV, beginning at a rate of 0.1 mg of ATP/kg of body weight/min with incremental increases until a rate of 1.0 mg/kg/min was achieved. The remaining 6 horses were given an equivalent volume of saline (0.9% NaCl) solution over the same time period. Colonic and systemic hemodynamic variables and colonic plasma nitric oxide (NO) concentrations were determined before, during, and after infusion.

Results—Infusion of ATP-MgCl2caused a rate-dependent decrease in systemic and colonic vascular resistance, principally via its vasodilatory effects. A rate of 0.3 mg of ATP/kg/min caused a significant decrease in systemic and colonic arterial pressure and colonic vascular resistance without a significant corresponding decrease in colonic arterial blood flow. Consistent alterations in NO concentrations of plasma obtained from colonic vasculature were not detected, despite profound vasodilatation of the colonic arterial vasculature.

Conclusions and Clinical Relevance—Results revealed that IV infusion of ATP-MgCl2may be beneficial in maintaining colonic perfusion in horses with ischemia of the gastrointestinal tract, provided a sufficient pressure gradient exists to maintain blood flow. (Am J Vet Res2001;62:1240–1249)
Effect of mammary secretions on functions of polymorphonuclear leukocytes in pigs
Authors: Österlundh Ingrid , Holst Henrik , Magnusson Ulf
Published: December 2005

Objective—To determine the effects of porcine mammary secretions on polymorphonuclear (PMN) leukocyte function and to relate concentrations of estradiol-17β and cortisol in mammary secretions to PMN cell function.

Sample Population—Mammary secretions from 10 healthy sows and blood PMN leukocytes from 27 healthy sows.

Procedure—Mammary secretions were collected within 24 hours after parturition (colostrum) and 12 to 13 days later (milk). Chemoattractant properties were assessed by use of a cell migration assay. Phagocytic capacity of PMN cells in colostrum and milk was assessed by recording chemiluminescence following phagocytosis ofEscherichia colior zymosan. Estradiol-17β and cortisol concentrations were determined by use of radioimmunoassays.

Results—Chemoattractant properties of colostrum and milk were significantly greater than that of zymosan-activated serum. However, chemoattractant properties did not differ significantly between the 2 types of secretions. The capacity of PMN cells in colostrum to phagocytose either zymosan orE coliwas less, compared with cells in milk, and the ability of cells in either type of mammary secretion to phagocytoseE coliwas greater than the ability to phagocytose zymosan. Concentrations of estradiol-17β and cortisol were greater in colostrum, compared with milk. No clear relation was evident between PMN cell activity and hormone concentrations in mammary secretions.

Conclusions and Clinical Relevance—Although chemoattractant properties of colostrum and milk did not differ, the phagocytic capacity of PMN cells in colostrum was significantly less than that of cells in milk. This may predispose sows to coliform mastitis during the early postparturient period. (Am J Vet Res2001;62:1250–1254)
Arrhythmogenic effect of hypercapnia in ducks anesthetized with halothane
Authors: Naganobu Kiyokazu , Hagio Mitsuyoshi , Sonoda Tatsunobu , Kagawa Kiyokazu , Mammoto Tadanori
Published: December 2005

Objective—To determine effects of hypercapnia on arrhythmias in ducks anesthetized with halothane.

Animals—12 ducks, 6 to 8 months old, weighing 1.1 to 1.6 kg.

Procedures—Each duck was anesthetized with a 1.5% mixture of halothane in oxygen, and anesthetic depth was stabilized during a 20-minute period. We added CO2to the inspired oxygen to produce CO2partial pressures of 40, 60, and 80 mm Hg in the inspired gas mixture. The CO2partial pressure was increased in a stepwise manner. When arrhythmias were not evident during inhalation of the gas mixture at a specific CO2partial pressure, the CO2partial pressure was maintained for 10 minutes before a sample was collected for blood gas analysis. When arrhythmias were detected, a sample for blood gas analysis was collected after the CO2partial pressure was maintained for at least 2 minutes, and CO2inhalation then was terminated.

Results—During the stabilization period, PaCO2(mean ± SD) was 33 ± 5 mm Hg,and arrhythmias were not detected. In 6 ducks, arrhythmias such as unifocal and multifocal premature ventricular contractions developed during inhalation of CO2. Mean PaCO2at which arrhythmias developed was 67 ± 12 mm Hg. In 5 of 6 ducks with arrhythmias, the arrhythmias disappeared after CO2inhalation was terminated.

Conclusion and Clinical Relevance—Analysis of data from this study indicated that hypercapnia can lead to arrhythmias in ducks during halothane-induced anesthesia. Thus, ventilatory support to maintain normocapnia is important for managing ducks anesthetized with halothane. (Am J Vet Res2001;62: 127–129)
Luteal and clinical response following administration of dinoprost tromethamine or cloprostenol at standard intramuscular sites or at the lumbosacral acupuncture point in mares
Authors: Nie Gary J. , Goodin Ashley N. , Braden Timothy D. , Wenzel James G. W.
Published: December 2005

Objective—To determine whether administration of a
microdose of prostaglandin at the BAI HUI acupuncture
point offers any advantage over IM injections for luteolysis,
ovulatory interval, or systemic response in mares.

Animals—17 mature cycling mares, 3 to 20 years of
age and weighing 400 to 500 kg.

Procedure—Conventional and microdoses of the
prostaglandin dinoprost tromethamine (PGF2α), the
analogue cloprostenol, or sterile water (control) were
administered to mares in 7 treatment groups.
Treatments were assigned by dose, administration site
(semimembranosus, semitendinosus, or lumbosacral
region), and treatment type (PGF2α, analogue, or sterile
water). Mares were observed for ovulatory interval and
systemic response to treatment, including heart, and
respiratory rates, rectal temperature, and sweat score.
Plasma progesterone concentrations were also determined
at the time of treatment and at 24-hour intervals
for 96 hours following treatment.

Results—Ovulatory interval was shortened and progesterone
concentrations decreased in prostaglandintreated
mares, compared with control mares, regardless
of dose or treatment site. However, no differences
in ovulatory interval were observed among
prostaglandin-treated mares. Mares treated with conventional
doses of PGF2α had greater systemic
responses than mares treated with microdoses of
PGF2α or sterile water.

Conclusions and Clinical Relevance—Administration
of prostaglandins at the BAI HUI acupuncture
point does not appear to offer any advantage over
administration at standard IM injection sites for induction
of luteolysis or to shorten the ovulatory interval.
However, administration of a microdose of the analogue
cloprostenol was effective at inducing luteolysis
and shortening ovulatory interval regardless of administration
site. (Am J Vet Res 2001;62:1285–1289)
Derivation and characterization of a live attenuated equine influenza vaccine virus
Authors: Youngner Julius S. , Whitaker-Dowling Patricia , Chambers Thomas M. , Rushlow Keith E. , Sebring Randy
Published: December 2005

Objective—To develop and characterize a cold-adapted live attenuated equine-2 influenza virus effective as an intranasal vaccine.

Animals—8 ponies approximately 18 months of age.

Procedures—A wild-type equine-2 virus, A/Equine/ Kentucky/1/91 (H3N8), was serially passaged in embryonated chicken eggs at temperatures gradually reduced in a stepwise manner from 34 C to 30 C to 28 C to 26 C. At different passages, infected allantoic fluids were tested for the ability of progeny virus to replicate in Madin-Darby canine kidney (MDCK) cells at 34 C and 39.5 C. Virus clones that replicated at 26 C in eggs and at 34 C in MDCK cells, but not at 39.5 C in MDCK cells, were tested for stability of the coldadapted, temperature-sensitive (ts), and protein synthesis phenotypes. A stable clone, P821, was evaluated for safety, ability to replicate, and immunogenicity after intranasal administration in ponies.

Results—Randomly selected clones from the 49th passage were all ts with plaquing efficiencies of < 10-6(ratio of 39.5 C:34 C) and retained this phenotype after 5 serial passages at 34 C in either embryonated eggs or MDCK cells. The clone selected as the vaccine candidate (P821) had the desired degree of attenuation. Administered intranasally to seronegative ponies, the virus caused no adverse reactions or overt signs of clinical disease, replicated in the upper portion of the respiratory tract, and induced a strong serum antibody response.

Conclusion and Clinical Relevance—A candidate live attenuated influenza vaccine virus was derived by cold-adaptation of a wild-type equine-2 influenza virus, A/Equine/Kentucky/1/91, in embryonated eggs. (Am J Vet Res2001;62:1290–1294)
Use of capillary electrophoresis to quantitate carbamylated hemoglobin concentrations in dogs with renal failure
Authors: Heiene Reidun , Vulliet P. Richard , Williams Robert L. , Cowgill Larry D.
Published: December 2005

Objective—To evaluate quantification of the amount of carbamylated hemoglobin (CarbHb), using capillary electrophoresis (CE) and a new dynamic capillary coating system to separate hemoglobin derivatives, and to assess the use of CarbHb amounts to evaluate long-term urea exposure and differential diagnoses of azotemia in dogs.

Animals—8 dogs with renal failure, 2 dogs with diabetes mellitus, and 7 control dogs.

Procedure—Optimal analytic conditions for separation of CarbHb and other hemoglobin derivatives in blood samples obtained from dogs were determined, using a commercial analysis system developed for the detection of glycohemoglobin Hb A1c (GlycHb) in human blood samples. Relative content of hemoglobin derivatives in blood from 10 dogs with renal failure or endocrine diseases were compared with values for 7 dogs without renal or endocrine diseases.

Results—Satisfactory resolution of hemoglobin derivatives was obtained, which permitted identification and quantitation of the amount of CarbHb as a percentage of the total amount of hemoglobin. Normal or increased amounts of GlycHb did not interfere with CarbHb analysis. Dogs with chronic renal failure had considerably higher peak amounts of CarbHb than dogs with acute renal failure, a dog with chronic renal failure that was treated by use of hemodialysis, or dogs without renal disease.

Conclusions and Clinical Relevance—Amounts of CarbHb in blood samples obtained from dogs can be readily quantified by use of capillary electrophoresis. Assessment of the amount of CarbHb can be used to facilitate evaluation of the cause of azotemia in dogs. (Am J Vet Res2001;62:1302–1306)
Use of a hyaluronate membrane for jejunal anastomosis in horses
Authors: Eggleston Randy B. , Mueller P.O. Eric , Quandt Jane E. , Neuwirth Lisa , Harmon Barry G. , Waguespack Wayne R. , Rainbow Mark E.
Published: December 2005

Objective—To compare the outcomes of doublelayer inverting anastomosis (DIA), single-layer anastomosis (SLA), and single-layer anastomosis combined with a hyaluronate membrane (SLA+HA-membrane) with respect to stomal diameter, adhesion formation, surgery time, and anastomotic healing in horses.

Animals—18 adult horses.

Procedure—Midline celiotomy and end-to-end anastomoses were performed. In control horses (n = 6), DIA was performed; in treated horses, SLA was performed (6) or SLA+HA-membrane was performed (6). Horses were euthanatized 21 days after surgery. Abdominal adhesions were evaluated grossly and histologically. Stomal diameters were measured ultrasonographically and compared with adjacent luminal diameters. Anastomotic healing was evaluated histologically for fibrosis and inflammation, tissue alignment, and inversion. Surgery times were recorded for the anastomotic procedure and compared among groups.

Results—There were significantly more adhesions in the SLA group, compared with the DIA and SLA+HAmembrane groups. Reduction in stomal diameters in the DIA group was significantly greater than the SLA and SLA+HA-membrane groups. Surgery times for the DIA group were significantly greater than the SLA and SLA+HA-membrane groups. Histologic findings of fibrosis, inflammation, and mucosal healing were similar among groups. There was significant tissue inversion in the DIA group, compared with the 2 treatment groups. Tissue alignment was not different among groups.

Conclusions and Clinical Relevance—Use of a SLA+HA-membrane was an effective small intestinal anastomotic technique. This technique was faster to perform and resulted in a larger stomal diameter, compared with the DIA technique and significantly fewer perianastomotic adhesions, compared with the SLA technique. (Am J Vet Res2001;62:1314–1319)
Evaluation of plasma clearance of inulin in clinically normal and partially nephrectomized cats
Authors: Miyamoto Kenji
Published: December 2005

Objective—To evaluate accuracy of measuring plasma clearance of inulin as an alternative renal function test for estimation of glomerular filtration rate (GFR) in cats.

Animals—10 cats, first studied with intact kidneys and subsequently studied following partial nephrectomy.

Procedure—Clearance studies were performed in 10 clinically normal cats; those same cats then underwent partial nephrectomy, and clearance studies were performed again. Plasma concentration of inulin was determined after administration at 50 mg/kg of body weight to cats while renally intact and 45 mg/kg after the partial nephrectomy. Plasma clearance of inulin (PCin) was determined by dividing the dose by the area under the plasma inulin concentration versus time curve. Results for PCin were compared with values obtained simultaneously for urinary clearance of exogenously administered creatinine (Ccr), a widely accepted method for measurement of GFR in cats with intact kidneys and cats with reduced renal mass.

Results—Results of PCin were strongly correlated (r2= 0.912, P < 0.001 ) with Ccr. Repeatability of determination of PCin was similar to that of Ccr. Sensitivity and specificity of PCin were superior and equivalent to that of Ccr, respectively.

Conclusions and Clinical Relevance—Determination of PCin provides a reliable estimate of GFR in cats and is a promising alternative to determining Ccr in cats. (Am J Vet Res2001;62:1332–1335)
Training failure among yearling horses
Authors: Hernandez Jorge , Hawkins Dan L.
Published: December 2005

Objective—To compare financial returns between pinhooked yearling horses (ie, bought and trained for approximately 5 months with the goal of selling the horse at "2-year-olds in training" sales) that had mild or severe training failure and horses that had planned versus nonplanned training failure.

Animals—40 Thoroughbred pinhooked yearling horses.

Procedure—During the period from September 1998 through and April 1999, 20 horses had mild training failure (1 to 11 days lost), and 20 horses had severe training failure (13 to 108 days lost). Horses were assigned to these 2 groups on the basis of frequency distribution (median) of days lost during training. Horses were also categorized on the basis of type of training failure (planned vs nonplanned training failure). The outcome of primary interest was financial return. Median financial returns were compared among groups by use of the Mann-WhitneyUtest.

Results—Median financial returns for horses that had severe training failure ($1,000) were significantly different, compared with horses that had mild training failure ($24,000). Analysis of results also indicated that median returns were significantly different among horses that had planned training failure (−$2,000; eg, horses with radiographic abnormalities detected during routine prepurchase examinations that required surgical treatment, resulting in days lost during training), compared with horses that did not ($10,000).

Conclusions and Clinical Relevance—Training failure has an economic impact on revenues in pinhooked yearling horses. Lameness, planned training failure, respiratory disease, and ringworm were common and important causes of training failure. (Am J Vet Res2001;62:1418–1422)
Cardiopulmonary effects of prolonged anesthesia via propofol-medetomidine infusion in ponies
Authors: Bettschart-Wolfensberger Regula , Bowen Marc I. , Freeman Sarah L. , Feller Renate , Bettschart Robert W. , Nolan Andrea , Clarke Kathleen W.
Published: December 2005

Objective—To determine cardiopulmonary effects of total IV anesthesia with propofol and medetomidine in ponies and effect of atipamezole on recovery.

Animals—10 ponies.

Procedure—After sedation was induced by IV administration of medetomidine (7 μg/kg of body weight), anesthesia was induced by IV administration of propofol (2 mg/kg) and maintained for 4 hours with infusions of medetomidine (3.5 μg/kg per hour) and propofol (0.07 to 0.11 mg/kg per minute). Spontaneous respiration was supplemented with oxygen. Cardiopulmonary measurements and blood concentrations of propofol were determined during anesthesia. Five ponies received atipamezole (60 μg/kg) during recovery.

Results—During anesthesia, mean cardiac index and heart rate increased significantly until 150 minutes, then decreased until cessation of anesthesia. Mean arterial pressure and systemic vascular resistance index increased significantly between 150 minutes and 4 hours. In 4 ponies, PaO2decreased to < 60 mm Hg. Mean blood propofol concentrations from 20 minutes after induction onwards ranged from 2.3 to 3.5 μg/ml. Recoveries were without complications and were complete within 28 minutes with atipamezole administration and 39 minutes without atipamezole administration.

Conclusions and Clinical Relevance—During total IV anesthesia of long duration with medetomidine-propofol, cardiovascular function is comparable to or better than under inhalation anesthesia. This technique may prove suitable in equids in which prompt recovery is essential; however, in some animals severe hypoxia may develop and oxygen supplementation may be necessary. (Am J Vet Res2001;62:1428–1435)
Evaluation of concurrent shedding of bovine coronavirus via the respiratory tract and enteric route in feedlot cattle
Authors: Cho Kyoung-Oh , Hoet Armando E. , Loerch Steven C. , Wittum Thomas E. , Saif Linda J.
Published: December 2005

Objective—To assess the relationship between shedding of bovine coronavirus (BCV) via the respiratory tract and enteric routes and the association with weight gain in feedlot cattle.

Animals—56 crossbred steers.

Procedures—Paired fecal samples and nasal swab specimens were obtained and were tested for BCV, using antigen-capture ELISA. Paired serum samples obtained were tested for antibodies to BCV, using antibody-detection ELISA. Information was collected on weight gain, clinical signs, and treatments for enteric and respiratory tract disease during the study period.

Results—Number of samples positive for bovine respiratory coronavirus (BRCV) or bovine enteric coro navirus (BECV) was 37/224 (17%) and 48/223 (22%), respectively. Some cattle (25/46, 45%) shed BECV and BRCV. There were 25/29 (86%) cattle positive for BECV that shed BRCV, but only 1/27 (4%) cattle negative to BECV shed BRCV. Twenty-seven of 48 (56%) paired nasal swab specimens and fecal samples positive for BECV were positive for BRCV. In contrast, only 10/175 (6%) paired nasal swab specimens and fecal samples negative for BECV were positive for BRCV. Only shedding of BECV was associated with significantly reduced weight gain. Seroconversion to BCV during the 21 days after arrival was detected in 95% of the cattle tested.

Conclusions and Clinical Implications—Feedlot cattle infected with BCV after transport shed BCV from the respiratory tract and in the feces. Fecal shedding of BCV was associated with significantly reduced weight gain. Developing appropriate control measures for BCV infections could help reduce the decreased weight gain observed among infected feedlot cattle. (Am J Vet Res2001;62:1436–1441)
Telomerase activity in clinically normal dogs and dogs with malignant lymphoma
Authors: Carioto Lisa M. , Kruth Stephen A. , Betts Dean H. , King W. Allan
Published: December 2005

Objectives—To determine whether telomerase activity was present in lymph nodes, buffy coat, and serum samples from dogs with malignant lymphoma (ML) and in liver, lymph node, buffy coat, and serum samples from clinically normal dogs

Sample Population—Tissue specimens and blood samples were obtained from 11 clinically normal adult dogs (age range, 1 to 4 years) and 14 client-owned dogs with ML.

Procedure—The telomere repeat amplification protocol assay was used to quantify telomerase activity in the tissues from clinically normal dogs and dogs with ML.

Results—Of 11 clinically normal dogs, 8 had lymph node samples, 5 had liver samples, and 1 had buffy coat samples with detectable telomerase activity. None of the serum samples from the clinically normal dogs had detectable telomerase activity. Of 14 dogs with ML, 9 had lymph node samples, 3 had buffy coat samples, and 1 had serum samples with measurable telomerase activity.

Conclusions and Clinical Relevance—Telomerase activity was not specific to tumor cells and overlapped with that found in cells from clinically normal dogs. Telomerase activity in neoplastic lymph nodes was not substantially different from that found in lymph nodes from clinically normal dogs. The determination of telomerase activity cannot be used as a sole diagnostic test for cancer. Therapeutic modalities directed toward the telomerase enzyme may not be feasible in dogs, because somatic tissues from clinically normal dogs possess variable amounts of telomerase activity. (Am J Vet Res2001;62:1442–1446)
Evaluation of a point-of-care coagulation analyzer for measurement of prothrombin time, activated partial thromboplastin time, and activated clotting time in dogs
Authors: Tseng Laura W. , Hughes Dez , Giger Urs
Published: December 2005

Objective—To evaluate a point-of-care coagulation analyzer (PCCA) in dogs with coagulopathies and healthy dogs.

Animals—27 healthy and 32 diseased dogs with and without evidence of bleeding.

Procedure—Prothrombin time (PT), activated partial thromboplastin time (aPTT), and activated clotting time (ACT) were determined, using a PCCA and standard methods.

Results—Using the PCCA, mean (± SD) PT of citrated whole blood (CWB) from healthy dogs was 14.5 ± 1.2 seconds, whereas PT of nonanticoagulated whole blood (NAWB) was 10.4 ± 0.5 seconds. Activated partial thromboplastin time using CWB was 86.4 ± 6.9 seconds, whereas aPTT was 71.2 ± 6.7 seconds using NAWB. Reference ranges for PT and aPTT using CWB were 12.2 to 16.8 seconds and 72.5 to 100.3 seconds, respectively. Activated clotting time in NAWB was 71 ± 11.8 seconds. Agreement with standard PT and aPTT methods using citrated plasma was good (overall agreement was 93% for PT and 87.5% for aPTT in CWB). Comparing CWB by the PCCA and conventional coagulation methods using citrated plasma, sensitivity and specificity were 85.7 and 95.5% for PT and 100 and 82.9% for aPTT, respectively. Overall agreement between the PCCA using NAWB and the clinical laboratory was 73% for PT and 88% for aPTT. Using NAWB for the PCCA and citrated plasma for conventional methods, sensitivity and specificity was 85.7 and 68.4% for PT and 86.7 and 88.9% for aPTT, respectively.

Conclusions and Clinical Relevance—The PCCA detected intrinsic, extrinsic, and common pathway abnormalities in a similar fashion to clinical laboratory tests. (Am J Vet Res2001;62:1455–1460)
Nucleotide sequence of the canine α IIb gene from platelet-derived cDNA
Authors: Lipscomb Desireè L. , Bourne Candace , Boudreaux Mary K.
Published: December 2005

Objective—To determine the nucleotide sequence of
the α
IIb
gene from canine platelet-derived cDNA.

Animals—3 adult dogs.

Procedure—First-strand cDNA was prepared from
total RNA isolated from canine platelets. The cDNA
was amplified, using specific primers in polymerase
chain reaction (PCR), and the nucleotide sequence
was obtained from purified PCR products.

Results—Except for the nucleotide at position 694,
results of all sequencing reactions of α
IIb
were identical
for canine platelet-derived cDNA. Canine α
IIb
had 3
fewer codons than α
IIb
of humans. The nucleotide and
deduced amino acid sequences of full-length canine
α
IIb
shared ≥ 83% similarity with the sequences
established for humans. Segments of canine α
IIb

nucleotide and deduced amino acid sequences were
≥ 78% similar to α
IIb
associated with 7 functional
domains (extracellular, transmembrane, cytoplasmic,
and 4 calcium-binding domains) in humans, with the
highest degree of similarity correlating with the
sequences of the 4 calcium-binding domains. Amino
acid residues associated with development of alloantibodies
in humans (Met837, Val837, Ile843, Ser843) are
not encoded by canine α
IIb
.

Conclusions and Clinical Relevance—The nucleotide
variation at position 694 of canine α
IIb
may represent a
polymorphism. The species differences in the α
IIb

sequence may contribute to variations in receptor-li
gand interactions. The high degree of α
IIb
sequence
conservation of the 4 calcium-binding domains implies
functional importance. Some disorders associated with
α
IIb
β3 in dogs are clinically analogous to diseases in
humans, and results indicate that dogs are an appropriate
model for the evaluation of gene therapy and
other treatments of platelet-associated disorders. (Am
J Vet Res 2001;62:1486–1492)
Chronic ingestion of high concentrations of cholecalciferol in cats
Authors: Sih Tracey R. , Morris James G. , Hickman M. Anne
Published: December 2005

Objective—To determine whether ingestion of 63 times the recommended amount of vitamin D3(cholecalciferol) results in renal calcification or damage in cats.

Animals—20 four-month-old kittens, 17 queens, and 20 kittens born to these queens.

Procedure—4-month-old kittens and queens were given a purified diet with 846 μg of cholecalciferol/kg of diet (high vitamin D3diet) or 118 μg of cholecalciferol/ kg of diet (control diet) for 18 months. Kittens born to queens were weaned onto the same diet given to dams.

Results—There were no apparent adverse effects of the high vitamin D3diet. Plasma cholecalciferol and 25-hydroxycholecalciferol (25-OHD3) concentrations of queens and 4-month-old kittens given the high vitamin D3diet significantly increased with time. At 6 months, plasma cholecalciferol concentrations in these kittens and queens were 140.0 ± 7.3 nmol/L and 423.6 ± 26.6 nmol/L, respectively (10 times initial values). Corresponding 25-OHD3concentration in queens was 587.5 ± 59.4 nmol/L (2.5-fold increase over initial values). At 3 months of age, kittens born to queens given the high vitamin D3diet had an increase in serum BUN and calcium concentrations and a decrease in RBC and serum total protein, albumin, and hemoglobin concentrations. By 18 months, these kittens had an increase in plasma cholecalciferol (276.0 ± 22.2 nmol/L) and 25-OHD3(1,071.9 ± 115.3 nmol/L) concentrations. However, all indices of renal function and the appearance of renal tissue on histologic evaluation were normal.

Conclusions and Clinical Relevance—These results indicate that cats are resistant to cholecalciferol toxicosis when the diet is otherwise complete and balanced. (Am J Vet Res2001;62:1500–1506)
Experimental infection of cats with Tritrichomonas foetus
Authors: Gookin Jody L. , Levy Michael G. , Law J. Mac , Papich Mark G. , Poore Matthew F. , Breitschwerdt Edward B.
Published: December 2005

Objective—To determine whether infection withTritrichomonas foetuscauses diarrhea in specific pathogen-free orCryptosporidiumcoinfected cats.

Animals—4 cats with subclinical cryptosporidiosis (group 1) and 4 specific-pathogen-free cats (group 2).

Procedure—Cats were infected orogastrically with an axenic culture ofT foetusisolated from a kitten with diarrhea. Direct microscopy and protozoal culture of feces, fecal character, serial colonic mucosal biopsy specimens, and response to treatment with nitazoxanide (NTZ; group 1) or prednisolone (groups 1 and 2) were assessed.

Results—Infection withT foetuspersisted in all cats for the entire 203-day study and resulted in diarrhea that resolved after 7 weeks. Group-1 cats had an earlier onset, more severe diarrhea, and increased number of trichomonads on direct fecal examination, compared with group-2 cats. Use of NTZ eliminated shedding ofT foetusandCryptosporidiumoocysts, but diarrhea consisting of trichomonad-containing feces recurred when treatment was discontinued. Prednisolone did not have an effect on infection withT foetusbut resulted in reappearance ofCryptosporidiumoocysts in the feces of 2 of 4 cats. During necropsy,T foetuswas isolated from contents of the ileum, cecum, and colon.Tritrichomonas foetusorganisms and antigen were detected on surface epithelia and within superficial detritus of the cecal and colonic mucosa.

Conclusions and Clinical Relevance—After experimental inoculation in cats,T foetusorganisms colonize the ileum, cecum, and colon, reside in close contact with the epithelium, and are associated with transient diarrhea that is exacerbated by coexisting cryptosporidiosis but not treatment with prednisolone. (Am J Vet Res2001;62:1690–1697)
Effect of topical anesthesia of the laryngeal mucosa on upper airway mechanics in exercising horses
Authors: Holcombe Susan J. , Derksen Frederik J. , Berney Cathy , Becker Adrianne C. , Horner Natalie T.
Published: December 2005

Objective—To determine the effect of desensitization of the laryngeal mucosal mechanoreceptors on upper airway mechanics in exercising horses.

Animals—6 Standardbreds.

Procedure—In study 1, videoendoscopic examinations were performed while horses ran on a treadmill with and without topical anesthesia of the laryngeal mucosa. In study 2, peak tracheal and nasopharyngeal pressures and airflows were obtained from horses during incremental treadmill exercise tests, with and without topical anesthesia of the laryngeal mucosa. A nasal occlusion test was performed on each horse while standing during an endoscopic examination for both trials.

Results—In study 1, horses had nasopharyngeal collapse while running on the treadmill when the laryngeal mucosa was anesthetized. In study 2, inspiratory upper airway and nasopharyngeal impedance were significantly higher, and peak tracheal inspiratory pressure, respiratory frequency, and minute ventilation were significantly lower in horses when the laryngeal mucosa was anesthetized, compared with values obtained when horses exercised without topical anesthesia. Peak inspiratory and expiratory airflows were lower in horses when the laryngeal mucosa was anesthetized, although differences did not quite reach significance (P= 0.06 and 0.09, respectively). During a nasal occlusion test, horses had episodes of nasopharyngeal collapse and dorsal displacement of the soft palate when the laryngeal mucosa was anesthetized. Upper airway function was normal in these horses without laryngeal mucosal anesthesia.

Conclusions and Clinical Relevance—Receptors within the laryngeal mucosa may be important in maintaining upper airway patency in exercising horses. (Am J Vet Res2001;62:1706–1710)
Repeatability of dorsolateral subluxation scores in dogs and correlation with macroscopic appearance of hip osteoarthritis
Authors: Lust George , Todhunter Rory J. , Erb Hollis N. , Dykes Nathan L. , Williams Alma J. , Burton-Wurster Nancy I. , Farese James P.
Published: December 2005

Objective—To determine whether dorsolateral subluxation (DLS) scores in young dogs could be used to reliably predict which dogs would develop evidence of hip osteoarthritis and whether DLS scores measured at various ages correlated with each other.

Animals—129 Labrador Retrievers, Greyhounds, and Labrador Retriever-Greyhound crossbreds.

Procedures—DLS scores were measured on radiographs taken at 4, 8, and 12 months of age and at necropsy (8 to 36 months of age). At necropsy, the hip joints were examined macroscopically and a score assigned for degree of cartilage degeneration.

Results—DLS scores at 4 (n = 35,rs= –0.62), 8 (n = 106,rs= –0.54), and 12 (n = 15,rs= –0.87) months of age were significantly correlated with cartilage degeneration scores, and DLS scores at 8 months of age were significantly correlated with scores obtained at the time of necropsy (n = 39,rs= 0.87). The DLS scores at 4 months of age were significantly different from scores at 8 months of age, but scores did not differ significantly thereafter. Likelihood ratios for cartilage lesions for low (< 45%), intermediate (≥ 45 but ≤ 55%), and high (> 55%) DLS scores at 8 months of age were 8.0, 2.6, and 0.2, respectively.

Conclusions and Clinical Relevance—Results suggest that DLS score at 8 months of age was a reasonable, albeit imperfect, predictor of the condition of the hip joint cartilage at necropsy. Thus, the DLS method might be useful for early identification of dogs with hip dysplasia. (Am J Vet Res2001;62:1711–1715)
Activity of an injectable, sustained-release formulation of moxidectin administered prophylactically to mixed-breed dogs to prevent infection with Dirofilaria immitis
Authors: Lok James B. , Knight David H. , Wang G. T. , Doscher Mary E. , Nolan Thomas J. , Hendrick Mattie J. , Steber William , Heaney Kathleen
Published: December 2005

Objective—To test the ability of a single injection of a sustained-release formulation of moxidectin (moxidectin SR) to protect dogs against heartworm infection for 180 days after inoculation with infective thirdstage larvae (L3) ofDirofilaria immitis.

Animals—32 adult mixed-breed dogs.

Procedure—Dogs were allocated to 4 groups on the basis of weight and sex. Dogs were injected SC with saline (0.9% NaCl) solution or moxidectin SR at the rate of 0.06, 0.17, or 0.5 mg/kg of body weight (day 0). Each dog was inoculated SC with 50D immitisL3 180 days later. On days 330 and 331, dogs were euthanatized. The heart, lungs, and thoracic cavity were examined, and number and sex of heartworms were determined.

Results—A mean of 35.9 heartworms was recovered from untreated control dogs. Fourteen worms were recovered from 1 of 8 dogs given moxidectin SR at the lowest dosage, and none of the dogs in the 2 highest moxidectin treatment groups were infected. Small barely palpable granulomas were detected at injection sites of moxidectin-treated dogs. Frequency and size of granulomas were positively correlated with dose of moxidectin administered.

Conclusions and Clinical Relevance—A single dose of moxidectin SR at a dosage as low as 0.17 mg/kg can safely and reliably confer complete protection against infection after challenge-exposure withD immitisL3, and protection lasts for at least 180 days. This mode of prophylactic treatment against infection with heartworms effectively eliminates failure of prophylaxis that results from erratic administration of medications designed for monthly administration. (Am J Vet Res2001;62:1721–1726)
Pressure profilometry of the lumbosacral disk in dogs
Authors: Mitchell Richard A. S. , Innes John F. , McNally Donal
Published: December 2005

Objective—To investigate the biomechanical behavior
of the lumbosacral disk under compressive load in
dogs, using pressure profilometry, and to investigate
the relationship between pressure profile features
and background and disease variables.

Sample Population—23 lumbosacral disks and adjacent
vertebrae harvested from medium and large
breed dogs.

Procedure—A 1.3-mm unidirectional needle-mounted
pressure transducer was inserted into the disk in a
ventral-to-dorsal manner while the disk was loaded in
compression by a materials testing machine.
Withdrawal of the transducer resulted in a pressure
profile for cranial and lateral stress. Pressure profiles
were analyzed, and relationships to age and gross evidence
of degeneration were investigated.

Results—There was a moderate positive correlation
between age and degree of nuclear degeneration
(r
s = 0.420, P = 0.046), but no relationship between
age and mean nuclear pressure was detected. Mean
nuclear pressure correlated negatively with severity of
degenerative changes in the nucleus pulposus.
Receiver operator characteristic curves to evaluate
mean nuclear pressure as a diagnostic test for nuclear
degeneration revealed a sensitivity and specificity of
82 and 83%, respectively. In addition, age was moderately
correlated with the magnitude of stress peaks
(r
s = –0.571, P = 0.004). Stress peaks were not related
to the severity of nuclear degeneration.

Conclusions and Clinical Relevance—Determination
of the mean nuclear pressure by disk profilometry
provides information on the severity of lumbosacral
disk degeneration with a high degree of sensitivity
and specificity. The magnitude of single stress
peaks within the dorsal annulus fibrosus is correlated
with age and may not necessarily reflect advancing
degeneration. (Am J Vet Res 2001;62:1734–1739)
Validation of a novel high-sensitivity radioimmunoassay procedure for measurement of total thyroxine concentration in psittacine birds and snakes
Authors: Greenacre Cheryl B. , Young Diane W. , Behrend Ellen N. , Wilson G. Heather
Published: December 2005

Objective—To validate a novel high-sensitivity radioimmunoassay (RIA) procedure developed to accurately measure the relatively low serum total thyroxine (T4) concentrations of birds and reptiles and to establish initial reference ranges for T4concentration in selected species of psittacine birds and snakes.

Animals—56 healthy nonmolting adult psittacine birds representing 6 species and 42 captive snakes representing 4 species.

Procedure—A solid-phase RIA designed to measure free T4concentrations in dialysates of human serum samples was used without dialysis to evaluate total T4concentration in treated samples obtained from birds and reptiles. Serum T4binding components were removed to allow assay of undialyzed samples. Assay validation was assessed by determining recovery of expected amounts of T4in treated samples that were serially diluted or to which T4was added. Intra- and interassay coefficient of variation (CV) was determined.

Results—Mean recovery of T4added at 4 concentrations ranged from 84.9 to 115.0% and 95.8 to 119.4% in snakes and birds, respectively. Intra- and interassay CV was 3.8 and 11.3%, respectively. Serum total T4concentrations for 5 species of birds ranged from 2.02 to 7.68 nmol/L but ranged from 3.17 to 142 nmol/L for blue-fronted Amazon parrots; concentrations ranged from 0.21 to 6.06 nmol/L for the 4 species of snakes.

Conclusions and Clinical Relevance—This new RIA method provides a commercially available, accurate, and sensitive method for measurement of the relatively low serum T4concentrations of birds and snakes. Initial ranges for the species evaluated were established. (Am J Vet Res2001;62:1750–1767)
Correlations among time and frequency measures of heart rate variability recorded by use of a Holter monitor in overtly healthy Doberman Pinschers with and without echocardiographic evidence of dilated cardiomyopathy
Authors: Calvert Clay A. , Wall T. Michelle
Published: December 2005

Objective—To determine correlations between timedomain and frequency-domain variables of heart rate variability (HRV) derived from 24-hour recordings obtained by use of an ambulatory electrocardiographic recorder (Holter monitor).

Animals—59 overtly healthy Doberman Pinschers (41 without echocardiographic evidence of cardiomyopathy and 18 with precongestive heart failure attributable to cardiomyopathy).

Procedure—The HRV was analyzed from 24-hour recordings. Variables were calculated from the entire 24-hour recording as well as 4 user-selected time epochs. Comparisons were made for total power to SD of normal beat-to-normal-beat (NN) intervals (SDNN), ultra-low frequency power to SD of the means of NN intervals, low-frequency power and verylow- frequency power to mean of the SD of NN intervals, and high-frequency (HF) power to the root mean square successive difference of NN intervals (RMSSD) and percentage of NN intervals that varied from the previous NN interval by > 50 milliseconds (PNN50).

Results—58 of 66 (88%) comparisons revealed significant values, indicating that relationships between variables were not random (r> 0.7 in 41 of 66 [62%]) comparisons). Strong correlations (r> 0.8) were found between the square root of total power and SDNN and between HF power and RMSSD.

Conclusions and Clinical Relevance—Time-domain surrogates for variables of frequency-domain analysis variables that correlated in the dogs reported here are the same ones that reportedly correlate in humans. When 24-hour recordings obtained by use of a Holter monitor are used to calculate HRV, SDNN and total power as well as RMSSD and HF power are interchangeable. (Am J Vet Res2001;62:1787–1792)