Effect of Intravenous or Perivascular Injection of Synthetic Adrenocorticotropic Hormone on Stimulation Test Results in Dogs.

BACKGROUND: Standard protocols for adrenocorticotropic hormone (ACTH) stimulation testing (ACTHst) often involve intravenous (IV) injection of corticotropin. ACTH might be unintentionally injected into the perivascular (PV) space. OBJECTIVE: To compare stimulation test results after IV and PV injections of ACTH. ANIMALS: Twenty privately owned dogs were studied: 10 healthy and 10 with trilostane-treated naturally occurring hyperadrenocorticism (HAC). METHODS: Prospective study. Each of 20 dogs underwent 2 ACTHst not <4 nor more than 14 days apart. Five healthy and 5 HAC dogs had an IV ACTHst first and PV second; 5 healthy and 5 HAC dogs had a PV ACTHst first and IV second. Blood samples for measurement of serum cortisol concentration were collected before and 1 hour after ACTH administration. RESULTS: No significant difference in results was demonstrated when comparing serum cortisol concentrations after IV and PV ACTH administration in all 20 dogs (median µg/dL; interval µg/dL: 8.2; 1.4-17.4 versus 7.8; 0.9-16.9; P = .23). No significant difference in results was demonstrated when comparing serum cortisol concentrations after IV and PV ACTH administration in the 10 healthy dogs (median µg/dL; interval µg/dL: 10.9; 7.3-17.4 versus 10.6; 7.1-16.9; P = .54) or in the 10 HAC dogs (median µg/dL; interval µg/dL: 6.3; 1.4-8.6 versus 5.2; 0.9-8.7; P = .061). CONCLUSIONS AND CLINICAL IMPORTANCE: Perivascular administration of ACTH does not significantly alter stimulation test results in healthy dogs or in dogs with HAC undergoing therapy with trilostane.

Association of Hypercalcemia Before Treatment With Hypocalcemia After Treatment in Dogs With Primary Hyperparathyroidism.

BACKGROUND: Development of hypocalcemia after treatment of hyperparathyroidism results in increased costs and risk of poorer outcomes. Previous studies have shown conflicting data about predictors of hypocalcemia after these procedures. HYPOTHESIS/OBJECTIVES: The objective of this study was to investigate whether ionized calcium (iCa) concentrations before treatment are predictive of hypocalcemia or its clinical signs after surgical removal or heat ablation in dogs with primary hyperparathyroidism. ANIMALS: Fifty-four dogs with primary hyperparathyroidism (29 female, 25 male; 49 retrospective, 5 prospective). METHODS: Dogs were enrolled if they met the inclusion criteria: persistent hypercalcemia (iCa >1.41 mmol/L) due to primary hyperparathyroidism and absence of preemptive calcitriol treatment. All dogs were treated with parathyroidectomy (n = 37) or percutaneous ultrasound-guided heat ablation (n = 17). After treatment, iCa was monitored twice daily until plateau or intervention. RESULTS: There was a moderate correlation between before-treatment hypercalcemia and after-treatment hypocalcemia. The prospective study was terminated due to ethical concerns given findings in the retrospective section. All dogs were placed into groups according to their pretreatment iCa: 1.46-1.61 mmol/L, 1.62-1.71 mmol/L, iCa 1.72-1.81 mmol/L, or >1.81 mmol/L. After treatment, the mean lowest iCa for each group, respectively, was 1.19, 1.18, 1.13, and 1.01 mmol/L. There was a significant association between higher group and proportion of dogs with iCa <1.00 mmol/L (P = .014). CONCLUSIONS AND CLINICAL IMPORTANCE: This study demonstrates a moderate correlation between iCa concentration before treatment and hypocalcemia after treatment. Dogs with higher initial iCa concentrations should be treated to prevent rapid decline and development of clinical hypocalcemia.

Comparison of adrenocorticotropic hormone stimulation test results started 2 versus 4 hours after trilostane administration in dogs with naturally occurring hyperadrenocorticism.

BACKGROUND: Trilostane medical treatment of naturally occurring hyperadrenocorticism (NOH) in dogs is common, as is use of the adrenocorticotropic hormone (ACTH) stimulation test (ACTHst) in monitoring response to treatment. There is uncertainty regarding when the ACTHst should be started relative to time of trilostane administration. OBJECTIVE: To compare ACTHst results in dogs being treated for NOH with trilostane when the test is begun 2 versus 4 hours after trilostane administration. ANIMALS: Twenty-one privately owned dogs with NOH, each treated with trilostane for at least 30 days. METHODS: Each dog had 2 ACTHst completed, 1 started 2 hours and the other 4 hours after trilostane administration. The second test was started no sooner than 46 hours and no later than 74 hours after the first. RESULTS: For all 21 dogs, the mean post-ACTH serum cortisol concentration from tests started 2 hours after trilostane administration (5.4 ± 3.7 µg/dL) was significantly lower (P = .03) as compared with results from the tests started 4 hours after administration (6.5 ± 4.5 µg/dL). CONCLUSIONS: Results of ACTHst started at different times yield significantly different results. Dogs with NOH, treated with trilostane, and monitored with ACTHst results should have all of their subsequent ACTHst tests begun at or about the same time after trilostane administration.

Serum inhibin concentration in dogs with adrenal gland disease and in healthy dogs.

BACKGROUND: 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. OBJECTIVE: To determine serum inhibin concentration in dogs with adrenal gland disease and in healthy dogs. ANIMALS: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS AND CLINICAL IMPORTANCE: 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.

Trilostane dose versus body weight in the treatment of naturally occurring pituitary-dependent hyperadrenocorticism in dogs.

BACKGROUND: Trilostane is commonly used in the treatment of dogs with naturally occurring pituitary-dependent hyperadrenocorticism (PDH). Dose recommendations have varied from the manufacturer and the literature. HYPOTHESIS: As body weight increases, dose/kg or dosage/day of trilostane required to control the clinical signs of PDH decreases. ANIMALS: 70 dogs with naturally occurring hyperadrenocorticism. METHODS: Retrospective study. Each dog must have been treated for at least 6 months and should have shown a "good response" to trilostane, as determined by owners. Statistical comparisons of dose and dosage were made after the dogs were separated into groups weighing <15 or >15 kg; groups weighing ≤10, 10.1-20, 20.1-30, and ≥30 kg; and then groups based on body surface area versus dose/kg and total amount of trilostane required to control the condition. RESULTS: There was no significant difference in trilostane dose in mg/kg of body weight or in the total amount of trilostane required daily to control clinical signs, except when the dose for dogs weighing >30 kg was compared with that for the other groups. However, despite lack of statistical significance when comparing groups, there was a significant trend using polynomial regression analysis, suggesting that as body weight increases, the amount of trilostane (mg/kg/dose as well as mg/kg/daily dosage) required to control clinical signs decreases. CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs weighing >30 kg, and possibly those weighing >15 kg, might require smaller amounts of trilostane per dose or per day than those weighing less, to control PDH-associated clinical signs.

Comparison of IV and IM formulations of synthetic ACTH for ACTH stimulation tests in healthy dogs.

BACKGROUND: Two commercially available forms of synthetic ACTH are used to diagnose and monitor hyper- and hypoadrenocorticism in dogs. OBJECTIVE: To compare the biologic activity of the liquid and lyophilized forms of cosyntropin. ANIMALS: Eighteen privately owned healthy dogs were included. METHODS: Dogs were assigned to one of 2 groups of 9 dogs each. Group 1 dogs were tested with the lyophilized product first and the liquid solution 30-60 days later. The Group 2 dogs were tested with the liquid solution first and the lyophilized drug 30-60 days later. For the ACTH stimulation tests, serum samples were collected before and 1 hour after IM administration of 0.25 mg reconstituted lyophilized product or 1 hour after IV administration of 0.25 mg of liquid solution. Cortisol concentrations of all serum samples were measured by use of a commercial cortisol radioimmunoassay. RESULTS: Serum cortisol concentrations before and after ACTH stimulation did not differ significantly between groups (P = .57). In addition, no individual dog had as much as a 20% difference in serum cortisol concentrations after administration of either ACTH formulation. CONCLUSIONS AND CLINICAL IMPORTANCE: Given the lack of significant differences of the ACTH stimulation test results, the lyophilized and liquid solution products can be used interchangeably.

Predictive factors and the effect of phenoxybenzamine on outcome in dogs undergoing adrenalectomy for pheochromocytoma.

BACKGROUND: 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. HYPOTHESIS: Dogs treated with PBZ before adrenalectomy have increased survival compared with untreated dogs. ANIMALS: Forty-eight dogs that underwent adrenalectomy for pheochromocytoma. METHODS: 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. RESULTS: 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). CONCLUSIONS AND CLINICAL IMPORTANCE: Results from this retrospective study support treatment with PBZ before surgical removal of pheochromocytoma in dogs.

Frequency and risk factors for urinary tract infection in cats with diabetes mellitus.

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.

Lymphoma as a model for chronic illness: effects on adrenocortical function testing.

Many dogs with chronic illness have serum biochemical abnormalities consistent with hyperadrenocorticism (HAC). Lymphoma (LSA) is a chronic disease of dogs. The purpose of this study was to evaluate adrenocortical screening test results in dogs with LSA to evaluate their specificity. Criteria for inclusion in the study included a diagnosis of LSA, an expected survival time of 16-56 weeks, no glucocorticoid treatment beyond 4 weeks after the initiation of chemotherapy, no evidence of HAC, and owner consent. Post-ACTH stimulation plasma cortisol concentrations (PACs), urine cortisol : creatinine (UC : Cr) ratios, and maximal left adrenal width measurements were performed at the time of LSA diagnosis before the initiation of chemotherapy and at 16, 24, 32, 40, and 52 weeks or until the loss of remission or the development of another disease. Ten dogs met the criteria for inclusion. Forty-two PACs were performed; 1 abnormal, 2 borderline, and 39 normal values were detected. Thirty-five maximal left adrenal width measurements were obtained; 0 abnormal, 5 borderline, and 30 normal measurements were detected. Thirty-six UC : Cr ratios were obtained, with 26 abnormal, 4 borderline, and 6 normal values detected and 9 of 10 dogs having at least 1 abnormal value. These data suggest that in dogs with LSA, the UC : Cr ratio frequently is abnormal and may not be a specific test for HAC, or it may be the most sensitive test for increases in cortisol secretion due to chronic illness. Maximal left adrenal width measurements and PACs were almost always normal and may be more specific for HAC or less sensitive for demonstrating chronic increases in cortisol secretion.

Biochemical basis for the hypercoagulable state seen in Cushing syndrome; discussion 1006-7.

HYPOTHESIS: Cushing syndrome (CS) is associated with a hypercoagulable state that results in a 4-fold increase in the incidence of pulmonary embolism, deep venous thrombosis, and a 4-fold mortality rate compared with the general population. The incidence of CS in humans is approximately 2 to 5 per million per year, whereas in dogs it is much higher. The clinical complications of CS in humans are also manifested in dogs. We used a dog model of CS to better define the biochemical basis for the hypercoagulable state seen in the disease. DESIGN: A consecutive sample of dogs with CS and a cohort of healthy control dogs identified at a "well-dog check" were enrolled. All dogs underwent blood assays to identify the levels of procoagulant factors, natural antithrombotics, and the degree of ongoing activation of the coagulation cascade. SETTING: University veterinary medical teaching hospital. RESULTS: A total of 86 dogs were enrolled, 56 with CS and 30 control dogs. Levels of procoagulation factors II, V, VII, IX, X, XII, and fibrinogen were significantly increased in dogs with CS (P<.05). The natural antithrombotic antithrombin was significantly decreased in dogs with CS (P<.02). Thrombin-antithrombin complexes, a marker of subclinical thrombosis, were significantly increased in dogs with CS (P<.05). CONCLUSIONS: The hypercoagulable state of CS is demonstrated by an increase in thrombin-antithrombin complexes. This hypercoagulable state may be caused in part by (1) an elevation of procoagulant factors, and (2) a decrease in antithrombin. Because of the similar clinical and biochemical changes between dogs with CS and humans, this canine model may be a useful tool for the future study of the hypercoagulable state in CS.

Nontraumatic rupture of an adrenal gland tumor causing intra-abdominal or retroperitoneal hemorrhage in four dogs.

Diagnosis and surgical management of intra-abdominal or retroperitoneal hemorrhage in 4 dogs with rupture of an adrenal gland tumor were determined. All 4 dogs were lethargic and weak with pale mucous membranes on initial examination. Three dogs did not have any history of clinical signs of hyperadrenocorticism or pheochromocytoma prior to examination. In 3 of the dogs, a mass in the area of the adrenal gland was identified with ultrasonography prior to surgery. All dogs developed ventricular premature contractions before or during anesthesia. Three dogs survived adrenalectomy; 1 dog was euthanatized during surgery because of an inability to achieve adequate hemostasis. The remaining 3 dogs all survived more than 5 months after surgery; 1 was euthanatized 9 months after surgery because of rupture of a hepatic mass. On the basis of these results, we suggest that hemodynamic stabilization followed by adrenalectomy is the treatment of choice for dogs with nontraumatic rupture of an adrenal gland tumor and resulting life-threatening hemorrhage.

Use of percutaneous ethanol injection for treatment of bilateral hyperplastic thyroid nodules in cats.

OBJECTIVE: 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. ANIMALS: 7 cats. PROCEDURE: 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. RESULTS: 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. CONCLUSIONS AND CLINICAL RELEVANCE: 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.

Percutaneous ultrasonographically guided radiofrequency heat ablation for treatment of primary hyperparathyroidism in dogs.

OBJECTIVE: To evaluate the efficacy and safety of ultrasonographically guided radiofrequency heat ablation of parathyroid masses in dogs with primary hyperparathyroidism. DESIGN: Clinical trial. ANIMALS: 11 dogs. PROCEDURE: 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. RESULTS: 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. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasonographically guided radiofrequency heat ablation of parathyroid masses is a safe and effective alternative to surgery in dogs with primary hyperparathyroidism.

Reliability of history and physical examination findings for assessing control of glycemia in dogs with diabetes mellitus: 53 cases (1995-1998).

OBJECTIVE: To evaluate the reliability of history and physical examination findings for assessing control of glycemia in insulin-treated diabetic dogs. DESIGN: Retrospective study. ANIMALS: 53 insulin-treated dogs with diabetes mellitus. PROCEDURE: 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. RESULTS: 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. CONCLUSIONS AND CLINICAL RELEVANCE: Reliance on history, physical examination findings, and changes in body weight are effective for initially assessing control of glycemia in insulin-treated diabetic dogs.

Prevalence of pituitary tumors among diabetic cats with insulin resistance.

OBJECTIVE: 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. DESIGN: Case series. ANIMALS: 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. PROCEDURE: 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. RESULTS: 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. CONCLUSIONS AND CLINICAL RELEVANCE: 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.

Effect of the alpha-glucosidase inhibitor acarbose on control of glycemia in dogs with naturally acquired diabetes mellitus.

OBJECTIVE: To evaluate effect of acarbose on control of glycemia in dogs with diabetes mellitus. DESIGN: Prospective randomized crossover controlled trial. ANIMALS: 5 dogs with naturally acquired diabetes mellitus. PROCEDURE: 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. RESULTS: 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. CONCLUSIONS AND CLINICAL RELEVANCE: 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.

Effect of dietary insoluble fiber on control of glycemia in cats with naturally acquired diabetes mellitus.

OBJECTIVE: To evaluate effects of dietary insoluble fiber on control of glycemia in cats with naturally acquired diabetes mellitus. DESIGN: Randomized controlled crossover trial. ANIMALS: 16 cats with naturally acquired diabetes mellitus. PROCEDURE: 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. RESULTS: 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. CONCLUSIONS AND CLINICAL RELEVANCE: These results support feeding a commercially available diet containing approximately 12% insoluble fiber (dry-matter basis) to cats with naturally acquired diabetes mellitus.

Percutaneous ultrasound-guided chemical parathyroid ablation for treatment of primary hyperparathyroidism in dogs.

OBJECTIVE: To evaluate the efficacy, feasibility, and safety of ultrasound-guided chemical ablation of parathyroid masses in dogs with primary hyperparathyroidism. DESIGN: Prospective clinical trial. ANIMALS: 8 dogs. PROCEDURE: In all dogs, a solitary parathyroid mass was evident ultrasonographically. Dogs were anesthetized with propofol, and a 27-gauge needle was directed into the parathyroid mass under ultrasound guidance. Ethanol (96%) was injected into the mass until there was evidence of diffusion of fluid throughout the mass. Serum total calcium, ionized calcium, phosphorus, and parathyroid hormone (PTH) concentrations were monitored daily for 5 to 7 days after the ablation procedure and again 1, 3, and 6 months after the procedure. Dogs were also monitored for adverse effects. Follow-up ultrasonography was performed 5 days and 1 month after the ablation procedure. RESULTS: One injection was required in 7 dogs, and 2 injections were required in 1. Serum total and ionized calcium concentrations were within reference ranges within 24 hours after treatment in 7 dogs and within 5 days in 1 dog. Serum PTH concentration decreased and serum phosphorus concentration increased within 24 hours after treatment in all 8 dogs. Transient hypocalcemia developed in 4 dogs during the first 5 days after treatment, but only 1 dog required treatment for hypocalcemic tetany. Hypercalcemia recurred in 1 dog 1 month after the procedure and surgical removal of the parathyroid mass was required. Other adverse effects were not reported. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasound-guided chemical ablation of parathyroid masses is a safe and effective alternative to surgery for dogs with primary hyperparathyroidism.