Labrador Retriever Research Articles

Performance Comparison of Genomic Best Linear Unbiased Prediction and Four Machine Learning Models for Estimating Genomic Breeding Values in Working Dogs

This study investigates the efficacy of various genomic prediction models—Genomic Best Linear Unbiased Prediction (GBLUP), Random Forest (RF), Support Vector Machine (SVM), Extreme Gradient Boosting (XGB), and Multilayer Perceptron (MLP)—in predicting genomic breeding values (gEBVs). The phenotypic data include three binary health traits (anodontia, distichiasis, oral papillomatosis) and one behavioral trait (distraction) in a population of guide dogs. These traits impact the potential for success in guide dogs and are therefore routinely characterized but were chosen based on differences in heritability and case counts specifically to assess gEBV model performance. Utilizing a dataset from The Seeing Eye organization, which includes German Shepherds (n = 482), Golden Retrievers (n = 239), Labrador Retrievers (n = 1188), and Labrador and Golden Retriever crosses (n = 111), we assessed model performance within and across different breeds, trait heritability, case counts, and SNP marker densities. Our results indicate that no significant differences were found in model performance across varying heritabilities, case counts, or SNP densities, with all models performing similarly. Given its lack of need for parameter optimization, GBLUP was the most efficient model. Distichiasis showed the highest overall predictive performance, likely due to its higher heritability, while anodontia and distraction exhibited moderate accuracy, and oral papillomatosis had the lowest accuracy, correlating with its low heritability. These findings underscore that lower density SNP datasets can effectively construct gEBVs, suggesting that high-cost, high-density genotyping may not always be necessary. Additionally, the similar performance of all models indicates that simpler models like GBLUP, which requires less fine tuning, may be sufficient for genomic prediction in canine breeding programs. The research highlights the importance of standardized phenotypic assessments and carefully constructed reference populations to optimize the utility of genomic selection in canine breeding programs.

ИНТЕРСТИЦИАЛЬНО-КЛЕТОЧНАЯ ОПУХОЛЬ СЕМЕННИКА У КОБЕЛЯ: КЛИНИЧЕСКИЙ СЛУЧАЙ

The aim of the study is to describe the clinical and morphological features of the manifestation, diagno-sis, and postoperative histological verification of a feminizing tumor that developed from Leydig cells in the cryptorchid testis of a 3-year-old Labrador dog named Biscuit. During the clinical andrological examination of the male, symmetrical bilateral alopecia of the sides of the abdomen, hypertrophy of the milk packets and their nipples were noted. During the examination of the scrotum, one testis was not found, while ex-amining the prepuce and penis, it was also noted that the penis was visually reduced in size, and the pre-puce hangs from the abdominal wall. Ultrasound of the scrotum: the left testicle is not visualized, the right one is located in the scrotum, measuring 26 x 12 mm. Ultrasound of the abdominal cavity and small pel-vis: liver, spleen, kidneys and bladder without pathological features. The left testicle is located in the ab-dominal cavity, enlarged, 31 x 27 mm in size, its structure is heterogeneous, diffuse hypoechoic for-mations without clear contours are visualized. The prostate gland is enlarged, oval, 74 x 51 mm in size, its structure is heterogeneous, multiple anechoic structures are visualized with an uneven contour up to 21 x 15 mm in size. Thus, according to the results of ultrasound, the dog was diagnosed with a neoplasm in the left cryptorchid testis and prostatic hypertrophy with multiple cysts. Intraoperative visual examination of the abdominal cavity confirmed the preoperative diagnosis. There were no technical difficulties during the resection of a cryptorchid testis affected by a tumor and a testicle localized in the scrotum. The postopera-tive period passed without complications. Approximately 2.5 months later. after resection of the tumor (to-tal bilateral orchiepididymitectomy), the signs of sex inversion disappeared in the male and the coat was fully restored. The results of the pathohistological examination of the postoperative material showed that instead of the expected sertolioma, the pathognomonic signs of which are estrogenic alopecia and gyne-comastia, the dog was diagnosed with leidigoma. The presented clinical case demonstrates that endocrine alopecia and gynecomastia are not only a classic manifestation of sertolioma, but in some cases, signs of sex inversion can also be associated with Leydig tumor.

Incidence and risk factors for insulinoma diagnosed in dogs under primary veterinary care in the UK

Insulinoma is the most common pancreatic tumor diagnosed in dogs. This study aimed to report incidence risk, breed predispositions and other demographic risk factors for insulinoma diagnosed in dogs under primary veterinary care in the UK. The VetCompass Program supports research on anonymized electronic health records (EHRs) from dogs under UK veterinary care. This study included all VetCompass EHRs from dogs under primary veterinary care during 2019. Multivariable logistic regression analysis was used to evaluate demographic risk factors for insulinoma diagnosis. Of 2,250,741 study dogs, 278 were confirmed as insulinoma cases at any date. The estimated 2019 incidence risk was 0.003% (95% CI 0.002–0.004%). Compared to crossbreeds, predisposed breeds included Dogue de Bordeaux, German Pointer, Flat Coated Retriever, Boxer and West Highland White Terrier. The Labrador Retriever showed decreased odds for insulinoma diagnosis. Additionally, being a terrier breed and being a breed predisposed to other endocrine cancers were associated with increased odds for insulinoma diagnosis. Other risk factors associated with increased odds for insulinoma diagnosis included being female neutered, being 9 - <15 years of age, having an adult median bodyweight of 20 - <30 kg and having a bodyweight above the median for the sex/breed. This is the first study to report the epidemiology of canine insulinoma in dogs under primary veterinary care, resulting in crucial leads for further research in the epidemiology and etiology of canine insulinoma and possible links of canine insulinoma with other canine endocrine cancers. Additionally, the results can aid veterinarians to identify dogs at greater risk of insulinoma.

High-field MRI findings in epileptic dogs with a normal inter-ictal neurological examination.

Epilepsy is one of the most common chronic neurological conditions affecting dogs. Previous research exploring the likelihood of a structural cause of epilepsy specifically in dogs with a normal inter-ictal examination is limited to a small population of dogs using low-field MRI. The aims of this study were to establish high-field (1.0T and 1.5T) MRI findings in dogs presenting with epileptic seizures and a normal inter-ictal examination. Medical records were retrospectively searched for dogs presenting with at least two epileptic seizure events more than 24 h apart. To be included in the study, patients had to have a normal neurological examination, high-field MRI of the brain and have had metabolic and toxic causes excluded. Four hundred and twelve dogs were eligible for inclusion. Crossbreeds were most commonly affected (n = 63, 15.3%) followed by Border collies (n = 39, 9.5%) and Labrador retrievers (n = 26, 6.3%). Seventy-six dogs (18.5%) had abnormalities detected on MRI, 60 (78.9%) of which were considered to be incidental. Overall, 16 dogs (3.9%) had a structural cause of their epileptic seizures including neoplasia (n = 13, 81.3%), anomalous (n = 2, 12.5%) and meningoencephalitis of unknown origin (MUO) (n = 1, 6.3%). When split into age group at first epileptic seizure structural lesions were documented in 0/66 dogs aged <1 year, 4/256 (1.6%) dogs aged ≥1 year ≤6 years (three neoplastic and one anomalous), 3/51 (5.9%) aged >6 years ≤8 years (two neoplastic and one MUO), and 9/39 (23.1%) dogs aged >8 years (eight neoplastic, one anomalous). Multivariate analysis identified two risk factors for structural disease: increasing age at first epileptic seizure (p < 0.001, OR = 4.390, CI 2.338-8.072) and a history of status epilepticus (p = 0.049, OR = 4.389, CI 1.010-19.078). Structural lesions are an uncommon cause of epilepsy at any age in dogs with a normal inter-ictal examination.

Predicting parturition in a 3-year-old Labrador Retriever.

Predicting parturition in a 3-year-old Labrador Retriever.

A Prospective Study Investigating the Health Outcomes of Bitches Neutered Prepubertally or Post-Pubertally.

There are scant studies of associations between the pubertal status at neutering and subsequent health outcomes of female dogs. This study examined health data for Labrador and Golden Retriever crossbreed bitches neutered by ovariohysterectomy either before (PrePN, n = 155) or after (PostPN, n = 151) puberty using a prospective study design. Data were extracted from an electronic database containing detailed health records for all bitches. Cruciate ligament disease occurred in significantly more PrePN (n = 11) than PostPN bitches (n = 1; Yates Chi-square = 6.784, D.F. = 1, p = 0.009), and PrePN bitches had lower probabilities of remaining free from osteoarthritis (χ2 = 5.777, D.F. = 1, p = 0.016). Additionally, PrePN bitches were diagnosed with atopic dermatitis (PrePN: 3.9 ± 0.6 years, PostPN: 1.6 ± 0.3 years; Mann-Whitney U test = 90.5, p = 0.008) and perivulval dermatitis (PrePN: 4.7 ± 0.9 years, PostPN: 0.8 ± 0.1 years; Mann-Whitney U test = 40.0, p = 0.002) at significantly older ages and had lower probabilities of remaining free from otitis externa (χ2 = 7.090, D.F. = 1, p = 0.008). No associations were identified between the pubertal status at neutering and the incidence of any urogenital disease, including urinary incontinence, which was diagnosed in a small number of bitches (one PrePN and six PostPN). The results suggest that prepubertal neutering may have a detrimental effect on some future musculoskeletal and immune diseases in bitches of these crossbreeds, providing important information to support neutering policies and to help maintain optimal dog welfare.

Rare mixed uterine teratoma with ovarian involvement in a Labrador Retriever dog

Rare mixed uterine teratoma with ovarian involvement in a Labrador Retriever dog

Fleece-Lined Whelping Pools Associated with Reduced Incidence of Canine Hip Dysplasia in a Guide Dog Program.

Using genetic selection, Guide Dogs for the Blind (GDB) has reduced the incidence rate of canine hip dysplasia (CHD). However, given that CHD is polygenic and multifactorial, environmental factors may impact the expression of this developmental condition. The objective of this original, correlational research was to investigate the relationship between the substrate in the whelping pool used from birth to 3 weeks of age and CHD diagnosis. This retrospective study included 5649 dogs (Labrador Retrievers, Golden Retrievers, and Labrador-Golden Retriever crosses) at GDB. A total of 2785 dogs were whelped between 1 July 2012 and 28 November 2015, when the whelping pools were lined with newspaper, and 2864 dogs were whelped between 5 March 2016 and 29 December 2019, when the whelping pools were lined with fleece. Bayesian regression modeling of the CHD diagnoses and PennHIP distraction index scores identified that dogs in the fleece group had a lower risk for CHD diagnosis but similar PennHIP scores compared to the newspaper group. Golden Retrievers had the highest risk of CHD diagnosis and PennHIP scores, followed by Labrador-Golden Retriever crosses and finally Labrador Retrievers, with the lowest risk of CHD diagnosis and PennHIP scores. No sex differences were identified for CHD diagnosis, but males had lower PennHIP scores than females. These results provide correlational evidence that housing-related environmental factors during the first three weeks of development-specifically, the substrate in the whelping pool-are associated with lifelong orthopedic health.

The role of breed versus personality and other demographic factors in predicting chasing behaviour in dogs

Dogs chase for many reasons, in play, when hunting and potentially to remove a threat. However, assumptions are often made as to why dogs chase particular targets, for example breed or personality are often used as explanations. Little research has investigated chasing behaviour except in relation to predation, therefore we aimed to determine dog-related characteristics predictive for chasing in relation to specific targets, with a particular emphasis on the relative role of breed versus personality, two specific and measurable constructs. An online survey for dog owners about their dog’s chasing habits yielded 903 usable responses. Wildlife, cats and other dogs were the most frequently chased targets and the influence of personality and breed varied with each target. Trait level impulsivity significantly affected the likelihood of a dog chasing targets such as vehicles and cyclists, while components of positive activation (reward sensitivity) affected the likelihood of individuals chasing household appliances and objects in the wind. Considering breed, German Shepherds were more likely to chase cats and things blown in the wind while Border Collies were more likely to chase vehicles and household appliances. Labrador Retrievers were less likely to chase horses, vehicles and joggers. These results shed light on the motivational and emotional basis of chasing, and its heterogeneity in relation to different targets.

Ureteral Haemangiosarcoma in a Dog: Rare Primary Tumour With Unusual Metastasis to the Contralateral Kidney

A dog (neutered male, 11 years old, Labrador retriever) underwent abdominal ultrasound, which revealed a 7 cm diameter tumour (caudal region of the left kidney). The animal showed symptoms of weight loss, apathy, haematuria, and abdominal pain. A computed tomography (CT) scan confirmed the presence of a tumour originating from the ureter. Following surgery to remove the ureter with the attached kidney, a histopathological examination was performed. The tumour was classified as a haemangiosarcoma. After the initial recovery, 2 months after surgery, the dog was diagnosed with a tumour in the other kidney. A fine needle biopsy was carried out. A haemangiosarcoma metastasis was suspected. Neoplasms of the ureter are a rare pathology. This is the first case in which metastasis to the second kidney has been confirmed.

Clinical management of viper envenomation in a Labrador retriever: A case report

Clinical management of viper envenomation in a Labrador retriever: A case report

The effectiveness of genetic markers and the role of environmental factors in hip dysplasia and osteochondritis dissecans of the shoulder in German Shepherd, Labrador Retriever, and German Wirehaired Pointer (Deutsch Drahthaar) dogs

The effectiveness of genetic markers and the role of environmental factors in hip dysplasia and osteochondritis dissecans of the shoulder in German Shepherd, Labrador Retriever, and German Wirehaired Pointer (Deutsch Drahthaar) dogs

Hematobiochemical profiles and cardiac biomarker assessment in Labrador retriever dogs

Hematobiochemical profiles and cardiac biomarker assessment in Labrador retriever dogs

Mastocytomas in dogs: the most common complications of surgical interventions

Mast cell tumors (MCTs) - is a malignant tumor consisting of mast cells (mastocytes). In English-language literature it is found under the terms "mast cell tumor", "mast cell sarcoma". It is highly common in dogs and is extremely important in the veterinary oncology field. Some breeds are predisposed to MCT development, including Boxer; Bull Terrier; French Bulldog; Golden Retriever; Labrador Retriever; Shar-pei; and Dachshund. On the other hand, some breeds present a lower risk of MCT development, including the German Shepherd, Chihuahua, Poodle, Yorkshire Terrier, and Cocker Spaniel. The metastatic potential of MCTs varies according to its histopathological classification, occurring in less than 10% of cases of well-differentiated mast cell tumors, in 5% to 22% of moderately differentiated neoplasms, and in 55% to 95% of poorly differentiated cases. In order to exclude tumor metastasis to internal organs, it is recommended to perform ultrasound of the abdominal cavity, computed tomography, with further determination of the metastasis site. In 8 out of 10 cases, we encountered a strong reaction to the suture material, regardless of its choice, as well as abundant exudation and alternation of various drainage systems. To wash the wound pocket and treat it, we used a 0.9% sodium chloride solution, or a combination of 0.9% sodium chloride solution and betadine in a ratio of 1:10. When using a 0.05% chlorhexidine solution, a decrease in the regenerative ability of the tissue and painful sensations during washing were eliminated. The further prognosis depends on the results of histological examination, the degree of malignancy, high/medium/low differentiated according to Patnaik and Kiupel. With highly differentiated mastocytoma, wide boundaries and clean edges of resection, the risk of metastasis is minimal and there is no need for chemotherapeutic treatment. However, it is always necessary to monitor the condition of the animal: a checkup by an oncologist, ultrasound of the liver and spleen monthly for the first 3 months, then gradually reduce the number of visits to 1 every 3 months three times, 1 every six months. Further recommendations for visits will depend on the oncologist' s discretion.

Solitary pulmonary metastasis at presentation in a dog with anal sac adenocarcinoma without nodal metastasis

AbstractA 10‐year‐old, male, neutered labrador retriever was diagnosed with a left‐sided anal sac adenocarcinoma. At diagnosis, staging with an abdominal computed tomography revealed no intraabdominal lymph node enlargement. Thoracic radiographs revealed a soft tissue pulmonary nodule with cytology consistent with a carcinoma. The dog underwent a left anal sacculectomy, and re‐presented 24 days later for a lung lobectomy in which histopathology represented primary anal sac adenocarcinoma metastasis. Forty‐nine days after initial presentation, the dog was referred for a right distal radial lytic lesion in which cytology was concerning for osteosarcoma. After 132 days of initial presentation, an abdominal ultrasound revealed normal‐sized iliosacral lymph nodes. The dog was humanely euthanased 446 days after initial diagnosis. This case report describes a dog who had a solitary metastatic pulmonary nodule from apocrine gland anal sac adenocarcinoma at the time of presentation with no nodal metastasis identified, which is atypical compared to previous reports.

What is your diagnosis? Cerebrospinal fluid from a Labrador Retriever.

What is your diagnosis? Cerebrospinal fluid from a Labrador Retriever.

Chronic progressive left hind limb lameness in an 11-month-old intact female Labrador Retriever Poodle cross.

Chronic progressive left hind limb lameness in an 11-month-old intact female Labrador Retriever Poodle cross.

Quantification of Doppler Indices, Contrast Ultrasound Enhancement Phases and Perfusion Parameters of Splenic Parenchyma in Healthy Dogs

Background: The spleen can be affected by a variety of vascular problems. Affected tissue neovascularization in these conditions can be effectively analysed using imaging modalities such as Doppler and contrast enhanced ultrasonography (CEUS). Methods: Nine healthy dogs were included in this clinical study comprising two breeds of Labrador Retrievers, German Shepherds, and Beagles and one breed each of Crossbred, Pug, and Pitbulls. Pulsed-wave Doppler indices and contrast-enhanced perfusion parameters of the splenic vasculature were obtained by performing spectral Doppler sonography and CEUS using a second-generation ultrasound contrast agent (Sonovue). Result: The mean ± SE value of splenic vein’s Doppler indices were 10.94±2.04 cm/s (PSV), 6.92±1.28 cm/s (EDV), 6.44±1.57 cm/s (MV), 0.35±0.05 (RI) and 0.75±0.17 (PI), while the indices of splenic artery were 31.21±3.12 cm/s (PSV), 8.95±1.63 cm/s (EDV), 13.98±1.95 cm/s (MV), 0.71±0.04 (RI), 1.75± 0.24 (PI). Arterial and venous phases were visible on a CEUS of the splenic parenchyma. The mean ± SE value of the contrast enhanced splenic perfusion parameters (measured in seconds) were as follows: arrival time = 7.00 ± 0.33; time to initial peak = 15.05 ± 0.46; time to final peak = 28.92±1.06; decline time = 97.89±2.82; washout time = 152.22± 9.10.

Circumflex left aortic arch: a new vascular ring anomaly in dogs.

To describe the circumflex left aortic arch as a new form of canine congenital vascular ring anomaly leading to esophageal constriction. 3 large-breed dogs of variable age: a 9-month-old entire male German Shepherd Dog-Rottweiler cross, a 17-week-old entire male German Shepherd Dog, and a 9-year-old neutered female Labrador Retriever, seen between April 2022 and May 2023. Dogs presented for chronic postprandial regurgitation and poor growth. One dog presented for a hard mass on the caudal mandibular region. Computed tomography revealed a normal leftward-oriented cranial half and an abnormal caudal half of the aortic arch crossing toward the right dorsal hemithorax leading to esophageal constriction in all dogs. In addition, 1 dog presented with a right patent ductus arteriosus and 1 with an aberrant right subclavian artery. Circumflex left aortic arch is a newly discovered rare type of congenital vascular ring anomaly in dogs, which presents a similar anatomical derangement to the human form. Clinical signs include postprandial regurgitation and poor growth. Circumflex left aortic arch vascular anomaly cannot be surgically corrected via the left thoracotomy that is commonly used for the more common vascular ring anomalies in dogs. Computed tomography is a useful diagnostic modality for the diagnosis of this condition, detection of concomitant congenital vascular malformations, evaluation of associated pathologies, and surgical planning.

Pneumonia aspirativa em cão

Aspiration pneumonia is a pathology resulting from the inhalation of liquid or solid contents via the airways, which leads to inflammation in the lung parenchyma. The course of the disease varies according to the amount and type of material aspirated, as well as the animal's general state of health. The symptoms of the disease are usually acute and severe. In this sense, the drug therapy chosen for treatment depends on the degree of lung involvement and the clinical signs. The surgical procedure of total or partial lobectomy can be advantageous when the lung lesions are irreversible and clinical therapy has been unsuccessful. The aim of this paper is to report the case of aspiration pneumonia in a Labrador retriever bitch who presented with pulmonary crackles after drowning and was given a pulmonary lobectomy. Computed tomography was used to confirm the diagnosis of aspiration pneumonia. This highlights the importance of carrying out complementary tests in order to offer the animal a better therapeutic approach