Objective: To determine the efficacy of an avirulent Lawsonia intracellularis vaccine in preventing proliferative enteropathy in weanling foals. Animals: 12 healthy weanling foals. Procedures: Foals were randomly assigned to a vaccinated, nonvaccinated, or control group. Vaccinated foals received an avirulent porcine L intracellularis frozen-thawed vaccine intrarectally 60 and 30 days prior to experimental challenge. On day 1, vaccinated and nonvaccinated foals were challenged via nasogastric intubation with a virulent heterologous isolate of L intracellularis. Control foals were not challenged. Clinical observation and ultrasonographic evaluation of the small intestine were performed, and body weight, serum concentration of total solids, fecal excretion of L intracellularis, and seroconversion were measured for each foal until day 56. Diseased foals were treated with antimicrobials and supportive are. Results: None of the 4 vaccinated foals developed clinical disease following challenge with virulent L intracellularis. Three of 4 nonvaccinated foals developed moderate to severe clinical signs compatible with proliferative enteropathy, hypoproteinemia, and thickened small intestinal loops. Vaccinated foals had significantly less fecal shedding of L intracellularis than nonvaccinated foals. Serologic responses between vaccinated and nonvaccinated foals after challenge were similar. Control foals remained clinically unaffected with no evidence of fecal shedding and seroconversion. Conclusions and Clinical Relevance: Intrarectal administration of a commercial avirulent porcine vaccine against L intracellularis resulted in complete protection against proliferative enteropathy in the foals in this study and may also reduce environmental contamination with the organism on endemic farms.

The detection and subspeciation of Campylobacter fetus subsp. venerealis (CFV) from veterinary samples is important for both clinical and economic reasons. Campylobacter fetus subsp. venerealis is the causative agent of bovine genital campylobacteriosis, a venereal disease that can lead to serious reproductive problems in cattle, and strict international regulations require animals and animal products to be CFV-free for trade. This study evaluated methods reported in the literature for CFV detection and reports the translation of an extensively tested CFV-specific polymerase chain reaction (PCR) primer set; including the VenSF/VenSR primers and a real-time, quantitative PCR (qPCR) platform using SYBR Green chemistry. Three methods of preputial sample preparation for direct qPCR were evaluated and a heat lysis DNA extraction method was shown to allow for CFV detection at the level of approximately one cell equivalent per reaction (or 1.0 × 10(3) CFU/mL) from prepuce. The optimized sample preparation and qPCR protocols were then used to evaluate 3 western Canadian bull cohorts, which included 377 bulls, for CFV. The qPCR assay detected 11 positive bulls for the CFV-specific parA gene target. DNA sequence data confirmed the identity of the amplified product and revealed that positive samples were comprised of 2 sequence types; one identical to previously reported CFV parA gene sequences and one with a 9% sequence divergence. These results add valuable information towards our understanding of an important CFV subspeciation target and offer a significantly improved format for an internationally recognized PCR test.

Objective: To identify gait characteristics during trotting on a treadmill in nonlame Labrador Retrievers presumed predisposed or not predisposed to cranial cruciate ligament disease (CCLD). Animals: Clinically normal Labrador Retrievers presumed predisposed (n = 10) or not predisposed (7) to CCLD. Procedures: The right hind limb of each dog was classified by use of a predictive score equation that combined tibial plateau angle and femoral anteversion angle as presumed predisposed (high score [> −1.5]) or not predisposed (low score [≤ −1.5]) to CCLD. Tarsal joint, stifle joint, and hip joint kinematics, net moments, and powers were computed. Results: The stifle joint was held at a greater degree of flexion in limbs presumed predisposed to CCLD (130.9° vs 139.3°). More power was generated by muscles acting on the stifle joint in the early stance phase of limbs presumed to be predisposed to CCLD (2.93 vs 1.64 W/kg). The tarsal joint did not reach the same degree of extension in limbs presumed predisposed to CCLD, compared with that in limbs presumed not predisposed to CCLD (179.0° vs 161.0°). Velocity, stance time, vertical and craniocaudal forces, angular velocities, and net joint muscle moments did not differ between groups. Conclusions and Clinical Relevance: Gait mechanics of dogs with high (> −1.5) and low (≤ −1.5) tibial plateau angle and femoral anteversion angle scores were characterized on a treadmill, which may help in the identification of dogs predisposed to CCLD.

Objective: To determine reference ranges for serum cobalamin (Cbl), urine methylmalonic acid (uMMA), and plasma total homocysteine (tHcys) concentrations and to compare values for healthy control dogs with values for Border Collies (BCs), a breed in which hereditary cobalamin deficiency has been identified. Animals: 113 BCs, 35 healthy control dogs fed a typical diet, and 12 healthy dogs fed a bone and raw food diet exclusively. Procedures: Urine and blood samples were obtained from each dog and Cbl, uMMA, and tHcys concentrations were determined. Results: Reference ranges for Cbl (261 to 1,001 ng/L), uMMA (0 to 4.2 mmol/mol of creatinine), and tHcys (4.3 to 18.4 μmol/L) concentrations were determined. Four BCs had a Cbl concentration lower than the assay detection limit (150 ng/L); median uMMA and tHcys concentrations in these dogs were 4,064 mmol/mol of creatinine and 51.5 μmol/L, respectively. Clinical abnormalities included stunted growth, lethargy, anemia, and proteinuria. Abnormalities improved after administration of cobalamin. Of the 109 healthy BCs with Cbl and tHcys concentrations within reference ranges, 41 (37.6%) had a high uMMA concentration (range, 5 to 360 mmol/mol). Results for dogs fed raw food were similar to those for control dogs. Conclusions and Clinical Relevance: Hereditary cobalamin deficiency is a rare disease with various clinical signs. The finding of methylmalonic aciduria in healthy eucobalaminemic BCs and BCs with clinical signs of Cbl deficiency was surprising and indicated these dogs may have defects in intracellular processing of Cbl or intestinal Cbl malabsorption, respectively. Studies investigating Cbl absorption and metabolic pathways are warranted.

Objective: To investigate the effects of gonadectomy on collagen homeostasis in cranial cruciate ligaments of male rabbits. Animals: 30 sexually immature (16-week-old) male New Zealand White rabbits. Procedures: Rabbits were randomly assigned to 5 groups of 6 rabbits each: sexually intact, placebo (control group); castrated, placebo; castrated, testosterone; castrated, dihydrotestosterone; and castrated, 17β-estradiol (E2). Control rabbits underwent a sham operation, and all other rabbits underwent gonadectomy. At the time of gonadectomy, the placebo and sex hormones were administered via slow-release pellets implanted subcutaneously as assigned. After 21 days of hormone supplementation, measurements were obtained of serum testosterone and E2 concentrations, ligament collagen characteristics, and androgen receptor, estrogen receoptor α, and matrix metalloproteinase expression. Results: Following gonadectomy and hormone supplementation, the treatment groups differed in serum testosterone and E2 concentrations to various degrees. Collagen concentrations were lower and fiber diameters higher in the absence of sex hormones, in association with the degrees of estrogen receptor a and androgen receptor expression. Although differences were detected among the groups in matrix metalloproteinase expression, these differences were not significant. Conclusions and Clinical Relevance: Sex hormones appeared to play a role in cranial cruciate ligament homeostasis in male rabbits. Physiologic changes triggered by the lack of sex hormones following gonadectomy in sexually immature rabbits may potentially predispose those rabbits to orthopedic injuries.

Objective: To determine whether an interferon (IFN)-γ response sufficient to categorize cattle as positive for tuberculosis can be detected in blood collected at commencement of exsanguination at slaughter. Animals: 15 Holstein cows. Procedures: 12 cows were experimentally sensitized by SC injection with inactivated Mycobacterium bovis in mineral oil, which induced an immune response that mimicked natural infection with M bovis. Three nonsensitized control cows were injected SC with mineral oil alone. By 5 weeks after injection, only the 12 sensitized cows had positive results for tuberculosis with whole blood IFN-γ assay. At that time, all 15 cows were sent to slaughter and samples of blood were collected from each cow immediately before stunning and at commencement of exsanguination (within 90 seconds after stunning). A whole blood IFN-γ assay was performed on the samples. Conditional probability and paired t tests were used to analyze changes in the categorical test interpretation and qualitative IFN-γ production, respectively. Results: All 12 sensitized cows had positive results for tuberculosis in samples obtained immediately before stunning, and 9 retained positive results for samples obtained at commencement of exsanguination. There was a significant decrease in the mean background-corrected IFN-γ ELISA optical density values for samples obtained at commencement of exsanguination. Conclusions and Clinical Relevance: IFN-γ response sufficient to classify cattle as positive for tuberculosis could be detected in blood collected at commencement of exsanguination. These findings support further development and use of the IFN-γ assay on blood samples collected at exsanguination as part of a bovine tuberculosis surveillance program.

Objective: To retrospectively assess the safety and efficacy of recombinant human granulocyte colony-stimulating factor (G-CSF) used as part of autologous bone marrow transplantation in dogs with lymphoma. Animals: 21 dogs with lymphoma at any disease stage. Procedures: Medical records of dogs with lymphoma that underwent intensified chemotherapy and received an autologous bone marrow transplant following owner administration of recombinant human G-CSF (5 μg/kg, SC, q 12 h) for 7 days between January 2007 and July 2009 were reviewed. Results of physical examinations and CBCs performed before and at intervals during a 24-month period after G-CSF treatment were assessed. The safety of recombinant human G-CSF administration was determined via assessment of both short-term (ie, during the 7-day G-CSF treatment period) and long-term adverse effects. Results: None of the dogs developed any adverse effect attributable to the administration of recombinant human G-CSF during G-CSF administration or during follow-up periods of 1 month to 2 years (median follow-up period, 4 months). Among the 18 dogs for which CBC results were available for analysis, mean circulating neutrophil count significantly increased after administration of recombinant human G-CSF, compared with value before treatment. Conclusions and Clinical Relevance: Results indicated that recombinant human G-CSF administered SC at a dosage of 5 μg/kg every 12 hours for 7 days appeared to be safe and effective when used in dogs with lymphoma that were undergoing autologous bone marrow transplant.

Objective: To identify cardiac mechanisms that contribute to adaptation to high altitudes in Tibetan antelope (Pantholops hodgsonii). Animals: 9 male Tibetan antelope and 10 male Tibetan sheep (Ovis aries). Procedures: Tibetan antelope and Tibetan sheep inhabiting a region with an altitude of 4,300 m were captured, and several cardiac variables were measured. Expression of genes for atrial natriuretic peptide, brain natriuretic peptide, and calcium-calmodulin–dependent protein kinase II δ was measured via real-time PCR assay. Results: Ratios of heart weight to body weight for Tibetan antelope were significantly greater than those of Tibetan sheep, but ratios of right-left ventricular weights were similar. Mean ± SD baseline heart rate (26.33 ± 6.15 beats/min) and systolic arterial blood pressure (97.75 ± 9.56 mm Hg) of antelope were significantly lower than those of sheep (34.20 ± 6.57 beats/min and 130.06 ± 17.79 mm Hg, respectively). The maximum rate of rise in ventricular pressure in antelope was similar to that in Tibetan sheep, but after exposure to air providing a fraction of inspired oxygen of 14.6% or 12.5% (ie, hypoxic conditions), the maximum rate of rise in ventricular pressure of the antelope increased significantly to 145.1% or 148.1%, respectively, whereas that of the sheep decreased to 68.4% or 70.5%, respectively. Gene expression of calcium-calmodulin–dependent protein kinase II δ and atrial natriuretic peptide, but not brain natriuretic peptide, in the left ventricle of the heart was significantly higher in antelope than in sheep. Conclusions and Clinical Relevance: Hearts of the Tibetan antelope in this study were well adapted to high-altitude hypoxia as shown by higher heart weight ratios, cardiac contractility in hypoxic conditions, and expression of key genes regulating cardiac contractility and cardiac hypertrophy, compared with values for Tibetan sheep.

Germanium biotite, a natural mineral, has been used as a feed supplement to reinforce innate immune ability. The aim of the present study was to evaluate the effects of germanium biotite on the adsorptive and inhibition of growth abilities against Escherichia (E.) coli and Salmonella spp. in vitro. Two strains of enterotoxigenic E. coli and four strains of two Salmonella serotypes (Salmonella Derby and Salmonella Typhimurium), major bacterial diarrheal pathogens, were used for this experiment. The absorptive ability of germanium biotite against most Salmonella used in present experiment was observed weakly. The germanium biotite, however, showed significant effect of bacterial growth inhibition in most experiment bacteria. These results suggest that the use of the germanium biotite as feed supplement could alleviate diarrhea following inhibition of bacteria growth. It is also presumed that antibiotics usage for farm animals, considered as causes of antibiotic residue in meat and emerging antibiotic resistance, could be reduced through the use of germanium biotite as a feed supplement, in place of antibiotics used for the prevention of diarrhea.

Dirofilaria (D.) immitis is an important canine parasitic nematode in dogs. D. immitis parasitizes the right ventricle and pulmonary artery of dogs. An ivermectin and pyrantel pamoate compound (IPPC) was administered to dogs naturally infected with this parasite. IPPC is composed of 68.0, 136.0 and 272.0 ㎍ of ivermectin and 57.0, 114.0 and 227.0 mg pyrantel pamoate for small, middle, and large animals. Ivermectin has activity against nematodes and ectoparasites in dogs. Pyrantel pamoate is also effective against nematodes in dogs. Our results showed that this drug combination has good efficacy in D. immitis infected dogs.