Healthy German Shepherd Dogs Research Articles

Longitudinal evaluation of the cutaneous and rectal microbiota of German shepherd dogs with perianal fistulas undergoing therapy with ciclosporin and ketoconazole.

Perianal fistulas are painful ulcers or sinus tracts that disproportionately affect German shepherd dogs and are proposed as a spontaneous animal model of fistulising Crohn's disease. To characterise the rectal and cutaneous microbiota in German shepherd dogs with perianal fistulas and to investigate longitudinal shifts with lesion resolution during immunomodulatory therapy. Eleven German shepherd dogs with perianal fistulas and 15 healthy German shepherd dogs. Affected dogs were evaluated and swabbed at three visits, 30 days apart, while undergoing treatment with ciclosporin and ketoconazole. Healthy German shepherd dogs were contemporaneously sampled. Sites included the rectum, perianal skin and axilla. The microbiome was evaluated following sequencing of the V4 hypervariable region of the 16S ribosomal RNA (rRNA) gene. Alpha diversity was not significantly different between healthy and affected dogs at each of the three body sites (p > 0.5), yet rectal and perianal beta diversities from affected dogs differed significantly from those of healthy dogs at Day 0 (p = 0.004). Rectal and perianal relative abundance of Prevotella spp. increased and perianal Staphylococcus spp. relative abundance decreased in affected dogs over time, coincident with lesion resolution. Changes in lesional cutaneous and rectal microbiota occur in German shepherd dogs with perianal fistulas and shift over time with lesion resolution during immunomodulatory therapy. Further investigations of the role of cutaneous and enteric microbiota in the pathogenesis of perianal fistulas, and whether manipulation of microbial populations may ameliorate disease, are needed.

Long-term examinations of the lumbal disc and facet joint changes in 5 German Shepard dogs

The purpose of this first-time long-term observational study was to evaluate the changes of the caudal lumbar spine at the locations L5/6, L6/7, and L7/S1 in 5 German shepherd dogs over a 6-year time period using computed tomography (CT) and magnetic resonance imaging (MRI). The dogs had a mean age of 26 months at the time of the first examination. In addition, it was evaluated whether a breeding examination, with regard to disc degeneration, is justified in young dog. The locations L7/S1, L6/7, and L5/6 were examined in more detail with regard to their signal intensity changes, the facet joint angle changes in dorsal (dors) and transverse (trans) planes, and disc surface changes in sagittal (sag) and transverse (trans) reconstruction planes with CT and MRT in 2015 and 2021. All data were collected computer-based and analyzed statistically. Subsequently, the results were compared to the measured signal intensity and to the subjective disc degeneration grading according to Seiler used in practice. Over the period of 6 years a significant loss of the measured signal intensity of the intervertebral discs in the transverse plane and an overall facet joint widening in the transverse plane of 0.54° as well as in the dorsal plane of 1.8° was evident. In addition, there was no evidence of a relationship between the size of the facet joint angle and the degree of disc degeneration. Furthermore, regardless of the initial degree of degeneration, the discs showed low signal intensity and higher Seiler grade during follow-up. The results of the present study group indicate that an inconspicuous condition of the lumbar intervertebral discs at the time of the initial breeding examination in the young dog does not allow an accurate prediction of the subsequent degree of degeneration and that there are ongoing remodeling processes at the facet joints even in healthy German shepherd dogs.

Electrocardiographic Evaluation of Cardiac Rhythm: A Comparative Study of Apparently Healthy German Shepherd Dogs Versus Dogs with Cardiac Affections

Background: The objective of the present study was to define existence of age and body weight related cardiac structural and functional changes in both healthy GSD as well as those having structural or functional cardiac affections. Thus the present study was conducted to establish the reference values of various parameters of ECG based on age and body weight and further evaluation of clinical cases based on these reference values. Method: The present study was conducted on eight apparently healthy German shepherd dogs aged 36-72 months with body weight 22-33.2 kg free from cardio-thoracic diseases to establish the reference values of various electrocardiographic parameters (Group-I) and used to evaluate the cardiac rhythm in 3 GSD dogs having some cardiac diseases (Group-II) based on the reference values obtained from Group-I. Result: Heart rate showed negative correlation with age and body weight. Positive correlation of amplitude of S and T wave, QRS complex, duration of T wave, P-R interval and R-R interval with age and body weight; amplitude of Q wave, duration of P wave and Q-T interval with body weight was observed. Negative correlation of amplitude of P and R wave, S-T interval with age and body weight; amplitude of Q wave, duration of P wave and Q-T interval with age was observed.

A Canine Gait Analysis Protocol for Back Movement Assessment in German Shepherd Dogs.

Objective—To design and test a motion analysis protocol for the gait analysis of adult German Shepherd (GS) dogs with a focus in the analyses of their back movements. Animals—Eight clinically healthy adult large-sized GS dogs (age, 4 ± 1.3 years; weight, 38.8 ± 4.2 kg). Procedures—A six-camera stereo-photogrammetric system and two force platforms were used for data acquisition. Experimental acquisition sessions consisted of static and gait trials. During gait trials, each dog walked along a 6 m long walkway at self-selected speed and a total of six gait cycles were recorded. Results—Grand mean and standard deviation of ground reaction forces of fore and hind limbs are reported. Spatial-temporal parameters averaged over gait cycles and subjects, their mean, standard deviation and coefficient of variance are analyzed. Joint kinematics for the hip, stifle and tarsal joints and their average range of motion (ROM) values, and their 95% Confidence Interval (CI) values of kinematics curves are reported. Conclusions and Clinical Relevance—This study provides normative data of healthy GS dogs to form a preliminary basis in the analysis of the spatial-temporal parameters, kinematics and kinetics during quadrupedal stance posture and gait. Also, a new back movement protocol enabling a multi-segment back model is provided. Results show that the proposed gait analysis protocol may become a useful and objective tool for the evaluation of canine treatment with special focus on the back movement.

Pulmonary veno-occlusive disease as a cause of severe pulmonary hypertension in a dog

BackgroundPulmonary veno-occlusive disease (PVOD) is a rare cause of pulmonary arterial hypertension (PAH) in humans and can be classified in idiopathic, heritable, drug and radiation-induced, and associated with connective tissue disease or human immunodeficiency virus infection. Recently, biallelic mutations of the EIF2AK4 gene have been discovered as a cause for an autosomal recessive form of PVOD in humans. In dogs, PAH is poorly characterized and is generally considered to be idiopathic or secondary to (for example) congenital left-to right cardiovascular shunts or heartworm disease. However, recently, the pathologic features resembling human PVOD were retrospectively described in post-mortem lung samples of dogs presenting with respiratory distress and idiopathic pulmonary hypertension (PH), which suggests that PVOD contributes to an unknown percentage of cases with unexplained PH. In dogs, information on the clinical presentation of PVOD is scarce and the cause and pathogenesis of this disease is still unknown.Case presentationAn 11-year-old, intact male German Shepherd dog (GSD) was presented with a 2-day history of acute-onset dyspnea and generalized weakness. Physical examination, laboratory analysis, thoracic radiography, echocardiography, a computed tomography scan and an ante mortem lung biopsy demonstrated severe arterial hypoxemia and severe PH but were not diagnostic for a known disease syndrome. Based on the poor reaction to therapy with oxygen, sildenafil, pimobendan and dexamethasone the dog was euthanized. Histopathology of the lungs showed venous and arterial remodelling, segmental congestion of alveolar capillaries and foci of vascular changes similar to human pulmonary capillary hemangiomatosis, indicating that the dog suffered from PVOD. Whole genome sequencing analysis was performed on the case and a healthy GSD. Validation was performed by Sanger sequencing of five additional GSD's unknown for any form of respiratory stress and aged ≥ 10 years. No causal variants were found in the genes that are known to be involved in human PVOD and PAH.ConclusionsThis case report confirms that PVOD should be a diagnostic consideration in dogs presenting with dyspnea and unexplained PH. In the present case, no casual genetic mutations known to be involved in humans with PVOD and PAH were found.

Photography-based method for assessing fluorescein clearance test in dogs

BackgroundThe fluorescein clearance test (FCT) provides insight into the tear film dynamics. The purpose of this study was to describe an inexpensive and practical method for assessing FCT in dogs, using photography and software analysis, and to assess the retention time of 1 vs. 2 eye drops on the canine ocular surface.Methods(i) In vivo - Eight healthy German Shepherd dogs were recruited. Following topical anesthesia with 0.5% proxymetacaine, each eye sequentially received (1 week apart) either 1 drop (35 μL) or 2 drops (70 μL) of 0.5% fluorescein. A Schirmer strip was inserted in the ventral conjunctival fornix for 10 s at the following times: each 10 min for 100 min, 24 h, 48 h and 72 h. (ii) In vitro - Schirmer strips were placed for 10 s in contact with microplate wells containing 1 or 2 drops of 0.5% fluorescein. In both experiments, the fluorescein-impregnated Schirmer strips were immediately imaged, and the area and intensity of fluorescein uptake were analyzed with ImageJ software. For the in vitro experiment, images were evaluated by the same examiner (repeatability) or two examiners (reproducibility).ResultsPhotography-based FCT was easy to perform and showed high repeatability and reproducibility (coefficients of variation ≤2.75%). In vivo, the area and intensity of fluorescein uptake on Schirmer strips were significantly greater at 30 min and 40 min post- fluorescein instillation in the 2 drops vs. 1 drop groups (p ≤ 0.044). Compared to baseline, the residual fluorescein uptake on Schirmer strips was < 5% at 60 min and 90 min in the 1 drop and 2 drops groups, respectively.ConclusionsPhotography-based FCT is a practical and reliable diagnostic tool with various clinical and research applications in veterinary medicine. Instillation of two drops provided greater amount and longer retention on the anesthetized canine ocular surface than a single drop. Fluorescein clearance time of a single drop in dolichocephalic dogs is 60 min.

Frequency of Normal versus Support Trot in the Healthy German Shepherd Dog

Frequency of Normal versus Support Trot in the Healthy German Shepherd Dog

Feasibility and echocardiographic characteristics of a three-minute stage dobutamine stress test in healthy dogs

Introduction. Dobutamine stress test (DST) is used as a method of functional cardiac examination in human medicine due to dobutamine?s effect, which is similar to moderate physical exercise. The aim of this study was to assess the feasibility and echocardiographic characteristics of a conventional DST in dogs. Materials and Methods. Ten clinically healthy German Shepherd dogs were submitted to a conventional 3-minute stage DST protocol (the initial dose 7.5 ?g/kg/min was increased at 3-minute intervals by 5 ?g/kg/min until a maximum dosage of 42.5 ?g/kg/ min; the maximum DST duration was 24 minutes), which is used in human medicine. Dobutamine action was monitored by noninvasive diagnostic methods (simultaneously lead II electrocardiography and transthoracic echocardiography). Left ventricular echocardiographic parameters were measured at baseline and at the peak of DST. Results and Conclusions. The duration of conventional DST in dogs was 19.4?4.06 minutes. During the DST, sinus tachycardia was registered with no abnormalities of cardiac rhythm. The adverse effects registered in this study were excitement, panting and weakness. Interventricular septum thickness in systole (P=0.0093) and diastole (P=0.0080) increased significantly at the peak of DST. The left ventricular end-systolic dimension (P=0.0077) and the diastolic wall stress index (P=0.0125) decreased significantly at the peak of DST. A 3-minute stage with increased doses of dobutamine is a feasible method for the DST in dogs. The registered changes could be explained by the dobutamine effects through ?1 adrenergic receptors. This pharmacological stress test induces significant changes in left ventricular echocardiographic parameters in healthy adult dogs. Dogs exhibit transient signs like sinus tachycardia, excitement, panting and weakness during DST. Additional research on DST should evaluate the diagnostic value of this protocol in dogs suffering from cardiac disease.

The Influence of Short Duration Exercise on the Concentration of C-Reactive Protein and Selected Haematological and Biochemical Parameters in the Blood of German Shepherd Dogs

Abstract Short-term intensive exercise may be associated with many short-lasting metabolic changes. These changes depend on the duration and intensity of the exercise. The aim of our study was to determine potential changes in C-reactive protein (CRP) and selected haematological and biochemical parameters in clinically healthy German shepherd dogs before short duration high-intensity exercise and 6 hours after the exercise. During the study, the dogs were subjected to the following defensive training: detaining a figurant running away from a dog (2×) and detaining with a counterattack (2×). The running distance was 200 m at a mean speed of 28 km.h-1. The investigation of haematological parameters revealed a significant decrease in the mean values of platelet haematocrit (PCT) 6 hours after the training. Significant differences in the levels determined before and after exercise were observed also for phosphorus (P) and for iron (Fe). At the same time, we observed a significant increase in the mean calcium (Ca) level and a significant decrease in sodium (Na) and chlorides (Cl). The activity of aspartate aminotransferase (AST) significantly increased after exercise. Concentrations of acute phase C-reactive proteins were increased 6 hours after exercise in comparison to those before exercise but the difference was insignificant. Although the concentration of CRP was increased insignificantly after the exercise, when interpreting concentrations of this nonspecific indicator of inflammation, one should keep in mind that intensive exercise may also affect its concentrations.

Comparison of cellular location and expression of Plakophilin-2 in epidermal cells from nonlesional atopic skin and healthy skin in German shepherd dogs.

BackgroundCanine atopic dermatitis (CAD) is an inflammatory and pruritic allergic skin disease caused by interactions between genetic and environmental factors. Previously, a genome‐wide significant risk locus on canine chromosome 27 for CAD was identified in German shepherd dogs (GSDs) and Plakophilin‐2 (PKP2) was defined as the top candidate gene. PKP2 constitutes a crucial component of desmosomes and also is important in signalling, metabolic and transcriptional activities.ObjectivesThe main objective was to evaluate the role of PKP2 in CAD by investigating PKP2 expression and desmosome structure in nonlesional skin from CAD‐affected (carrying the top GWAS SNP risk allele) and healthy GSDs. We also aimed at defining the cell types in the skin that express PKP2 and its intracellular location.Animals/MethodsSkin biopsies were collected from nine CAD‐affected and five control GSDs. The biopsies were frozen for immunofluorescence and fixed for electron microscopy immunolabelling and morphology.ResultsWe observed the novel finding of PKP2 expression in dendritic cells and T cells in dog skin. Moreover, we detected that PKP2 was more evenly expressed within keratinocytes compared to its desmosomal binding‐partner plakoglobin. PKP2 protein was located in the nucleus and on keratin filaments attached to desmosomes. No difference in PKP2 abundance between CAD cases and controls was observed.ConclusionPlakophilin‐2 protein in dog skin is expressed in both epithelial and immune cells; based on its subcellular location its functional role is implicated in both nuclear and structural processes.

Age-dependent electrocardiographic and echocardiographic changes in German Shepherd dogs.

By causing numerous changes in the cardiovascular system, ageing leads to a decreased threshold for clinical manifestation of heart disease. The aim of this study was to define the existence of cardiac structural and functional changes in healthy dogs of different age. Radiographic, electrocardiographic (ECG) and echocardiographic examinations of 20 clinically healthy German Shepherd dogs were performed in order to define the values of relevant parameters. Afterwards, the values of cardio examinations were compared between young and old dogs and statistically analyzed. The ECG recordings did not show the appearance of clinically significant arrhythmias, nor was their appearance significantly different between dogs of different age. Statistically significant differences in QRS duration (P<0.05) and R wave amplitude (P<0.05) existed between groups, but all values were within the range of ECG reference values for healthy dogs. Concerning structural changes, the left ventricle wall thickness at end-diastole (LVWd) and end-systole (LVWs), and the relative wall thickness (RWT) between young and old dogs differed significantly (P<0.001, P<0.05, P<0.05, respectively). These differences in heart structure were not accompanied by systolic dysfunction, estimated by a left ventricle shortening fraction. The diastolic wall stress index (WSID) was significantly decreased in old dogs (P<0.05). Young and old dogs showed similar electrical and systolic function. Old dogs had different cardiac structure compared to the young dogs, which could result in diastolic function change.

Association of DLA-DQB1 alleles with exocrine pancreatic insufficiency in Pembroke Welsh Corgis.

Exocrine pancreatic insufficiency (EPI) is a digestive disorder resulting from the insufficient secretion of enzymes from the pancreas. In dogs, this condition is often attributed to pancreatic acinar atrophy, wherein the enzyme-producing acinar cells are believed to be destroyed through an autoimmune process. Although EPI affects many diverse breeds, to date, molecular studies have been limited to the German Shepherd dog. A recent study of major histocompatibility genes in diseased and healthy German Shepherd dogs identified both risk and protective haplotypes. Herein, we genotyped DLA-DQB1 in Pembroke Welsh Corgis to determine whether dog leukocyte antigen alleles contribute to the pathogenesis of EPI across dog breeds. We evaluated 14 affected and 43 control Pembroke Welsh Corgis, which were selected based on an age of onset similar to German Shepherd dogs. We identified one protective allele (odds ratio = 0.13, P-value = 0.044) and one risk allele (odds ratio = 3.8, P-value = 0.047). As in German Shepherd dogs, the risk allele is a duplication of DLA-DQB1 (alleles DQB1*013:03 and 017:01); however, Pembroke Welsh Corgis have acquired a single polymorphism on DQB1*017:01. Thus, the DLA-DQB1 duplication is a risk allele for EPI in at least two breeds.

Serum concentrations of lipids and lipoproteins and their correlations with thyroid hormones in clinically healthy German shepherd dogs: Effects of season, sex and age

Although there are many evidences regard to the relationship between serum thyroid hormones, cholesterol, triglyceride and lipoproteins in different animals, but there are limited references in dogs. The aim of this study was to determine the correlation between thyroid hormones and concentrations of serum lipid and lipoprotein profiles, and also to detect relationship between the measured parameters in different season, sex and age groups of dogs in Ahvaz district, Southwest of Iran, on 2011. Blood samples were taken from the cephalic vein of 60 clinically healthy and non-pregnant native dogs in two seasons (summer and winter) and in two age groups ( 3 years). Sampling was done only once from each animal (30 dogs in every season). The serum concentrations of cholesterol, triglyceride (T.G), very low density lipoproteins (VLDL-cholesterol), low density lipoproteins (LDL-cholesterol), high density lipoproteins (HDL-cholesterol and their correlations with thyroxine (T4) and triiodothyronine (T3) hormones were measured in the studied dogs. The mean serum concentrations of cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol (mmol/L), T4 and T3 (µmol/L) were measured in the present survey. The above parameters were also obtained in two summer and winter seasons. Season had a significant effect on T.G, HDL, LDL and VLDL levels in the studied dogs (p 0.05). No significant differences were detected for the measured cholesterol, T3 and T4 parameters in different age, sex and season groups (p>0.05). To the best of our knowledge, there was no previous research regarding the correlation of the thyroid hormones with the serum lipids and lipoproteins in dogs in Iran. Our results showed that thyroid hormones affect T.G, HDL, LDL and VLDL levels and observed seasonal change in serum may be partly due to changes in thyroid hormones.

Time-domain signal-averaged electrocardiogram in healthy German Shepherd and Boxer dogs

Signal-averaged electrocardiogram (SAECG) identifies ventricular late potentials (LP), low-amplitude electrical signals that are markers of slow cardiac conduction in fibrous myocardium, consisting in a predictive factor for sudden death in dogs at risk of sustained ventricular tachycardia. The aim of this study was to establish reference values of SAECG for German Shepherd and Boxer dogs. SAECG was performed in 19 German Shepherd and 28 Boxer client-owned dogs, and parameters analyzed were QRSd (duration of filtered QRS), LAS&lt;40μV (duration of low-amplitude signals in terminal portion of filtered QRS) and RMS40 (root square of mean voltage over the last 40 milliseconds of filtered QRS), with two different filters (25-250 Hz and 40-250 Hz). Statistical analyses was achieved by T Student test (p&lt;0.05) to identify differences between the two groups and between the values obtained with the two filters. No statistical difference was found in SAECG variables between the two breeds with the two different filters (p&gt;0.05). Achieving normal values of SAECG in German Shepherd and Boxer dogs is important to further research late potentials in animals of these breeds with hereditary ventricular tachycardia or arrhythmogenic cardiomyopathy and identification of individuals at high risk of cardiac-related sudden death.

Evaluation of vertical forces in the pads of German Shepherd dogs

To evaluate vertical forces in the pads of German Shepherd dogs by relative percentage among total limb vertical forces using a pressure sensitive walkway. A pressure sensitive walkway was used to collect vertical force data for each pad of the limbs of 16 healthy client-owned German Shepherd dogs used for kinetic gait analysis. The vertical force for each pad was evaluated as a percentage of total limb vertical force. Weight distribution among limbs was also recorded. Velocity and acceleration were within a range of 1.3 and 1.6 ± 0.1 m/s². The ANOVA test was used to compare data and the paired t-test was used to assess symmetry (p <0.05). The peak vertical force was higher on the metacarpal pad than on the metatarsal pad. Peak vertical force was highest on the metacarpal pad and metatarsal pad followed by the digital pads 3, 4 and 5 of the forelimb, and on the hindlimb by digital pads 3 and 4. Vertical impulse was greatest in the metacarpal pad and digital pads 3 and 4 of the forelimb and hindlimb respectively, followed by digital pads 3, 4, and 5 of the forelimb and the metatarsal pad. A vertical force distribution pattern was observed on the pads of the German Shepherd dogs. These data are important for improving the understanding of vertical force distribution during gait and to assess orthopaedic conditions.

Kinematic analysis in healthy and hip-dysplastic German Shepherd dogs

This study investigated kinematic patterns in clinically normal German Shepherd dogs (GSDs) compared to those with hip dysplasia and with no clinical signs of lameness. Two groups of GSDs, including 10 clinically healthy dogs (G1) and 10 with hip dysplasia (G2), were trotted on a treadmill at a constant speed. Kinematic data were collected by a 3-camera system and analysed by a motion-analysis program. Flexion and extension joint angles and angular velocities were determined for the shoulder, elbow, carpal, hip, stifle, and tarsal joints. Within each group, the differences between the right and left limbs in all kinematic variables were not significant. Minimum angle, angular displacement and minimum angular velocity did not differ between groups. Significant differences were observed in the maximum angular velocity and maximum angle of the hip joint (dysplastic>healthy), and in the maximum angular velocity of the carpal joint (healthy>dysplastic). It was concluded that, when trotting on a treadmill, dysplastic dogs with no signs of lameness may present joint kinematic alterations in the hind as well as the forelimbs.

Resting and dobutamine stress test induced serum concentrations of brain natriuretic peptide in German Shepherd dogs

Studies of clinical uses of brain natriuretic peptide (BNP) represent one of the most important advances in cardiology since the introduction of echocardiography as a clinical diagnostic procedure. Defining the clinical potential of BNP in canine cardiology has not been completed yet. The aim of this study is to measure BNP concentrations in healthy German Shepherd dogs of different ages as a baseline in resting and when conventional protocol of the dobutamine stress test (DST) is applied to dogs. Concentrations of BNP were measured in blood serum by the radioimmunoassay method. The values of BNP concentrations were compared to cardiac parameters obtained by standard cardiac diagnostic procedures (radiology, electrocardiography and echocardiography). No significant differences in serum BNP concentrations existed in dogs of different ages. A statistically significant increase in BNP concentrations was registered after DST. These changes in BNP concentrations were related to ST/T electrocardiographic changes, and correlated to changes in the left ventricular internal diameter in systole (LVESD). These data suggest that BNP is not increased in aged dogs with normal cardiac systolic function and renal function, and that myocardial ischemia leads to a significant increase in BNP concentrations even in dogs with normal left ventricular function.

MR‐IMAGING OF LUMBOSACRAL INTERVERTEBRAL DISC DEGENERATION IN CLINICALLY SOUNDGERMAN SHEPHERD DOGS COMPARED TO OTHER BREEDS

German shepherd dogs are overrepresented in the group of dogs with cauda equina compression syndrome due to degenerative lumbosacral stenosis. A congenital predisposition for early degeneration of the lumbosacral intervertebral disc has been suspected. Our aims were to assess the morphologic appearance of the lumbosacral intervertebral disc and the lumbosacral junction in healthy German shepherd dogs compared to other breeds and to evaluate for an early onset of degenerative changes. The lumbosacral spine of 110 clinically sound German shepherd dogs and 47 healthy dogs of other large breeds was examined using magnetic resonance (MR) imaging. The degeneration of every intervertebral disc was graded using an established classification system. Signal intensity of the entire lumbosacral disc and the nucleus pulposus was determined independently. Lumbosacral malalignment was assessed according to a previously described method. The findings for the German shepherd dogs were compared to those of the other breeds. Although most dogs were younger than 18 months at the date of examination, significantly higher grades of degeneration were detected for the lumbosacral intervertebral disc of German shepherd dogs (P < 0.003). Degeneration of the lumbosacral intervertebral disc was independent from findings in the other lumbar discs. We conclude that the German shepherd dog has a predisposition for degenerative changes in the lumbosacral intervertebral disc.

Avaliação por eletrocardiografia contínua (holter) em cães da raça Pastor Alemão praticantes de atividade física regular

ABSTRACT The pattern for ambulatory electrocardiography was evaluated in 25 healthy German Shepherd dogs. The influences of gender, age, and physical activity in HR maximum, mean, and minimum (HRmx, HRme, and HRmin, respectively) were studied. The physically active dogs (PA) showed lower HRme than sedentary animals (S) (P=0.03), whereas HRmx and HRmin were not altered (P=0.06 and P=0.65, respectively). The HRme was 80.89 ± 13.85 for PA and 112.94 ± 35.71 for S. No effect of gender and age on HR was observed. It is possible to state that the physical activity can modulate the sinus node of the dogs. Keywords: dog, German Shepherd, ambulatory electrocardiography, physical activity REFERENCIAS BIBLIOGRAFICAS BILLMAN, G.E. Aerobic exercise conditioning: a nonpharmacological antiarrhythmic intervention. J. Appl. Physiol ., v.92, p.446-454, 2002. DIXON, E.M.; KAMATH, M.V.; MCCARTNEY, N. et al. Neural regulation of heart rate variability in endurance athletes and sedentary controls. Cardiovasc. Res

Cultivation and molecular identification ofEhrlichia canisandEhrlichia chaffeensisfrom a naturally co‐infected dog in Venezuela

Diagnosis of canine ehrlichiosis in Venezuela is normally performed by examination of buffy coat smears (BCS). Characteristic inclusion bodies are frequently observed in leukocytes and platelets from dogs with clinical signs of the disease. The purpose of this study was to investigate the co-infection of a dog with Ehrlichia canis and E hrlichia chaffeensis using microbiological and molecular techniques. Primary cultures of monocytes from a dog showing signs of ehrlichiosis were performed. Ehrlichial inclusions in blood cells were demonstrated by BCS and in cultured cell smears with direct immunofluorescence and Dip Quick staining. Nested PCR analysis was performed with DNA from blood samples and cultures, using primers specific for E. canis and E. chaffeensis. The amplified DNA fragments were sequenced to confirm the specificity of the amplifications. The BCS of the naturally infected dog contained intracellular morulae. Ehrlichial inclusions were observed 9 days after inoculation of the primary cultures. After 3 passages with monocytes from a healthy dog, 65% of infected cells, and cells with >60 morulae were observed. A healthy female German Shepherd dog, seronegative for E. canis and E. chaffeensis antigens and without contact to ticks, was inoculated with an infected culture. The animal developed signs of canine monocytic ehrlichiosis and became seropositive. Nested PCR results and sequencing of amplified DNA fragments demonstrated the simultaneous presence of E. canis and E. chaffeensis in both dogs. This is the first report of E. chaffeensis in dogs in South America. This organism was previously identified in dogs by PCR only in the United States.