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- Author or Editor: Stephen A. Kruth x
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Abstract
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 Res 2001;62:1442–1446)
Abstract
Objective—To evaluate the safety, with respect to the development of gastric ulcers and erosions, of concurrent administration of meloxicam and dexamethasone for 3 days to healthy dogs.
Animals—20 conditioned purpose-bred research Beagles.
Procedure—Seven days prior to treatment, dogs were anesthetized for endoscopic evaluation of the upper portion of the gastrointestinal tract (ie, the gastric and duodenal mucosa). Five regions of the gastroduodenal area were scored by 2 investigators. Dogs were randomly assigned to 1 of 4 treatment groups as follows: saline-saline, dexamethasonesaline, saline-meloxicam, and dexamethasone-meloxicam groups. On days 1, 2, and 3, dogs received either dexamethasone or saline (0.9% NaCl) solution injections SC twice daily. On days 2, 3, and 4, dogs received either meloxicam or saline solution injections SC once daily. On day 2, dogs were anesthetized for a sham surgery (ie, electrostimulation). On day 5, the gastroduodenal area of each dog was reevaluated by use of endoscopic evaluation and histologic examination of biopsy specimens.
Results—The total endoscopic score of the dexamethasone- meloxicam group was significantly greater than the scores of the other groups. The dexamethasone- saline group had a mean cumulative score that was significantly greater than the saline-meloxicam or saline-saline groups. Endoscopic scores of the salinemeloxicam group were not significantly different from scores of the saline-saline group. No significant differences in histologic findings were found between groups.
Conclusions and Clinical Relevance—In healthy dogs, meloxicam appears to be safe with regard to adverse effects on the gastrointestinal tract. Concurrent administration of dexamethasone and meloxicam is more likely to cause gastric erosions than meloxicam administration alone. (Am J Vet Res 2003;63:1369–1375)
Abstract
Objective—To describe the effects of lithium carbonate on thrombopoiesis in clinically normal dogs and in dogs treated with carboplatin.
Animals—18 young adult sexually intact female Beagles.
Procedures—Dogs were assigned to each of 3 treatment groups (6 dogs/group). Group 1 received 150 mg of lithium carbonate (14 to 16 mg/kg), PO, every 12 hours on days 1 through 21. Group 2 received carboplatin (300 mg/m2, IV) on day 0 and cephalexin (30 mg/kg, PO, q 12 h) on days 14 through 21. Group 3 received lithium, carboplatin, and cephalexin at the aforementioned doses and schedules. Plasma lithium and blood platelet concentrations were measured on days 0, 2, 4, 7, 9, 11, 14, 16, 18, and 21. Number of megakaryocytes in bone marrow specimens and the percentage of large unstained cells and CD34+ mononuclear cells in bone marrow aspirates were determined on days 0, 7, 14, and 21 by manual enumeration, automated hematologic analysis, and flow cytometric immunophenotyping, respectively.
Results—Plasma lithium concentrations ranged from 0.12 to 2.41 mmol/L. All dogs given lithium achieved a concentration within the target interval of 0.5 to 1.5 mmol/L by days 4 to 7. Thrombopoiesis was increased in dogs receiving lithium alone. All dogs given carboplatin developed mild thrombocytopenia. There were no differences between group 2 and group 3 throughout the study.
Conclusions and Clinical Relevance—Lithium stimulated thrombopoiesis in clinically normal dogs. Lithium administration at the doses and schedules used, with concurrent administration of cephalexin, did not prevent thrombocytopenia induced by carboplatin.
Abstract
Objective—To characterize a population of dogs from a tertiary care center with 2 or more endocrine disorders, including the specific disorders and time intervals between diagnosis of each disorder.
Design—Retrospective case series.
Animals—35 dogs with 2 or more endocrine disorders.
Procedures—Medical records were reviewed, and the following was recorded: clinical signs, physical examination findings, and the results of CBC, serum biochemical analysis, urinalysis, aerobic bacterial culture of urine samples, endocrine testing, diagnostic imaging, and necropsy.
Results—35 dogs with more than 1 endocrine disorder were identified. Seventy-seven percent (27/35) of the dogs were male, and the mean age at the time of diagnosis of the first endocrinopathy was 7.9 years. Miniature Schnauzer was the most common breed. Twenty-eight of 35 (80%) dogs had 2 disorders; 7 (20%) had 3 disorders. The most common combinations of disorders included diabetes mellitus and hyperadrenocorticism in 57.1 % (20/35) of dogs; hypoadrenocorticism and hypothyroidism in 22.9% (8/35) of dogs; and diabetes mellitus and hypothyroidism in 28.6% (10/35) of dogs. A mean of 14.5 months elapsed between diagnosis of the first and second endocrine disorders, whereas there was a mean of 31.1 months between diagnosis of the first and third endocrine disorders.
Conclusions and Clinical Relevance—Results suggested that the occurrence of multiple endocrine disorders was uncommon in dogs. The most common combinations of endocrine disorders in this population of dogs were diabetes mellitus and hyperadrenocorticism, followed by hypoadrenocorticism and hypothyroidism.
Abstract
Case Description—A 9-year-old 6.9-kg (15.18-lb) castrated male Siamese cat was evaluated because of a 3-year history of repeated hemorrhage from the right metacarpal pad.
Clinical Findings—Physical examination findings were unremarkable except for a 2-mm-diameter erosion of the right metacarpal pad. A CBC revealed marked thrombocytopenia. Serum biochemical analyses, retroviral screening, thoracic radiography, and abdominal ultrasonography revealed no abnormalities. Via ultrasonographic examination, the vasculature in the right metacarpal pad appeared increased, compared with that of the left pad; an aberrant arterial plexus that was confined to the metacarpal pad was identified via arterial angiography.
Treatment and Outcome—Surgical resection of the metacarpal pad (without digital pad transposition) with primary closure was performed. Histologic evaluation of the pad tissue revealed invasive cutaneous angiomatosis. The incision healed without complications, and limb function was considered normal. Administration of prednisone (2 mg/kg [0.91 mg/lb], PO, q 24 h) was initiated 4 weeks prior to surgery to treat suspected immune-mediated thrombocytopenia and continued afterwards with a tapering dosage. Platelet count was within reference limits 4 months after surgery; at 12 months, there was no evidence of recurrence of abnormal vasculature in the right metacarpal pad region.
Clinical Relevance—Complete resection of the metacarpal pad (without pad transposition) resulted in successful and well-tolerated treatment of cutaneous angiomatosis of the metacarpal pad of a cat. Recurrence of abnormal vasculature was not evident at a 12-month follow-up examination. Thrombocytopenia is commonly associated with vascular anomalies in humans and may have been a contributing factor in this cat.
Abstract
Objective—To describe the effects of prednisone and acetylsalicylic acid (ASA) on results of thromboelastography in healthy dogs.
Animals—16 male mixed-breed dogs.
Procedures—Dogs were randomly assigned to 3 treatment groups (4 dogs/group) that received prednisone (median dose, 2.07 mg/kg), ASA (median dose, 0.51 mg/kg), or both drugs, PO, every 24 hours from days 0 through 6. Another group received no treatment (control dogs; n = 4). Thromboelastography variables (reaction time, clotting time, α-angle, maximum amplitude [MA], global clot strength, coagulation index, and percentage of clot lysis at 60 minutes [CL60]) were evaluated in blood samples collected (prior to drug administration in treated dogs) on days 0 (baseline), 2, 4, and 6.
Results—Administration of ASA alone did not alter TEG variables. For treatment effect, mean global clot strength was increased in the prednisone and drug combination groups, compared with values for control dogs; MA was also increased in the prednisone and drug combination groups, compared with that of controls. For treatment-by-time effect, median CL60 was increased in the prednisone group on day 6, compared with baseline value in the same dogs and with median CL60 of the control group on day 6. Median CL60 was also increased in the drug combination group on day 6, compared with the baseline value and with that of the control group on day 6.
Conclusions and Clinical Relevance—Prednisone administered at approximately 2 mg/kg/d, PO, for 7 days with or without concurrently administered ASA increased clot strength and decreased clot lysis in healthy dogs.
Abstract
OBJECTIVE To determine, by means of MRI, the time to maximal contrast enhancement in T1-weighted images following IV administration of gadoxetic acid in healthy dogs and assess the impact of gadoxetic acid on the signal intensity of T2-weighted images.
ANIMALS 7 healthy dogs.
PROCEDURES No hepatic abnormalities were detected during ultrasonographic examination. Each dog was anesthetized and positioned in dorsal recumbency for MRI. Transverse T1- and T2-weighted images of the liver were acquired prior to and following (at 5-minute intervals) IV injection of 0.1 mL of gadoxetic acid/kg. Signal intensity of the liver parenchyma was measured in 3 regions of interest in the T1- and T2-weighted images before and at various times point after contrast agent administration. Time versus signal-to-noise ratio curves were plotted to determine time to maximal contrast enhancement and contrast agent–related changes in signal intensity in T2-weighted images.
RESULTS Analysis of T1-weighted images revealed that mean ± SD time to maximal enhancement after gadoxetic acid injection was 10.5 ± 3.99 minutes. Signal intensity of T2-weighted images was not significantly affected by gadoxetic acid administration. No injection-related adverse effects were observed in any dog.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that gadoxetic acid can be used for hepatic MRI in healthy dogs and the resultant hepatic enhancement patterns are similar to those described for humans. Maximal contrast enhancement occurred between 10 and 15 minutes after contrast agent injection; thus, T2-weighted images may be obtained in the interval between injection and maximal enhancement for a more time-efficient clinical protocol.
