Long-term follow-up of renal function in dogs after treatment for ACTH-dependent hyperadrenocorticism

Description of serum symmetric dimethylarginine concentration and of urinary SDS-AGE pattern in dogs with ACTH dependent hyperadrenocorticism

Serum symmetric dimethylarginine (SDMA) and patterns of urinary protein separated by sodium dodecyl sulfate agarose gel electrophoresis (SDS-AGE) have not been investigated as biomarkers in dogs with ACTH-dependent hyperadrenocorticism (ADHAC). This exploratory prospective study aimed to evaluate SDMA, serum creatinine (sCR), and SDS-AGE in dogs with ADHAC with and without proteinuria (ADHAC-P and ADHAC-nP, respectively). Thirty-five pet dogs classified as ADHAC-P (n=16), ADHAC-nP (n=6) and healthy (n=13) were included. Renal biomarkers were evaluated in all dogs at diagnosis. Baseline concentration of SDMA was not significantly different between the three groups (P = 0.15) whereas sCr was significantly lower in dogs in ADHAC dogs compared to healthy dogs (88.0 µmol/L [70.4-132.6; 79.2-114.4]) whether they had proteinuria or not (P = 0.014 and 0.002, respectively). However, baseline concentrations of sCr and SDMA were not significantly different between dogs with ADHAC-P dogs (SDMA, 8 µg/dL [5-12; 7-9]; sCr, 57.2 µmol/L [35.2-212.2; 52.8-92.4]) and ADHAC-nP dogs (SDMA, 8.5 µg/dL [7-13; 8-10]; sCr, 70.4 µmol/L [61.6-79.2; 61.6-70.4]) (P = 0.35 and P = 0.41, respectively). Proteinuria in dogs with ADHAC-P was mainly of glomerular origin (SDS-AGE pattern: glomerular in 10/16 dogs; mixed glomerular/tubular in four dogs). In our study, SDMA was neither significantly different in dogs with ADHAC whether they were proteinuric or not, nor between ADHAC and healthy dogs. Urinary electrophoresis provides additional information to the UPC and further investigations are needed to determine whether it may help identify dogs with ADHAC-P requiring specific antiproteinuric treatment.

Prevalence of Systemic Hypertension and Control of Systolic Blood Pressure in a Cohort of 14 Dogs with Adrenal-Dependent Hypercortisolism during the First Year of Trilostane Treatment or after Adrenalectomy

Hypercortisolism in dogs is frequently associated with systemic hypertension (SH). However, there are no studies evaluating the changes in systolic blood pressure (SBP) in dogs with adrenal-dependent hypercortisolism (ADH) during trilostane treatment or after adrenalectomy and their response to antihypertensive treatments. For this reason, the objectives of this study were to evaluate the changes in SBP in dogs with ADH during the first year of trilostane treatment or after adrenalectomy, the relation with clinical control of hypercortisolism and certain laboratory parameters, and the response to antihypertensive drugs. Fourteen dogs newly diagnosed with ADH were prospectively included and evaluated at diagnosis (T0) and 1, 3, 6, and 12 months after (T1, T3, T6, and T12, respectively). Dogs were classified as hypertensive (HT; SBP ≥ 160 mmHg) and non-hypertensive. In HT dogs, benazepril was considered as the first-line drug, and, if necessary, amlodipine was prescribed. The prevalence of SH at T0 was 79%, and it was reduced to 25% at T12. Blood pressure (BP) was not associated with disease control or selected laboratory parameters at any endpoint. Only 22% of dogs with SH needed more than one drug to normalize their SBP. In all dogs surgically treated that were HT at T0, BP normalized at T3.

The relationships between sediment findings and culture results and the presence of proteinuria in canine urine samples

OBJECTIVES

To assess relationships between urine sediment and microbial culture findings and the presence of proteinuria in canine urine samples, and to assess the change in the percentage of proteinuric samples and urine protein-to-creatinine ratio when urine abnormalities resolve.

MATERIALS AND METHODS

Canine urine samples collected via cystocentesis and submitted for culture and contemporaneous urinalysis (including urine protein-to-creatinine ratio) were retrospectively identified. Dogs receiving corticosteroids were excluded. Associations between haematuria (red blood cells>5/high-power field), pyuria (white blood cells>5/high-power field), presence of microorganisms on microscopy, active sediment, and positive culture and proteinuria (urine protein-to-creatinine ratio>0.5) were investigated. Patient characteristics were considered possible confounders. In dogs with repeat urinalysis, the associations between active sediment and positive culture resolution on proteinuria and urine protein-to-creatinine ratio were assessed.

RESULTS

One hundred and ninety-two of 491 samples were proteinuric (39.1%). Age was positively associated with proteinuria. In the multivariable analysis corrected for age, active sediment was the only variable significantly associated with proteinuria (adjusted odds ratio: 2.12; 95% confidence interval: 1.44 to 3.11); however, only 49.8% of samples with active sediment were proteinuric. Neither resolution of active sediment nor positive culture were associated with reduced proportions of proteinuric samples (from 57.9% to 42.1% and from 40.0% to 25.0%, respectively) or significant reductions in urine protein-to-creatinine ratio (median change: -0.16 and -0.14, respectively).

CLINICAL SIGNIFICANCE

Attributing proteinuria to urinalysis abnormalities or a positive urine culture in canine cystocentesis samples is not supported by our findings, and could result in alternative causes of proteinuria (e.g. renal proteinuria) being overlooked.

Re-evaluation of the low-dose dexamethasone suppression test in dogs

OBJECTIVES

This study aims to re-evaluate the low-dose dexamethasone suppression test 8-hour cortisol cut-point for the diagnosis of hypercortisolism in dogs using a solid-phase, competitive chemiluminescent enzyme immunoassay.

MATERIALS AND METHODS

Twenty-seven client-owned dogs with naturally occurring hypercortisolism and 30 healthy control dogs were prospectively recruited. Performance of the low-dose dexamethasone suppression test was assessed using sensitivity, specificity and a receiver operating characteristic curve compared to a clinical diagnosis of hypercortisolism including response to treatment.

RESULTS

Twenty-four dogs were diagnosed with pituitary-dependent hypercortisolism and three with adrenal-dependent hypercortisolism. In 30 healthy control dogs, 8-hour post-dexamethasone cortisol concentrations ranged from 5.5 to 39 nmol/L. A receiver operating characteristic curve curve constructed from the 8-hour post-dexamethasone cortisol concentrations of hypercortisolism and control dogs demonstrated that the most discriminatory cut-point was more than 39 nmol/L with sensitivity of 85.2% (95% confidence interval, 67.5% to 94.1%) and specificity of 100% (95% confidence interval, 88.7% to 100.0%) and an area under the curve of 0.963.

CLINICAL SIGNIFICANCE

The optimal cut-point of more than 36 nmol/L proposed by this study is similar to the currently accepted 8-hour cortisol concentration cut-point for diagnosing hypercortisolism when using a solid-phase, competitive chemiluminescent enzyme immunoassay.

Evaluation of 1,2-O-dilauryl-rac-glycero glutaric acid-(6'-methylresorufin) ester (DGGR) and 1,2-diglyceride lipase assays in dogs with naturally occurring hypercortisolism

1,2-O-dilauryl-rac-glycero glutaric acid-(6'-methylresorufin) ester (DGGR) lipase activity has been proposed as a faster and less expensive test used in the diagnosis of acute pancreatitis (AP) compared to canine pancreatic lipase immunoreactivity (cPLI), which is considered the most sensitive and specific serum test available for dogs. Elevations in lipase activity have been observed in dogs with naturally occurring hypercortisolism (HC) and in those treated with exogenous steroids, which complicates the diagnosis of AP in dogs with HC. We compared lipase activity measured by DGGR and 1,2-diglyceride (1,2-DiG) assays in 22 dogs with HC, 22 with AP, and 22 healthy dogs. The dogs with HC had no clinical signs or ultrasonographic findings consistent with AP. DGGR lipase activity was elevated in 64% and 73% of the dogs with HC and AP, respectively, and in 18% of healthy dogs. 1,2-DiG lipase activity was high in 23% and 36% of the dogs with HC and AP, respectively, and in 5% of the healthy dogs. Both DGGR and 1,2-DiG lipase activities were significantly different between the healthy dogs and the other 2 groups, whereas no differences were detected between the dogs with HC and those with AP. Our results support a lack of specificity for both DGGR and 1,2-DiG lipase activity assays in aiding the diagnosis of AP in dogs with HC.

Changes in systolic blood pressure in dogs with pituitary dependent hyperadrenocorticism during the first year of trilostane treatment

Background

Systemic hypertension (SH) is common in dogs and humans with hypercortisolism and can persist after treatment.

Objectives

To evaluate changes in prevalence of SH and systolic blood pressure (SBP) in dogs with pituitary‐dependent hyperadrenocorticism (PDH) during the first year of trilostane treatment, its relationship with disease control and selected laboratory variables, and their response to antihypertensive treatment.

Animals

Fifty‐one dogs with PDH treated with trilostane Q12h.

Methods

Prospective case series study. Dogs were evaluated at diagnosis (T0) and 1, 3, 6, and 12 months (T12). Dogs were classified as nonhypertensive (SBP < 160 mm Hg) or hypertensive (SBP≥160 mm Hg) and subclassified according to target organ damage (TOD) risk. Hypertensive dogs were treated with benazepril and, if control of SH was not achieved, amlodipine was added.

Results

Prevalence of SH decreased from T0 (36/51) to T12 (17/37; P = .01). Changes in SBP during the study were influenced by the risk of TOD at T0. In severely hypertensive (SBP ≥ 180 mm Hg) dogs, the decrease in SBP was more pronounced whereas in normotensive (SBP < 140 mm Hg) dogs SBP increased slightly (P = .00). Blood pressure was not associated with disease control. Antihypertensive treatment was needed in 31/51 dogs, and in 13/31 dogs additional SH control with amlodipine was required. One third of nonhypertensive dogs at T0 required treatment with benazepril because SH developed during follow‐up.

Conclusions and Clinical Importance

In dogs with PDH, SBP should be measured at every visit, regardless of disease control or SBP at diagnosis. More than 1 drug may be necessary to manage SH in affected dogs.

Prevalence and risk factors associated with systemic hypertension in dogs with spontaneous hyperadrenocorticism

Background

Systemic hypertension (SH) is common in dogs with hyperadrenocorticism (HAC) however there are not many studies assessing its prevalence and risk factors.

Objectives

To determine the prevalence and severity of SH in dogs with HAC and its association with clinical and laboratory findings to identify potential risk factors.

Animals

Sixty‐six client owned dogs with spontaneous HAC.

Methods

Retrospective cross‐sectional study. Medical records of dogs with HAC were reviewed. Systolic blood pressure (SBP) was measured using Doppler ultrasonography. Clinical signs, physical examination findings and clinicopathologic data (CBC, serum biochemistry and electrolytes, urinalysis and urinary culture, and adrenal function tests) were reviewed for analysis.

Results

Prevalence of SH (≥150 mm Hg) was 82% (54/66) and prevalence of severe SH (≥180 mm Hg) was 46% (30/66). All dogs with thrombocytosis had SH (P = .002), and a platelet count ≥438 × 10³/μL was 100% specific and 61.1% sensitive to predict SH (AUC = .802, P = .001). Median potassium levels were lower in hypertensive dogs (4.1 mEq/L, range 3.1‐5.4 mEq/L) than in normotensive ones (4.5 mEq/L, range 4.0‐5.0 mEq/L) (P = .007). Dogs with UPC ≥ 0.5 had higher median SBP than those without proteinuria (P = .03). Dogs with concurrent diabetes mellitus seemed to have a reduced risk of SH (OR = .118, 95%CI = .022‐.626, P = .02).

Conclusions and Clinical Importance

Systemic hypertension is common in dogs with HAC and is frequently severe. Blood pressure should be routinely assessed in these dogs, especially if thrombocytosis, proteinuria or low potassium concentrations are present.

Urinary proteome and metabolome in dogs (Canis lupus familiaris): The effect of chronic kidney disease

Chronic kidney disease (CKD) is a progressive and irreversible disease. Although urine is an ideal biological sample for proteomics and metabolomics studies, sensitive and specific biomarkers are currently lacking in dogs. This study characterised dog urine proteome and metabolome aiming to identify and possibly quantify putative biomarkers of CKD in dogs. Twenty-two healthy dogs and 28 dogs with spontaneous CKD were selected and urine samples were collected. Urinary proteome was separated by SDS-PAGE and analysed by mass spectrometry, while urinary metabolome was analysed in protein-depleted samples by 1D ¹H NMR spectra. The most abundant proteins in urine samples from healthy dogs were uromodulin, albumin and, in entire male dogs, arginine esterase. In urine samples from CKD dogs, the concentrations of uromodulin and albumin were significantly lower and higher, respectively, than in healthy dogs. In addition, these samples were characterised by a more complex protein pattern indicating mixed glomerular (protein bands ≥65 kDa) and tubular (protein bands <65 kDa) proteinuria. Urine spectra acquired by NMR allowed the identification of 86 metabolites in healthy dogs, belonging to 49 different pathways mainly involved in amino acid metabolism, purine and aminoacyl-tRNA biosynthesis or tricarboxylic acid cycle. Seventeen metabolites showed significantly different concentrations when comparing healthy and CKD dogs. In particular, carnosine, trigonelline, and cis-aconitate, might be suggested as putative biomarkers of CKD in dogs. SIGNIFICANCE: Urine is an ideal biological sample, however few proteomics and metabolomics studies investigated this fluid in dogs and in the context of CKD (chronic kidney disease). In this research, applying a multi-omics approach, new insights were gained regarding the molecular changes triggered by this disease in canine urinary proteome and metabolome. In particular, the involvement of the tubular component was highlighted, suggesting uromodulin, trigonelline and carnosine as possible biomarkers of CKD in dogs.

Urine cortisol-creatinine and protein-creatinine ratios in urine samples from healthy dogs collected at home and in hospital

Background

Recently, urine protein:creatinine ratios (UPC) were shown to be lower in urine samples from dogs collected at home (AH) as compared to those collected in hospital (IH). Stress‐inducing procedures and travel to the hospital have been hypothesized to cause prerenal proteinuria.

Objectives

Evaluate patient stress using urine cortisol:creatinine ratios (UCCr) and correlate UCCr to UPC in urine samples obtained AH and IH.

Animals

Thirty‐six healthy, client‐owned dogs.

Methods

Prospective, non‐masked study. Two voided urine samples were obtained (AH and IH). Complete urinalysis as well as UPC and UCCr were performed. Clients graded their dogs' stress level AH, in transport, and IH.

Results

The UCCr was significantly higher in IH samples than in AH samples (P < .0001), but UPC was not significantly different between AH and IH urine samples (P = .14). In all samples and in both collection settings, UCCr was not significantly correlated with UPC. Travel time and time IH were not correlated with change in UCCr or UPC. In 8 dogs with borderline or overt proteinuria, no significant difference was found in UPC between settings, but UCCr was significantly higher in IH samples.

Conclusions and Clinical Importance

The UPC was not higher when measured in urine samples collected IH compared to AH. Dogs had higher UCCr IH, but UCCr was not associated with UPC. Stress, as estimated by UCCr, did not affect proteinuria. Further evidence is needed to support the claim that stress may result in proteinuria in healthy dogs.

ACVIM consensus statement: Guidelines for the identification, evaluation, and management of systemic hypertension in dogs and cats

An update to the 2007 American College of Veterinary Internal Medicine (ACVIM) consensus statement on the identification, evaluation, and management of systemic hypertension in dogs and cats was presented at the 2017 ACVIM Forum in National Harbor, MD. The updated consensus statement is presented here. The consensus statement aims to provide guidance on appropriate diagnosis and treatment of hypertension in dogs and cats.

Evaluation of individual low-dose dexamethasone suppression test patterns in naturally occurring hyperadrenocorticism in dogs

BACKGROUND

Dogs with hyperadrenocorticism (HAC) may be more mildly affected at the time of diagnosis today, which could influence the prevalence of associated clinical and clinicopathological abnormalities and diagnostic test performance. Different low-dose dexamethasone suppression test (LDDST) result patterns have not been evaluated individually.

OBJECTIVES

To assess the current features of HAC and evaluate if the diagnostic test performance of individual LDDST result patterns differ.

ANIMALS

One hundred and twenty-three dogs undergoing investigation for HAC.

METHODS

Retrospective evaluation of dogs in which a LDDST was performed and HAC confirmed or excluded by alternative means. Cases with basal cortisol concentrations (t0 ) < 1 μg/dL were excluded. Each LDDST result was classified as (a) complete suppression (t3 and t8  < 1 μg/dL), (b) lack of suppression (t3 and t8  > 1 μg/dL and both > 50% t0 ), (c) partial suppression (t3 and t8  > 1 μg/dL but either < 50% t0 ), (d) escape (t8  > 1 μg/dL and t3  < 1 μg/dL) or (e) inverse (t3  > 1 μg/dL and t8  < 1 μg/dL) pattern.

RESULTS

Fifty-nine (48%) dogs were diagnosed with HAC and 64 (52%) with non-adrenal illness. Hyperadrenocorticism cases had similar clinicopathological abnormalities compared to previous reports. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) (95% confidence interval [CI]) of the LDDST for diagnosing HAC were 96.6 (91.9-100)%, 67.2 (55.7-78.7)%, 73.1 (63.2-82.9)%, and 95.6 (89.5-100)%, respectively. Lack of suppression pattern had the highest PPV (93.9 [85.8-100]%) followed by the partial suppression pattern (67.9 [50.6-85.2]%) and escape or inverse pattern (36.8 [15.1-58.5]%).

CONCLUSIONS AND CLINICAL IMPORTANCE

A lack of suppression LDDST pattern has the highest PPV for diagnosing HAC followed by a partial suppression pattern. By contrast, the escape or inverse pattern provided limited support of HAC.

Decrease of nitric oxide and increase in diastolic blood pressure are two events that affect renal function in dogs with pituitary dependent hyperadrenocorticism

Hyperadrenocorticism is a frequent disease in dogs. The excess of circulating cortisol affects different organs and metabolic pathways, producing severe adverse effects that endanger the animal’s life. Among these effects, hypertension and renal damage can be mentioned. A group of 20 dogs with pituitary dependent hyperadrenocorticism (PDH) and 12 control dogs were used to study the following parameters: cortisol and nitric oxide (NO nit/nit) concentrations, diastolic and systolic blood pressure, renal artery resistance index by Doppler ultrasound, the rate of glomerular filtration by radio-renogram excretion and the presence of proteins in urine. Dogs with PDH showed a significantly lower NO nit/nit (P<0.0001) than the controls and this correlated with high values of diastolic and systolic pressure (r = -0.87; P<0.0001 and r = -0.81; P<0.0001 respectively). Most dogs (80%) are hypertensive mainly due to an increase in diastolic pressure, which correlated positively with the UPC (r = 0.8; P<0.001) and negatively with the glomerular rate of filtration (r = -0.58; P=0.007). Systolic pressure only increased in 60% of the cases and did not correlate with the mentioned variables. In PDH the decrease of NO affects blood pressure. The diastolic pressure would seem to have the greatest impact on the kidneys, therefore its evaluation and control are important to avoid and/or control renal damage.

Urine protein electrophoresis study in dogs with pituitary dependent hyperadrenocorticism during therapy with trilostane

ABSTRACT: Hyperadrenocorticism is one of the most common endocrine disorders in dogs. Regarding to the kidneys, chronic hypercortisolemia can cause damage to the glomerulus, and evolve into chronic kidney disease. This study evaluated nine normotensive dogs with pituitary dependent hyperadrenocorticism, before and after therapy with trilostane, during the follow-up period of six months, in order to investigate the development of pathological proteinuria by quantitative (urinary protein-to-creatinine ratio) and qualitative (urinary protein electrophoresis) methods, and also to monitor its intensity over the course of the disease and therapy. The main renal lesion detected in dogs with hyperadrenocorticism was in the tubular segment, evidenced by the prevalence of urinary protein bands of lower molecular weight, indicating the lack absorption of these proteins in the proximal segment of the nephron. Low molecular weight proteins persisted throughout the follow-up. Regarding the future of routine veterinary medical clinic in the care of patients with hyperadrenocorticism, the assessments of proteinuria determinations by the urinary protein-to-creatinin ratio and urinary protein electrophoresis, according to the results obtained in this study, can add more information about the renal damage in these animals, and contribute to the prognosis.

Comparison of Survival Times for Dogs with Pituitary-Dependent Hyperadrenocorticism in a Primary-Care Hospital: Treated with Trilostane versus Untreated

Background

Although pituitary‐dependent hyperadrenocorticism (PDH) is one of the most common endocrinopathies in dogs, the effects of withholding treatment on survival time in dogs with PDH remain unclear.

Hypothesis/Objectives

The purpose of this study was to clarify the effects of treatment in dogs with PDH by comparing survival times between dogs treated with trilostane and untreated dogs.

Animals

Forty‐three dogs diagnosed with PDH at a primary‐care hospital in Japan between June 2009 and January 2014.

Methods

Retrospective cohort study. The medical records of dogs with PDH treated with trilostane (n = 17) or left untreated (n = 26) were reviewed retrospectively. Survival analysis at 2 years after diagnosis of PDH was performed.

Results

Median survival time for the trilostane group was not reached (95% confidence interval [CI], 443 days–not applicable) and was significantly longer than the 506 days (95% CI, 292–564 days; P = .016) for the untreated group. Multivariate Cox proportional hazards analysis (including age at diagnosis, basal cortisol concentration at diagnosis, and treatment group) only identified assignment to the untreated group (hazard ratio, 5.01; 95% CI, 1.63–15.44) as associated with increased mortality.

Conclusions and Clinical Importance

The results of this retrospective cohort study suggest that withholding treatment for dogs with PDH might be associated with a higher risk of death. This represents the largest study to date to report survival times of untreated dogs with PDH.

Validation of an electrophoretic method to detect albuminuria in cats

Objectives The aims of this study were to validate a semi-automated high-resolution electrophoretic technique to quantify urinary albumin in healthy and diseased cats, and to evaluate its diagnostic performance in cases of proteinuria and renal diseases. Methods Urine samples were collected from 88 cats (healthy; chronic kidney disease [CKD]; lower urinary tract disease [LUTD]; non-urinary tract diseases [OTHER]). Urine samples were routinely analysed and high-resolution electrophoresis (HRE) was performed. Within-assay and between-assay variability, linearity, accuracy, recovery and the lowest detectable and quantifiable bands were calculated. Receiver operating curve (ROC) analysis was also performed. Results All coefficients of variation were <10%, percentage recovery was between 97% and 109% with a high linearity (r = 0.99). HRE allowed the visualisation of a faint band of albumin and a diffused band between alpha and beta zones in healthy cats, while profiles from diseased cats were variable. Albumin (mg/dl) and urine albumin:creatinine ratio (UAC) were significantly ( P <0.05) different between healthy and diseased cats. After ROC analysis, UAC values of 0.035 and 0.074 had a high sensitivity and high specificity, respectively, to classify proteinuria and identify borderline proteinuric cats. Moreover, a UAC of 0.017 had a high sensitivity in distinguishing between healthy and diseased cats. However, UAC was not able to distinguish between renal (CKD) and non-renal diseases (LUTD/OTHER), probably owing to the pathophysiology of CKD in cats, which is characterised by low-grade proteinuria and less glomerular involvement than in dogs. Conclusions and relevance HRE is an accurate and precise method that could be used to measure albuminuria in cats. UAC was useful to correctly classify proteinuria and to discriminate between healthy and diseased cats. HRE might also provide additional information on urine proteins with a profile of all proteins (albumin and globulins) to aid clinicians in the diagnosis of diseases characterised by proteinuria.

Prognostic factors for survival in dogs with pituitary-dependent hypercortisolism treated with trilostane

Pituitary-dependent hypercortisolism (PDH) is one of the most frequent endocrinopathies in dogs, but prognostic factors are largely unknown. The aim of this retrospective case series study was to determine the prognostic value of different clinical and clinicopathological variables evaluated in dogs newly diagnosed with PDH that were subsequently treated with trilostane. Medical records from one referral centre were evaluated. Eighty-five dogs with PDH were included. The median survival time was 852 days (range 2-3210 days); 60/85 (70 per cent) and 25/85 (29 per cent) dogs survived more than one and three years, respectively. In multivariable model analysis the length of survival of older dogs (HR 1.24, 95% CI 1.09 to 1.40) and dogs with higher serum phosphate concentrations (HR 1.35, 95% CI 1.01 to 1.81) was shorter. Serum phosphate concentrations were above the reference range in 37/85 (44 per cent) of animals. Clinical signs, liver enzymes, serum cortisol concentrations of the endocrine tests, proteinuria, systolic hypertension, the presence of concomitant disorders, and the frequency of trilostane administration were not associated with survival time. Hyperphosphataemia is a common finding in dogs with newly diagnosed PDH and represents a negative prognostic factor.

Canine pancreatic-specific lipase concentrations in clinically healthy dogs and dogs with naturally occurring hyperadrenocorticism

Background

Specificity of canine pancreatic lipase immunoreactivity (cPLI) assays in dogs with hyperadrenocorticism (HAC) is unknown.

Hypothesis

Results of cPLI assays differ for clinically healthy dogs and dogs with HAC.

Animals

Seventeen healthy dogs and 20 dogs with HAC diagnosed by ACTH stimulation test results without evidence of clinical pancreatitis.

Methods

Dogs were enrolled between December 2009 and November 2010. Serum cPLI concentrations were determined by quantitative (Spec cPL test, SPEC) and semiquantitative (SNAP cPL test, SNAP) assays. Results were categorized as normal, equivocal, or abnormal (SPEC) or negative or positive (SNAP). Associations between group and cPLI were assessed using Fisher's exact test or the Mann–Whitney U‐test. Spearman rank correlation coefficients (ρ) were determined for SNAP and SPEC results. Significance was set at P < .05.

Results

Spec cPL test concentrations were significantly (P < .001) higher in dogs with HAC (491.1 μg/L) than in healthy dogs (75.2 μg/L), with more abnormal SPEC results in HAC dogs (P < .001). There were more (P = .002) positive SNAP results in dogs with HAC (55%) than in healthy dogs (6%). SNAP and SPEC results were highly correlated (ρ = 0.85; P < .001).

Conclusions and Clinical Importance

Dogs with HAC had higher SPEC concentrations and more positive SNAP results than clinically healthy dogs with normal ACTH stimulation test results. Specificity of SPEC and SNAP assays in HAC dogs without clinical pancreatitis were 65 and 45%, respectively. Pending further study, SNAP and SPEC results should be interpreted cautiously in dogs with HAC to avoid false diagnosis of concurrent pancreatitis.

Trilostane therapy for treatment of spontaneous hyperadrenocorticism in cats: 15 cases (2004-2012)

BACKGROUND

Medical treatment with trilostane improves clinical signs, causes unclear insulin requirement changes, and variable survival times in cats.

OBJECTIVES/HYPOTHESIS

To characterize the long-term efficacy of trilostane in treating cats with hyperadrenocorticism (HAC).

ANIMALS

Fifteen client-owned cats with spontaneous HAC.

METHODS

Multicenter descriptive retrospective study with a search performed on all medical records for cats diagnosed with spontaneous HAC.

RESULTS

Clinical signs (13 of 15 cats) and ACTH stimulation testing results (13 of 15) improved with trilostane therapy. Diabetes mellitus was reported in 9/15 cases. Insulin requirements decreased by 36% within 2 months in 6/9 diabetic cats. Median survival time was 617 days for all cats (range 80-1,278 days). Complications included weight loss, urinary tract infections, chronic kidney disease, seizures, and recurrent pancreatitis. Hypocortisolemia was documented in 1 case. Cause of death occurred as a result of nonadrenal or nondiabetic illnesses (renal failure, seizures [caused by hypoglycemia or unknown]), or lymphoma.

CONCLUSIONS AND CLINICAL IMPORTANCE

Trilostane ameliorates clinical signs of HAC in cats, is tolerated well in the long term, and can lead to improved regulation of diabetes.

Urinary biomarkers for acute kidney injury in dogs

Routinely, kidney dysfunction and decreased glomerular filtration rate (GFR) are diagnosed by the evaluation of changes in the serum creatinine (SCr) and blood urea nitrogen (BUN) concentrations. However, neither of these tests is sensitive or specific enough for the early diagnosis of impaired kidney function because they are both affected by other renal and nonrenal factors. Furthermore, kidney injury can be present in the absence of kidney dysfunction. Renal reserve enables normal GFR even when nephrons are damaged. Renal biomarkers, especially those present in urine, may be useful for the study of both acute and chronic nephropathies. The aim of this review is to describe the current status of urinary biomarkers as diagnostic tools for kidney injury in dogs with particular focus on acute kidney injury (AKI). The International Renal Interest Society (IRIS) canine AKI grading system and the implementation of urinary biomarkers in this system also are discussed. The discovery of novel urinary biomarkers has emerged from hypotheses about the pathophysiology of kidney injury, but few proteomic urine screening approaches have been described in dogs. Lack of standardization of biomarker assays further complicates the comparison of novel canine urinary biomarker validation results among studies. Future research should focus on novel biomarkers of renal origin and evaluate promising biomarkers in different clinical conditions. Validation of selected urinary biomarkers in the diagnosis of canine kidney diseases must include dogs with both renal and nonrenal diseases to evaluate their sensitivity, specificity as well as their negative and positive predictive values.

Clinical approach to advanced renal function testing in dogs and cats

Serum creatinine concentration is insensitive for detecting kidney injury and does not assist in differentiation between glomerular versus tubular damage. Advanced renal function tests, including glomerular filtration rate testing, determining fractional excretion of electrolytes, and assay of urine biomarkers, may allow earlier detection of reduced renal function mass, differentiation of renal from non-renal causes of azotemia, and assist with localization of damage. This article reviews the principles, indications, and limitations of these tests and describes their use in sample clinical scenarios.