Effects of orchidectomy in selective biochemical analytes in Beagle dogs

The objective of this study was to evaluate the possible effects of orchidectomy and associate hormonal changes on circulating concentrations of acute-phase proteins (APPs) (CRP--C-reactive protein; Hp--haptoglobin; Cp--ceruloplasmin), adiponectin and IGF-1 in dogs. For this, a total of five adult Beagle dogs were subjected to orchidectomy. Blood samples were taken before neutering, during six consecutive days and on weeks 2, 4, 8 and 12 after surgery. Appropriate diet regime was maintained to keep stable body weight of the dogs. Concentrations of APPs significantly increased on days 2-3 for CRP and 2-7 for Hp and Cp. On days 3-4 after neutering, adiponectin levels were significantly lower than before surgery (p<0.05 and <0.01, respectively). After this initial change, adiponectin did not show any significant alteration during the 3 months. Serum IGF-1 concentrations were significantly decreased at days 2-5 after neutering. In addition, on weeks 8 and 12 serum IGF-1 levels were significantly lower (p<0.001 and <0.01 respectively) in comparison with those before surgery. In conclusion, orchidectomy induced a short-term inflammatory process that was associated with the increase in serum levels of APPs and decrease in IGF-1 and adiponectin levels. However, orchidectomy did not result in long-term changes of circulating concentrations of APPs or adiponectin. Although a decrease in IGF-1 levels was recorded 2 months after surgery, possibly as a consequence of associated decrease in androgen levels or food restriction.     

Effects of mithramycin on calcium metabolism and bone in dogs.

Mithramycin (0.1 mg/kg) was administered intravenously to eight Beagle dogs on days 0 and 7 to determine its effects on calcium and phosphorus metabolism, serum parathyroid hormone concentration, osteoclastic bone resorption, and serum biochemical and hematologic parameters. Ionized calcium concentration was paradoxically increased on day 1 and decreased on day 8 in association with an increased serum parathyroid hormone concentration. Serum phosphorus concentration was decreased on days 1 and 2. Osteoclastic bone resorption in iliac cancellous bone was significantly decreased on day 8. There were mild increases in serum alkaline phosphatase (days 1, 2, 4, 8, 9), aspartate aminotransferase (day 9), and gammaglutamyl transpeptidase (days 7, 9) activities. Platelet numbers were increased on days 7 through 13, and packed red blood cell volumes were mildly decreased. This investigation demonstrates that two doses of mithramycin can be administered safely to dogs and may inhibit bone resorption in diseases associated with increased osteoclastic bone resorption, such as humoral hypercalcemia of malignancy.     

Effects of food intake on pharmacokinetics of mosapride in beagle dogs

This study was performed to determine the pharmacokinetic profile of mosapride in fasting and fed states. A single 5‐mg oral dose of mosapride was administered to fasted (n = 15) and fed (n = 12) beagle dogs, and the plasma concentrations of mosapride were measured by liquid chromatography–tandem mass spectrometry. The resultant data were analyzed by noncompartmental analysis (NCA). Mosapride was absorbed in fasted and fed dogs with similar T_max. Both C_max and AUC were significantly higher in the fasting group than in fed dogs, being four times (10.51 μg/mL vs. 2.76 μg/mL) and 3.5 times higher (38.53 h·μg/mL vs. 10.22 h·μg/mL), respectively. These findings suggest that food intake affects the pharmacokinetics of mosapride and that the dosage regimen for this drug need to be reconsidered.     

Effects of calcium supplementation and sunlight exposure on growing beagle dogs

Nine 7-week-old Beagle dogs were given 2.3 g of dietary calcium supplementation once a day and were exposed to sunlight to permit endogenous vitamin D formation. After 70 days, the serum calcium and phosphorus concentrations, thyroid morphometry, and bone density and composition were compared with those values in a similar group of 10 dogs not given calcium supplementation and maintained in restricted, artificial light. Lower serum calcium and phosphorus concentrations in the supplement-fed dogs may be attributed to hypercalcitonism, which was assumed to be present because of increased proportions of C cells and decreased proportions of thyroid follicles. They also had significantly more trabecular bone of a lower specific gravity containing more water and less combustible matter. The findings indicate that the high dietary calcium intake and sunlight exposure induced C-cell hyperplasia during a relatively short period of 70 days. It is possible that Beagles maintained through maturity on a diet high in calcium concentration and in outdoor runs may develop chronic C-cell hyperplasia. The possible contribution of high calcium intake and chronic C-cell hyperplasia to reduced thyroid function and skeletal changes is not yet clear.     

Pharmacokinetics of tildipirosin in beagle dogs

The objective of this study was to investigate the pharmacokinetic profile of tildipirosin (TD) in 24 beagle dogs following intravenous (i.v.) and intramuscular (i.m.) administration, respectively, at 2, 4, and 6 mg/kg. Plasma samples at certain time points (0–14 days) were collected, and the concentrations of drug were quantified by UPLC‐MS/MS. Plasma concentration–time data and relevant parameters were described by noncompartmental through WinNonlin 6.4 software. After single i.m. injection at 2, 4, and 6 mg/kg body weight, mean maximum concentration (C_max) was 412.73 ± 76.01, 1,051 ± 323, and 1,061 ± 352 ng/ml, respectively. Mean time to reach C_max was 0.36 ± 0.2, 0.08 ± 0.00, and 0.13 ± 0.07 hr after i.m. injection at 2, 4, and 6 mg/kg, respectively. The mean value of T_1/2λz for i.m. administration at doses of 2, 4, and 6 mg/kg was 71.39 ± 28.42, 91 .33 ± 50.02, and 96.43 ± 45.02 hr, respectively. The mean residence times were 63.81 ± 10.96, 35.83 ± 15.13, and 38.18 ± 16.77 hr for doses of 2, 4, and 6 mg/kg, respectively. These pharmacokinetic characteristics after i.m. administration indicated that TD could be rapidly distributed into tissues on account of the high lipid solubility and then released into plasma. In addition, the absolute bioavailability of 2 mg/kg after i.m. injection was 112%. No adverse effects were observed after i.v. and i.m. administration.     

Effects of long-term oral administration of ketoprofen in clinically healthy beagle dogs

To investigate the adverse effects of long-term administration of ketoprofen in dogs, ketoprofen (1 mg/kg) was administered to five clinically healthy beagle dogs (ketoprofen group) and gelatin capsules (control group) were administered to four clinically healthy beagle dogs for 30 days. We monitored the dogs through periodic physical examination, blood analyses, endoscopic examinations, fecal occult blood tests, renal function tests, urinalysis, urinary enzyme indices and cuticle bleeding time analysis. The lesions in the stomach, especially in the pyloric antrum, and fecal occult blood progressively worsened in the ketoprofen group. However, the differences between the ketoprofen group and the control group were not statistically significant. One dog in the ketoprofen group temporarily exhibited a decrease in renal plasma flow and two dogs exhibited enzymuria. However, these changes did not persist and the other examinations showed no significant difference between premedication and postmedication in the ketoprofen group. Therefore, the adverse effects of long-term administration of ketoprofen observed in this study were not clinically important in healthy dogs. Nevertheless, further investigation of adverse renal effects from long-term administration of ketoprofen is necessary in the dogs with subclinical renal disease.     

Effects of zoledronate on markers of bone metabolism and subchondral bone mineral density in dogs with experimentally induced cruciate-deficient osteoarthritis

OBJECTIVE: To evaluate effects of zoledronate on markers of bone metabolism in dogs after transection of the cranial cruciate ligament (CrCL). ANIMALS: 21 adult dogs. PROCEDURE: Unilateral CrCL transection was performed arthroscopically. Dogs were allocated to 3 groups (control group, low-dose zoledronate [10 microg/kg, SC, q 90 d for 12 months], and high-dose zoledronate [25 microg/kg, SC, q 90 d for 12 months]). Serum osteocalcin (OC), serum bone-specific alkaline phosphatase (BAP), and urine pyridinoline and deoxypyridinoline concentrations were measured at 0, 1, 3, 6, 9, and 12 months after surgery. Bone mineral density (BMD) was determined in the distal portion of the femur and proximal portion of the tibia via computed tomography at each time point. Data were analyzed by a repeated-measures ANOVA. RESULTS: oledronate inhibited OC in the high-dose group at 9 and 12 months and at 12 months in the low-dose group, compared with the control group. High-dose zoledronate decreased BAP concentrations 3 and 9 months after surgery. In the control group, BMD was decreased in the femoral condyle and caudal tibial plateau. Zoledronate prevented significant BMD decreases starting 1 month after transection, compared with control dogs. In the caudomedial aspect of the tibial plateau, both zoledronate groups had significant increases in BMD after 3 months, compared with control dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Zoledronate may reduce subchondral bone loss and effect markers of bone metabolism in dogs with experimentally induced instability of the stifle joint and subsequent development of osteoarthritis.     

Plasma lactate measurements in healthy beagle dogs

Plasma lactate concentrations were determined in venous blood samples collected from 60 healthy Beagles aged 5 to 9 months. The range of values (0.42 to 3.58 mmol/L) obtained with an enzymatic method in the present study was similar to values reported in smaller studies with the colorimetric procedures.     

Salivary secretory IgA concentrations in beagle dogs

The normal concentrations of salivary secretory IgA (sIgA) were examined, and the response of sIgA to acute stress was evaluated in dogs. Ten clinically healthy beagle dogs familiarized with the method of saliva sampling were used. During the non-stress period, saliva samples were collected between 0800 hr and 1700 hr at 1-hr intervals for 7 consecutive days and analyzed for sIgA concentration. After a 1-day control period, a noise stressor was presented for 15 min between 0845 hr and 0900 hr on 2 consecutive days. Saliva was collected at pre-stress, immediately after, 30 min after and 60 min after the stress. The average sIgA concentration over the 2-day period was compared with the control value. Environmental stimuli were restricted. During the non-stress period, significant variations were observed during the diurnal pattern, in which sIgA increased in the morning and then decreased; and the day-to-day variations were significant except at 0800 hr and 0900 hr. During the stress experiments, the sIgA concentration decreased significantly, immediately after and 30 min after the noise stress, and then increased to the same level as the control value by 60 min after the stress. When estimating the effectiveness of salivary sIgA as a marker of stress in dogs, the appropriate time for saliva sampling appears to be in the morning. Salivary sIgA was deemed potentially useful as a marker of stress in dogs.     

Influence of age on bronchoscopic findings in healthy beagle dogs

The aims of this study were to evaluate the effect of age on bronchoscopic features and bronchoalveolar lavage fluid (BALF) cellularity in dogs. Thirty healthy beagle dogs from three age groups were included: young dogs (10 months to 4.5 years of age; n = 8), middle-aged dogs (5–8 years old; n = 13) and older dogs (>8 years; n = 9). Haematology, thoracic radiography, bronchoscopy and bronchoalveolar lavage were performed; bronchoscopic findings were scored and BALF total and differential cell counts were determined. The total bronchoscopic score was higher in older dogs; these dogs had more irregular bronchial mucosa, more prominent mucosal vessels and bronchiectasis. Younger dogs had a higher percentage of neutrophils in BALF compared with middle-aged and old dogs and a higher percentage of lymphocytes in BALF compared with middle-aged dogs. The results show that age has an effect on bronchoscopic features of airways and the composition of BALF in the dog.     

Thyroid neoplasms in a colony of beagle dogs

The histologic, clinicopathologic, and epidemiologic features of spontaneous thyroid neoplasms were evaluated in a control population of Beagle dogs. The mean age of thyroid tumor-bearing dogs (16.2 years) as significantly higher than non-tumor-bearing dogs (13.6 years). Thirteen benign and 18 malignant tumors were identified, with the incidence of both tumors increasing rapidly near the mean age of 16.2 years for tumor-bearing dogs. The age-specific incidence of tumors was 1.1% per year at 8 to 12 years, increasing to 4.0% per year by 12 to 15 years and 67% over 17 years of age. Numbers of malignant tumors were greater than benign tumors at an earlier age. Approximately 44% of the malignant tumors metastasized but only 22% resulted in death of the dog. There was no difference in tumor incidence when compared according to sex, if total tumor numbers were considered or if tumors were separated into benign and malignant categories. The age at death of tumor-bearing dogs was not increased significantly by the surgical resection of the thyroid tumors. Of dogs with thyroid tumors, 15% had clinical diagnoses of hypothyroidism, and no dogs with thyroid tumors had diagnoses of hyperthyroidism.     

丙泊酚对比格犬DR心脏形态及超声心动图左心室功能的影响

丙泊酚是兽医临床上常用的一种短效麻醉药或镇静药。本试验基于胸部DR和超声心动图检查,结合心电图描记及血压测量,探究临床推荐镇静剂量的丙泊酚对比格犬心脏形态及左心室功能的影响。对8只成年比格犬以2.5mg/kg、0.4mg/s经静脉泵注丙泊酚,分别在给药前及给药后0,5,10,20和30 min拍摄背腹位(DV)、腹背位(VD)、左侧卧位(LL)和右侧卧位(RL)共4个体位胸部DR片,采用超声心动图法测量给药前、后左心室功能相关参数,实时描记心电图并监测血压。结果显示,通过胸部DR测量出比格犬椎体心脏比分(vertebral heart score,VHS)在LL(9.7±0.2)和RL(9.8±0.3)时差异不显著(P0.05)。与给药前相比,给药后比格犬心脏短轴和VHS在10,20和30min显著减少(P0.01);心胸宽比在20,30 min显著减小(P0.01或P0.05);左心室舒张末期容积(EDV)、每搏输出量(SV)、缩短分数(FS)和射血分数(EF)均显著下降(P0.01或P0.05)。试验表明临床推荐镇静剂量的丙泊酚可引起成年比格犬心脏形态显著改变,左心室功能显著降低。     

Mineralisation in kidney and stomach of beagle dogs

Histological examination of 753 Beagle dogs showed renal foci of calcification in 27.9% of males and 21.5% of females. In contrast, stomach calcification was observed in 6.2% of males and 5.2% of females examined. It is suggested that the focal calcification seen in both organs was possibly of dietary origin and may have been related to the phosphate content.     

Mammary tumors in a colony of beagle dogs

In a lifetime study, female beagle dogs in a closed colony were administered 226radium and 90strontium. An unirradiated control group was included in the study. A total of 223 of 356 dogs at risk developed 1,112 mammary proliferative growths (hyperplastic nodules and neoplasms). There was no correlation between occurrence and types of lesions in radiation and control groups. The age range for first occurrence of lesions was 10.4 to 13.9 years; hyperplastic nodule and benign mixed tumor occurred 1 to 2 years earlier than other lesions. A multiplicity of growths of similar or different morphological type were common throughout the lifetime of the dog. The female beagles, collectively, developed 244 hyperplastic nodules, 78 adenomas, 694 benign mixed tumors, 78 carcinomas, 14 malignant mixed tumors, and four myoepitheliomas. Proliferations occurred with increasing frequency from the cranial to caudal mammary glands. Metastasis was found in 77% of the dogs with carcinoma. The median time from diagnosis to metastasis was 10 months, but was shorter in dogs with infiltrative carcinoma.