R W Nelson

University of California, Davis, Davis, CA, United States

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Publications (83)138.7 Total impact

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    ABSTRACT: Studies in humans identified the synthesis and secretion of inhibin from adrenocortical tumors, but not pheochromocytoma (PHEO). Inhibin has not been examined in dogs as a serum biomarker for adrenal gland tumors. To determine serum inhibin concentration in dogs with adrenal gland disease and in healthy dogs. Forty-eight neutered dogs with adrenal disease including pituitary-dependent hyperadrenocorticism (PDH, 17), adrenocortical tumor (18), and PHEO (13), and 41 healthy intact or neutered dogs. Prospective observational study. Dogs were diagnosed with PDH, adrenocortical tumor (hyperadrenocorticism or noncortisol secreting), or PHEO based on clinical signs, endocrine function tests, abdominal ultrasound examination, and histopathology. Inhibin concentration was measured by radioimmunoassay in serum before and after ACTH stimulation, and before and after treatment. In neutered dogs, median inhibin concentration was significantly higher in dogs with adrenocortical tumors (0.82 ng/mL) and PDH (0.16 ng/mL) than in dogs with PHEO and healthy dogs (both undetectable). Median inhibin concentration was significantly higher in dogs with adrenocortical tumors than in those with PDH and decreased after adrenalectomy. Median inhibin concentration was significantly higher in intact than in neutered healthy dogs and was similar in pre- and post-ACTH stimulation. Sensitivity, specificity, and accuracy of serum inhibin concentration for identifying an adrenal tumor as a PHEO were 100, 88.9, and 93.6%, respectively. Adrenocortical tumors and PDH but not PHEOs are associated with increased serum inhibin concentration; undetectable inhibin is highly supportive of PHEO in neutered dogs with adrenal tumors.
    Journal of Veterinary Internal Medicine 01/2013; 27(1):76-82. · 2.06 Impact Factor
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    ABSTRACT: Alternative insulin preparations are needed when NPH insulin is ineffective in diabetic dogs. This study evaluated the efficacy of recombinant human protamine zinc insulin (rhPZI) for treating diabetic dogs. rhPZI is effective for treating diabetic dogs. Six newly diagnosed and 11 insulin-treated diabetic dogs. Prospective clinical trial. Dogs were treated with rhPZI for 60 days. Control of glycemia was assessed on days 7, 14, 30, and 60 by evaluation of history, physical examination, body weight, serum fructosamine concentration, and blood glucose concentrations measured before and 2, 4, 6, 8, and 10 hours after rhPZI administration. Adjustments in dosage of rhPZI were made as needed to control glycemia. rhPZI administration resulted in a significant decrease in 10-hour mean blood glucose (MBG(10h) ; 299 ± 115 versus 457 ± 38 mg/dL, X ± SD, P = .0003) and serum fructosamine (478 ± 83 versus 557 ± 104 μmol/L, P = .006) concentration at day 60, compared with day 1, respectively. By day 60, polyuria and polydipsia had improved in 14, body weight was stable or increased in 16, MBG(10h) had decreased in 16, and serum fructosamine concentration had decreased in 11 of 17 dogs, compared with day 1. Hypoglycemia (<80 mg/dL) was the only consistent adverse event. rhPZI is effective in diabetic dogs and can be considered as an alternative treatment in diabetic dogs that are poorly controlled using other insulin preparations.
    Journal of Veterinary Internal Medicine 12/2011; 26(1):109-15. · 2.06 Impact Factor
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    R W Nelson, K Henley, C Cole
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    ABSTRACT: This study describes the efficacy of a new protamine zinc recombinant human insulin (PZIR) preparation for treating diabetic cats. To evaluate effects of PZIR on control of glycemia in cats with newly diagnosed or poorly controlled diabetes mellitus. One hundred and thirty-three diabetic cats 120 newly diagnosed and 13 previously treated. Prospective, uncontrolled clinical trial. Cats were treated with PZIR twice daily for 45 days. Control of glycemia was assessed on days 7, 14, 30, and 45 by evaluation of change in water consumption, frequency of urination, appetite, and body weight, serum fructosamine concentration, and blood glucose concentrations determined 1, 3, 5, 7, and 9 hours after administration of PZIR. Adjustments in dosage of PZIR were made as needed to control glycemia. PZIR administration resulted in a significant decrease in 9-hour mean blood glucose (199+/-114 versus 417+/-83 mg/dL, X+/-SD, P<.001) and serum fructosamine (375+/-117 versus 505+/-96 micromol/L, P<.001) concentration and a significant increase in mean body weight (5.9+/-1.4 versus 5.4+/-1.5 kg, P=.017) in 133 diabetic cats at day 45 compared with day 0, respectively. By day 45, polyuria and polydipsia had improved in 79% (105 of 133), 89% (118 of 133) had a good body condition, and 9-hour mean blood glucose concentration, serum fructosamine concentration, or both had improved in 84% (112 of 133) of the cats compared with day 0. Hypoglycemia (<80 mg/dL) was identified in 151 of 678, 9-hour serial blood glucose determinations and in 85 of 133 diabetic cats. Hypoglycemia causing clinical signs was confirmed in 2 diabetic cats. PZIR is effective for controlling glycemia in diabetic cats and can be used as an initial treatment or as an alternative treatment in diabetic cats that do not respond to treatment with other insulin preparations.
    Journal of Veterinary Internal Medicine 08/2009; 23(4):787-93. · 2.06 Impact Factor
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    ABSTRACT: Some studies in dogs undergoing adrenalectomy for pheochromocytoma suggest that anesthetic complications and perioperative mortality are common. In humans, surgical outcome has improved with the use of phenoxybenzamine (PBZ) before adrenalectomy. Dogs treated with PBZ before adrenalectomy have increased survival compared with untreated dogs. Forty-eight dogs that underwent adrenalectomy for pheochromocytoma. A retrospective medical record review for dogs that underwent adrenalectomy for pheochromocytoma at a veterinary medical teaching hospital over the period from January 1986 through December 2005. Twenty-three of 48 dogs were pretreated with PBZ (median dosage: 0.6 mg/kg PO q12h) for a median duration of 20 days before adrenalectomy. Duration of anesthesia and surgery, percentage of dogs with pheochromocytoma involving the right versus left adrenal gland, size of tumor, and presence of vascular invasion were similar for PBZ-treated and untreated dogs. Thirty-three (69%) of 48 dogs survived adrenalectomy in the perioperative period. PBZ-treated dogs had a significantly (P = .014) decreased mortality rate compared with untreated dogs (13 versus 48%, respectively). Additional significant prognostic factors for improved survival included younger age (P = .028), lack of intraoperative arrhythmias (P = .0075), and decreased surgical time (P = .0089). Results from this retrospective study support treatment with PBZ before surgical removal of pheochromocytoma in dogs.
    Journal of Veterinary Internal Medicine 10/2008; 22(6):1333-9. · 2.06 Impact Factor
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    ABSTRACT: Background: Identification and control of infections are important in the management of diabetic cats. Urinary tract infections have not been well characterized in diabetic cats. This retrospective study was performed to review and characterize urinary tract infections in diabetic cats.Hypothesis: Urinary tract infections are common in diabetic cats.Animals: A review was made of the medical records of 141 diabetic cats that had had urine obtained for culture by antepubic cystocentesis and that had not been treated with antibiotics, undergone urinary tract catheterization or urinary tract surgery within 2 weeks of urine collection or had urethral obstruction at the time of urine collection.Methods: A review of medical records.Results: Urinary tract infection was identified in 18 of 141 diabetic cats. Escherichia coli was the most common isolate (67%). Female cats were at increased risk (prevalence odds ratios [POR], 3.7; 95% confidence interval [CI], 1.3 to 10.2; P= .013). Clinical signs of lower urinary tract disease and findings on urine sediment examination were good predictors of positive urine cultures.Conclusions and Clinical Importance: Urinary tract infections are common in diabetic cats regardless of status of diabetic control, suggesting routine monitoring with urine sediment exams or urine culture is warranted.
    Journal of Veterinary Internal Medicine 06/2006; 20(4):850 - 855. · 2.06 Impact Factor
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    ABSTRACT: Identification and control of infections are important in the management of diabetic cats. Urinary tract infections have not been well characterized in diabetic cats. This retrospective study was performed to review and characterize urinary tract infections in diabetic cats. Urinary tract infections are common in diabetic cats. A review was made of the medical records of 141 diabetic cats that had had urine obtained for culture by antepubic cystocentesis and that had not been treated with antibiotics, undergone urinary tract catheterization or urinary tract surgery within 2 weeks of urine collection or had urethral obstruction at the time of urine collection. A review of medical records. Urinary tract infection was identified in 18 of 141 diabetic cats. Escherichia coli was the most common isolate (67%). Female cats were at increased risk (prevalence odds ratios [POR], 3.7; 95% confidence interval [CI], 1.3 to 10.2; P = .013). Clinical signs of lower urinary tract disease and findings on urine sediment examination were good predictors of positive urine cultures. Urinary tract infections are common in diabetic cats regardless of status of diabetic control, suggesting routine monitoring with urine sediment exams or urine culture is warranted.
    Journal of Veterinary Internal Medicine 01/2006; 20(4):850-5. · 2.06 Impact Factor
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    Journal of the American Veterinary Medical Association 05/2001; 218(8):1298-302. · 1.72 Impact Factor
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    ABSTRACT: To determine the efficacy and safety of percutaneous ethanol injection (PEI) for the treatment of hyperthyroidism caused by bilateral hyperplastic thyroid nodules in cats. DESIGN; Prospective study. 7 cats. Hyperthyroidism was diagnosed on the basis of clinical signs and increased serum total thyroxine (TT4) concentrations. The presence of 2 cervical thyroid nodules was confirmed by use of ultrasonography and technetium Tc 99m albumin thyroid scans. After the death of 1 cat that received PEI in both thyroid nodules at the same time, the protocol was changed to injecting ethanol into 1 nodule at a time, with at least 1 month between injections. Clinical signs, serum TT4 concentrations, serum ionized calcium concentrations, laryngeal function, findings on ultrasonographic examinations of the ventral cervical region, and results of thyroid scans were monitored. Serum TT4 concentrations transiently decreased in all 6 cats (into the reference range in 5 of 6 cats) within 4 days of the first staged ethanol injection. Each subsequent injection resulted in a transient decrease in serum TT4 concentration. The longest period of euthyroidism was 27 weeks. Adverse effects included Horner's syndrome, dysphonia, and laryngeal paralysis. One cat died of unrelated causes. One cat underwent bilateral thyroidectomy, 2 cats were treated with methimazole, and 2 cats that had increased serum TT4 concentrations were not treated further, because they remained clinically normal. Percutaneous ethanol ablation of bilateral thyroid nodules as a treatment for cats with hyperthyroidism is not recommended. This treatment is not as efficacious as the medical and surgical treatments presently used.
    Journal of the American Veterinary Medical Association 05/2001; 218(8):1293-7. · 1.72 Impact Factor
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    ABSTRACT: To evaluate the efficacy and safety of ultrasonographically guided radiofrequency heat ablation of parathyroid masses in dogs with primary hyperparathyroidism. Clinical trial. 11 dogs. In all dogs, either 1 or 2 parathyroid masses were evident ultrasonographically. Dogs were anesthetized, and a 20-gauge over-the-needle catheter was directed into the parathyroid mass via ultrasonographic guidance. Radiofrequency heat was applied to the stylet of the catheter until there was sonographically apparent change to the entire parenchyma of the mass. Serum total and ionized calcium and parathyroid hormone concentrations were monitored daily for 5 days after the ablation procedure and again at 1, 2, and 3-month intervals, if possible. Dogs were monitored for adverse effects. One treatment was required in 6 dogs, 2 treatments were required in 2 dogs, and treatment was unsuccessful in 3 dogs. Serum total and ionized calcium concentrations were within reference ranges within 2 days of the last procedure in all 8 successfully treated dogs. Serum parathyroid hormone concentration was decreased 24 hours after treatment in all 8 dogs. Hypocalcemia developed in 5 of the 8 successfully treated dogs, all of which required treatment. One dog had a transient voice change. Other adverse effects were not reported. Ultrasonographically guided radiofrequency heat ablation of parathyroid masses is a safe and effective alternative to surgery in dogs with primary hyperparathyroidism.
    Journal of the American Veterinary Medical Association 05/2001; 218(7):1106-10. · 1.72 Impact Factor
  • E C Feldman, R W Nelson
    Journal of Feline Medicine & Surgery 10/2000; 2(3):153-8. · 1.08 Impact Factor
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    ABSTRACT: To evaluate the reliability of history and physical examination findings for assessing control of glycemia in insulin-treated diabetic dogs. Retrospective study. 53 insulin-treated dogs with diabetes mellitus. Medical records of insulin-treated diabetic dogs from June 1995 to June 1998 were reviewed, and information on owner perception of their dog's response to insulin treatment, physical examination findings, body weight, insulin dosage, and concentrations of food-withheld (i.e., fasting) blood glucose (FBG), mean blood glucose (MBG) during an 8-hour period, blood glycosylated hemoglobin (GHb), and serum fructosamine was obtained. Owner's perception of their dog's response to insulin treatment, physical examination findings, and changes in body weight were used to classify control of glycemia as good or poor for each dog. The FBG, MBG/8 h, blood GHb, and serum fructosamine concentrations were compared between well-controlled and poorly controlled insulin-treated diabetic dogs. Presence or absence of polyuria, polydipsia, polyphagia, lethargy, and weakness were most helpful in classifying control of glycemia. Mean FBG and MBG/8 h concentrations, blood GHb concentrations, and serum fructosamine concentrations were significantly decreased in 25 well-controlled diabetic dogs, compared with 28 poorly controlled diabetic dogs. Most well-controlled diabetic dogs had concentrations of FBG between 100 and 300 mg/dl, MBG/8 h < or = 250 mg/dl, blood GHb < or = 7.5%, and serum fructosamine < or = 525 mumol/L, whereas most poorly controlled diabetic dogs had results that were greater than these values. Reliance on history, physical examination findings, and changes in body weight are effective for initially assessing control of glycemia in insulin-treated diabetic dogs.
    Journal of the American Veterinary Medical Association 08/2000; 217(1):48-53. · 1.72 Impact Factor
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    ABSTRACT: To determine prevalence of pituitary tumors, detectable by means of computed tomography or magnetic resonance imaging, in cats with insulin resistance suspected to have acromegaly or hyperadrenocorticism versus cats with well-controlled diabetes mellitus. Case series. 16 cats with insulin resistance that were also suspected to have acromegaly (n = 12) or pituitary-dependent hyperadrenocorticism (4) and 8 cats with well-controlled diabetes mellitus. Computed tomography was performed on all 16 cats with insulin resistance and 2 cats in which diabetes mellitus was well-controlled. The remaining 6 cats in which diabetes mellitus was well-controlled underwent magnetic resonance imaging. Images were obtained before and immediately after i.v. administration of contrast medium. Computed tomography revealed a mass in the region of the pituitary gland in all 16 cats with insulin resistance. Maximum width of the masses ranged from 4.4 to 12.7 mm; maximum height ranged from 3.1 to 12.6 mm. Results of computed tomography performed on 2 cats with well-controlled diabetes and magnetic resonance imaging performed on the remaining 6 cats were considered normal. Results suggest that cats with insulin resistance suspected to have acromegaly or pituitary-dependent hyperadrenocorticism are likely to have a pituitary mass detectable by means of computed tomography or magnetic resonance imaging.
    Journal of the American Veterinary Medical Association 07/2000; 216(11):1765-8. · 1.72 Impact Factor
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    ABSTRACT: To evaluate effects of dietary insoluble fiber on control of glycemia in cats with naturally acquired diabetes mellitus. Randomized controlled crossover trial. 16 cats with naturally acquired diabetes mellitus. Cats were fed a diet high in insoluble fiber (HF) containing 12% cellulose (dry-matter basis) or a diet low in insoluble fiber (LF) for 24 weeks; they were fed the other diet for the subsequent 24 weeks. Caloric intake and insulin treatment were adjusted to maintain stable body weight and control of glycemia, respectively. Cats were allowed an adaptation period of 6 weeks after initiation of a diet, after which control of glycemia was evaluated at 6-week intervals for 18 weeks. Variables assessed included serum glucose concentration measured during the preprandial state, blood glycated hemoglobin concentration, serum glucose concentration measured at 2-hour intervals for 12 hours beginning at the time of the morning insulin injection, 12-hour mean serum glucose concentration, and mean fluctuation in serum glucose concentration from the 12-hour mean serum glucose concentration. Mean daily caloric intake, body weight, or daily insulin dosage did not differ significantly between cats when fed HF and LF diets. Mean preprandial serum glucose concentration, most post-prandial serum glucose concentrations, and the 12-hour mean serum glucose concentration were significantly lower when cats consumed the HF diet, compared with values when cats consumed the LF diet. These results support feeding a commercially available diet containing approximately 12% insoluble fiber (dry-matter basis) to cats with naturally acquired diabetes mellitus.
    Journal of the American Veterinary Medical Association 05/2000; 216(7):1082-8. · 1.72 Impact Factor
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    ABSTRACT: To evaluate effect of acarbose on control of glycemia in dogs with diabetes mellitus. Prospective randomized crossover controlled trial. 5 dogs with naturally acquired diabetes mellitus. Dogs were treated with acarbose and placebo for 2 months each: in 1 of 2 randomly assigned treatment sequences. Dogs that weighed < or = 10 kg (22 lb; n = 3) or > 10 kg (2) were given 25 or 50 mg of acarbose, respectively, at each meal for 2 weeks, then 50 or 100 mg of acarbose, respectively, at each meal for 6 weeks, with a 1-month interval between treatments. Caloric intake, type of insulin, and frequency of insulin administration were kept constant, and insulin dosage was adjusted as needed to maintain control of glycemia. Serum glucose concentrations, blood glycosylated hemoglobin concentration, and serum fructosamine concentration were determined. Significant differences in mean body weight and daily insulin dosage among dogs treated with acarbose and placebo were not found. Mean preprandial serum glucose concentration, 8-hour mean serum glucose concentration, and blood glycosylated hemoglobin concentration were significantly lower in dogs treated with insulin and acarbose, compared with insulin and placebo. Semisoft to watery feces developed in 3 dogs treated with acarbose. Acarbose may be useful as an adjunctive treatment in diabetic dogs in which cause for poor glycemic control cannot be identified, and insulin treatment alone is ineffective.
    Journal of the American Veterinary Medical Association 04/2000; 216(8):1265-9. · 1.72 Impact Factor
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    ABSTRACT: To compare outcome of surgical versus medical treatment of dogs with beta cell neoplasia. Retrospective study. 39 dogs with clinical signs of hypoglycemia and serum glucose and insulin concentrations consistent with a diagnosis of beta cell neoplasia. Information on signalment; clinical history; physical examination findings; results of CBC, serum biochemical analyses, and urinalysis; serum glucose and insulin concentrations; results of thoracic radiography and abdominal ultrasonography; treatment and treatment complications; survival time; and cause of death were obtained from medical records. 26 dogs underwent exploratory celiotomy and partial pancreatectomy; 13 dogs were treated medically (i.e., dietary change and prednisone). Median survival time was significantly longer for dogs treated surgically than for dogs treated medically. Significant differences were not found in mean age, body weight, duration of clinical signs prior to diagnosis, serum glucose and insulin concentration, or results of other serum biochemical tests between dogs treated surgically and dogs treated medically; also, there was no significant correlation between any of these parameters and survival time for either group of dogs. Results suggest that exploratory celiotomy and partial pancreatectomy are indicated once a tentative diagnosis of beta cell neoplasia is established in dogs.
    Journal of the American Veterinary Medical Association 08/1999; 215(2):226-30. · 1.72 Impact Factor
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    ABSTRACT: To correlate serum fructosamine concentrations with established measures of glycemic control and to compare serum fructosamine and blood glycosylated hemoglobin (GHb) concentrations as a means for assessing glycemic control in diabetic cats. Longitudinal cohort study. 26 healthy cats, 5 cats with stress-induced hyperglycemia, 15 untreated diabetic cats, and 36 treated diabetic cats. Control of glycemia was classified and monitored and serum fructosamine and blood GHb concentrations were measured for 12 poorly controlled diabetic cats before and after improving glycemic control, 8 well-controlled treated diabetic cats before and after glycemic control deteriorated, and 5 cats with diabetes mellitus before and after onset of stress-induced hyperglycemia. Mean serum fructosamine and blood GHb concentrations were significantly higher in untreated diabetic cats, compared with healthy cats, and in 24 poorly controlled diabetic cats, compared with 12 well-controlled diabetic cats. Mean serum fructosamine and blood GHb concentrations decreased significantly in 12 poorly controlled diabetic cats after improving glycemic control and increased significantly in 8 well-controlled diabetic cats after glycemic control deteriorated. A significant stress-induced increase in mean blood glucose concentration was evident 12 hours after insulin administration, but not in 5 docile diabetic cats that became fractious. Serum fructosamine and blood GHb concentrations are clinically useful tools for monitoring control of glycemia in cats with diabetes mellitus.
    Journal of the American Veterinary Medical Association 07/1999; 214(12):1794-8. · 1.72 Impact Factor
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    ABSTRACT: Medical records of 10 cats with transient clinical diabetes mellitus were reviewed. At the time diabetes was diagnosed, clinical signs included polyuria and polydipsia (10 cats), weight loss (8 cats), polyphagia (3 cats), lethargy (2 cats), and inappetence (1 cat). Mean (+/- SD) fasting blood glucose concentration was 454 +/- 121 mg/dL, mean blood glucose concentration during an 8-hour period (MBG/8 hours) was 378 +/- 72 mg/dL, and glycosuria and trace ketonuria were identified in 10 and 5 cats, respectively. Baseline serum insulin concentration was undetectable (6 cats) or within the reference range (4 cats) and serum insulin concentration did not increase after i.v. glucagon administration in any cat. Insulin-antagonistic drugs were being administered to 5 cats and concurrent disorders were identified in all cats. Management of diabetes included administration of glipizide (6 cats), insulin (3 cats), or both (1 cat), discontinuation of insulin-antagonistic drugs, and treatment of concurrent disorders. Insulin and glipizide treatment was discontinued 4-16 weeks (mean, 7 weeks) after the initial diagnosis of diabetes was confirmed. At the time treatment for diabetes was discontinued, clinical signs had resolved, mean fasting blood glucose concentration was 102 +/- 48 mg/dL, MBG/ 8 hours was 96 +/- 32 mg/dL, glycosuria and ketonuria were not identified in any cat, and concurrent disorders (except mild renal insufficiency in 1 cat) had resolved. Significant (P < .05) increases occurred in postglucagon serum insulin concentrations, insulin peak response, and total insulin secretion, compared with values obtained when clinical diabetes was diagnosed. Histologic abnormalities were identified in pancreatic islets of 5 cats in which pancreatic biopsies were obtained and included decreased number of islets (4 cats), islet amyloidosis (3 cats), and vacuolar degeneration of islet cells (3 cats). Mean beta cell density was significantly (P < .001) decreased in diabetic cats compared with control cats (1.4 +/- 0.7 versus 2.6 +/- 0.5%, respectively). Cells within islets stained positive for insulin, however, the number of insulin-staining cells per islet and the intensity of insulin staining were decreased in 5 and 2 cats, respectively. Clinical diabetes had not recurred in 1 cat after 6 years, in 4 cats lost to follow-up after 1.5, 1.5, 2.0, and 2.5 years, and in 2 cats that died 6 months and 5.5 years after clinical diabetes resolved. Clinical diabetes recurred in 3 cats after 6 months, 14 months, and 3.4 years, respectively. These findings suggest that cats with transient clinical diabetes have pancreatic islet pathology, including decreased beta cell density, and that treatment of diabetes and concurrent disorders results in improved beta cell function, reestablishment of euglycemia, and a transition from a clinical to subclinical diabetic state.
    Journal of Veterinary Internal Medicine 01/1999; 13(1):28-35. · 2.06 Impact Factor
  • J C Scott-Moncrieff, R W Nelson
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    ABSTRACT: To determine whether measuring change in serum thyroid-stimulating hormone (TSH) concentration in response to thyrotropin-releasing hormone (TRH) administration can be used as a test of thyroid function in dogs suspected of having hypothyroidism. Case-cohort study. 13 healthy dogs, 20 hypothyroid dogs, and 18 euthyroid dogs with concurrent diseases. Blood samples were collected before and 30 minutes after TRH administration, and serum TSH concentration was measured. The 13 healthy dogs were used to establish a reference range for change in TSH concentration after TRH administration. The remaining 38 dogs were categorized as hypothyroid or euthyroid on the basis of baseline total thyroxine (T4) and TSH concentrations, T4 concentration 4 hours after TRH administration, and clinical response to administration of sodium levothyroxine. Median baseline TSH concentration was 0.25 ng/ml (range, 0.03 to 0.44 ng/ml) in healthy dogs, 0.93 ng/ml (0.21 to 3.5 ng/ml) in hypothyroid dogs, and 0.21 ng/ml (0.03 to 0.63 ng/ml) in euthyroid dogs with concurrent diseases. Median percentage change in TSH concentration after TRH administration was 207% (range, 25 to 2,200%) in healthy dogs, 24% (-21 to 134%) in hypothyroid dogs, and 167% (69 to 1,800%) in euthyroid dogs with concurrent diseases. Overall accuracy of using the TRH-induced change in TSH concentration to identify hypothyroid dogs was 90%. Although percentage change in TSH concentration in response to TRH administration can be used to differentiate euthyroid from hypothyroid dogs, the test has little advantage over measurement of baseline TSH and total or free T4 concentration.
    Journal of the American Veterinary Medical Association 12/1998; 213(10):1435-8. · 1.72 Impact Factor
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    ABSTRACT: To determine prevalence and severity of systemic arterial hypertension and proteinuria in dogs with naturally developing diabetes mellitus (DM) and to determine whether these abnormalities were related to age, sex, duration of DM, or degree of control of glycemia. Case series and cohort study. Fifty dogs with naturally developing DM. Blood pressure was measured in all 50 dogs. Thirty-eight dogs were evaluated once, and 12 were evaluated sequentially. Thirty-five were evaluated for proteinuria by determining protein-to-creatinine ratio in urine (n = 35) or by electrophoresis of urine (33). Hypertension was detected in 23 on the basis of a systolic pressure > 160 mm HG (12 dogs), a diastolic pressure > 100 mm HG (21), or a mean pressure > 120 mm HG (23). All dogs with systolic hypertension had concurrent diastolic and mean hypertension, and 19 of 21 dogs with diastolic hypertension had concurrent high mean pressure. Ten of 12 dogs reevaluated at subsequent visits had no change in blood pressure. Blood pressure remained consistent in 3 dogs tested at different times during the day on a single visit. Duration of DM and presence of proteinuria were significant predictors of hypertension. Seven of 35 (20%) dogs had an increased protein-to-creatinine ratio in their urine. Albumin concentration and albumin-to-creatinine ratio were significantly higher in urine from diabetic dogs, compared with healthy, nondiabetic dogs. Hypertension was associated with an increased albumin-to-creatinine ratio. Systemic hypertension and proteinuria may be common in diabetic dogs, but the clinical importance of these findings are, as yet, unknown.
    Journal of the American Veterinary Medical Association 10/1998; 213(6):822-5. · 1.72 Impact Factor
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    ABSTRACT: Acromegaly was diagnosed in 3 cats with insulin-resistant diabetes mellitus (DM) on the basis of history and physical examination findings, which ruled out other causes of insulin-resistant DM, and by documenting high plasma concentrations of growth hormone. Computed tomography revealed a mass in the area of the pituitary gland in each cat. Pituitary gland tumors were irradiated with cobalt 60, and none of the cats developed complications to radiotherapy. Each cat received a total dose of 48 Gy of cobalt 60 during 12 treatments. After completion of radiotherapy, insulin requirements were less for all cats, although in 1 cat, this improvement was transient. Diabetes mellitus resolved in 2 of 3 cats. After treatment, decreases in insulin requirements correlated with decreases in plasma growth hormone concentrations in 2 of 3 cats in which DM resolved. On the basis of these findings, irradiation of pituitary gland tumors appears to be a treatment option for cats with acromegaly.
    Journal of the American Veterinary Medical Association 09/1998; 213(3):374-6. · 1.72 Impact Factor

Publication Stats

870 Citations
138.70 Total Impact Points

Institutions

  • 1989–2011
    • University of California, Davis
      • • Veterinary Medicine Teaching & Research Center
      • • Department of Veterinary Medicine and Epidemiology
      • • School of Veterinary Medicine
      • • School of Medicine
      Davis, CA, United States
  • 1999
    • CSU Mentor
      Long Beach, California, United States
  • 1987–1998
    • Purdue University
      • Department of Veterinary Clinical Sciences (VCS)
      West Lafayette, IN, United States
  • 1997
    • Beverly Hospital, Montebello CA
      Montebello, California, United States
  • 1992
    • Shreveport Veterinary Internal Medicine
      Shreveport, Louisiana, United States