Association between diabetes mellitus, hypothyroidism or hyperadrenocorticism, and atherosclerosis in dogs

Effects of Dietary Intake of Marine Ingredients on the Circulating Total Cholesterol Concentration in Domestic Dogs: A Systematic Review and Meta-Analysis

A high circulating total cholesterol (TC) concentration increases the risk for atherosclerosis in the domestic dog. Intake of marine foods is associated with a lowering effect on circulating TC concentration in humans and rodents, but the reported effects of marine ingredients on the TC concentration in domestic dogs has not yet been reviewed. The main aim was to investigate the effects of consuming marine ingredients on the TC concentration in domestic dogs. A systematic literature search was performed using the databases PubMed, Web of Science and Embase, structured around the population (domestic dogs), intervention (source and type of marine ingredients, dose, duration), comparator (control diet) and the primary outcome (circulating TC). Articles were assessed for risk of bias using the SYRCLE's tool. A meta-analysis was conducted in Review Manager v. 5.4.1 (the Cochrane Collaboration), comprising 12 articles with 243 dogs. Consumption of marine oils resulted in a significantly lower circulating TC concentration relative to comparator groups (mean difference -0.70 mmol/L, 95% CI (-1.21, -0.18), p = 0.008), with high statistical heterogeneity (I2 = 78%). The risk of bias is unclear since few of the entries in the SYRCLE's tool were addressed. We did not identify any studies using marine proteins or marine organisms other that fish. To conclude, intake of marine oils results in a lower TC concentration in dogs, thus reducing an important risk factor for atherosclerosis in canines. This study was registered at www.crd.york.ac.uk/PROSPERO/ as CRD42023396943.

Treatment of Ezetimibe lowers total and low-density lipoprotein cholesterol in hypercholesterolemic dogs with hyperadorenocorticism

Ezetimibe is a cholesterol absorption inhibitor that blocks the intestinal absorption of both biliary and dietary cholesterol, thereby lowering primarily low density lipoprotein-cholesterol (LDL-chol) in human studies. This study aimed to investigate the effects of ezetimibe on dyslipidemia control in nine dogs with hypercholesterolemia. Changes in total cholesterol (T-chol) and each lipoprotein fractions were evaluated at 0, 2, and 4 months following initiation of ezetimibe treatment. A significant decrease in T-chol was observed, and a mean T-chol concentration below 400 mg/dL was achieved at 2 and 4 months. Furthermore, a significant decrease in LDL-chol was observed (-53.3% and -64.3% at 2 and 4 months, respectively). Taken together, treatment of ezetimibe could lower LDL-chol levels in dogs with hypercholesterolemia.

Assessment of the likelihood of hypothyroidism in dogs diagnosed with and treated for hypothyroidism at primary care practices: 102 cases (2016-2021)

BACKGROUND

There is a possibility that an incorrect diagnosis of hypothyroidism could be made in euthyroid dogs, and the prevalence of hypothyroidism in the dog population remains unknown.

OBJECTIVES

To retrospectively assess the percentage of dogs diagnosed with, and treated for, hypothyroidism at first opinion practice which are likely to be hypothyroid and require levothyroxine supplementation.

ANIMALS

One hundred two client-owned dogs were included in this study.

MATERIALS AND METHODS

The computerized databases of 7 first opinion practices were searched to identify dogs treated with levothyroxine supplementation. Three European College of Veterinary Internal Medicine-Companian Animals (ECVIM-CA) diplomates independently assigned 1 of 4 clinical assessments to each case as follows: confirmed or likely hypothyroid, hypothyroidism suspected but not confirmed, hypothyroidism considered unlikely, and no reason to suspect hypothyroidism. They commented as to whether or not they thought levothyroxine supplementation was appropriate.

RESULTS

The clinical assessments of "confirmed or likely hypothyroid"; "Hypothyroidism suspected but not confirmed"; "Hypothyroidism considered unlikely"; and "No reason to suspect hypothyroidism" was assigned respectively by Clinician 1 to 38.2%, 5.9%, 3.9%, and 52% of cases, by Clinician 2 to 48%, 22.6%, 22.6%, 6.9% of cases, and by Clinician 3 to 55.9%, 11.8%, 13.7% and 18.6%. Clinician 1, Clinician 2, and Clinician 3 considered levothyroxine supplementation not indicated in 58.8%, 52.9%, and 45.1% of cases, respectively.

CONCLUSION

These results support the concern that hypothyroidism might be overly and incorrectly diagnosed in first opinion practice, and that thyroid function testing should be performed only in those dogs with a high pretest probability of the disease.

Factors associated with thrombotic disease in dogs with renal proteinuria: A retrospective of 150 cases

BACKGROUND

Knowledge of additional risk factors for thrombotic disease (TD) among dogs with renal proteinuria is limited; these might differ for TD affecting the systemic arterial (AT), systemic venous (VT), and pulmonary circulation (PT).

HYPOTHESIS/OBJECTIVES

To compare signalment and clinicopathological data between dogs with renal proteinuria with or without TD, and between dogs with AT, VT, and PT.

ANIMALS

One hundred fifty client-owned dogs with renal proteinuria, 50 of which had TD.

METHODS

Retrospective case-controlled study. A database search (2004-2021) identified proteinuric dogs (UPC > 2) with and without TD. Clinicopathological data were obtained from the records. TD and non-TD (NTD) groups were compared by binary logistic regression, and AT, VT, and PT groups by multinomial regression. Normal data presented as mean ± SD, non-normal data presented as median [25th, 75th percentiles].

RESULTS

Cavalier King Charles Spaniels were overrepresented in the TD group (OR = 98.8, 95% CI 2.09-4671, P = .02). Compared to NTD cases, TD cases had higher concentration of neutrophils (11.06 [8.92, 16.58] × 109 /L vs 7.31 [5.63, 11.06] × 109 /L, P = .02), and lower concentration of eosinophils (0 [0, 0.21] × 109 /L vs 0.17 [0.04, 0.41] × 109 /L, P = .002) in blood, and lower serum albumin (2.45 ± 0.73 g/dL vs 2.83 ± 0.73 g/dL, P = .04). AT cases had higher serum albumin concentrations than VT cases (2.73 ± 0.48 g/dL vs 2.17 ± 0.49 g/dL, P = .03) and were older than PT cases (10.6 ± 2.6 years vs 7.0 ± 4.3 years, P = .008). VT cases were older (9.1 ± 4.2 years vs 7.0 ± 4.3 years, P = .008) and had higher serum cholesterol concentration (398 [309-692 mg/dL] vs 255 [155-402 mg/dL], P = .03) than PT cases.

CONCLUSIONS AND CLINICAL IMPORTANCE

Differences between thrombus locations could reflect differences in pathogenesis.

Feeding of fish oil and medium-chain triglycerides to canines impacts circulating structural and energetic lipids, endocannabinoids, and non-lipid metabolite profiles

Introduction

The effect of medium-chain fatty acid-containing triglycerides (MCT), long-chain polyunsaturated fatty acid-containing triglycerides from fish oil (FO), and their combination (FO+MCT) on the serum metabolome of dogs (Canis familiaris) was evaluated.

Methods

Dogs (N = 64) were randomized to either a control food, one with 7% MCT, one with FO (0.18% eicosapentaenoate and 1.3% docosahexaenoate), or one with FO+MCT for 28 days following a 14-day washout period on the control food. Serum metabolites were analyzed via chromatography followed by mass spectrometry.

Results

Additive effects of serum metabolites were observed for a number of metabolite classes, including fatty acids, phospholipids, acylated amines including endocannabinoids, alpha-oxidized fatty acids, and methyl donors. Some effects of the addition of FO+MCT were different when the oils were combined compared with when each oil was fed separately, namely for acylcarnitines, omega-oxidized dicarboxylic acids, and amino acids. Several potentially beneficial effects on health were observed, including decreased circulating triglycerides and total cholesterol with the addition of FO (with or without MCT) and decreases in N-acyl taurines with the addition of MCT, FO, or FO+MCT.

Discussion

Overall, the results of this study provide a phenotypic characterization of the serum lipidomic response to dietary supplementation of long-chain n3-polyunsaturated and medium-chain saturated fats in canines.

Ultrasound Evaluation of Extracranial Cerebral Circulation (The Common, External and Internal Carotid Artery) in Different Breeds of Dogs

Noninvasive Doppler ultrasonography (US) examination is a standard method for the clinical evaluation of the carotid arteries. Extracranial cerebral circulation includes the common carotid artery (CCA), the external carotid artery (ECA), and the extracranial part of the internal carotid artery (ICA). The present study was conducted with the objective of assessing physiological normative values and describing the appearance of spectral waveforms of extracranial arteries in 104 healthy dogs of eight breeds divided into four groups according to weight. We also focused on searching for correlations for carotid blood velocities with the resistive index (RI), body weight and diameter, and differences between observers and the influence of sex in the calculations of Doppler parameters. In the evaluated breeds, significant differences were found in the velocity of peak systolic velocity (PSV) and end diastolic velocity (EDV). There was a strong correlation between body weight and peak systolic velocity, the RI index and CCA diameter. The intra-observer agreement for the PSV and EDV parameters in each vessel was considered excellent reliability, and overall interobserver agreement showed very good reliability. This study could improve the descriptions of physiological values and waveforms recorded in carotid arteries. Defining the physiological values of velocity and the resistive index (RI) helps in the easier identification of pathology and diagnosis of disease. Our results may be used for further studies of vascular diseases in veterinary medicine that correlate with the pathology of neurological disorders of ischemic origin, further in thromboembolism, oncologic disease and degenerative, proliferative and inflammatory diseases of the arteries that lead to stenosis.

Feline obesity causes hematological and biochemical changes and oxidative stress - a pilot study

Obesity, an extremely important factor in feline clinical practice, is estimated to affect up to one third of the feline population. Moreover, it can trigger chronic inflammation, which could predispose to oxidative stress by increasing reactive oxygen species, thereby generating potentially irreversible cellular damage. This study analyzed hematological, biochemical and oxidative stress profiles at various degrees of feline obesity. Forty-five cats were selected and divided into three groups: control (n = 17), overweight (n = 13) and obese (n = 15), after clinical and laboratory evaluation and body condition score. Biochemical and oxidative stress analyses were performed using a photocolorimeter and hematological analyses were performed in a veterinary cell counter. Obese cats showed increased mean corpuscular volume (MCV), red cell distribution width (RDW), HDL cholesterol and triglycerides and decreased activity of gamma-glutamyl transferase (GGT) than control cats, although within the reference ranges for the species. As for oxidative stress, obese cats showed higher total antioxidant capacity (TAC), by the inhibition of 2,2'-Azino-Bis-3-Ethylbenzthiazoline-6-Sulfonic Acid (ABTS), inhibition of ABTS associated with horseradish peroxidase (ABTS + HRP), cupric ion reducing antioxidant capacity (CUPRAC) and ferric reducing antioxidant power (FRAP) methods, while overweight cats had a higher TAC-ABTS + HRP and TAC-FRAP than control cats. We conclude that the conditions of natural obesity and overweight in the feline species alter its hematological, biochemical and oxidative stress parameters.

Effects of ACTH-Induced Long-Term Hypercortisolism on the Transcriptome of Canine Visceral Adipose Tissue

Cushing’s syndrome, or hypercortisolism (HC), a common endocrinopathy in adult dogs, is caused by chronic hypercortisolemia. Among different metabolic disorders, this syndrome is associated with enhanced subcutaneous lipolysis and visceral adiposity. However, effects of HC in adipose tissue, especially regarding visceral adipose tissue (VAT), are still poorly understood. Herein, the transcriptomic effects of chronic HC on VAT of dogs were evaluated. For this, subcutaneously implanted ACTH-releasing pumps were used, followed by deep RNA sequencing of the canine VAT. Prolonged HC seems to affect a plethora of regulatory mechanisms in VAT of treated dogs, with 1190 differentially expressed genes (DEGs, p and FDR < 0.01) being found. The 691 downregulated DEGs were mostly associated with functional terms like cell adhesion and migration, intracellular signaling, immune response, extracellular matrix and angiogenesis. Treatment also appeared to modulate local glucocorticoid and insulin signaling and hormonal sensitivity, and several factors, e.g., TIMP4, FGF1, CCR2, CXCR4 and HSD11B1/2, were identified as possible important players in the glucocorticoid-related expansion of VAT. Modulation of their function during chronic HC might present interesting targets for further clinical studies. Similarities in the effects of chronic HC on VAT of dogs and humans are highlighted.

Serum Lipidome Signatures of Dogs with Different Endocrinopathies Associated with Hyperlipidemia

Hyperlipidemia (hypertriglyceridemia, hypercholesterolemia) is a common finding in human and veterinary patients with endocrinopathies (e.g., hypothyroidism and hypercortisolism (Cushing's syndrome; CS)). Despite emerging use of lipidomics technology in medicine, the lipid profiles of these endocrinopathies have not been evaluated and characterized in dogs. The aim of this study was to compare the serum lipidomes of dogs with naturally occurring CS or hypothyroidism with those of healthy dogs. Serum samples from 39 dogs with CS, 45 dogs with hypothyroidism, and 10 healthy beagle dogs were analyzed using a targeted lipidomics approach with liquid chromatography-mass spectrometry. There were significant differences between the lipidomes of dogs with CS, hypothyroidism, and the healthy dogs. The most significant changes were found in the lysophosphatidylcholines, lysophosphatidylethanolamines, lysophosphatidylinositols, phosphatidylcholines, phosphatidylethanolamines, phosphatidylglycerols, ceramides, and sphingosine 1-phosphates. Lipid alterations were especially pronounced in dogs with hypothyroidism. Several changes suggested a more atherogenic lipid profile in dogs with HT than in dogs with CS. In this study, we found so far unknown effects of naturally occurring hypothyroidism and CS on lipid metabolism in dogs. Our findings provide starting points to further examine differences in occurrence of atherosclerotic lesion formation between the two diseases.

Myxedema Coma and Acute Hepatopathy in a Dog with Severe Atherosclerosis

A 9-year-old male intact mixed-breed dog was presented to The Ohio State University Veterinary Medical Center for evaluation of two days' duration of weakness, lethargy, inappetence, and one episode of vomiting the day of presentation. On presentation, the dog was depressed and tetraparetic. He was noted to be icteric and dehydrated. Obesity and truncal alopecia with a "rat tail" appearance were observed. Diagnostic testing revealed evidence of an acute hepatopathy and peritonitis. Given the dog's neurologic status, physical examination abnormalities, including a "tragic facial expression", and hyperlipidemia, there was concern for possible myxedema coma. A thyroid panel was consistent with hypothyroidism. The dog experienced respiratory arrest prior to initiation of therapy, and an autopsy confirmed the presence of subacute necrotizing cholangiohepatitis, marked atherosclerosis, and severe thyroid atrophy. These clinical and pathologic changes were supportive of myxedema coma.

Acute Hepatopathy in a Dog Secondary to Hypothyroidism-Induced Atherosclerotic Infarction and Necrosis

A 7 yr old male beagle was examined because of lethargy, anorexia, and cranial abdominal discomfort. Significant clinicopathologic abnormalities included severe liver enzyme elevations and hypercholesterolemia. Abdominal imaging identified vascular compromise of the left lateral liver lobe and a gallbladder mucocele. Following liver lobectomy and cholecystectomy, the dog's clinical signs resolved, and liver enzymes substantially improved. Diffuse hepatocellular infarction and necrosis secondary to multifocal atherosclerosis was present on histopathology of the liver. Hypothyroidism was subsequently diagnosed. Restoration of euthyroidism with oral levothyroxine therapy resolved the remaining liver enzyme elevations and hypercholesterolemia. To the author's knowledge, this is the first case report of hypothyroidism resulting in a clinically apparent and resolvable acute hepatopathy due to atherosclerosis. Clinicians should include atherosclerosis as a differential diagnosis for dogs with an acute hepatopathy and investigate dogs for hypothyroidism if atherosclerosis is diagnosed on liver biopsy.

Thrombin Generation Assay and Hemostatic Profile for Elucidating Hypercoagulability in Endogenous Canine Hyperadrenocorticism

Canine hyperadrenocorticism is a common endocrine disorder caused by chronic secretion of glucocorticoid, often associated with hypercoagulability and secondary thrombosis. The thrombin generation assay (TGA) evaluates hemostasis globally by measuring endogenous thrombin potential. We aimed to determine whether TGA is suitable for assessing hypercoagulability in dogs with endogenous hyperadrenocorticism (HAC), and to correlate TGA with coagulation markers including fibrinogen, antithrombin (AT), D-dimer, prothrombin time (PT) and activated partial thromboplastin time (aPTT), and with routine laboratory tests for elucidating prothrombotic mechanisms and evaluating their utility as hypercoagulability screening tests. Thrombin generation performed with high activator concentration showed significantly higher endogenous thrombin potential (ETP) (P = .0239) and peak thrombin (P = .0281) in Cushing patients. Fibrinogen (P = <.0001) and AT (P = .0444) activities were significantly higher in the HAC group, while those of PT (P = .0046) and aPTT (P = .0002) were lower. Basal cortisol levels correlated positively with fibrinogen (r = 0.4503; P = .0355) and negatively with AT activity (r = -0.4580; P = .0280). Fibrinogen and hematocrit values were inversely correlated (r = -0.4853; P = .0076). Our study confirmed the presence of higher thrombin generation in dogs with HAC. However, TGA performed with lower activator concentrations was unsuitable for detecting hypercoagulability. Higher AT and fibrinogen levels and lower aPTT activity were identified in dogs with HAC relative to controls suggesting a potential role for the combined use of these assays when assessing hypercoagulability in canine hyperadrenocorticism.

Radiography and ct features of atherosclerosis in two miniature schnauzer dogs

Two miniature Schnauzer dogs with chronic pancreatitis were investigated. Both dogs showed systemic hypertension and increased concentrations of triglycerides and C-reactive protein. Abdominal radiography revealed cylindrical calcification in the retroperitoneum, and computed tomography (CT) showed extensive calcification of the abdominal and peripheral arteries in both dogs. Metastases and other dystrophic conditions that can cause arterial calcification were excluded based on the laboratory tests, and the dogs were diagnosed with atherosclerosis ante mortem. Atherosclerosis should be considered when extensive arterial calcification is observed on abdominal radiography or CT in miniature Schnauzers.

Efficacy of a micronized, nanocrystal fenofibrate formulation in treatment of hyperlipidemia in dogs

Background

Safe, effective, and readily available drug therapies are required for the management of hyperlipidemia and its associated complications in dogs.

Objectives

To investigate the efficacy of a micronized, nanocrystal formulation of fenofibrate (Tricor) in the treatment of hyperlipidemia in dogs.

Animals

Ten client‐owned dogs with primary (n = 7) and secondary (n = 3) hyperlipidemia. All dogs had hypertriglyceridemia at baseline; 3 dogs also had hypercholesterolemia.

Methods

Prospective dose‐escalation study. Dogs were treated with fenofibrate orally once daily in up to 3 cycles of 21 days each. Fenofibrate dose was increased at the end of each cycle if hypertriglyceridemia persisted and adverse effects were not documented. Complete blood count, biochemistry, and urine protein:creatinine ratio were collected serially. Baseline (T0) parameters were compared to time of maximal reduction in serum triglyceride concentrations (T1) and reported as median (range).

Results

Triglycerides normalized in all dogs (T0 = 662 mg/dL [189‐2391]; T1 = 113 mg/dL [81‐132]; P = .002). Fenofibrate dose at T1 = 6.4 mg/kg PO q24h (range, 2.2‐13.5). T1 was achieved at 3 (n = 4), 6 (n = 4), and 9 (n = 2) weeks. Serum cholesterol concentrations decreased in 9 of 10 dogs. Quiet demeanor and firm stools in 1 dog were the only reported adverse reactions. Fenofibrate administration resulted in a significant reduction in median alkaline phosphatase activity (P = .049).

Conclusions and Clinical Importance

Over 21 to 63 days, TriCor was effective in the management of primary and secondary hyperlipidemia in dogs.

Age-Related Arteriolar Changes With Lipid and Amyloid Deposits in the Gonads of Dogs

Arteriolar lesions with lipid and/or amyloid deposits are frequently detected in canine gonads by routine histopathologic examination; however, they have never been examined in detail. In the present study, a total of 139 testes/epididymides and 200 ovaries from 72 male (4 months to 14 years old) and 105 female (7 months to 16 years old) dogs were examined for arteriolar lesions. Arteriolar lesions were detected in 21 of 72 male dogs (29%) and 54 of 105 female dogs (51%). These lesions were histologically classified into 4 types: "fibromuscular hypertrophy," characterized by thickening of the tunica intima; "focal vasculitis," characterized by mononuclear cell infiltration; "vacuolar change," consisting of lipid accumulation and infiltration of foamy cells; and "hyalinosis," characterized by irregular thickening with amyloid deposits. In the lesions of vacuolar change and hyalinosis, lipid deposition and infiltration of α-SMA-positive cells and Iba-1-positive cells were also observed. Foamy cells and amyloid deposits were immunopositive for apolipoproteins and oxidized low-density lipoprotein-related proteins. These results indicate that vacuolar change is possibly an early stage of atherosclerosis, and that amyloid may deposit as a consequence of the microenvironment associated with atherogenesis. Logistic regression analysis revealed that arteriolar lesions with lipid deposits were associated with age and interstitial cell tumors in male dogs, and with age in female dogs. Aging is likely an important risk factor of arteriolar lesions with lipid deposits of the canine gonads.

Assessment of postprandial hyperglycemia and circadian fluctuation of glucose concentrations in diabetic dogs using a flash glucose monitoring system

BACKGROUND

Postprandial hyperglycemia (PPH) and circadian glucose concentration fluctuations recorded in the home environment of dogs with naturally occurring diabetes mellitus (DM) have not been reported.

OBJECTIVES

To determine if a flash glucose monitoring system (FGMS; FreeStyle Libre) can detect PPH and circadian fluctuations in glucose concentrations in dogs with variably controlled DM.

ANIMALS

Fourteen client-owned dogs with DM.

METHODS

Prospective observational study. Interstitial glucose (IG) concentrations measured by the FGMS during a 13-day study period were analyzed.

RESULTS

A total of 17, 446 FGMS IG concentrations were analyzed. For all dogs analyzed together, median IG concentration measured within 30 (288 mg/dL), 60 (286 mg/dL), 90 (285 mg/dL), and 120 (285 mg/dL) minutes of meals was each significantly higher than the median IG concentration at all other times (260 mg/dL, 259 mg/dL, 258 mg/dL, and 257 mg/dL, respectively; range, 40-500 mg/dL; P < .001 for each). Median night-time IG concentration measured from all dogs on 3,547 samples recorded between 1:00 am and 6:00 am (268 mg/dL; range, 40-500 mg/dL) was significantly higher than median IG measured on 13, 899 samples at all other time points (259 mg/dL; range, 40-500 mg/dL; P < .001).

CONCLUSIONS AND CLINICAL IMPORTANCE

The FGMS can be used for future studies of PPH and circadian fluctuations of glucose concentrations in dogs with DM in their home environment.

Fenofibrate treatment for severe hypertriglyceridemia in dogs

Lipid disorders are relatively common in dogs. Hyperlipidemia can be primary or secondary to other diseases. In humans, fenofibrate is used to control hypertriglyceridemia. In dogs, there are no studies evaluating fenofibrate in hypertriglyceridemia. The aim of the study was to evaluate the safety and efficacy of fenofibrate to control severe hypertriglyceridemia in dogs. A total of 124 dogs (n = 124) with severe hypertriglyceridemia (>300 mg/dL, 3.39 mmol/L) were randomly distributed in the fenofibrate group (n = 64) and the diet group (n = 60). Dogs of the fenofibrate group were treated with fenofibrate (10 mg/Kg) once daily. Dogs of the diet group were treated with low-fat diet (10%). Serum triglycerides (TGs), total cholesterol (TC), liver enzymes, and creatine kinase concentrations were evaluated, before and after 1 mo of medical or dietary treatment. Triglyceride concentrations were reduced with fenofibrate (P < 0.001), and 85.93% of the dogs normalized their levels. Triglyceride concentrations also decreased with low-fat diet (P < 0.001), but only 26.6% of the dogs normalized their levels. Triglyceride concentrations were reduced with fenofibrate (P < 0.01) and with low-fat diet (P < 0.01). Of the cases with hypercholesterolemia, 53.7% and 50% of the dogs normalized their TC concentrations, with fenofibrate and diet, respectively. No significant adverse effects were observed (3% showed diarrhea). Fenofibrate was safe and effective in reducing and normalizing TG concentrations in dogs with severe hypertriglyceridemia, regardless of the cause of hyperlipidemia. The low-fat diet was effective in reducing, but not normalizing, TG concentrations. Fenofibrate and low-fat diet were effective in reducing TC concentrations. This is the first study evaluating fibrates in dogs with severe hypertriglyceridemia and comparing results with a low-fat diet.

The Serum and Saliva Proteome of Dogs with Diabetes Mellitus

This study aims to evaluate the changes in salivary and serum proteomes that occur in canine diabetes mellitus type-1 (DM) through a high-throughput quantitative proteomic analysis. The proteomes of 10 paired serum and saliva samples from healthy controls (HC group, n = 5) and dogs with untreated DM (DM group, n = 5) were analyzed using Tandem Mass Tags (TMT)-based proteomic approach. Additionally, 24 serum samples from healthy controls and untreated DM were used to validate haptoglobin in serum. The TMT analysis quantified 767 and 389 proteins in saliva and serum, respectively. Of those, 16 unique proteins in serum and 26 in saliva were differently represented between DM and HC groups. The verification of haptoglobin in serum was in concordance with the proteomic data. Our results pointed out changes in both saliva and serum proteomes that reflect different physiopathological changes in dogs with DM. Although some of the proteins identified here, such as malate dehydrogenase or glyceraldehyde-3-phosphate dehydrogenase, were previously related with DM in dogs, most of the proteins modulated in serum and saliva are described in canine DM for the first time and could be a source of potential biomarkers of the disease. Additionally, the molecular function, biological process, pathways and protein class of the differential proteins were revealed, which could improve the understanding of the disease's pathological mechanisms.

Effects of treatment with lispro and neutral protamine Hagedorn insulins on serum fructosamine and postprandial blood glucose concentrations in dogs with clinically well-controlled diabetes mellitus and postprandial hyperglycemia

OBJECTIVE

To assess effects of basal-bolus insulin treatment (BBIT) with lispro and neutral protamine Hagedorn (NPH) insulins, compared with NPH insulin alone, on serum fructosamine concentration (SFC) and postprandial blood glucose concentration (BGC) in dogs with clinically well-controlled diabetes mellitus and postprandial hyperglycemia fed a high insoluble fiber-content diet.

ANIMALS

6 client-owned dogs with diabetes mellitus.

PROCEDURES

Blood samples were collected for BGC and SFC measurement in hospitalized dogs just before feeding and routine SC NPH insulin administration (time 0); samples were collected for BGC measurement every 30 minutes for 2 hours, then every 2 hours for up to 10 additional hours. Postprandial hyperglycemia was identified when BGC 30 minutes after insulin administration exceeded BGC at time 0 or the 1-hour time point. For BBIT, owners were instructed to continue NPH insulin administration at the usual dosage at home (q 12 h, with feeding) and to administer lispro insulin (0.1 U/Kg, SC) separately at the time of NPH injections. Two weeks later, SFC and BGC measurements were repeated; results at the start and end of the study were compared statistically.

RESULTS

Median SFC was significantly higher at the start (400 μmol/L) than at the end (390 μmol/L) of the study. Median 1-hour (313 mg/dL) and 1.5-hour (239 mg/dL) BGC measurements at the start of the study were significantly higher than those at the end of the study (117 and 94 mg/dL, respectively).

CONCLUSIONS AND CLINICAL RELEVANCE

In this sample of dogs with well-controlled diabetes mellitus, addition of lispro insulin to an existing treatment regimen of NPH insulin and dietary management significantly decreased postprandial BGCs. Further study of BBIT for dogs with diabetes mellitus is warranted.

Epigallocatechin-3-gallate activates the AMP-activated protein kinase signaling pathway to reduce lipid accumulation in canine hepatocytes

Epigallocatechin-3-gallate (EGCG) plays a crucial role in hepatic lipid metabolism. However, the underlying regulatory mechanism of hepatic lipid metabolism by EGCG in canine is unclear. Primary canine hepatocytes were treated with EGCG (0.01, 0.1, or 1 μM) and BML-275 (an AMP-activated protein kinase [AMPK] inhibitor) to study the effects of EGCG on the gene and protein expressions associated with AMPK signaling pathway. Data showed that treatment with EGCG had greater activation of AMPK, as well as greater expression levels and transcriptional activity of peroxisome proliferator activated receptor-α (PPARα) along with upregulated messenger RNA (mRNA) abundance and protein abundance of PPARα-target genes. EGCG decreased the expression levels and transcriptional activity of sterol regulatory element-binding protein 1c (SREBP-1c) along with downregulated mRNA abundance and protein abundance of SREBP-1c target genes. Of particular interest, exogenous BML-275 could reduce or eliminate the effects of EGCG on lipid metabolism in canine hepatocytes. Furthermore, the content of triglyceride was significantly decreased in the EGCG-treated groups. These results suggest that EGCG might be a potential agent in preventing high-fat diet-induced lipid accumulation in small animals.

Imaging Ischemic and Hemorrhagic Disease of the Brain in Dogs

Strokes, both ischemic and hemorrhagic, are the most common underlying cause of acute, non-progressive encephalopathy in dogs. In effect, substantial information detailing the underlying causes and predisposing factors, affected vessels, imaging features, and outcomes based on location and extent of injury is available. The features of canine strokes on both computed tomography (CT) and magnetic resonance imaging (MRI) have been described in numerous studies. This summary article serves as a compilation of these various descriptions. Drawing from the established and emerging stroke evaluation sequences used in the investigation of strokes in humans, this summary describes all theoretically available sequences. Particular detail is given to logistics of image acquisition, description of imaging findings, and each sequence's advantages and disadvantages. As the imaging features of both forms of strokes are highly representative of the underlying pathophysiologic stages in the hours to months following stroke onset, the descriptions of strokes at various stages are also discussed. It is unlikely that canine strokes can be diagnosed within the same rapid time frame as human strokes, and therefore the opportunity for thrombolytic intervention in ischemic strokes is unattainable. However, a thorough understanding of the appearance of strokes at various stages can aid the clinician when presented with a patient that has developed a stroke in the days or weeks prior to evaluation. Additionally, investigation into new imaging techniques may increase the sensitivity and specificity of stroke diagnosis, as well as provide new ways to monitor strokes over time.

Comparação das artérias carótidas comuns de equinos e muares por ultrassonografia modo-B e Doppler espectral e a relação com a massa corpórea

RESUMO A ultrassonografia convencional e o Doppler espectral nas artérias carótidas comuns em equinos e muares são considerados escassos, diferentemente do que ocorre na medicina humana. Este trabalho propôs comparar as artérias carótidas comuns de equinos e muares por ultrassonografia modo-B e Doppler espectral, além de verificar as diferenças dessas variáveis entre os gêneros desses animais e a relação com a massa corpórea. Foram avaliados os seguintes parâmetros: massa corpórea, diâmetros das artérias, espessura da camada íntima-média (EIM), índice de resistividade (IR), índice de pulsatilidade (IP), velocidade sistólica (VS), velocidade diastólica (VD) e velocidade média (VM). Salvo a massa corpórea, esses parâmetros foram obtidos de três regiões (cranial, médio e caudal) e submetidos à análise conjuntamente. Os diâmetros das artérias carótidas comuns são diferentes entre equinos e muares, com valores menores nos equinos. O IR, o IP, a VS e a VM diferiram entre equinos e muares, sendo maiores nos equinos, e a VD superior nos muares. Não foi observada diferença das variáveis do modo-B e Doppler entre gêneros nos equinos, diferentemente dos muares, cujos machos apresentaram valores maiores do diâmetro, do IR e do IP, mas menores da VS e da VM. A massa corpórea não influenciou as variáveis do modo-B, independentemente do gênero, mas apresenta correlação significativa nas variáveis do modo Doppler. As artérias carótidas comuns de equinos e muares são diferentes pelos exames ultrassonográficos modo-B e Doppler espectral. O gênero não influencia no modo-B e no Doppler nos equinos, porém influencia parcialmente nos muares. A massa corpórea de equinos e de muares, independentemente do gênero, não tem associação com as variáveis do modo-B, apenas com o Doppler.

Starch sources influence lipidaemia of diabetic dogs

BACKGROUND

Hyperlipidaemia is considered a cause of other diseases that are clinically important and potentially life threatening. Combination of pea and barley as exclusive starch sources is known to interfere with glycemic control in diabetic dogs, but their effect on lipid profile of hiperlipidaemic dogs is yet to be evaluated. Twelve adult diabetic dogs were fed three dry extruded diets with different starch sources and different fat levels: peas and barley (PB), maize (Mi), and peas, barley and rice (Ba) with 15.7, 15.6 and 9.0% of their dry matter as fat, respectively. Plasmatic cholesterol and triglycerides concentration curves over 10 h were obtained after 60 days on each diet and with the same NPH insulin dose. ANOVA test or Friedman test were used to compare the dietary effects on triglycerides and cholesterol variables among the diets.

RESULTS

Dogs presented lower mean (p = 0.05), fasting (p = 0.03), and time 8-h postprandial (p = 0.05) triglyceridemia after PB diet period than Ba diet period and time 4-h postprandial (p = 0.02) lower after PB than Mi diet. Cholesterolemia mean, minimum, maximum, area under the cholesterol curve and times points: 2, 4, 6, 8 and 10-h postprandial, had lower values after PB ingestion in comparison to Mi, without difference to Ba diet.

CONCLUSION

Inclusion of pea and barley, as exclusive starch sources, in therapeutic diets for diabetic dogs can minimize plasmatic triglycerides and cholesterol concentration at fasting and at different postprandial time, compared to the maize diet or diet with lesser fat content.

Changes in the Canine Plasma Lipidome after Short- and Long-Term Excess Glucocorticoid Exposure

Glucocorticoids (GCs) are critical regulators of metabolic control in mammals and their aberrant function has been linked to several pathologies. GCs are widely used in human and veterinary clinical practice as potent anti-inflammatory and immune suppressive agents. Dyslipidaemia is a frequently observed consequence of GC treatment, typified by increased lipolysis, lipid mobilization, liponeogenesis, and adipogenesis. Dogs with excess GC show hyperlipidaemia, hypertension, and a higher risk of developing type 2 diabetes mellitus, but the risk of developing atherosclerotic lesions is low as compared to humans. This study aimed to examine alterations in the canine plasma lipidome in a model of experimentally induced short-term and long-term GC excess. Both treatments led to significant plasma lipidome alterations, which were more pronounced after long-term excess steroid exposure. In particular, monohexosylceramides, phosphatidylinositols, ether phosphatidylcholines, acyl phosphatidylcholines, triacylglycerols and sphingosine 1-phosphates showed significant changes. The present study highlights the hitherto unknown effects of GCs on lipid metabolism, which will be important in the further elucidation of the role and function of GCs as drugs and in metabolic and cardiovascular diseases.

Coronary arteriovenous malformation in a dog with a complex arrhythmia and hypothyroidism

A four-year-old Japanese Akita was referred for investigation of lethargy, exercise intolerance, and an irregular heart rhythm. He was diagnosed with atrial fibrillation, a complex ventricular arrhythmia, and hypothyroidism. Echocardiography identified a nest of anomalous vessels surrounding the heart and shunting into the pulmonary artery. Computed tomography confirmed a coronary arteriovenous malformation consisting of a coronary-to-pulmonary arterial communication and an associated complex nest of tortuous vessels, which was thought to be an incidental finding. Clinical signs improved with levothyroxine and antiarrhythmic treatment. Describing an unusual coronary artery anomaly as well, this case serves as a reminder to critically evaluate the hemodynamic significance of structural cardiac disease and to screen for systemic disease in patients with arrhythmias.

Lipemic uveitis and its etiologies in dogs: 75 cases

OBJECTIVE

To describe clinical features of dogs with lipemic uveitis (LU).

ANIMALS STUDIED

Seventy-five dogs (114 eyes) with LU.

PROCEDURES

Medical records of dogs examined by the Cornell University ophthalmology service with a clinical diagnosis of LU between 2008 and 2017 were analyzed. Signalment and clinical case aspects, including concurrent ocular disease, systemic disease, and previous ophthalmic surgery, were recorded.

RESULTS

Lipemic uveitis was diagnosed in 114 eyes of 75 dogs. The mean (±standard deviation) age of dogs was 9.0 years (±2.7 years). Miniature Schnauzers and Yorkshire Terriers were statistically overrepresented compared to the ophthalmology canine referral population. Lipemic flare varied in severity with loss of menace response due to markedly opaque flare seen in 15/114 eyes (13%). Two dogs developed LU after dietary indiscretion. Forty-nine eyes (43%) had concurrent ocular disease, most commonly keratoconjunctivitis sicca, ulcerative keratitis, and cataracts. Pseudophakia was present in 75/114 eyes (66%) and LU developed within 30 days of an intraocular surgical procedure in 63/114 eyes (55%). Hypertriglyceridemia was noted in 52 dogs of the 55 dogs tested (95%). Systemic disease affected 54/75 dogs (72%), of which diabetes mellitus, hyperadrenocorticism, and hypothyroidism were overrepresented compared to the referral population. Primary hyperlipidemia was identified in 12 dogs. Lipemic uveitis resolved at first reevaluation in 92/110 eyes (84%) and recurred in 6/114 eyes (5%) after complete resolution.

CONCLUSIONS

Development of lipemic uveitis in dogs appears to require the combination of hyperlipidemia and uveitis. Systemic disease is commonly associated with LU in dogs.

The companion dog as a model for human aging and mortality

Around the world, human populations have experienced large increases in average lifespan over the last 150 years, and while individuals are living longer, they are spending more years of life with multiple chronic morbidities. Researchers have used numerous laboratory animal models to understand the biological and environmental factors that influence aging, morbidity, and longevity. However, the most commonly studied animal species, laboratory mice and rats, do not experience environmental conditions similar to those to which humans are exposed, nor do we often diagnose them with many of the naturally occurring pathologies seen in humans. Recently, the companion dog has been proposed as a powerful model to better understand the genetic and environmental determinants of morbidity and mortality in humans. However, it is not known to what extent the age‐related dynamics of morbidity, comorbidity, and mortality are shared between humans and dogs. Here, we present the first large‐scale comparison of human and canine patterns of age‐specific morbidity and mortality. We find that many chronic conditions that commonly occur in human populations (obesity, arthritis, hypothyroidism, and diabetes), and which are associated with comorbidities, are also associated with similarly high levels of comorbidity in companion dogs. We also find significant similarities in the effect of age on disease risk in humans and dogs, with neoplastic, congenital, and metabolic causes of death showing similar age trajectories between the two species. Overall, our study suggests that the companion dog may be an ideal translational model to study the many complex facets of human morbidity and mortality.

Doenças do sistema nervoso central em cães

RESUMO: São descritas doenças do sistema nervoso central (SNC) em cães diagnosticadas no sertão da Paraíba. Os registros de necropsia de 1.205 cães foram revisados. Em 354 casos (29,38%) foram registrados história clínica de alterações do sistema nervoso. Duzentos e noventa e seis casos tiveram diagnóstico definitivo e 58 foram inconclusivos. As doenças infecciosas foram observadas em 59,60% (211/354) de casos que representam a principal causa de distúrbios neurológicos; 53% dos casos (186/354) foram representadas por doenças virais; 3,11% (11/354) foram de etiologia parasitária, 2,54% (9/354) foram causadas por bactérias e 1,41% (5/354) por fungos. Os agentes físicos representaram a segunda causa mais importante de transtornos do SNC com 9,89% (35/354) e os tumores a terceira causa com 5,93% (21/354). Outras alterações pouco frequentes foram alterações metabólicas secundárias a insuficiência hepática ou renal, representando 2,54% (9/354). Casos raros de hidrocefalia congênita foram observados, 1,41% (5/354). Os casos de manifestações neurológicas associadas a alterações vasculares, degenerativas e inflamatórias não infecciosas, muitas das quais uma causa específica não foi estabelecida representaram 4,24% (15/354); Estavam dentro das seguintes categorias de doenças: Infartos isquêmicos e hemorrágicos (6/15), necrose vascular fibrinoide (5/15), doença do disco intervertebral (2/15), meningoencefalite granulomatosa (1/15) e granuloma de colesterol (1/15). Os distúrbios do sistema nervoso central representam uma importante causa de morte ou eutanásia em cães na região semiárida da Paraíba. Os sinais clínicos variaram de acordo com o agente envolvido, localização e distribuição das lesões. O conhecimento dos principais agentes que pode afetar o SNC canino é importante ao fazer uma lista de diagnóstico diferencial.

Canine Diabetes Mellitus Associated Ocular Disease

Diabetes mellitus (DM) is a commonly encountered disease in companion animal veterinary practice. Ocular complications in dogs with DM are thought to be common but there are no reports of the overall incidence of DM-associated ocular disease. Some complications, such as cataracts and ocular surface disease, can lead to vision loss and significant morbidity among DM patients, therefore early recognition and intervention are essential for successful outcomes. The purpose of this article is to provide a review of several currently known or suspected ocular diseases associated with DM.

Kastration der Hündin – neue und alte Erkenntnisse zu Vor- und Nachteilen

Die Beratung von Hundehaltern bezüglich der Vorteile und Nachteile sowie des optimalen Zeitpunktes der Kastration einer Hündin ist komplex und sollte sich auf verlässliche Daten aus der Wissenschaft stützen sowie individuelle Belange berücksichtigen. Bei genauerer Betrachtung der aktuellen Publikationen zu diesem Thema fällt auf, dass einige lange für robust gehaltene Informationen etwas angepasst oder aktualisiert werden müssen. Ein offensichtlicher Vorteil der elektiven Kastration ist, dass Erkrankungen der Ovarien und sexualsteroidabhängige Erkrankungen wie Metropathien nicht auftreten. Weiterhin ist ein gewisser protektiver Effekt einer frühzeitigen Kastration auf die Entstehung von Mammatumoren anzunehmen, wenngleich dafür derzeit eine schwache wissenschaftliche Evidenz besteht und der Effekt vermutlich geringer ausfällt, als in einigen älteren Publikationen angegeben wurde. Die Kastration hat jedoch auch Nachteile. Als häufigste negative Folge wird seit Jahrzehnten die Harninkontinenz beschrieben. Aussagen zur Inzidenz sowie zu weiteren Einflussfaktoren, wie Kastrationszeitpunkt in Bezug zur Pubertät, sind jedoch uneinheitlich. Aktuell werden vor allem das gehäufte Auftreten verschiedener Tumorerkrankungen, die nicht direkt mit dem Reproduktionstrakt in Verbindung stehen, sowie ein höheres Risiko für Erkrankungen des Bewegungsapparats bei kastrierten Tieren diskutiert. Weitere Einflussfaktoren wie der Ernährungszustand des Hundes, Alter und/oder Haltung wurden jedoch häufig nicht erfasst. Die Datenlage zur Auswirkung der Kastration auf den Stoffwechsel und das Immunsystem der Hündin ist derzeit ungenügend. Wünscht der Tierbesitzer eine Kastration, bedarf es in jedem Fall einer eingehenden Beratung, die individuelle, rasse- und haltungsbezogene Aspekte einschließt. Derzeit ist eine Kastration am ehesten zwischen der ersten und zweiten Läufigkeit zu empfehlen, da ein gewisser protektiver Effekt auf die Entstehung von Mammatumoren anzunehmen ist und das Risiko unerwünschter Nebenwirkungen nach heutigem Wissensstand moderat ausfällt.

Spectrophotometry and Ultracentrifugation for Measurement of Plasma Lipids in Dogs with Diabetes Mellitus

Background

There are conflicting reports of plasma lipoprotein lipid content in dogs with diabetes mellitus (DM).

Objectives

To determine lipoprotein lipid content of plasma of dogs with DM by spectrophotometry and ultracentrifugation; to compare lipoprotein lipid content in diabetic and healthy dogs; and to quantify apolipoprotein B‐100 (ApoB) in dogs with DM.

Animals

22 dogs with DM and 9 healthy dogs.

Methods

Cross‐sectional study. Triglyceride (TG), total cholesterol (TC), and high‐density lipoprotein cholesterol (HDL‐C) concentrations were measured by spectrophotometry. Very low‐density lipoprotein cholesterol (VLDL‐C) and low‐density lipoprotein cholesterol (LDL‐C) concentrations were calculated after ultracentrifugation. Non‐HDL‐C cholesterol was calculated by subtracting HDL‐C from TC. ApoB was quantified by ELISA. The Mann‐Whitney test was used for comparison of median lipoprotein concentrations, and Spearman's correlation was used to assess associations between ApoB and lipoprotein fractions.

Results

All values are reported in mg/dL. Median TG (122), TC (343.5), HDL‐C, (200), VLDL‐C, (27) LDL‐C (68), non‐HDL‐C (114), and ApoB (320) were significantly higher in dogs with DM, compared to healthy dogs (57, 197, 168, 12, 16, 31, and 258, respectively, P‐values 0.0079, <0.001, 0.029, 0.011, <0.001, <0.001, 0.025, respectively). A significant association was found between ApoB and LDL‐C (Spearman's rho = 0.41, P = 0.022) and between ApoB and non‐HDL‐C (Spearman's rho = 0.40, P = 0.027).

Conclusions and Clinical Importance

Dyslipidemia of dogs with DM is characterized by pronounced increases in LDL‐C and non‐HDL‐C concentrations, although all lipoprotein fractions are significantly increased. Knowledge of specific lipoprotein fraction alterations in dogs with DM can enhance treatment options for diabetic dyslipidemia in dogs.

Cardiac and Metabolic Variables in Obese Dogs

Background

The etiology of obesity‐related cardiac dysfunction (ORCD) is linked to metabolic syndrome in people. Studies have indicated that obese dogs have components of metabolic syndrome, warranting evaluation for ORCD in obese dogs.

Objectives

To evaluate cardiac structure and function and metabolic variables in obese dogs compared to ideal weight dogs.

Animals

Forty‐six healthy, small‐breed (<25 pounds), obese dogs (n = 29) compared to ideal weight dogs (n = 17).

Methods

A cross‐sectional study of cardiac structure and function by standard and strain echocardiographic measurements and quantification of serum metabolic variables (insulin:glucose ratios, lipid analysis, adiponectin, inflammatory markers).

Results

Compared to the ideal weight controls, obese dogs had cardiac changes characterized by an increased interventricular septal width in diastole to left ventricular internal dimension in diastole ratio, decreased ratios of peak early to peak late left ventricular inflow velocities, and ratios of peak early to peak late mitral annular tissue velocities, and increased fractional shortening and ejection fraction percentages. The left ventricular posterior wall width in diastole to left ventricular internal dimension in diastole ratios were not significantly different between groups. Systolic blood pressure was not significantly different between groups. Obese dogs had metabolic derangements characterized by increased insulin:glucose ratios, dyslipidemias with increased cholesterol, triglyceride, and high‐density lipoprotein concentrations, decreased adiponectin concentrations, and increased concentrations of interleukin 8 and keratinocyte‐derived chemokine‐like inflammatory cytokines.

Conclusions and Clinical Importance

Compared to ideal weight controls, obese dogs have alterations in cardiac structure and function as well as insulin resistance, dyslipidemia, hypoadiponectinemia, and increased concentrations of inflammatory markers. These findings warrant additional studies to investigate inflammation, dyslipidemia, and possibly systemic hypertension as potential contributing factors for altered cardiac function.

Therapy of Canine Hyperlipidemia with Bezafibrate

BACKGROUND

Bezafibrate (BZF) is effective in the treatment of hypertriglyceridemia in human patients, but there are no data on its use in dogs.

OBJECTIVE

To assess the safety of BZF in hyperlipidemic dogs and its efficacy in decreasing serum triglyceride (TG) and cholesterol (CHO) concentrations.

ANIMALS

Forty-six dogs, 26 females and 20 males, mean (±SD) age of 9 (±3) years, with TG ≥150 mg/dL (33 dogs also were hypercholesterolemic [>300 mg/dL]).

METHODS

Prospective, uncontrolled clinical trial. Dogs were treated with bezafibrate once daily, using 200 mg tablets at a dosage of 4-10 mg/kg (depending on body weight). Serum TG and CHO concentrations and alanine aminotransferase (ALT) and creatine kinase (CK) activity before and after 30 days of treatment were compared.

RESULTS

Sixteen dogs (34.8%) had primary hyperlipidemia, and 30 dogs (65.2%) had secondary hyperlipidemia (including spontaneous hyperadrenocorticism [41.3%, n = 19/46], chronic treatment with glucocorticoids [10.8%, n = 5/46], and hypothyroidism [15.2%, n = 7/46]). After 30 days, serum TG concentration normalized (<150 mg/dL) in 42 dogs (91.3%) and CHO concentration normalized (<270 mg/dL) in 22 of 33 dogs (66.7%). There was no difference in baseline TG concentration between the primary and secondary hyperlipidemia subgroups, but the decrease in TG concentration after treatment was greater in the primary hyperlipidemia subgroup. No adverse effects were observed, but ALT activity decreased significantly after 30 days of treatment.

CONCLUSIONS AND CLINICAL IMPORTANCE

Over 30 days, BZF was safe and effective in treatment of primary and secondary hyperlipidemia in dogs.

Arterial pulse wave propagation velocity in healthy dogs by pulse wave Doppler ultrasound

The aim of this study was to prospectively evaluate the carotid-femoral pulse wave velocity (PWV) values in healthy dogs using pulse wave Doppler ultrasound. A secondary aim was to determine the feasibility of this method and to report the intra- and interobserver reproducibilities of the PWV in conscious dogs. The data were studied in 30 healthy, adult, male (n = 15) and female (n = 15) dogs. The time interval marked between the R wave peak of the electrocardiogram and the intersection of the blood flow wave upstroke of the Doppler spectrum with the baseline of zero frequency was determined for the carotid (T₁) and for the femoral (T₂) arteries. The distance covered by the pulse wave (L) was determined. The PWV was then calculated using the following formula: L/T₂ - T₁. The mean values of PWV calculated from the total sample (n = 30) evaluated were 13.41 ± 2.20 m/s. No significant statistical difference was observed for the PWV measurements between males (14.82 ± 3.18 m/s) and females (12.64 ± 2.45 m/s). The analysis revealed no intra nor interobserver differences. A reasonable reproducibility of the PWV measurements was showed by intraclass correlation coefficients (ICC), and the coefficients of variation (CV). These data demonstrate that noninvasive vascular Doppler analysis is a feasible and reproducible method to determine the carotid-femoral PWV in dogs.

Bartonella-associated inflammatory cardiomyopathy in a dog

A 6-year-old, male, mongrel dog was presented for acute onset of dyspnea and cough. At admission, the dog was cachectic and severely depressed. The electrocardiogram showed a sinus rhythm conducted with left bundle truncular branch block and interrupted by frequent multiform ventricular ectopic beats organized in allorhythmias. Thoracic radiographs revealed a marked cardiomegaly with perihilar edema, whereas transthoracic echocardiography revealed a dilated cardiomyopathy with segmental dyskinesis. Furosemide, enalapril, pimobendan, and mexiletine were prescribed, and a Holter was scheduled after resolution of congestive heart failure. Three days later, the dog died suddenly during sleep. Histopathology revealed diffuse myocyte hypertrophy with multifocal hemorrhages, alternating to areas of severe replacement fibrosis and lymphoplasmocytic infiltrates. Immunohystochemistry stains were strongly positive for T-lymphocyte infiltration (CD3) and weakly positive for B-lymphocytes (CD79). Polymerase chain reaction was positive for Bartonella spp. Based on these results, a post-mortem diagnosis of bacterial inflammatory cardiomyopathy was made.

Evaluation of endothelin-1 and MMPs-2, -9, -14 in cerebrospinal fluid as indirect indicators of blood-brain barrier dysfunction in chronic canine hypothyroidism

Chronic canine hypothyroidism is associated with blood-brain barrier (BBB) disruption. We hypothesized that this change is mediated by endothelin-1(ET-1) and matrix metalloproteinases (MMP) -2, -9, and -14, as evidenced by increased concentrations of these proteins in cerebrospinal fluid (CSF) compared to controls. CSF from 18 dogs, 9 controls and 9 with experimentally induced hypothyroidism was collected before and 6, 12, and 18 months after induction of hypothyroidism. Concentrations of ET-1 using an ELISA kit, and for MMP-2, -9, and -14 using gelatinase zymography were measured in CSF. ET-1 was undetectable in CSF of control and hypothyroid dogs at all time-points. Constitutively expressed MMP-2 was detectable in CSF samples in all dogs at all time-points. No other MMPs were detectable in CSF. No differences in CSF concentrations of ET-1 and MMP-2, 9, and 14 were found between hypothyroid and euthyroid dogs. Therefore, ET-1 and MMP-2, 9, and 14 are unlikely to be primary mediators of BBB damage in chronically hypothyroid dogs.

Intracorneal stromal hemorrhage in dogs and its associations with ocular and systemic disease: 39 cases

OBJECTIVE

To describe clinical features of dogs diagnosed with stromal intracorneal hemorrhage (ICH).

ANIMALS STUDIED

Retrospective case series of 39 dogs (44 eyes) with ICH.

PROCEDURES

Medical records of dogs evaluated by the Cornell University ophthalmology service were searched to identify animals with a clinical diagnosis of ICH between 2005 and 2014. Signalment and clinical details, including concurrent ocular disease, concurrent systemic disease, diagnostic tests performed, outcome of hemorrhage, presenting client complaint, and treatment, were recorded.

RESULTS

Intracorneal hemorrhage was identified in 44 eyes of 39 dogs. The mean (±standard deviation) age of dogs was 11.5 years (±2.8 years). The Bichon Frise breed and older dogs were statistically over-represented relative to the entire ophthalmology service canine referral population during the same time period. Concurrent ocular disease was present in 40 eyes (91%) and included keratoconjunctivitis sicca, cataracts, and corneal ulcers. Twenty-three dogs (59%) suffered from concurrent systemic disease, most frequently diabetes mellitus, hyperadrenocorticism, hypothyroidism, and systemic hypertension. Less commonly, life-threatening systemic conditions were identified in dogs with ICH including immune-mediated hemolytic anemia, immune-mediated thrombocytopenia, metastatic neoplasia, and sepsis. Intracorneal hemorrhage was found in all corneal locations, and corneal vascularization was present in each affected eye.

CONCLUSIONS

Intracorneal hemorrhage is an uncommon condition in dogs that occurs in association with corneal vascularization. The risk of ICH may be increased due to certain ocular and systemic diseases. Although uncommon, ICH may also be an ocular manifestation of severe immune-mediated, infectious, and neoplastic systemic diseases in dogs.

Preliminary Analysis of Modified Low-Density Lipoproteins in the Serum of Healthy and Obese Dogs and Cats

Oxidized low-density lipoprotein (LDL) is thought to play an important role in the inflammatory response associated with human obesity. The purpose of this preliminary study was to determine oxidized LDL concentrations in healthy dogs and cats, and to evaluate whether obesity affects oxidized LDL concentration, using 39 cats and 19 dogs that had visited two different veterinary clinics in Japan. We hypothesized that oxidized LDL concentrations measured against body condition score (BCS) may have a potential value in evaluating the qualities of accumulated or circulating lipids in obese dogs and cats that do not show signs of metabolic diseases. The mean oxidized LDL value in BCS3 dogs (2.4 ± 0.9 μg/dl) was very similar to that of BCS5 dogs (2.2 ± 0.3 μg/dl). The mean oxidized LDL value of BCS4 dogs was 7.2 ± 10.3 μg/dl and the highest among three groups. BCS4 dogs included two dogs whose oxidized LDL values were higher than the mean oxidized LDL value of healthy humans (11.2 ± 0.3 μg/dl). On the other hand, the mean oxidized LDL value of BCS3 cats was 2.5 ± 0.9 μg/dl, and those of BCS4 and 5 cats were higher than that of BCS3, but there was no significant difference. The BCS4 cat group included one cat with a higher oxidized LDL value, and the BCS5 group also included two cats with oxidized LDL values higher than the mean oxidized LDL value of healthy humans. Interestingly, the oxidized LDL values in two obese dogs and three obese cats were indeed higher than the mean oxidized LDL value of humans with coronary artery disease (20.1 ± 1.1 μg/dl). In conclusion, this preliminary study showed reference ranges of oxidized dogs and cats against BCS. Obesity alone does not appear to have any direct effect on serum oxidized LDL values in healthy dogs and cats.

Use of intravenous insulin aspart for treatment of naturally occurring diabetic ketoacidosis in dogs

OBJECTIVES

To characterize the utility and safety of IV insulin aspart in the treatment of diabetes ketoacidosis (DKA) in dogs and to determine the times to resolution of hyperglycemia, ketonemia, and acidemia in dogs treated with IV insulin aspart.

DESIGN

Prospective noncontrolled single arm study of dogs with DKA between February 2010 and March 2011.

SETTING

University teaching hospital.

ANIMALS

Six dogs with spontaneous DKA and blood glucose (BG) concentration >13.8 mmol/L (250 mg/dL), pH between 7.0 and 7.35, and blood beta-hydroxybutyrate >2.0 mmol/L were treated with an IV continuous rate infusion (CRI) of aspart insulin. The time to biochemical resolution of DKA was defined as the time interval from when the IV CRI of aspart insulin began until marked hyperglycemia (BG concentration >13.8 mmol/L [250 mg/dL]), acidemia (venous pH <7.35), and ketonemia (beta-hydroxybutyrate concentration >2.0 mmol/L) resolved. Aspart insulin was administered as an IV CRI at an initial dose of 0.09 U/kg/h. The dose was adjusted according to a previously published protocol.

MEASUREMENTS AND MAIN RESULTS

The median time to biochemical resolution of DKA in dogs treated with insulin aspart was 28 hours (range, 20-116 h). Mean BG concentration decreased significantly from the time IV fluid resuscitation began (32.0 mmol/L [576 mg/dL]; range, 14.9-38.9 mmol/L [268-700 mg/dL]) until 6 hours later when IV aspart insulin CRI began (20.1 mmol/L [363 mg/dL]; range, 9.4-26.1 mmol/L [169-470 mg/dL], P = 0.03). No adverse effects were observed in association with IV insulin aspart administration. Median cost of hospitalization was US$3,477 (range, US$1,483-10,469). Median total units per kilogram of administered IV insulin aspart was 2.97 U/kg (range, 2.04-10.52 U/kg).

CONCLUSIONS

Intravenous CRI of insulin aspart is a safe and effective treatment for DKA in dogs. IV fluid resuscitation is recommended prior to insulin administration.

Increased serum concentrations of adiponectin in canine hypothyroidism

Serum concentrations of adiponectin were compared between sex-matched hypothyroid (n = 18) and euthyroid (n = 18) client-owned dogs with comparable ages and body condition scores (BCS). Concentrations of adiponectin (mean; 95% confidence interval) were significantly (P < 0.01) higher in hypothyroid (17.2 µg/mL; 12.1-20.5 µg/mL) than healthy (8.0 µg/mL; 5.6-11.4 µg/mL) dogs following adjustment for potential confounders (BCS, age and sex). Serum concentrations of adiponectin were significantly negatively associated with concentrations of total thyroxine (P <0.05) and positively correlated with concentrations of cholesterol (r = 0.6, P <0.01) in hypothyroid dogs. In conclusion, this study demonstrated increased serum concentrations of adiponectin in dogs with hypothyroidism. Suggestive of the presence of resistance to adiponectin that could have contributed to development of hyperlipidemia and insulin resistance in these dogs or alternatively, could be a consequence of these metabolic alterations.