Clinical features of muscle stiffness in 37 dogs with concurrent naturally occurring hypercortisolism.

BACKGROUND: Severe muscle stiffness (SMS) in dogs with hypercortisolism (HC) is uncommon. OBJECTIVES: To evaluate signalment, presentation, treatments, and long-term outcomes of dogs with concurrent HC and SMS. ANIMALS: Thirty-seven dogs. METHODS: Medical records of dogs with HC and concurrent SMS were recruited from 10 institutions. Clinical information, test results, therapeutic responses, and survival times were reviewed. RESULTS: All 37 dogs with HC and SMS had pituitary-dependent hypercortisolism (PDH); 36/37 weighed <20 kg. Signs and test results were typical of PDH aside from SMS, initially diagnosed in all 4 limbs in 9, pelvic limbs of 22, and thoracic limbs of 6 dogs. Hypercortisolism and SMS were diagnosed together in 3 dogs; HC 1-36 months before SMS in 23; SMS 1-12 months before HC in 11. Mitotane or trilostane, given to control HC in 36/37 dogs, improved or resolved HC signs in 28; SMS did not resolve, remaining static or worsening in 31/36 dogs, mildly improving in 5/19 dogs given additional therapies. Progression of SMS included additional limbs in 10 dogs and the masticatory muscles of 2. The median survival time from diagnosis of SMS was 965 days (range, 8-1188). CONCLUSIONS AND CLINICAL IMPORTANCE: Concurrent SMS and HC is uncommon, possibly affecting only dogs with PDH. Development of SMS might occur before or after diagnosis of HC. Apart from SMS, the clinical picture and survival time of these dogs seem indistinguishable from those of dogs with HC in general. However, while muscle weakness usually resolves with HC treatment SMS does not.

Whole transcriptome analysis of canine pheochromocytoma and paraganglioma.

Pheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors arising from the chromaffin cells in the adrenal medulla and extra-adrenal paraganglia, respectively. Local invasion, concurrent disorders, and metastases prevent surgical removal, which is the most effective treatment to date. Given the current lack of effective medical treatment, there is a need for novel therapeutic strategies. To identify druggable pathways driving PPGL development, we performed RNA sequencing on PPGLs (n = 19) and normal adrenal medullas (NAMs; n = 10) of dogs. Principal component analysis (PCA) revealed that PPGLs clearly clustered apart from NAMs. In total, 4,218 genes were differentially expressed between PPGLs and NAMs. Of these, 232 had a log2 fold change of >3 or < -3, of which 149 were upregulated in PPGLs, and 83 were downregulated. Compared with NAMs, PPGLs had increased expression of genes related to the cell cycle, tumor development, progression and metastasis, hypoxia and angiogenesis, and the Wnt signaling pathway, and decreased expression of genes related to adrenal steroidogenesis. Our data revealed several overexpressed genes that could provide targets for novel therapeutics, such as Ret Proto-Oncogene (RET), Dopamine Receptor D2 (DRD2), and Secreted Frizzled Related Protein 2 (SFRP2). Based on the PCA, PPGLs were classified into 2 groups, of which group 1 had significantly higher Ki67 scores (p = 0.035) and shorter survival times (p = 0.04) than group 2. Increased expression of 1 of the differentially expressed genes between group 1 and 2, pleiotrophin (PTN), appeared to correlate with a more aggressive tumor phenotype. This study has shed light on the transcriptomic profile of canine PPGL, yielding new insights into the pathogenesis of these tumors in dogs, and revealed potential novel targets for therapy. In addition, we identified 2 transcriptionally distinct groups of PPGLs that had significantly different survival times.

Evaluation of Weight Gain, Clinicopathological and Radiographic Changes after Early Diagnosis and Treatment of Congenital Hypothyroidism in Cats.

Congenital hypothyroidism is uncommon in cats. This case report describes weight gain, clinicopathological and radiographic changes after early diagnosis and treatment of congenital hypothyroidism in three British shorthair cats' siblings. Data were assessed at 53 (diagnosis), 83, 185 and 365 days of age. Correlations between serum insulin-like growth factor-1 (IGF-1) and body weight, levothyroxine dose, total thyroxine, and thyroid-stimulating hormone concentrations were evaluated. The body weights of the congenital hypothyroid kittens were compared with those of their two healthy siblings and British shorthair kittens of the same age. At diagnosis, the congenital hypothyroid kittens showed a significantly lower body weight compared to the healthy siblings (p = 0.03). After diagnosis, oral levothyroxine supplementation was started. The difference in body weight was no longer observed after one month of treatment. The clinical signs, clinicopathological and radiographic abnormalities ameliorated after one month of treatment. IGF-1 concentration was significantly positively correlated with body weight (rs = 0.80, p < 0.002). In conclusion, resolution of the clinical signs, achieving a consistent within-breed weight, and improvement of the clinicopathological and radiographic parameters demonstrated the importance of the early diagnosis and treatment of feline congenital hypothyroidism.

Fecal microbiota and inflammatory and antioxidant status of obese and lean dogs, and the effect of caloric restriction.

Introduction: Obesity is the most common nutritional disease in dogs, and is generally managed by caloric restriction. Gut microbiota alteration could represent a predisposing factor for obesity development, which has been associated with a low-grade inflammatory condition and an impaired antioxidant status. Besides, weight loss has been shown to influence the gut microbiota composition and reduce the inflammatory response and oxidative stress. Method: However, these insights in canine obesity have not been fully elucidated. The aim of this study was to assess the differences in serum and inflammatory parameters, antioxidant status, fecal microbiota and bacterial metabolites in 16 obese and 15 lean client-owned dogs and how these parameters in obese may be influenced by caloric restriction. First, for 30 days, all dogs received a high-protein, high-fiber diet in amounts to maintain their body weight; later, obese dogs were fed for 180 days the same diet in restricted amounts to promote weight loss. Results: Before the introduction of the experimental diet (T0), small differences in fecal microbial populations were detected between obese and lean dogs, but bacterial diversity and main bacterial metabolites did not differ. The fecal Dysbiosis Index (DI) was within the reference range (< 0) in most of dogs of both groups. Compared to lean dogs, obese dogs showed higher serum concentrations of acute-phase proteins, total thyroxine (TT4), and antioxidant capacity. Compared to T0, dietary treatment affected the fecal microbiota of obese dogs, decreasing the abundance of Firmicutes and increasing Bacteroides spp. However, these changes did not significantly affect the DI. The caloric restriction failed to exert significative changes on a large scale on bacterial populations. Consequently, the DI, bacterial diversity indices and metabolites were unaffected in obese dogs. Caloric restriction was not associated with a reduction of inflammatory markers or an improvement of the antioxidant status, while an increase of TT4 has been observed. Discussion: In summary, the present results underline that canine obesity is associated with chronic inflammation. This study highlights that changes on fecal microbiota of obese dogs induced by the characteristics of the diet should be differentiated from those that are the consequence of the reduced energy intake.

The accuracy and precision of insulin administration using human and veterinary pen-injectors and syringes for administration of insulin.

BACKGROUND: Many diabetic dogs and cats require small doses of insulin that must be administered accurately. OBJECTIVES: To compare the accuracy and precision of insulin syringes and pen-injectors. ANIMALS: None. METHODS: To determine how accurately and precisely insulin doses are delivered, 0.5, 1, 2, 4, 8, and 16 U doses were dispensed 25 times from 5 SoloSTARs, 5 FlexPens, 5 KwikPens, 5 JuniorSTARs, 5 VetPens 0.5-8 U, 5 VetPens 1-16 U, and by 5 veterinarians using 30 U/0.3 mL and 40 U/mL insulin syringes. Each dose was weighed, using a precision balance, and the intended and delivered doses were compared. RESULTS: All pen-injectors delivered less insulin than the intended dose, underdosage being inversely proportional to insulin dose. The differences between the intended and the delivered dose were not significant using JuniorSTAR and VetPen 0.5-8 U at insulin doses of 0.5, 1, 2, and 4 U, using the 30 U/0.3 mL insulin syringe at the 4 U dose and using the 40 U/mL insulin syringe at the 4, 8, and 16 U doses. With all the devices, precision increased with increasing doses of insulin. The coefficient of variation was <8% for all 6 pen-injectors. Conversely, using 30 U/0.3 mL and 40 U/mL syringes at an insulin dosage of 0.5 U the coefficients of variation were 12.08% and 9.39%, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: JuniorSTAR and VetPen 0.5-8 U were more accurate than the other devices when delivering ≤2 U doses, while the delivery of 8 and 16 U doses was more accurate using 40 U/mL syringes.

Calcium and phosphate homeostasis in dogs with newly diagnosed naturally occurring hypercortisolism.

BACKGROUND: Hypercortisolism affects calcium and phosphate metabolism in dogs; however, the exact mechanisms are not completely understood. OBJECTIVES: To evaluate circulating concentrations of whole parathormone (wPTH), 25-hydroxyvitamin D (25-(OH)D), calcitriol, and fibroblast growth factor-23 (FGF-23) in dogs with naturally occurring hypercortisolism (NOHC) and healthy dogs, and their association with calcium and phosphate homeostasis. ANIMALS: Twenty-three client-owned dogs with NOHC, and 12 client or staff-owned healthy dogs. METHODS: Prospective cross-sectional study. The circulating concentrations of total calcium, ionized calcium (iCa), phosphate, wPTH, 25-(OH)D, calcitriol and FGF-23, and the urinary fractional excretion of phosphate (FEP) and calcium (FECa) were compared between dogs with NOHC before treatment and healthy dogs. RESULTS: Dogs with NOHC had higher mean serum phosphate concentrations (4.81 mg/dL, SD ± 0.71 vs 3.86 mg/dL, SD ± 0.60; P < .001), median FECa (0.43%, range, 0.03-2.44 vs 0.15%, range, 0.06-0.35; P = .005), and median serum wPTH concentrations (54.6 pg/mL, range, 23.7-490 vs 24.6 pg/mL, range, 5.5-56.4; P = .003) as compared to the controls. Circulating concentrations of total calcium, iCa, and calcitriol and the FEP did not differ between groups, whereas the serum 25-(OH)D concentrations were lower in dogs with NOHC as compared to the controls (70.2 pg/mL, SD ± 42.3 vs 106.3 pg/mL, SD ± 35.3; P = .02). The dogs with NOHC had lower plasma FGF-23 concentrations than controls (316.6 pg/mL, range, 120.8-575.6 vs 448.7 pg/mL, range, 244.8-753; P = .03). CONCLUSIONS AND CLINICAL IMPORTANCE: Urine loss of calcium and hyperphosphatemia could contribute to the adrenal secondary hyperparathyroidism.

Feline plasma adrenocorticotropic hormone: validation of a chemiluminescent assay and concentrations in cats with hypercortisolism, primary hypoadrenocorticism and other diseases.

OBJECTIVES: The aims of this study were to validate a commercially available chemiluminescent assay for measurement of feline plasma adrenocorticotropic hormone concentration (ACTH), to determine the normal reference interval (RI) of plasma ACTH in healthy cats, to assess plasma ACTH in cats with naturally occurring hypercortisolism (HC), primary hypoadrenocorticism (PH) and other diseases (OD), and to evaluate the effect of aprotinin on plasma ACTH degradation. METHODS: Forty healthy cats, 10 with HC, 11 with PH and 30 with OD, were included. The chemiluminescent enzyme immunometric assay was evaluated by measurement of intra-assay precision, interassay precision and linearity. The RI for plasma ACTH in healthy cats was established using robust methods. Plasma ACTH of samples collected with and without aprotinin, stored at 4°C and assayed over a 6-day period, was measured. RESULTS: The intra-assay coefficients of variance (CVs) ranged from 2.7% to 4.3% and interassay CVs from 3.3% to 10.7%. Dilution studies showed excellent accuracy (R2 >0.99). The RI for plasma ACTH in healthy cats was 32-370 pg/ml. Plasma ACTH was not significantly different between healthy cats and the OD group. Cats with pituitary-dependent hypercortisolism (PDH) and PH had significantly higher plasma ACTH than the other groups. Plasma ACTH did not show significant differences when samples collected with and without aprotinin were compared. CONCLUSIONS AND RELEVANCE: The Immulite chemiluminescent assay is a valid technique for measuring plasma ACTH in cats and the RI of plasma ACTH is quite wide. Owing to the low overlap between healthy or OD cats and cats with HC or PH, the measurement of plasma ACTH appears to be useful and should be included in the diagnostic work-up when HC or PH are suspected. Furthermore, the measurement of plasma ACTH may be an accurate test for differentiating PDH from adrenal-dependent hypercortisolism.

Comparison of methods to monitor dogs with hypercortisolism treated with trilostane.

BACKGROUND: The use of adrenocorticotropic hormone stimulation test as method to monitor efficacy of trilostane treatment of hypercortisolism (HC) in dogs has been questioned. OBJECTIVES: To evaluate and compare 12 methods with which to monitor efficacy of trilostane treatment in dogs with HC. ANIMALS: Forty-five client-owned dogs with HC treated with trilostane q12h. METHODS: Prospective cross-sectional observational study. The dogs were categorized as well-controlled, undercontrolled, and unwell through a clinical score obtained from an owner questionnaire. The ability to correctly identify trilostane-treatment control of dogs with HC with the following variables was evaluated: before trilostane serum cortisol (prepill), before-ACTH serum cortisol, post-ACTH serum cortisol, plasma endogenous ACTH concentrations, prepill/eACTH ratio, serum haptoglobin (Hp) concentration, serum alanine aminotransferase (ALT), gamma-glutamyl transferase (γGT) and alkaline phosphatase activity, urine specific gravity, and urinary cortisol : creatinine ratio. RESULTS: Ninety-four re-evaluations of 44 dogs were included; 5 re-evaluations of 5 unwell dogs were excluded. Haptoglobin was significantly associated with the clinical score (P < .001) and in the receiver operating characteristic analysis, Hp cutoff of 151 mg/dL correctly identified 90.0% of well-controlled dogs (specificity) and 65.6% of undercontrolled dogs (sensitivity). Alanine aminotransferase (P = .01) and γGT (P = .009) were significantly higher in undercontrolled dogs. Cutoff of ALT and γGT greater than or equal to 86 U/L and 5.8 U/L, respectively, were significantly associated with poor control of HC by trilostane. CONCLUSIONS AND CLINICAL IMPORTANCE: Of all the 12 variables, Hp, and to a lesser degree ALT and γGT, could be considered additional tools to the clinical picture to identify well-controlled and undercontrolled trilostane-treated dogs.

Comparison between a flash glucose monitoring system and a portable blood glucose meter for monitoring dogs with diabetes mellitus.

BACKGROUND: Flash glucose monitoring system (FGMS; FreeStyle Libre) was recently validated for use in diabetic dogs (DD). It is not known if this system is clinically useful in monitoring DD. OBJECTIVE: To compare the clinical utility of FGMS against blood glucose curves (BGCs) obtained with a portable blood glucose meter (PBGM) in monitoring DD. ANIMALS: Twenty dogs with diabetes mellitus. METHODS: Prospective study. Dogs with diabetes mellitus on insulin treatment for at least 1 month were included. Comparisons of insulin dose recommendations based on the in-hospital GCs acquired using FGMS and a PBGM, consecutive-day interstitial GCs (IGCs) acquired at home using the FGMS, and consecutive-day, home vs hospital IGCs acquired using the FGMS were made using concordance analysis. RESULTS: There was good concordance between insulin dose recommendations based on FGMS and PBGM generated GCs and IGCs obtained in the 2 different environments on 2 consecutive days, but almost absent concordance between IGCs obtained on 2 consecutive days at home. Glucose nadirs were detected in 34/43 (79%) of Ambulatory Glucose Profile (AGP) reports of the FGMS. In comparison, concordant glucose nadirs were identified in 14/34 (41%) BGCs using PBGM. The individual FGMS scans and PBGM identified 60% and 9% of low IG/hypoglycemic episodes, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: Insulin dose adjustments based on BGCs can be suboptimal. The FGMS allows a more accurate identification of the glucose nadirs and hypoglycemic episodes compared to the use of a PBGM and assessment of day-to-day variations in glycemic control.

Accuracy of a flash glucose monitoring system in dogs with diabetic ketoacidosis.

BACKGROUND: A factory-calibrated flash glucose monitoring system (FGMS; FreeStyle Libre) recently was evaluated in dogs with uncomplicated diabetes mellitus. It is not known if this system is reliable during diabetic ketoacidosis (DKA). OBJECTIVES: To assess the performance of the FGMS in dogs with DKA and to determine the effect of severity of ketosis and acidosis, lactate concentration, body condition score (BCS), and time wearing the sensor on the accuracy of the device. ANIMALS: Fourteen client-owned dogs with DKA. METHODS: The interstitial glucose (IG) measurements were compared with blood glucose (BG) measurements obtained using a validated portable glucometer. The influence of changes in metabolic variables (ß-hydroxybutyrate, pH, bicarbonate, and lactate) and the effect of BCS and time wearing on sensor performance were evaluated. Accuracy was determined by fulfillment of ISO15197:2013 criteria. RESULTS: Metabolic variables, BCS, and time wearing were not associated with the accuracy of the sensor. Good agreement between IG measurements and BG was obtained both before and after DKA resolution (r = .88 and r = .93, respectively). Analytical accuracy was not achieved, whereas clinical accuracy was demonstrated with 100% and 99.6% of results in zones A + B of the Parkes consensus error grid analysis before and after DKA resolution, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: Changes in metabolic variables, BCS, and time wearing do not seem to affect agreement between IG and BG. Despite not fulfilling the ISO requirements, the FGMS provides clinically accurate estimates of BG in dogs with DKA.

Comparison of serum fructosamine and glycated hemoglobin values for assessment of glycemic control in dogs with diabetes mellitus.

OBJECTIVE: To evaluate the performance of 2 assays for measurement of serum fructosamine (SF) and glycated hemoglobin (HbA1c) values in dogs and to compare the usefulness of the 2 glycated proteins for assessment of glycemic control in dogs with diabetes mellitus (DM). SAMPLE: Blood samples from 40 healthy dogs, 13 diabetic dogs, and 23 anemic normoglycemic nondiabetic dogs and results of 200 assessments of glycemic control in 46 diabetic dogs. PROCEDURES: Colorimetric and immunoturbidimetric methods were used for measurement of SF and HbA1c values, respectively. Linearity and precision were determined. The usefulness of SF and HbA1c values for assessment of glycemic control was evaluated with a clinical scoring method used as the reference standard. Cutoff values obtained from receiver operating characteristic curves were used to identify the percentage of dogs correctly categorized by means of SF and HbA1c values. RESULTS: Mean intra-assay and interassay coefficients of variation were 3.8% and 2.5%, respectively, for the SF assay, and 1.2% and 1.8%, respectively, for the HbA1c assay. Excellent linearity (R2 > 0.99) was obtained for both assays. Values for SF and HbA1c were inversely correlated (r = -0.40 and -0.33, respectively) with clinical score and correctly indicated glycemic control in 99 of 200 (50%) and 88 of 200 (44%) assessments, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: The SF and HbA1c assays were precise, had good linearity, and appeared to be suitable for routine use in veterinary medicine. However, they performed poorly for classifying glycemic control in diabetic dogs.