Canine Breeds Research Articles

Dog10K: an integrated Dog10K database summarizing canine multi-omics.

The diversity observed in canine breed phenotypes, together with their risk for heritabily disorders of relevance to dogs and humans, makes the species an ideal subject for studies aimed at understanding the genetic basis of complex traits and human biomedical models. Dog10K is an ongoing international collaboration that aims to uncover the genetic basis of phenotypic diversity, disease, behavior, and domestication history of dogs. To best present and make the extensive data accessible and user friendly, we have established the Dog10K (http://dog10k.kiz.ac.cn/) database, a comprehensive-omics resource summarizing multiple types of data. This database integrates single nucleotide variants (SNVs) from 1987 canine genomes, de-novo mutations (DNMs) from 43 dog breeds with>40×sequence, RNA-seq data of 105057 single nuclei from hippocampus, 74067 single cells from leukocytesand 30 blood samples from published canid studies. We provide clear visualization, statistics, browse, searching, and downloading functions for all data. We have integrated three analysis tools, Selscan, LiftOver and AgeConversion, to aid researchers in custom exploration of the comprehensive-omics data. The Dog10K database will serve as a foundational platform for analyzing, presenting and utilizing canine multi-omics data.

Relative Tumour Volume in Canine Oral Melanoma Staging and Prognosis.

Melanoma is one of the most common canine oral malignant tumours and is highly aggressive and metastatic, even at the early stages of development. Surgery relies on wide excision of the primary tumour and regional lymphadenectomy, with or without adjuvant therapy. Tumour location and size are important when considering staging, which ultimately affects the curative intent of surgery. Nevertheless, absolute tumour volume (TV) is not related to the vast phenotypic variability within canine breeds. This study aimed to determine the cutoff values of two ratios-tumour-to-head volume (THR) and tumour-to-body volume (TBR)-and assess whether they could be associated with the odds of finding metastasis at presentation and/or the likelihood of achieving tumour-free excision margins. A retrospective case series involving 51 dogs was used to evaluate the preoperative head/neck and chest computed tomography and histopathology of the primary mass and excised lymph nodes. Higher TV, THR% and TBR% values were associated with bone lysis and mitotic count (MC). The Ki67 index was significantly associated with local and distant metastases at presentation, whereas MC was associated with local metastasis alone. Tumour-infiltrated surgical margins were associated with caudally located tumours, regardless of the tumour size. Dogs with lymph node metastasis at presentation were seven times more prone to have local relapse. TV, THR% and TBR% values were positively associated with local lymph node metastasis at presentation. Cutoff values for both TV and TBR% were proposed to predict lymph node metastasis at presentation (TV = 6.423 cm3 and TBR% = 0.043), being supported by post-surgical survival analysis.

Signalment, clinical characteristics and outcomes of an Australian population of dogs with steroid responsive meningitis-arteritis (SRMA) - 124 cases (2013-2023).

Variations in canine breeds presenting with steroid responsive meningitis-arteritis (SRMA) have been observed across different geographical regions internationally. However, there are no published studies describing affected dogs in an Australian population to date. This descriptive study aimed to characterise the signalment, as well as the clinical characteristics and outcomes in an Australian population of client-owned dogs with SRMA. Medical records from five veterinary referral hospitals in the state of New South Wales between 2013 and 2023 were retrospectively reviewed. One hundred and twenty four dogs were included in the study. The breeds which presented with SRMA most commonly included Golden Retriever (19/124, 15.3%), Italian Greyhound (11/124, 8.8%), Boxer (8/124, 6.5%), "Cavoodle" (Cavalier King Charles Spaniel x Poodle) (8/124, 6.5%), Corgi (7/124, 5.6%), Border Collie (6/124, 4.8%) and Australian Kelpie (5/124, 4.0%). The disease was observed more commonly in males, representing 79/124 (63.7%) of dogs. Presenting concerns, examination findings and laboratory abnormalities were otherwise consistent with international studies. The frequency of ≥1 relapse for dogs with a ≥6-month follow-up period was 32/85 (37.6%). A higher frequency of ≥1 relapse was seen in female dogs and in Corgi and Italian Greyhound breeds. All Corgis who relapsed demonstrated multiple relapses. In conclusion, this study observed a variation in breeds presenting with SRMA compared to international publications, which may reflect both differences in breed popularity, as well as varying interbreed susceptibility dependent on geographical location.

From small to tall: breed-varied household pet dogs can be trained to detect Parkinson’s Disease

Parkinson’s Disease (PD) is a clinically diagnosed disease that carries a reported misdiagnosis rate of 10–20%. Recent scientific discoveries have provided evidence of volatile organic compounds in sebum that are unique to patients with PD. The primary objective of this study was to determine if companion dogs could be trained to distinguish between sebum samples provided by PD-positive patients and PD-negative human controls. This was a randomized, handler-blind, controlled study. Twenty-three canines of varying breeds, ages, and environmental backgrounds were included. The study period encompassed 200 total working days from 2021 to 2022. Factors investigated included donor gender and levodopa drug affectivity, as well as canine breed, age, and duration of training time. The findings in this study were compiled from data collected during the final two years of a seven-year research program. For this two-year reporting period, when averaged as a group, the 23 dogs were 89% sensitive and 87% specific to olfactory distinction between PD-positive and PD-negative human donor samples. Ten of the twenty-three dogs averaged 90% or higher in both sensitivity and specificity. In 161 separate trials, a dog was presented with both novel PD-positive and PD-negative samples. For these novel exposures, the dogs collectively averaged 86% sensitivity and 89% specificity. PD medication was also investigated and was found to have no discernible impact on canine sensitivity or specificity results. Study findings support the application of companion dogs, trained with force-free, reward-based methodologies, for the detection of PD-positive and PD-negative samples under controlled conditions.

Adaptive and innate immune response of Leishmania infantum infection in Cirneco dell’Etna dog breed

Leishmania spp. are an intracellular protozoa present in many countries around the world. In Europe, both the parasite and the disease it causes, leishmaniasis, are endemic in the Mediterranean basin. Clinical signs and severity of disease are highly variable depending on the host in both humans and dogs, traditionally considered the main reservoir of the parasite. The reason for these differences is not known, but it has been speculated that some hosts present immune response, related to activation of Th1 and Th17, capable of controlling the spread of the parasite, and that these immune responses are related to the genetic background of the host. The Ibizan hound, an autochthonous canine breed of the Mediterranean basin, has been postulated as a breed resistant to infection, but other canine breeds evolutionarily close to it and native to this region have not been studied. One of them is the Cirneco dell’Etna, native to the island of Sicily in southern Italy. In this study, the immune response against L. infantum infection in this canine breed was analysed. The results showed that infected dogs of this breed present high levels of several cytokines related to Th1 and Th17 immune response, and significant correlation between serum levels of cytokines related to disease resistance. Further studies are necessary in this canine breed to determine the mechanisms of immune response and genetic background related to L. infantum infection control.

Treatment of Canine Intervertebral Disc Disease with Traditional Chinese Veterinary Medicine

Intervertebral disc disease (IVDD) in dogs is a common medical problem encountered by small animal practitioners. It normally occurs in both small and large canine breeds. From a conventional medical perspective there are two treatment options available for these patients, conservative medical management, or surgical intervention. There is, however, an effective third option available, traditional Chinese veterinary medicine (TCVM). This article will discuss how to use TCVM in the treatment of canine IVDD patients, results that can be expected, and a case series of 12 dogs affected with IVDD.

Myostatin serum levels depends on age and diet in athletic and no athletic dogs

Myostatin is a growth factor related to muscular mass atrophy via mTOR pathway inhibition. Mutations in this gene have been correlated with high muscular mass development in different species of mammals, including human and dogs. Different studies have shown that sport practice increases myostatin gene expression. Some of them were conducted in canine breeds selected for different sport practices, including mushing sports. In this study, body weight, muscular mass, and serum levels of myostatin were analysed in different canine breeds, selected, and not selected for sprint and middle-distance racing, and the effect on epidemiological factors was evaluated. Sex, reproductive status, and canine breed affects body weight and muscular mass, being higher in males, and in sled canine breed. Age has an effect in body weight and myostatin serum levels, being lower in elder dogs. Sport practice and type of diet had an effect in muscular mass development but not in myostatin serum levels. Results showed a high positive correlation between muscular mass and body weight but not with myostatin levels. These results suggest that independent-myostatin mechanisms of mTOR pathway regulation could be related to muscular mass development in dogs.

Machine Learning in Assessing Canine Bone Fracture Risk: A Retrospective and Predictive Approach

In the ever-evolving world of veterinary care, the occurrence of bone fractures in canines poses a common and complex problem, especially in extra-small breeds and dogs that are less than 1 year old. The objective of this research is to fill a gap in predicting the risk of canine bone fractures. A machine learning method using a random forest classifier was constructed. The algorithm was trained on a dataset consisting of 2261 cases that included several factors, such as canine age, gender, breed, and weight. The performance of the algorithm was assessed by examining its capacity to forecast the probability of fractures occurring. The findings of our study indicate that the tool has the capability to provide dependable predictions of fracture risk, consistent with our extensive dataset on fractures in canines. However, these results should be considered preliminary due to the limited sample size. This discovery is a crucial tool for veterinary practitioners, allowing them to take preventive measures to manage and prevent fractures. In conclusion, the implementation of this prediction tool has the potential to significantly transform the quality of care in the field of veterinary medicine by enabling the detection of patients at high risk, hence enabling the implementation of timely and customized preventive measures.

Effect of Breed on Hematological and Biochemical Parameters of Apparently Healthy Dogs Infected with Zoonotic Pathogens Endemic to the Mediterranean Basin.

Dogs are considered the main reservoir of several zoonoses endemic to the Mediterranean Basin. In this study, a prevalence of infections and coinfections of canine vector-borne diseases was analyzed in apparently healthy dogs of different canine pure breeds in Sicily (Italy), where these diseases are endemic. The seroprevalence of Leishmania infantum, Ricketsia ricketsii, Anaplasma phagocytophilum, and Erlichia canis was assessed, as single and coinfections. Biochemical and hematological parameters were evaluated, and epidemiological factors, including sex, age, and canine breed, were recovered. The most frequent infection was L. infantum (45.61%), following R. ricketsii (36.84%), both as single, double, or triple coinfections. Coinfections change the biochemical and hematological parameters of the host, and canine breeds are related to the infection frequency and the parameters observed during infections. Changes in the complete blood count (CBC) and biochemical values also differ between canine breeds, with the Cirneco dell'Etna dogs infected with L. infantum being the animals presenting the most interesting results in our study. High values of RBC, hemoglobin, hematocrit, mean corpuscular hemoglobin (MCH), the albumin/globulin (A/G) ratio, and albumin and low levels of β-2 globulin and γ-globulin were found only in this canine breed, suggesting some resistance to infection in these dogs. Future studies about the immune response of this canine breed could be interesting to determine their possible resistance to zoonotic pathogens, such as L. infantum.

Increased susceptibility to Mycobacterium avium complex infection in miniature Schnauzer dogs caused by a codon deletion in CARD9

Mammals are generally resistant to Mycobacterium avium complex (MAC) infections. We report here on a primary immunodeficiency disorder causing increased susceptibility to MAC infections in a canine breed. Adult Miniature Schnauzers developing progressive systemic MAC infections were related to a common founder, and pedigree analysis was consistent with an autosomal recessive trait. A genome-wide association study and homozygosity mapping using 8 infected, 9 non-infected relatives, and 160 control Miniature Schnauzers detected an associated region on chromosome 9. Whole genome sequencing of 2 MAC-infected dogs identified a codon deletion in the CARD9 gene (c.493_495del; p.Lys165del). Genotyping of Miniature Schnauzers revealed the presence of this mutant CARD9 allele worldwide, and all tested MAC-infected dogs were homozygous mutants. Peripheral blood mononuclear cells from a dog homozygous for the CARD9 variant exhibited a dysfunctional CARD9 protein with impaired TNF-α production upon stimulation with the fungal polysaccharide β-glucan that activates the CARD9-coupled C-type lectin receptor, Dectin-1. While CARD9-deficient knockout mice are susceptible to experimental challenges by fungi and mycobacteria, Miniature Schnauzer dogs with systemic MAC susceptibility represent the first spontaneous animal model of CARD9 deficiency, which will help to further elucidate host defense mechanisms against mycobacteria and fungi and assess potential therapies for animals and humans.

Pharmacogenomics of poor drug metabolism in greyhounds: Canine P450 oxidoreductase genetic variation, breed heterogeneity, and functional characterization.

Greyhounds metabolize cytochrome P450 (CYP) 2B11 substrates more slowly than other dog breeds. However, CYP2B11 gene variants associated with decreased CYP2B11 expression do not fully explain reduced CYP2B11 activity in this breed. P450 oxidoreductase (POR) is an essential redox partner for all CYPs. POR protein variants can enhance or repress CYP enzyme function in a CYP isoform and substrate dependent manner. The study objectives were to identify POR protein variants in greyhounds and determine their effect on coexpressed CYP2B11 and CYP2D15 enzyme function. Gene sequencing identified two missense variants (Glu315Gln and Asp570Glu) forming four alleles, POR-H1 (reference), POR-H2 (570Glu), POR-H3 (315Gln, 570Glu) and POR-H4 (315Gln). Out of 68 dog breeds surveyed, POR-H2 was widely distributed across multiple breeds, while POR-H3 was largely restricted to greyhounds and Scottish deerhounds (35% allele frequencies), and POR-H4 was rare. Three-dimensional protein structure modelling indicated significant effects of Glu315Gln (but not Asp570Glu) on protein flexibility through loss of a salt bridge between Glu315 and Arg519. Recombinant POR-H1 (reference) and each POR variant (H2-H4) were expressed alone or with CYP2B11 or CYP2D15 in insect cells. No substantial effects on POR protein expression or enzyme activity (cytochrome c reduction) were observed for any POR variant (versus POR-H1) when expressed alone or with CYP2B11 or CYP2D15. Furthermore, there were no effects on CYP2B11 or CYP2D15 protein expression, or on CYP2D15 enzyme kinetics by any POR variant (versus POR-H1). However, Vmax values for 7-benzyloxyresorufin, propofol and bupropion oxidation by CYP2B11 were significantly reduced by coexpression with POR-H3 (by 34-37%) and POR-H4 (by 65-72%) compared with POR-H1. Km values were unaffected. Our results indicate that the Glu315Gln mutation (common to POR-H3 and POR-H4) reduces CYP2B11 enzyme function without affecting at least one other major canine hepatic P450 (CYP2D15). Additional in vivo studies are warranted to confirm these findings.

Clinicopathologic profiles of canine ocular melanosis: A comparative study between cairn terriers and non-cairn terriers.

To identify canine breeds at risk for ocular melanosis and to compare the clinical and histologic features between affected Cairn Terriers (CTs) and non-Cairn Terriers (NCTs). Relative risk (RR) analysis and retrospective cohort study of dogs histologically diagnosed with ocular melanosis. The COPLOW archive was searched for globe submissions diagnosed with ocular melanosis. Six hundred fifty globes were included, and RR analysis was performed to identify at-risk NCT breeds. A cohort of 360 CT and NCT globes diagnosed from 2013 to 2023 were included in the retrospective cohort study. Clinical data were collected from submission forms, medical records, and follow-up surveys. One hundred fifty-seven submissions underwent masked histologic review. Immunohistochemical staining for CD204 was performed to determine the predominance of melanophages in affected uvea from five NCTs. At-risk NCT breeds included the Boxer, Labrador Retriever, and French Bulldog. Glaucoma was the reported reason for enucleation in 79.4% of submissions. At enucleation, clinical features less prevalent in NCTs than CTs included pigmentary abnormalities in the contralateral eye (33.7% vs. 63.1%, p = .0008) and abnormal episcleral/scleral pigmentation in the enucleated globe (25.4% vs. 53.6%, p = .0008). Histologic involvement of the episclera was also less frequent in NCTs than in CTs (39.7% vs. 76.9%, p = .008). Concurrent melanocytic neoplasms arising in melanosis were more common in NCTs (24.4%) than CTs (3.9%). Melanophages were not predominant in any samples evaluated immunohistochemically. Several popular NCT breeds carry risk for ocular melanosis, and some clinicopathologic disease features may differ from those described in CTs.

Role of Inflammation in Canine Primary Glaucoma.

Primary glaucoma is a painful, progressive, and blinding disease reported in many canine breeds, characterized by intraocular pressure (IOP) elevation in the absence of antecedent intraocular disease. Clinical observations of dogs with primary glaucoma suggest that many affected eyes develop concurrent intraocular inflammation in addition to elevated IOP. In this work, we summarize the current knowledge that relates inflammation to primary glaucoma in dogs, reviewing studies focused on genetics, physiology, histopathology, bioanalysis of ocular fluids, therapeutics, and clinical outcomes of glaucomatous patients. Through disruption of the blood-aqueous and blood-retinal barriers, pigment dispersion, and biochemical changes to the aqueous humor and tear film, the pathogenesis of canine primary glaucoma appears to involve inflammatory changes to various extents and with various consequences from the front to the back of the eye. Among others, inflammation further impacts IOP by reducing aqueous humor outflow at the level of the iridocorneal angle and accelerates vision loss by promoting neuronal degeneration. As such, the vicious cycle of ocular inflammation and IOP elevation might warrant the use of anti-inflammatory medications as a core component of the treatment regime for dogs with primary glaucoma, either therapeutically (i.e., actively glaucomatous eye) or prophylactically in the yet unaffected contralateral eye.

Multiocular defect in the Old English Sheepdog: A canine form of Stickler syndrome type II associated with a missense variant in the collagen-type gene COL11A1.

Multiocular defect has been described in different canine breeds, including the Old English Sheepdog. Affected dogs typically present with multiple and various ocular abnormalities. We carried out whole genome sequencing on an Old English Sheepdog that had been diagnosed with hereditary cataracts at the age of five and then referred to a board-certified veterinary ophthalmologist due to owner-reported visual deterioration. An ophthalmic assessment revealed that there was bilateral vitreal degeneration, macrophthalmos, and spherophakia in addition to cataracts. Follow-up consultations revealed cataract progression, retinal detachment, uveitis and secondary glaucoma. Whole genome sequence filtered variants private to the case, shared with another Old English Sheepdog genome and predicted to be deleterious were genotyped in an initial cohort of six Old English Sheepdogs (three affected by multiocular defect and three control dogs without evidence of inherited eye disease). Only one of the twenty-two variants segregated correctly with multiocular defect. The variant is a single nucleotide substitution, located in the collagen-type gene COL11A1, c.1775T>C, that causes an amino acid change, p.Phe1592Ser. Genotyping of an additional 14 Old English Sheepdogs affected by multiocular defect revealed a dominant mode of inheritance with four cases heterozygous for the variant. Further genotyping of hereditary cataract-affected Old English Sheepdogs revealed segregation of the variant in eight out of nine dogs. In humans, variants in the COL11A1 gene are associated with Stickler syndrome type II, also dominantly inherited.

Clinical outcome of idiopathic juvenile ventricular arrhythmias in 25 dogs

Introduction/ObjectivesJuvenile ventricular arrhythmias in the absence of structural heart disease have been characterized in a small number of canine breeds with limited long-term follow up. The objective of this study was to describe the clinical outcome of dogs with JVA presenting to a university teaching hospital. Animals, materials, methodsTwenty five dogs, less than two years old with idiopathic ventricular arrhythmias were retrospectively identified via a medical record search. Young dogs with ventricular arrhythmias were excluded if they had structural heart disease, systemic illness, or an abnormal troponin (if performed). Electrocardiographic and Holter monitor data was evaluated for arrhythmia frequency and complexity at the time of diagnosis and over time. Long-term follow up was achieved through client and primary veterinarian contact. ResultsBreeds included German Shepherd (eight), Boxer (four), Great Dane (three), mixed breed (two) and one each of the following: Anatolian Shepherd, French Bulldog, golden retriever, Great Pyrenees, Labrador retriever, Shiloh Shepherd, miniature Poodle and Siberian Husky. The average age at diagnosis was 7.9 months (range, 2–22 months). The overall median survival was 10.96 years (range, 1.75–15.66 years). There was an average reduction in the number of ventricular beats by 86.7 % per year (P value −0.0257) based on Holter data. ConclusionIn most cases, idiopathic juvenile ventricular arrhythmias had a favorable long-term prognosis with reduced ectopy over time in this case series. Juvenile ventricular arrhythmias remains a diagnosis of exclusion but can be considered in a broader range of dog breeds than previously described.

Allele and genotype frequencies for primary hereditary cataract, multifocal retinopathy 1, and degenerative myelopathy in Pyrenean Mountain dog from Italy

Pyrenean Mountain Dog (PMD) is an ancient dog breed firstly described in XIV century in the Pyrenees Region and nowadays diffused both in Europe and in the US. Hereditary Cataract (HC), defined as the inherited opacity of the lens, involves clinical signs ranging from reduced vision to glaucoma. A molecular basis of HC was firstly described in Staffordshire Bull Terriers and then reported in multiple canine breeds. The HC-associated variation is a single nucleotide deletion in HSF4 gene that introduces a premature stop codon (c.962del, p.Ala321*). Multifocal Retinopathy 1 (MR) is an ocular disorder characterized by multiple areas of retinal degeneration, caused in various dog breeds (including PMD) by a single nucleotide variant (SNV) in BEST1 gene that generates a premature stop codon (c.73G>A, p.Arg25*). Degenerative Myelopathy (DM) is an adult-onset, progressive neurodegenerative disease and it is associated to a SNV in SOD1 gene causing a change in aminoacidic sequence of the protein (c.118G>A, p.Glu40Lys). This causative variant has been described in various dog breeds, including PMD. Aim of this study was to determine the allele frequencies for the abovementioned three genetic diseases in the Italian breeding PMD population. The survey found no dogs carrying the allele (deletion) associated with HC, while three dogs (6 %) were heterozygous (G/A) for the MR-associated variant, and seven dogs (13 %) were heterozygous (G/A) for the DM-associated alteration, indicating that the variant alleles frequency were 0 %, 3 %, and 7 %, respectively. Appropriate mating management is suggested for the prevention of genetic diseases spreading in the PMD population.

MAMMARY GLAND DEVELOPMENT IN DOGS AND CATS IN RELATION TO THEIR SEXUAL CYCLE

"The mammary gland is a modified sweat gland specialized in milk secretion, whose development is synchronized with the sexual function, being directly influenced by the stages of the sexual cycle in both canids and felines. Knowledge of morphology and physiology is essential for a correct approach of the mammary diseases, an important pathology affecting two categories: the adult female and the newborns. There are numerous controversies in the literature regarding the terminology and duration of the dog and cat sexual cycle, leading to the existent variability of the information. However, for the bitch it is unanimously accepted that most canine breeds have two estrous periods per year, usually in spring and autumn. This period can be systematically divided into proestrus, estrus, luteal phase and anestrus. In this species, the proestrus and estrus periods are long and necessarily accompanied by a long luteal phase. These are then followed by anestrus, which is not influenced by the season, unlike the cat. The queen is a seasonally polyestrous animal, which in the absence of mating goes into estrus every 2-3 weeks throughout the breeding season. She will have repeated cycles in the breeding season, which will only be interrupted by gestation, pseudo-gestation or various ailments. The aim of this review is to describe the estrus cycle in dogs and cats, and its connection with mammary gland development, a gland with unique growth due to the fact that the final stage of development is reached in the adult female only during gestation."

Computer-aided diagnosis of Canine Hip Dysplasia using deep learning approach in a novel X-ray image dataset

ABSTRACT Canine Hip Dysplasia (CHD) is a congenital disease with a polygenic hereditary component, characterised by abnormal development of the coxo-femoral joint which results in poor coaptation of the femoral head in the acetabulum; the disease rapidly progresses to osteoarthritis of the hip. While dysplasia has been recognised in practically all canine breeds, it is much more common and of concern in medium and large dog breeds with rapid development. Dysplasia in predisposed breeds, particularly the German Shepherd, is the object of screening based on systematic radiological control in some countries. Our collected dataset comprises 507 X-ray images of dogs affected by hip dysplasia (HD). These images were meticulously evaluated using six Deep Convolutional Neural Network (CNN) models. Following an extensive analysis of the top-performing models, VGG16 emerged as the leader, achieving remarkable accuracy, recall, and precision scores of 98.32%, 98.35%, and 98.44%, respectively. Leveraging deep learning (DL) techniques, this approach excels in diagnosing CHD from hip X-rays with a high degree of accuracy.

The polarity and shape of the T wave in lead V-10 in Chihuahuas

The T-wave in the canine electrocardiogram can be positive, negative, or biphasic in most leads, while his amplitude should not be greater than 25% of the R wave. However, since the 1960’s persists controversy regarding the polarity of the T wave in Chihuahuas when compared to other canine breeds. This study aimed to clarify the polarity and shape of the T-wave in the lead V-10 in a group of healthy Chihuahuas. Retrospective eletrocardiographic study with a sample of 20 private client-owned Chihuahuas. The conclusion was that the polarity of the T-wave is usually negative and the shape is asymmetric, type “slow-fast/down-up”, in all dogs studied.

3D Digital and Printed Hearts from Different Canine Breeds as an Educational Tool for Radiographic Interpretation

Three-dimensional (3D) printing is a new method of creating anatomical models, which can enhance the training of students and health professionals. The large breed-variation in dogs means that interpretation of thoracic radiographs can be challenging for the inexperienced radiologist. The aim of this study was to develop digital and printed 3D cardiac models from six canine breeds and evaluate their use as a tool for studying breed variations in radiology. The printed and digital 3D cardiac models were used by postgraduate veterinary students in diagnostic imaging along with a theoretical class on the subject and students completed a pre- and post-test, assessing cardiac size on thoracic radiographs in order to verify the usefulness of the models. The students then completed a satisfaction questionnaire on a Likert scale. There was a significant difference between the pre-test and the post-test results, with greater accuracy after using the 3D models. More errors were made in pre-test interpretation of radiographs from English Cocker Spaniel, English Bulldog, and Yorkshire Terrier and there were a significantly higher number of correct answers after using the 3D models. The vast majority of responses to all questions in the satisfaction questionnaire were positive, with partial or total agreement of the participants. This study demonstrates that digitally printed cardiac models from different breeds of dogs are effective learning tools. They helped students to better understand the relevant spatial relationship and cardiac morphology and to compare this anatomy with the radiographic image. Models are provided in 3D PDF and STL files for download.