Normal Healthy Dogs Research Articles

Investigation of Hepatozoon Canis Related Alterations in the Haemato Biochemical Profile of Dogs

Aims: Hepatozoonosis, caused by a protozoan parasite Hepatozoon canis, is important for canine health due to its ability to cause chronic, debilitating disease, and the challenges it presents in terms of diagnosis and management. The present study was conducted to see the effect of H. canis infection on various haematological and biochemical parameters as compared to the normal healthy dogs in order to understand the disease pattern and suspecting the disease. Study Design: The clinically affected dogs that come to the veterinary hospital with symptoms of hepatozoonosis were included in the study. Haematological and biochemical parameters of dogs found positive for hepatozoonosis were analysed. The values of these parameters were subsequently compared to healthy animals in order to identify any significant difference caused by H. canis. Place and Duration of Study: The studied was conducted at Department of Veterinary Medicine, DUVASU Mathura, India. Total 212 blood samples were collected from the dogs that were brought for the treatment in between February 2023 to March 2024. Methodology: Total 212 dogs were included in the present study out of this 46 dogs were found positive with H. canis using PCR based molecular test. These positive animals were subjected to study the changes in biochemical parameters like blood urea nitrogen, creatinine, alkaline phosphatase, alanine transaminase, aspartate amino transferase, total leucocyte count, total erythrocyte count, haemoglobin, haematocrit, erythrocyte indices (MCV, MCH, MCHC), differential leucocyte count, platelet count and platelet indices (MPV, PDW) using autoanalyzer. Student's t-test in Graphpad Prism was used to compare these values to healthy animals. Results: The study confirms that Hepatozoonosis leads to significant haematological and biochemical changes in dogs. Infected dogs have lower Hb, TEC, and PCV than healthy animals, indicating anaemia. Thrombocytopenia and leukocytosis were also observed in the infected animals. Non-significant differences in MCV, MCH, and MCHC indicate normocytic, normochromic anaemia. Anisocytosis and non-regenerative anaemia is indicated by significant RDW-CV increases with decrease in MCV values. Increased liver-specific enzymes like ALT, AST, and ALP and kidney-related enzymes like BUN and CRT suggest hepatic and renal involvement in disease pathophysiology. Conclusion: In hepatozoonosis, haemato- biochemical parameters like non-regenerative anaemia. anisocytosis, thrombocytopenia, leukocytosis, low serum protein concentration and increased ALT, AST, ALP and BUN values may be used as non-specific biomarkers. The results can be used in making clinical decisions and monitoring therapeutic responses in cases of hepatozoonosis.

Advancing canine mammary tumor diagnostics: Unraveling the diagnostic potential of Cytokeratin 19 through droplet digital PCR analysis

Cytokeratin 19 (CK19) is a complex intracytoplasmic cytoskeletal protein primarily localized in the ducts of the mammary gland and skin epithelial cells. In humans, the expression of CK19 gene within circulating tumor cells (CTCs) extracted from blood samples of breast cancer patients reflects tumor cell activity, offering valuable insights for predicting early metastatic relapse or monitoring treatment effectiveness. However, knowledge of serum tumor markers is limited in veterinary oncology. Recently, droplet digital PCR (ddPCR), has been employed to explore rare target genes due to its heightened sensitivity and accuracy as a novel molecular diagnostic tool. The objectives of this study were to investigate the expression of the CK19 mRNA in CTCs, non-neoplastic mammary tissues, and both benign and malignant canine mammary tumors (CMTs) through ddPCR analysis. In Study I, we optimized the discard volume for blood samples to reduce CK19 contamination from skin epithelial cells post-venipuncture. The results revealed that discarding the initial 3 mL of blood was adequate and effective in eliminating CK19 mRNA contamination. In Study II, after the removal of the initial 3 mL of blood, we investigated CK19 mRNA-positive CTCs in the peripheral blood of normal healthy dogs, including those with benign and malignant CMTs. Intriguingly, CK19 mRNA was undetectable in all blood samples. The expression of CK19 mRNA in mammary tissues was investigated in Study III. The copy number (CN) ratios of the CK19 gene in non-neoplastic mammary tissues (14.77 ± 14.65) were significantly higher (P < 0.05) than those in benign (4.23 ± 3.35) and malignant groups (6.56 ± 5.64). Notably, no difference was observed between the benign and malignant groups. In conclusion, CK19 mRNA appeared unlikely to be a suitable candidate as a biomarker in the peripheral blood of CMTs, while the CN ratio in mammary tissues could serve as a potential discriminator between non-neoplastic and CMT groups, complementing the gold standard of histopathological examination.

Alterations in serum concentrations of visfatin and betatrophin in dogs with hypothyroidism.

Hypothyroidism in dogs is associated with obesity and altered lipid and carbohydrate metabolism. The adipokines, visfatin, and betatrophin, affect glucose tolerance. Betatrophin is involved in lipid regulation. Visfatin and betatrophin serum concentrations are altered in hypothyroid dogs. Dogs with naturally occurring hypothyroidism (n = 25) and healthy dogs (n = 25). Insulin, visfatin, and betatrophin serum concentrations were measured in all dogs and 19 of the hypothyroid dogs after 30 days of thyroxine treatment. Body condition score (BCS) was determined (1-9 scale). Visfatin concentrations were lower in hypothyroid compared with healthy dogs (mean, 95% confidence interval [CI]; 2.0 ng/mL, 1.2-3.3 vs 5.1 ng/mL, 3.3-7.8; P = .004) and increased post-treatment (3.1 ng/mL, 1.9-4.9 vs 2.6 ng/mL, 1.6-4.1; P = .05). Betatrophin concentrations were lower in lean to normal (body condition score [BCS], 3-5) hypothyroid dogs compared to lean to normal healthy dogs (52 pg/mL, 9-307 vs 597 pg/mL, 216-1648; P = .03), but were not different between overweight (BCS, 6-9) hypothyroid and healthy dogs (341 pg/L, 168-695 vs 178 pg/mL, 77-415; P = .26), and decreased post-treatment in overweight dogs (206 pg/mL, 87-488 vs 268 pg/mL, 112-640; P = .004). Visfatin concentrations were higher in overweight compared with lean to normal dogs (4.7 ng/mL, 3.3-6.6 vs 2.2 ng/mL, 1.2-4.2; P = .04). Betatrophin concentrations were positively correlated with BCS (r = .47, P = .02) and insulin concentrations (r = .48, P = .03) in hypothyroid dogs and negatively correlated with BCS (r = -.47, P = .02) and thyroid stimulating hormone concentrations (r = -.56, P = .01) in healthy dogs. Hypothyroidism in dogs is associated with alterations in visfatin and betatrophin concentrations that partially resolve with thyroxine treatment.

Comparison of the quantity and antimicrobial activity of host defence peptides in ear canals between healthy and atopic dogs: A preliminary study.

Host defence peptides (HDPs) are involved in cutaneous immune defence. The secretion of HDPs in the ears of healthy normal and noninfected atopic dogs has not been measured. The aim of this study was to quantify the concentrations of β-defensins (cBD3)-like and cathelicidin (cCath) HDPs in ears of healthy and atopic dogs without infectious otitis, additionally to evaluate the antimicrobial effect of the HDPs obtained. Ten healthy and 20 atopic dogs with mild inflammatory, noninfectious otitis were included. Absence of infection was determined by cytological evaluation, and the severity of clinical signs, if present, was assessed by a previously validated score (Otitis Externa Scoring System for Clinical Study, OTIS-3). The left ear canal of each dog was rinsed with 2 mL of sodium phosphate buffer. The solution obtained was analysed by enzyme-linked immunosorbent assay to quantify HDPs. Additionally, aural secretions were incubated with two concentrations (5 × 105 and 5 × 104 colony-forming units/mL) of Staphylococcus pseudintermedius and the bacterial density measured after 24 h of incubation. Data were statistically analysed. Significance was set as p ≤ 0.05. There was a significantly lower concentration of HDPs from atopic ears when compared with those from normal healthy dogs (cBD3-like: p = 0.0007; cCath: p = 0.049). There was minimal to variable antimicrobial activity in the aural secretions of both groups. This study showed, for the first time, that the ear canals of atopic dogs with mild noninfectious otitis contain a lower concentration of cBD3-like and cCath HDPs than those of healthy dogs with normal ears. A consistent antimicrobial activity was not present in the aural secretions from either group.

Urine Residual Volume in Normal Dogs Determined by Direct Measurement and Comparison to Two-Dimensional Ultrasonographic Measurement.

Normal urine residual volume (URV) in dogs has not previously been established by direct measurement. Twenty-two client-owned normal healthy dogs (8 female spayed, 12 male castrated, 2 male intact) without history of urinary abnormalities were included. Dogs were walked outside for 5 min to allow for natural voiding, immediately followed by urinary bladder ultrasound and urinary catheterization. The URV was recorded, and the ultrasound images were used to estimate URV for each dog. There was no significant difference between male and female URV; therefore, all data were pooled. With a 90% confidence interval, URV was 0-0.47 mL/kg with a mean URV of 0.21 mL/kg and a median value of 0.175 mL/kg. There was no significant difference between the measured URV and the ultrasound-determined URV. This case series supports previously established normal URV in the dog; however, a reference interval based on a larger population of dogs with further evaluation of body size/weight, sex, and neuter status is recommended to be established for use in clinical setting to differentiate normal urination from urinary retention in patients.

Effects of tiletamine-zolazepam versus propofol on peri-induction intraocular pressure (IOP) in dogs: a prospective, randomized, blinded crossover study

Introduction: Anesthesia induction agents have the potential to cause severe ocular side effects, resulting in lasting damage to the eye. The purpose of this study is to determine the effects of tiletamine-zolazepam on IOP compared to propofol when used as an induction agent in normal healthy dogs.

Evaluation of serum mineral status in dermatological disorders of dogs

The study was undertaken to evaluate serum mineral status, specifically zinc, copper and selenium in dogs affected with dermatological disorders in comparison to normal healthy dogs. The study included 40 dogs of 2-5 years of age with skin diseases presented to University Veterinary Hospitals at Mannuthy and Kokkalai under the Kerala Veterinary and Animal Sciences University, and ten apparently healthy dogs brought to the hospital for routine health check-up which served as control. Serum concentrations of the three minerals were compared not only between normal and dogs with skin diseases as a whole but also between individual skin diseases- six different skin diseases- with the control group. On comparing the dogs with skin ailments (n=40) and control group, the serum mineral levels analysed through Atomic Absorption Spectrophotometry (AAS) revealed that the concentration of zinc was significantly lower (p&lt;0.01) in the diseased group (0.53 ± 0.04 mg/L) of dogs (n=40) than the control group (1.11 ± 0.09 mg/L) and the serum copper concentration was also significantly reduced (p&lt;0.05) in diseased dogs (0.91 ± 0.08 mg/L) with respect to the control animals (1.23 ± 0.11 mg/L). The serum selenium concentration of diseased group of animals(n=40), however failed to show any significant difference from the control group of animals. The outcome of the study suggests a need for supplementation of zinc and copper in dogs with skin ailments like canine demodicosis that relapse even after prolonged therapy with acaricides.

Haemato-Biochemical Alterations in Dogs with Vomition

Vomition is a common clinical presentation in small animal practice and may be associated with gastrointestinal and systemic diseases. Fifty cases of vomition in dogs were studied at Veterinary Clinical Complex of the College in Anand during the period of six months for clinical and haemato-biochemical alterations in comparison to 8 normal healthy dogs. Among 50 dogs, the incidence of vomiting possibly due to Parvo viral infection, pyometra, renal disorders, encylostoma infection, pseudo-pregnancy, hepatic disorders, thrombocytopenia, neutrophilia and dietary abnormalities was in 44.0, 2.0, 14.0, 14.0, 2.0, 4.0, 2.0, 14.0 and 4.0 % cases, respectively. The levels of PCV, TLC and basophils were increased significantly (p less than 0.05) with decreased Hb in dogs suffering with vomiting as compared to healthy control group. The serum biochemical examinations revealed significantly (p less than 0.05) decreased mean serum albumin concentration and increased serum creatinine, BUN, ALT and AST values in dogs with vomiting as compared to healthy control group. However, TEC, lymphocyes, neutrophils, eosinophils, monocytes counts and serum total protein did not vary significantly between vomiting and healthy dogs.

Left ventricular systolic function in dogs with pulmonic stenosis.

Background and Aim:Pulmonic stenosis (PS) is the most common congenital heart disease in dogs. This condition causes right ventricle (RV) overload and disrupts overall systolic function. The aim of this study was to examine the alterations of cardiac electrical activity and mechanical function in dogs with PS compared to normal healthy dogs.Materials and Methods:The ventricular systolic function of dogs with PS was studied. Dogs were divided into two groups, PS (n=13) and control (CONT) (n=12). Measurements of blood pressure, electrocardiography (ECG), and echocardiography were performed.Results:PS dogs had exercise intolerance, with six experiencing syncope. ECG of PS dogs showed higher amplitudes of P, S, and T waves (p<0.01), and a lower R:S ratio (p<0.001) with longer QRS duration (p<0.001) compared to CONT dogs. Echocardiography demonstrated that the pulmonic flow velocity and pressure gradient (PG) between the RV and the pulmonary artery of PS dogs were significantly higher than CONT dogs (p<0.001). The RV free wall thickness to the left ventricular posterior wall thickness ratio and the right atrium to the left atrium diameter ratio was higher (p<0.001), while interventricular septum (IVS) was thicker (p<0.01) in PS dogs compared with CONT dogs (p<0.001). The systolic function in PS dogs showed higher pulmonic valve velocity time integral (PVVTI) value (p<0.001) and longer pulmonic valve ejection time (ET) (p<0.05) than CONT dogs. However, aortic valve VTI (AVVTI) value and aortic valve ET were not significantly different between the groups, although fractional shortening in PS dogs was higher. In PS dogs, PG showed a significant positive correlation with PVVTI: AVVTI ratio (p<0.05).Conclusion:PS had prolonged pulmonic valve opening. The thickening of the RV wall and IVS can cause a detrimental reduction of the left ventricular preload in PS dogs.

Micro RNA Transcriptome Profile in Canine Oral Melanoma.

MicroRNAs (miRNAs) dysregulation contribute the cancer pathogenesis. However, the miRNA profile of canine oral melanoma (COM), one of the frequent malignant melanoma in dogs is still unrevealed. The aim of this study is to reveal the miRNA profile in canine oral melanoma. MiRNAs profile of oral tissues from normal healthy dogs and COM patients were compared by next-generation sequencing. Along with tumour suppressor miRNAs, we report 30 oncogenic miRNAs in COM. The expressions of miRNAs were further confirmed by quantitative real-time PCR (qPCR). Pathway analysis showed that deregulated miRNAs impact on cancer and signalling pathways. Three oncogenic miRNAs targets (miR-450b, 301a, and 223) from human study also were down-regulated in COM and had a significant negative correlation with their respective miRNA. Furthermore, we found that miR-450b expression is higher in metastatic cells and regulated MMP9 expression through a PAX9-BMP4-MMP9 axis. In silico analysis indicated that miR-126, miR-20b, and miR-106a regulated the highest numbers of differentially expressed transcription factors with respect to human melanoma. Chromosomal enrichment analysis revealed the X chromosome was enriched with oncogenic miRNAs. We comprehensively analyzed the miRNA’s profile in COM which will be a useful resource for developing therapeutic interventions in both species.

Lack of Effect of Oral Melatonin on Platelet Parameters in Normal Healthy Dogs.

A randomized, prospective, blinded, placebo-controlled study on the effect of oral melatonin on platelet parameters was performed on 40 healthy dogs with normal physical examinations and no clinically significant findings on serum chemistry evaluation. Dogs were randomly assigned to the study group or the placebo-control group and administered oral melatonin or an oral inert tablet, respectively, for 28 days. Dogs in the study group were administered melatonin at 3 mg per os q 12 hr for dogs weighing <15 kg and 6 mg per os q 12 hr for dogs weighing 15 kg or more. Complete blood counts were obtained at 0, 7, 14, and 28 days of medication administration. No adverse effects or sedation were noted in any dog. The placebo group had a statistically significant transient increase in both plateletcrit and mean platelet volume on day 7 relative to baseline, which was not observed in the melatonin group. Oral melatonin did not appear to have a direct thrombopoietic effect in normal healthy dogs. Future studies are required to investigate the pharmacokinetics of melatonin in dogs and the potential benefits of melatonin in both thrombocytopenia and immune-mediated diseases.

Usefulness of noninvasive shear wave elastography for the assessment of hepatic fibrosis in dogs with hepatic disease.

BackgroundTwo‐dimensional shear wave elastography (2D‐SWE) can noninvasively evaluate hepatic elastic modulus as shear wave velocity (SWV). Additionally, it may predict the presence of clinical relevant hepatic fibrosis (≥F2) in dogs with hepatic disease.ObjectivesTo investigate whether SWV measured by 2D‐SWE can differentiate between dogs with (≥F2) and without (F0‐1) clinically relevant hepatic fibrosis.AnimalsTwenty‐eight client‐owned dogs with hepatic disease and 8 normal healthy Beagle dogs were enrolled.MethodsIn this cross‐sectional prospective study, SWVs were measured using 2D‐SWE in all dogs. Hepatic fibrosis stages and necroinflammatory activity grades were histopathologically evaluated using a histological scoring scheme that was adapted from the Ishak schema used in human medicine.ResultsMedian SWVs were significantly higher in dogs with clinically relevant hepatic fibrosis (2.04 m/s; range, 1.81‐2.26 m/s) than in healthy dogs (1.51 m/s; range, 1.44‐1.66 m/s; P = .007), and dogs without clinically relevant hepatic fibrosis (1.56 m/s; range, 1.37‐1.67 m/s; P < .001). However, no significant difference was found in the SWVs between dogs without clinically relevant hepatic fibrosis and healthy dogs (P = .99). Furthermore, median SWVs were not significantly different among dogs with necroinflammatory activity, those without necroinflammatory activity, and healthy dogs (Kruskal‐Wallis test, P = .12).Conclusions and Clinical ImportanceThe 2D‐SWE may be useful for predicting the presence of hepatic fibrosis in dogs with hepatic disease.

Onychomycosis Caused by Malassezia pachydermatis in a Dog

Background: Malassezia species are commensal skin organisms of warm-blooded vertebrates that can act as opportunistic pathogens. Malassezia pachydermatis is of importance in both veterinary and human medicine. Recognised initially as causes of infection of the skin, they are now known to be superficial commensals as well as potential causes of infections in domestic animals and more serious human conditions such as fungemia. They have also been implicated in the pathogenesis of allergic and other inflammatory diseases. Onychomycosis is defined as fungal infection of the claw (nail disease) caused by dermatophytes (Microsporum and Trichophyton genus), non-dermatophyte molds (hyaline and dematiaceous) and/or yeasts. The objective of this work was to report a case of canine onychomycosis by Malassezia pachydermatis based on reference standard diagnostics of this pathology.Case: A 9-year-old male West Highland White Terrier presented history of claw abnormality: brown staining and partly brittle. The dog has no apparent history of trauma on the affected claw and no skin disease was reported. Direct examination of claw was performed using the tape strip technique revealed Malassezia organisms. Nail fragments were cultured onto Sabouraud Dextrose Agar with Chloramphenicol and Cycloheximide. After 10 days of incubation (32ºC) nail fragments allowed the isolation of pure colonies of Malassezia pachydermatis. The histopathological evaluation was performed by Sector of Veterinary Clinical Pathology, Faculdade de Veterinária (FAVET/UFRGS) and fungal infection due to Malassezia pachydermatis was confirmed by histopathologic examination (Hematoxylin and eosin and Grocott’s methenamine silver stain) of the nail, that revealed abundant yeasts (blastoconidia).Discussion: Fungal infection of the skin, hair and nails are common and are primary caused by the dermatophyte molds. Non-dermatophyte molds isolated from nails constitute a long list, but only a few species cause onychomycoses. These include Scopulariopsis brevicaulis, Fusarium sp., Acremonium spp., Aspergillus spp., Penicillium spp. Yeasts like Malassezia and Candida spp. are saprophytes and usually represent incidental contaminants associated with a non-sterile specimen at mycological culture, however in some cases they may parasite the nails and become an etiological agent of the disease. M. pachydermatis, normally present on the skin and in the ear canal of dogs and cats, can act as opportunistic pathogenic microbe and frequently causes dermatitis and otitis in mammals. In the case of onychomycosis, there is little evidence that Malassezia yeasts are implicated in nail plate invasion, although this may be a rare occurrence. All species of the genus are obligatory lipid-dependent forms, with the exception of M. pachydermatis, as well as absence of keratinolytic ability. Malassezia organisms were commonly retrieved from the subungual claw fold region of normal healthy dogs (should be considered resident microflora of the normal canine claw fold). Some authors suggests that high numbers of yeast can be detected on cytological evaluation of the skin surface of the canine claw fold from allergic dogs in both the absence and presence of concurrent signs of pruritus and paronychia.

Serum biochemistry profile, inflammatory cytokines, adipokines and cardiovascular findings in obese dogs

The aim of this study was to evaluate the serum biochemistry profile, inflammatory cytokines, adipokines and cardiovascular findings in obese dogs. Twenty obese and 20 normal weight healthy pet dogs were recruited into the study, where they underwent blood testing and assessment of cardiovascular function (blood pressure analysis, electrocardiography and echocardiography). Higher concentrations of total cholesterol, triglycerides, lactate dehydrogenase, total serum proteins, α-globulins, total bilirubin, insulin, insulin:glucose ratio, alkaline phosphate and alanine aminotransferase were observed in obese dogs than dogs of normal weight. There were no differences in concentrations of tumour necrosis factor (TNF)-α or interleukin (IL)-6 between the two groups. Obese dogs had higher serum leptin but lower adiponectin concentrations than dogs of normal weight. Systolic arterial blood pressure was higher in obese dogs than dogs of normal weight. The values for the thickness of the free wall of the left ventricle and interventricular septal thickness were greater at end-diastole in obese dogs compared to dogs of normal weight. Four of 20 obese dogs were determined to have obesity-related metabolic dysfunction (ORMD). The findings indicate that a chronic inflammatory state is not necessarily evident in obese dogs, as has been described in human beings, and the criteria used for ORMD can be used to define this syndrome in dogs. In this study, canine obesity was associated with cardiac and vascular dysfunction.

Disposition of Extended Release Levetiracetam in Normal Healthy Dogs After Single Oral Dosing.

BackgroundLevetiracetam is an anticonvulsant used for control of canine epilepsy. An extended release preparation should improve dosing convenience.ObjectivesTo determine the disposition of extended release levetiracetam in normal dogs after single dosing.AnimalsPharmacokinetic study: 16 healthy, adult dogs.MethodsUsing a partially randomized crossover study, levetiracetam (30 mg/kg) was administered intravenously (IV) and orally (PO) as extended release preparation with or without food. Blood was collected for 24 hours (IV) or 36 hours (PO). Serum levetiracetam was quantitated by immunoassay and data were subjected to noncompartmental analysis.ResultsPharmacokinetic parameters for fasted versus fed animals, respectively, were (mean ± SEM): C max = 26.6 ± 2.38 and 30.7 ± 2.88 μ/mL, T max = 204.3 ± 18.9 and 393.8 ± 36.6 minutes, t 1/2 = 4.95 ± 0.55 and 4.48 ± 0.48 hours, MRT = 9.8 ± 0.72 and 10 ± 0.64 hours, MAT = 4.7 ± 0.38 and 5.6 ± 0.67 hours, and F = 1.04 ± 0.04 and 1.26 ± 0.07%. Significant differences were limited to T max (longer) and F (greater) in fed compared to fasted animals. Serum levetiracetam concentration remained above 5 μ/mL for approximately 20 hours in both fasted and fed animals.Conclusions and Clinical ImportanceExtended release levetiracetam (30 mg/kg q12h), with or without food, should maintain concentrations above the recommended minimum human therapeutic concentration.

Big endothelin-1 as a tumour marker for canine haemangiosarcoma

Haemangiosarcoma (HSA) is an important malignant neoplasm of dogs that originates from vascular endothelial cells. This study explored the suitability of using serum big endothelin-1 (ET-1) as a tumour marker for canine spontaneous HSA. Serum big ET-1 was measured in dogs with splenic HSA (n = 14), splenic malignant tumours other than HSA (n = 10), benign splenic lesions (n = 11) and normal healthy dogs (n = 17) by ELISA. Serum big ET-1 levels in dogs with HSA were significantly (P < 0.01) higher than in other dogs. High sensitivity (100%, 95% confidence interval 86–100%) and specificity (95%, 95% confidence interval 86–95%) for HSA diagnosis were obtained using a cut-off of 17 pg/mL according to receiver operating characteristic (ROC) curves (area under ROC curve 0.93). PPET1, ETA, VEGF and Hif1-α mRNA expression, measured by real-time PCR, were elevated in HSA compared with normal tissues. These findings suggest that elevated serum big ET-1 could be used as a diagnostic marker for canine HSA.

Plasma and platelet serotonin concentrations in healthy dogs and dogs with myxomatous mitral valve disease

ObjectivesSerotonin has been implicated in canine myxomatous mitral valve disease (MMVD); however, the sources of serotonin have not been fully elucidated. This study compared the concentration of serotonin in plasma and platelets of normal healthy small breed dogs with predisposition to MMVD and dogs with naturally occurring MMVD. Animals43 small-breed client-owned dogs with an approximate weight of <10 kg and age of 6 years or above were divided into 2 groups: a healthy control group (n = 20) and a group with echocardiographic evidence of MMVD (n = 23). Methods5 ml samples of blood were collected. Plasma and platelets were separated by centrifugation and assayed for serotonin measured by enzyme linked immunosorbent assay (ELISA). ResultsMedian plasma serotonin concentration was not significantly different (p = 0.3630) between normal healthy dogs (3.7 ng/ml) and dogs with MMVD (4.3 ng/ml). Males had higher plasma serotonin concentration than females (4.7 and 2.9 ng/ml respectively, p = 0.0043). Platelet serotonin concentration was not different between healthy dogs and dogs with MMVD (128.6 ng/109 platelets and 176.6 ng/109 platelets respectively, p = 0.4575). Age, echocardiographic indices and platelet count showed no correlation with plasma or platelet serotonin concentration. ConclusionsCirculating plasma serotonin is unlikely a major source of serotonin signaling in canine MMVD. Platelets could be a source of serotonin in canine MMVD through platelet adhesion to the mitral valve; however, the amount of serotonin stored in platelets of healthy dogs and dogs with MMVD is not different.

High‐frequency ultrasound biomicroscopy of the normal canine haired skin

The ultrasonographic appearance of the normal canine haired skin examined using high-frequency ultrasonography has not been described. To describe the echogenicity of normal canine haired skin using high-frequency (50MHz) ultrasonography and to compare ultrasonographic with histological measurements of skin thickness using snap-frozen tissue biopsy samples. Ten normal healthy beagle dogs. Ultrasonographic examination was performed on eight cutaneous sites by use of a 50MHz polyvinylidene difluoride transducer. The skin echogenicity was evaluated, and the mean of 10 skin thickness measurements was calculated. Ultrasonography results were compared with histological findings of skin cryosections stained with haematoxylin and eosin, as well as with histometric measurements of skin thickness. Differences in the ultrasonographic and histological measurements among biopsy sites, age and sex of the animals were also examined. The skin layers and hair follicles could be identified with high-frequency ultrasound biomicroscopy in all eight examination sites of all 10 dogs. There was a highly significant, positive association between the ultrasonographic and histological measurements (P<0.001) of skin thickness. For both ultrasonographic and histological skin thickness measurements, there were no statistically significant differences between sex, age or among the different examination sites. Cutaneous ultrasound biomicroscopy using a 50MHz transducer is a useful tool for the following applications: (i)to identify the skin layers (including the epidermis, dermis and subcutaneous fat); (ii)to demonstrate the hair follicles in various areas of the haired skin; and (iii)to measure the thickness of normal canine skin accurately.

Serum big endothelin-1 as a clinical marker for cardiopulmonary and neoplastic diseases in dogs

AimsMany studies of human subjects have demonstrated the utility of assessing serum levels of endothelin-1 (ET-1) and big ET-1 as clinical biomarkers in cardiopulmonary and neoplastic diseases. In this study we explored the feasibility of using serum big ET-1 as a reliable veterinary marker in dogs with various cardiopulmonary and neoplastic diseases. Main methodsSerum big ET-1 levels were measured by ELISA in dogs with cardiopulmonary (n=21) and neoplastic diseases (n=57). Dogs exhibiting cardiopulmonary disease were divided into two groups based on the velocity of tricuspid valve regurgitation (3.0>m/s) measured by ultrasound: without and with pulmonary hypertension. Big ET-1 levels for the dogs with the diseases were compared with levels in normal healthy dogs (n=17). Key findingsDogs with cardiopulmonary disease (4.6±4.6pmol/l) showed a significantly (P<0.01) higher level of big ET-1 than healthy control dogs (1.1±0.53pmol/l). Serum levels in the dogs with pulmonary hypertension (6.2±5.3pmol/l) were significantly (P<0.01) higher than those without pulmonary hypertension (2.0±0.6pmol/l). Dogs with hemangiosarcoma (5.6±2.2pmol/l), adenocarcinoma (2.0±1.8pmol/l), histiocytic sarcoma (3.3±1.9pmol/l), chondrosarcoma or osteosarcoma (3.0±1.6pmol/l) and hepatocellular carcinoma (2.7±1.8pmol/l) showed significantly (P<0.05) higher levels than healthy control dogs. SignificanceThese findings point to the potential of serum big ET-1 as a clinical marker for cardiopulmonary and neoplastic diseases in dogs.

Genome-Wide Association Analysis Identifies a Mutation in the Thiamine Transporter 2 (SLC19A3) Gene Associated with Alaskan Husky Encephalopathy

Alaskan Husky Encephalopathy (AHE) has been previously proposed as a mitochondrial encephalopathy based on neuropathological similarities with human Leigh Syndrome (LS). We studied 11 Alaskan Husky dogs with AHE, but found no abnormalities in respiratory chain enzyme activities in muscle and liver, or mutations in mitochondrial or nuclear genes that cause LS in people. A genome wide association study was performed using eight of the affected dogs and 20 related but unaffected control AHs using the Illumina canine HD array. SLC19A3 was identified as a positional candidate gene. This gene controls the uptake of thiamine in the CNS via expression of the thiamine transporter protein THTR2. Dogs have two copies of this gene located within the candidate interval (SLC19A3.2 – 43.36–43.38 Mb and SLC19A3.1 – 43.411–43.419 Mb) on chromosome 25. Expression analysis in a normal dog revealed that one of the paralogs, SLC19A3.1, was expressed in the brain and spinal cord while the other was not. Subsequent exon sequencing of SLC19A3.1 revealed a 4bp insertion and SNP in the second exon that is predicted to result in a functional protein truncation of 279 amino acids (c.624 insTTGC, c.625 C>A). All dogs with AHE were homozygous for this mutation, 15/41 healthy AH control dogs were heterozygous carriers while 26/41 normal healthy AH dogs were wild type. Furthermore, this mutation was not detected in another 187 dogs of different breeds. These results suggest that this mutation in SLC19A3.1, encoding a thiamine transporter protein, plays a critical role in the pathogenesis of AHE.