Urinary catecholamine and metanephrine to creatinine ratios in dogs with hyperadrenocorticism or pheochromocytoma, and in healthy dogs

Intraoperative hypertensive crisis in a dog with functional paraganglioma of the gall bladder

A 15-year-old spayed female mongrel presented with anorexia and an abdominal mass. The mass originated from the gall bladder and was surgically resected along with divisionectomy of the central hepatic division. Paroxysmal hypertension and tachycardia were noted during manipulation of the mass. Following resection, arterial blood pressure decreased significantly. Histopathological analysis confirmed a diagnosis of neuroendocrine neoplasm. Immunohistochemical staining for synaptophysin and chromogranin A yielded diffuse and strong positive results, while gastrin was positive in only 10% of the cells. The preoperative elevated concentrations of catecholamine in the urinalysis showed a marked decrease after surgery. Based on these findings, the tumour was diagnosed as a functional paraganglioma of the gall bladder. The patient has undergone regular thoracic radiographs and ultrasound examinations and, until 431 days after surgery, has shown no signs of metastases or recurrences. Based on our literature search, we report the first case of functional paraganglioma of the gall bladder in a dog.

Successful surgical removal of a pheochromocytoma in a mare via trans-costal approach

BACKGROUND

Pheochromocytomas have been previously reported in horses, but successful antemortem diagnosis and surgical removal without recurrence of clinical signs have not been described.

OBJECTIVE

To report the clinical presentation, diagnostic evaluation, surgical technique, anaesthetic management and post-operative care of a mare diagnosed with pheochromocytoma.

STUDY DESIGN

Clinical case report.

METHODS

An 18-year-old Quarter Horse mare presented for recurrent episodes of colic, profuse sweating, muscle fasciculations and agitation over a 2-month period. Clinical, clinicopathologic and ultrasonographic (transcutaneous, transrectal) abnormalities were consistent with a unilateral left-sided adrenal mass. Surgical removal of the mass was performed via a trans-costal approach with removal of the 18th rib and retraction of the left kidney to improve exposure. Associated vasculature was ligated, and the adrenal mass was removed and submitted for histopathology and immunohistochemistry.

RESULTS

A trans-costal surgical approach provided excellent visualisation of the adrenal mass and allowed for identification and ligation of associated vessels. Total surgical and anaesthesia time were 86 and 114 min, respectively. Several intraoperative (hypertension, tachycardia) and post-operative (colic with tachycardia, tachypnea, large colon pelvic flexure impaction and nasogastric reflux) complications were encountered and managed successfully. Immunohistochemistry demonstrated positive labelling for synaptophysin and chromogranin A, confirming diagnosis of pheochromocytoma. The mare had recovered well at 6-week recheck post-operatively and returned to training at 6 months post-operatively. No further clinical signs consistent with pheochromocytoma have been observed following removal.

CONCLUSIONS

The trans-costal approach allowed for surgical removal of a pheochromocytoma in a mare. Surgical removal of adrenal masses in horses may be associated with complications yet was successfully performed without subsequent recurrence of clinical signs associated with tumour presence and return to athletic use in this mare.

Reference intervals for plasma, urinary, and salivary concentrations of free metanephrines in dogs: Relevance to the diagnosis of pheochromocytoma

BACKGROUND

Measurement of free metanephrines is recommended for screening of pheochromocytoma (PCC) but requires appropriate reference intervals (RIs).

HYPOTHESIS/OBJECTIVES

To report RIs for plasma, urinary and salivary concentrations of free metanephrines and to determine the diagnostic performance of plasma free normetanephrine (pNMN) and metanephrine (pMN) concentrations in dogs with PCC, hypercortisolism (HC), and nonadrenal illness (NAI).

ANIMALS

Eighty healthy dogs, 11 PCC dogs, 25 HC dogs, 6 NAI dogs.

METHODS

Plasma, urine, and saliva were collected prospectively from healthy dogs, and free metanephrine concentrations were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In addition, medical records of dogs that had plasma free metanephrine concentrations measured by LC-MS/MS between 2018-2021 were studied retrospectively.

RESULTS

The RIs for free metanephrines in plasma, urine and saliva are reported. Dogs with PCC had significantly higher pNMN than dogs with HC (P < .001) and NAI (P = .002). The PCC dogs had significantly higher pMN than HC dogs (P < .001), but not higher than NAI dogs (P = .29). Using the upper reference limit, pNMN (>3.56 nmol/L) showed high sensitivity (100%, 95% confidence interval [CI]: 72-100) and specificity (94%, 95% CI: 79-99) for diagnosis of PCC, whereas pMN (>2.49 nmol/L) showed moderate sensitivity (73%, 95% CI: 39-94) and high specificity (94%, 95% CI: 79-99).

CONCLUSIONS AND CLINICAL IMPORTANCE

With establishment of these RIs, biochemical testing for PCC in dogs can be substantially improved. Measurement of pNMN is superior to pMN in dogs with PCC.

Imaging features of retroperitoneal extra-adrenal paragangliomas in 10 dogs

Retroperitoneal paragangliomas are rare tumors of the neuroendocrine system. Only a few canine case reports are available with rare descriptions of their imaging features. The objectives of this multi‐center, retrospective case series study were to describe the diagnostic imaging features of confirmed retroperitoneal paragangliomas and specify their location. Medical records and imaging studies of 10 affected dogs with cytological or histopathologic results concordant with retroperitoneal paragangliomas were evaluated. Dogs had a median age of 9 years. Four of them had clinical signs and laboratory reports compatible with excessive production of catecholamines. Six ultrasound, four CT, four radiographic, and one MRI studies were included. The paragangliomas did not have a specific location along the aorta. They were of various sizes (median 33 mm, range: 9–85 mm of length). Masses had heterogeneous parenchyma in six of 10 dogs, regardless of the imaging modality. Strong contrast enhancement was found in all CT studies. Encircling of at least one vessel was detected in six of 10 masses, clear invasion of a vessel was identified in one of 10 masses. In five of 10 cases, the masses were initially misconstrued as lymph nodes by the on‐site radiologist. Retroperitoneal paragangliomas appear along the abdominal aorta, often presenting heterogeneous parenchyma, possibly affecting the local vasculature, and displaying strong contrast enhancement on CT. Clinical signs can be secondary to mass effects or excessive catecholamine production. Underdiagnosis and misdiagnosis of this tumor are suspected as they can be silent, of small size, or confused with other structures.

18F-FDG PET/CT image findings of a dog with adrenocortical carcinoma

Background

In human medicine, 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has been used to differentiate between benign and malignant adrenal tumors and to identify metastases. However, canine adrenocortical carcinomas identified by 18F-FDG PET/computed tomography (CT) have not been reported.

Case presentation

A 13-year-old, castrated male, Cocker Spaniel dog with severe systolic hypertension exhibited an adrenal mass approximately 3.6 cm in diameter on ultrasonography. There was no evidence of pulmonary metastasis or vascular invasion on thoracic radiography and abdominal ultrasonography, respectively. 18F-FDG PET/CT was performed to identify the characteristics of the adrenal mass and the state of metastasis. One hour after injection of 5.46 MBq/kg 18F-FDG intravenously, the peripheral region of the adrenal mass visually revealed an increased 18F-FDG uptake, which was higher than that of the liver, and the central region of the mass exhibited necrosis. The maximal standardized uptake value (SUV) of the adrenal mass was 3.24; and relative SUV, calculated by dividing the maximal SUV of the adrenal tumor by the mean SUV of the normal liver, was 5.23. Adrenocortical carcinoma was tentatively diagnosed and surgical adrenalectomy was performed. Histopathologic examination of the resected adrenal mass revealed the characteristics of an adrenocortical carcinoma. After adrenalectomy, systolic blood pressure reduced to below 150 mmHg without any medication.

Conclusion

This is the first case report of 18F-FDG PET/CT findings in a dog with suspected adrenocortical carcinoma and may provide valuable diagnostic information for adrenocortical carcinoma in dogs.

Quantification of normetanephrine in canine urine using ELISA: evaluation of factors affecting results

Catecholamine release increases in dogs with pheochromocytomas and in situations of stress. Although plasma catecholamines degrade rapidly, their metabolites, normetanephrine (NME) and metanephrine (ME), are stable in acidified urine. Our aim was to verify a human urine ELISA kit for the quantification of NME and ME in canine urine and to determine the effects on metabolite stability of sampling time (morning or midday) and day (ordinary or day spent in a clinic). We analyzed 179 urine samples from 17 healthy dogs. For NME, the mean intra-assay CV was 6.0% for all samples and 4.3% for the canine control; inter-assay CVs were 3.3, 3.8, and 12% for high and low concentration human urine positive controls supplied in the ELISA kit and a positive canine control, respectively; spike-recovery was 90-101%. For ME, mean intra-assay CV was 6.5% for samples and 9.0% for the canine control; inter-assay CVs were 12.7, 7.2, and 22.5% for high and low concentration human urine positive controls supplied in the ELISA kit and a positive canine control, respectively; spike-recovery was 85-89%. Dilution recovery was unsatisfactory for both metabolites. Based on our verification results, NME was selected for remaining analyses. We found no effect on NME concentrations of acidification or room temperature storage for up to 24 h. The NME:creatinine ratio was higher after the first of 3 clinic days compared to the same morning (111.2 ± 5.5 vs. 82.9 ± 5.3; p < 0.0001), but not on the other days. NME verification results were generally superior to ME. Dilution studies were unsatisfactory for both metabolites. Given that NME was stable without acidification at room temperature, urine samples can be collected at home. The clinic environment can cause higher NME:creatinine ratios, especially in unaccustomed dogs.

Urinary free metanephrines measurement in dogs with adrenal gland diseases using a new simple liquid chromatography tandem mass spectrometry method

Measurement of urinary metanephrines in spot samples is used for the diagnosis of canine pheochromocytoma (PC). We describe a simple analytical method based on liquid chromatography tandem mass spectrometry (LC-MS/MS) for measuring free metanephrine (MN) and normetanephrine (NMN) in spot urine samples. Using the developed method, we evaluated the stability of urinary free-MN and free-NMN at various storing conditions. In addition, we assessed the feasibility of urinary free-MN and -NMN measurement for diagnosing PC. Urine samples were mixed with stable isotope internal standards and thereafter purified by ultrafiltration. The purified samples were analyzed by LC-MS/MS in the multiple reaction monitoring mode after separation on a multimode octa decyl silyl column. The coefficient of variation of free-MN and -NMN measurement was 7.6% and 5.5%, respectively. The linearity range was 0.5–10 µg/l for both analytes. Degradation was less than 10% for both analytes under any of the storage conditions. The median free-NMN ratio to creatinine of 9 PC dogs (595, range 144–47,961) was significantly higher (P<0.05) than that of 13 dogs with hypercortisolism (125, range 52–224) or 15 healthy dogs (85, range 50–117). The developed method is simple and may not require acidification of spot urine. The results of this preliminary retrospective study suggest that the measurement of urinary free metanephrines is a promising tool for diagnosing canine PC.

Urinary vanillylmandelic acid:creatinine ratio in dogs with pheochromocytoma

Pheochromocytoma diagnosis in dogs is challenging because biochemical tests are not always available. In humans, urinary vanillylmandelic acid (VMA) is part of a pheochromocytoma biochemical diagnostic profile, whereas its diagnostic accuracy is currently unknown in dogs with pheochromocytoma. Prospectively, VMA was determined by HPLC and expressed as the ratio with respect to urinary creatinine (VMA:C). The diagnostic accuracy of the VMA:C ratio was evaluated by analyzing the receiver operating characteristic (ROC) curve in 10 healthy dogs, 8 dogs with pituitary-dependent hypercortisolism, 8 dogs with adrenal-dependent hypercortisolism, and 7 dogs with pheochromocytoma. The pheochromocytoma diagnosis was confirmed by histology and immunohistochemistry in all tumors. The VMA:C ratio was significantly higher in dogs with pheochromocytoma (158 [53.4 to 230.8] × 10^-3) than in dogs with adrenal-dependent hypercortisolism (48.1 [24.3 to 144.9] × 10^-3; P < 0.05), dogs with pituitary-dependent hypercortisolism (37.5 [32 to 47.1] × 10^-3; P < 0.001), and healthy dogs (33.8 [13.3 to 87.9] × 10^-3; P < 0.001). When using a VMA:C ratio >58.2 × 10^-3 for pheochromocytoma diagnosis, a sensitivity of 85.7% and a specificity of 88.4% were obtained. Nevertheless, when using a cut-off ratio of 4 times the median VMA:C ratio determined in healthy dogs, there was no overlap (100% specificity). The area under the ROC curve indicated that the VMA:C ratio test could be used to discriminate between dogs with and without pheochromocytoma, what leads to the conclusion that it is useful for pheochromocytoma diagnosis in dogs.

Canine metabolomics advances

INTRODUCTION

Canis lupus familiaris is a domestic dog and many owners consider their pets as a family member. Medical bills with dogs are overcame only by the health care received by humans. Medical care is constantly progressing, and so is veterinary care. Metabolomics is the ''omic" technique aimed to the study of metabolome, low-molecular weight molecules, through biofluids or tissue samples. And it also allows to evaluate disease diagnosis and prognosis, therapeutic evaluation and toxicological studies.

OBJECTIVES

The goal of this paper is to review the current and potential applications of metabolomics in domestic dogs.

METHOD

ScienceDirect, Scopus, Reaxys and PubMed were searched for papers that performed canine metabolomics in any research area.

RESULTS

We analysed 38 papers, published until April 2019 in canine metabolomics approach. Metabolomic research in dogs so far can be divided into three areas: (a) Metabolomics studies in veterinary science, such as improving pet dogs health and welfare. (b) Diet, breeds and species discrimination. (c) Use of dogs as animal model in different diseases and drug development (evaluation toxicity and effect).

CONCLUSIONS

The results of this review showed that interest in metabolomics is growing in veterinary research. Several canine diseases have been evaluated with some promise for potential biomarker and/or disease mechanism discovery. Because canine metabolomics is a relatively new area, the researches spread across different research areas and with few studies in each area.

Use of Minimally Invasive Surgery in the Diagnosis and Treatment of Cancer in Dogs and Cats

Surgical management of neoplastic disease is common in veterinary medicine. Minimally invasive surgery (MIS) has gained widespread acceptance by veterinary surgeons and is experiencing rapid growth and frequency of use. Many neoplastic diseases in the abdomen and thorax of dogs and cats can be treated as effectively with MIS as with traditional open surgery. Additionally, MIS allows for less invasive options for organ biopsy in cancer patients either for initial diagnosis or for staging to inform prognosis and treatment. Despite the recent increase in MIS, additional research is required to further characterize the benefits to oncology patients and to ensure that surgical oncologic principles and patient outcomes are not compromised by the use of MIS.

Retrospective evaluation of toceranib phosphate (Palladia®) use in the treatment of inoperable, metastatic, or recurrent canine pheochromocytomas: 5 dogs (2014-2017)

BACKGROUND

Effective treatment options for inoperable, metastatic, or recurrent canine pheochromocytomas are lacking. In humans, specific germline mutations exist that drive the development of pheochromocytomas. Pharmaceutical blockade of these abnormalities with small molecule inhibitors are an effective treatment strategy. Similar mutations may exist in the dog, and thus, treatment with similar small molecule inhibitors may provide a survival advantage. The purpose of this study was to assess the role of toceranib phosphate in the treatment of inoperable, metastatic, or recurrent canine pheochromocytomas.

RESULTS

Retrospectively, medical records of dogs that had a diagnosis or suspect diagnosis of a pheochromocytoma were reviewed for information regarding response to toceranib phosphate and overall outcome. Five dogs were identified that fit the inclusion criteria. All five experienced clinical benefit (1 partial response, 4 stable disease). Progression-free interval (PFI) for the dog with the partial response was 61 weeks. PFI for the two dogs with stable measurable disease were 36 weeks and 28 weeks. PFI in the two dogs with stable metastatic disease were at least 11 weeks and 18 weeks.

CONCLUSIONS

Based on this limited series of dogs, the results suggest that toceranib may have biological activity in dogs with primary and metastatic pheochromocytomas. Larger studies are needed to define the use and response to toceranib in dogs with gross, microscopic, and metastatic pheochromocytoma.

Evaluation of an ELISA for metanephrines in feline urine

Catecholamines can be used to evaluate neuroendocrine tumors, stress, and potentially pain, but catecholamines degrade rapidly. Their metabolites normetanephrine (NME) and metanephrine (ME) have better stability in urine. In cats, urine sampling in a home environment would be beneficial to reduce effects of clinical stress and simplify sampling. We evaluated a human urine ELISA for analysis of NME and ME in feline urine, and investigated the effects of acidification, cat tray pellets, and storage time at room temperature up to 8.5 h. In 26 feline urine samples, mean NME concentration was 192 ± 80 ng/mL, mean intra- and inter-assay CV was 6.5% and 4.2%, respectively, and spike recovery was 98-101%, but dilutional recovery was unsatisfactory. For ME, mean intra- and inter-assay CV was 10.2% and 4.1%, respectively. Mean urine ME concentration was 32.1 ± 18.3 ng/mL, close to the kit's lowest standard, and spike recovery was 65-90%; the ELISA could not be validated for ME. The stability study, performed for NME on 12 urine samples, did not identify differences between acidified and non-acidified samples, cat tray pellets, or storage time, and no interaction effects. The ME ELISA was not suitable for feline urine; performance of the NME ELISA was acceptable, except for dilution recovery. For analysis of NME, feline urine can be sampled at home using cat tray pellets and stored at room temperature up to 8.5 h without acidification.

Effects of Trilostane on urinary Catecholamines and their metabolites in dogs with Hypercortisolism

BACKGROUND

Glucocorticoids influence the synthesis and metabolism of catecholamines (epinephrine and norepinephrine) and metanephrines (metanephrine and normetanephrine). The aim of this study was to measure urinary catecholamines and metanephrines in dogs with hypercortisolism before and during trilostane therapy. Urine samples were collected during initial work up and during therapy with trilostane in 14 dogs with hypercortisolism and in 25 healthy dogs. Epinephrine, norepinephrine, metanephrine and normetanephrine were measured using high-pressure liquid chromatography and expressed as ratios to urinary creatinine concentration.

RESULTS

Untreated dogs with hypercortisolism had significantly higher epinephrine, norepinephrine, and normetanephrine:creatinine ratios compared to healthy dogs. During trilostane therapy, urinary catecholamines and their metabolites did not decrease significantly. However, dogs with low post-ACTH cortisol concentrations during trilostane therapy had less increased epinephrine, norepinephrine and normetanephrine:creatinine ratios compared to healthy dogs. There was no correlation of urinary catecholamines and their metabolites with baseline or post-ACTH cortisol or endogenous ACTH concentrations during trilostane therapy.

CONCLUSION

Influences between steroid hormones and catecholamines seem to occur, as dogs with hypercortisolism have significantly higher urinary epinephrine, norepinephrine, and normetanephrine:creatinine ratios. Once-daily trilostane therapy does not lead to a significant decrease in catecholamines and their metabolites. Trilostane-treated dogs still have increased urinary epinephrine, norepinephrine and normetanephrine:creatinine ratios during trilostane therapy.

Urinary and plasma catecholamines and metanephrines in dogs with pheochromocytoma, hypercortisolism, nonadrenal disease and in healthy dogs

Background

Diagnosis of pheochromocytoma (PC) is based on a combination of clinical suspicion, finding an adrenal mass, increased plasma, and urine concentrations of catecholamine metabolites and is finally confirmed with histopathology. In human medicine, it is controversial whether biochemically testing plasma is superior to testing urine.

Objectives

To measure urinary and plasma catecholamines and metanephrines in healthy dogs, dogs with PC, hypercortisolism (HC), and nonadrenal diseases (NAD) and to determine the test with the best diagnostic performance for dogs with PC.

Animals

Seven PC dogs, 10 dogs with HC, 14 dogs with NAD, 10 healthy dogs.

Methods

Prospective diagnostic clinical study. Urine and heparin plasma samples were collected and stored at −80°C before analysis using high‐pressure liquid chromatography (HPLC) coupled to electrochemical detection or tandem mass spectrometry were performed. Urinary variables were expressed as ratios to urinary creatinine concentration.

Results

Dogs with PC had significantly higher urinary normetanephrine and metanephrine : creatinine ratios and significantly higher plasma‐total and free normetanephrine and plasma‐free metanephrine concentrations compared to the 3 other groups. There were no overlapping results of urinary normetanephrine concentrations between PC and all other groups, and only one PC dog with a plasma normetanephrine concentration in the range of the dogs with HC and NAD disease. Performances of total and free plasma variables were similar. Overlap of epinephrine and norepinephrine results between the groups was large with both urine and plasma.

Conclusion and clinical importance

Measurement of normetanephrine is the preferred biochemical test for PC and urine was superior to plasma.

Cortisol Response in Healthy and Diseased Dogs after Stimulation with a Depot Formulation of Synthetic ACTH

Background

The ACTH stimulation test is used to evaluate the adrenocortical reserve. Recently, the availability of the synthetic ACTH formulation was limited, causing major problems in clinical practice.

Objectives

The objective of this study was to evaluate poststimulation peak cortisol concentrations and the duration of the stimulatory effect of a depot ACTH preparation in dogs.

Animals

Twenty‐two healthy dogs, 10 dogs with suspected hypoadrenocorticism (HA) and 15 dogs with suspected hyperadrenocorticism (HC).

Methods

Prospective study. An ACTH stimulation test using a synthetic depot tetracosactide, administered intramuscularly (5 μg/kg or at least 0.1 mL) was performed. Blood samples for determination of cortisol were taken immediately before and 1, 2, 3, 4, 6, and 24 hours after stimulation.

Results

Peak cortisol concentrations were reached after 2–4 hours in all dogs. Cortisol concentrations 1 hour after stimulation were >9 μg/dL in all healthy dogs and >5 μg/dL in all dogs in which HA was excluded. None of the dogs with HA showed a cortisol‐increase above the detection‐limit of the assay. After 6 hours, cortisol concentrations had decreased in the healthy and HC group and were back to baseline after 24 hours.

Conclusions and Clinical Importance

The depot formulation can be used in place of the short‐acting ACTH to evaluate the adrenocortical reserve. Blood for peak cortisol concentrations should be drawn 3 hours after stimulation in cases in which HC is suspected; in HA‐suspected cases, blood sampling can take place after 1 hour. As the stimulatory effect is gone after 24 hours, interference with other hormonal tests is unlikely after that time.

Clinical findings in dogs with incidental adrenal gland lesions determined by ultrasonography: 151 cases (2007-2010)

OBJECTIVE

To determine the prevalence of and clinical features associated with incidental adrenal gland lesions (IAGLs) discovered during abdominal ultrasonography in dogs.

DESIGN

Retrospective case series.

ANIMALS

151 dogs with an IAGL and 400 control dogs.

PROCEDURES

Reports of ultrasonographic examinations of the abdomen of dogs performed during a 3.5-year period were reviewed. Adrenal glands were classified as having an IAGL if a nodule or mass was described or the width of either gland was ≥ 10 mm. For dogs with an IAGL, information regarding signalment, concurrent disorders, and outcome was obtained from the medical record. Findings were compared with those in a control population of 400 dogs examined during the same period.

RESULTS

An IAGL was detected in 151 of 3,748 (4%) dogs. Dogs with an IAGL were significantly older (median age, 11.25 years) and heavier (median body weight, 21 kg [46.2 lb]) than the control population (median age, 9.5 years; median body weight, 14 kg [30.8 lb]). Malignant tumors were reported in 6 of 20 (30%) dogs that underwent adrenal glandectomy or necropsy and had a maximum IAGL dimension that ranged from 20 to 46 mm; benign lesions all had a maximum dimension < 20 mm. Various coincidental conditions were reported in dogs with an IAGL, including nonadrenal gland malignant neoplasia in 43 (28.5%) dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

IAGLs were more likely in dogs ≥ 9 years of age. On the basis of this small data set, malignancy should be suspected for IAGLs ≥ 20 mm in maximum dimension.

Urinary corticoid concentrations measured by 5 different immunoassays and gas chromatography-mass spectrometry in healthy dogs and dogs with hypercortisolism at home and in the hospital

Background

Determination of the urinary corticoid‐to‐creatinine ratio (UCCR) is an important screening test in the diagnosis of hypercortisolism (HC). However, urinary cortisol metabolites interfere with cortisol measurement in immunoassays, leading to decreased specificity. Gas chromatography‐mass spectrometry (GC‐MS) is considered the gold standard for steroid hormone analysis, because it provides a high level of selectivity and accuracy.

Objectives

To prospectively compare the UCCR of healthy dogs and dogs with HC determined by 5 different immunoassays and by GC‐MS and to evaluate the influence of veterinary care on UCCR.

Animals

Twenty healthy dogs; 18 dogs with HC.

Methods

Urine was collected in the hospital and again after 6 days at home. Three chemiluminescence immunoassays (Access 2, Beckmann; Immulite 2000, DPC Siemens, with and without trichloromethane extraction) and 2 RIAs (Utrecht in house; Access Beckmann) were used. GC‐MS analyses were performed with Agilent 6890N/5973N. Urinary corticoid concentrations were related to urinary creatinine concentrations.

Results

Immunoassay results were significantly higher compared to GC‐MS results. Evaluation of bias plots and clinical assessment made on the basis of the assay results of each dog indicated substantial disagreement among the assays. Sensitivity varied from 37.5 to 75% and with selected assays was lower in samples from day 6 compared to day 0. GC‐MS was not superior to the immunoassays in discriminating healthy from HC dogs.

Conclusions and Clinical Importance

Considerable variation must be anticipated comparing different urinary cortisol assays. Establishing an assay‐ and laboratory‐specific reference range is critical when using UCCR.

Evaluation of baseline cortisol, endogenous ACTH, and cortisol/ACTH ratio to monitor trilostane treatment in dogs with pituitary-dependent hypercortisolism

BACKGROUND

The effectiveness of trilostane treatment is currently monitored by regular ACTH stimulation tests, which are time-consuming and expensive. Therefore, a monitoring system without a stimulation protocol and with less client expense would be preferable.

HYPOTHESIS/OBJECTIVES

The aim of our study was to evaluate if baseline cortisol, endogenous ACTH (ACTH) concentration or the baseline cortisol to ACTH ratio (cortisol/ACTH ratio) could replace the ACTH stimulation test.

ANIMALS

Forty trilostane-treated dogs with pituitary-dependent hypercortisolism (PDH) were included in this prospective study.

METHODS

A total of 148 ACTH stimulation tests and 77 ACTH concentrations and cortisol/ACTH ratios were analyzed. Control of cortisol release was classified according to cortisol concentration after ACTH administration as excessive (<1.5 μg/dL; group 1), adequate (1.5-5.4 μg/dL; group 2), or inadequate (>5.4 μg/dL; group 3).

RESULTS

Baseline cortisol concentrations had considerable overlap between excessively, adequately, and inadequately controlled dogs. Only baseline cortisol >4.4 μg/dL (in 12% of tests) was a reliable diagnosis of inadequate control. Endogenous ACTH concentrations did not differ between groups. The overlap of the cortisol/ACTH ratio between groups was large. Correct classification was only possible if the cortisol/ACTH ratio was >15, which occurred in 4% of tests.

CONCLUSIONS AND CLINICAL IMPORTANCE

To monitor trilostane treatment the ACTH stimulation test cannot be replaced by baseline cortisol, ACTH concentration, or the cortisol/ACTH ratio.

Metabolic complications of endocrine surgery in companion animals

Metabolic complications of endocrine surgery occur commonly and precautions should be taken to avoid potentially life-threatening situations and to lessen expense associated with a more extended hospital stay. Common complications of endocrine surgery as well as prevention strategies will be reviewed for pancreatic, parathyroid, and adrenal surgery.