Large Dogs Research Articles

What Is Your Diagnosis?

HistoryAn 8.7-year-old 3.9-kg (8.6-lb) spayed female Shih Tzu was evaluated for dyspnea and episodes of coughing that started after being retrieved from a dog daycare facility earlier in the day. The owners reported that a larger dog had collided with their Shih Tzu and that no other trauma or violent interactions had been observed. The owners also reported that their dog was not receiving any medications, was current on vaccinations, and had not had any previous abnormal clinical signs, except during an instance of pancreatitis 5 years earlier.On physical examination, the dog was quiet and alert and had

Conversion factors to derive organ doses for canine subjects undergoing CT examinations.

Although a large number of CT scans are being conducted on small animals, especially in Western countries, little is known of absorbed dose from veterinary CT scans. In the current retrospective analytical study, we estimated the radiation dose delivered to dogs from CT scans with various scan protocols and compared the results with those of human patients. We adopted a total of three computerized canine models with three sizes combined with a computer simulation model of a CT scanner. The eyes of the dog model received the greatest dose, 1.10 mGy/mGy, in the head scan, followed by a brain dose of 0.85 mGy/mGy. In the chest, abdomen-pelvis (AP), chest-abdomen-pelvis, and head-chest-abdomen-pelvis scans, the heart wall (0.93 mGy/mGy), ovaries (0.99 mGy/mGy), lungs (1.12 mGy/mGy), and thyroid (1.23 mGy/mGy) received the greatest organ doses, respectively. The smallest dog model received up to 1.4-fold greater organ doses than the largest dog in both the chest and AP scans. Overall, the medium-size canine model received organ doses comparable to those of the 1-year-old child model in the head scan, the 5-year-old child in chest scan, and the 10-year-old child in AP scan. The organ dose conversion factors derived from this study should help evaluate absorbed dose for canine patients undergoing CT exams.

Modified primary sacrocaudal surgical stabilisation in a large breed dog

AbstractSacrocaudal luxation can be associated with sacral and caudal nerve roots injury, potentially leading to loss of tail nociception, tail paralysis and urinary incontinence. In cats, several treatments have been proposed depending on the patient's neurological status. When sacrocaudal luxation is associated with loss of tail nociception, tail paralysis and preserved urinary continence, surgical stabilisation can be envisaged. This case report describes surgical reduction and stabilisation of sacrocaudal fracture‐luxation in a large 4‐year‐old crossbreed dog. On presentation tail motor and sensory function (tested at the tail base) were absent. Tail exploration/stabilisation with transarticular Kirshner pins and tension band wires was performed. Motor function returned over 14 days following surgery. Maintenance of sacrocaudal alignment was confirmed radiographically as long as two months following surgery. To the authors' knowledge, there is little information concerning prognosis for tail mobility recovery and surgical treatment efficacy for dogs. Moreover, several anatomical differences existed between cats' and dogs’ tails which must be considered during tail stabilisation.

Anti-arrhythmic investigations in large animal models of atrial fibrillation.

Atrial fibrillation (AF) constitutes an increasing health problem in the aging population. Animal models reflecting human phenotypes are needed to understand the mechanisms of AF, as well as to test new pharmacological interventions. In recent years, a number of large animal models, primarily pigs, goats, dog and horses have been used in AF research. These animals can to a certain extent recapitulate the human pathophysiological characteristics and serve as valuable tools in investigating new pharmacological interventions for treating AF. This review focuses on anti-arrhythmic investigations in large animals. Initially, spontaneous AF in small and large mammals is discussed. This is followed by a short presentation of frequently used methods for inducing short- and long-term AF. The major focus of the review is on anti-arrhythmic compounds either frequently used in the human clinic (ranolazine, flecainide, vernakalant and amiodarone) or being promising new AF medicine candidates (IK,Ach , ISK,Ca and IK2P blockers). LINKED ARTICLES: This article is part of a themed issue on Preclinical Models for Cardiovascular disease research (BJP 75th Anniversary). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.5/issuetoc.

Analysis of 7866 feline and canine uroliths submitted between 2014 and 2020 in the Netherlands

Analysis of large datasets of uroliths is necessary to illustrate the prevalence and risk factors of urolithiasis. Furthermore, it may help to improve treatment and prevention of urolithiasis. In this study, 7866 uroliths (44.5% feline and 55.5% canine) from veterinary practitioners in the Netherlands between 2014 and 2020 were analysed. Between 2014 and 2020 the distribution over the different types of uroliths remained similar over time. Female cats, obese cats, Domestic Shorthair cats, female dogs, and large breed dogs had an increased risk for struvite. Neutered cats, all cat breeds except Domestic Shorthair, neutered dogs, male dogs, intact male dogs, and small breed dogs had an increased risk for calcium oxalate urolithiasis. Cystine and urate were found predominantly in male dogs. Dalmatians were at highest risk for urate urolithiasis. The findings of this study in the Netherlands were similar to findings in previous studies from different countries. However, urate urolithiasis in the English Cocker Spaniel and cystine urolithiasis in the Yorkshire Terrier were new associations. Body condition score, information about recurrence of urolithiasis, medical history, and diet history should be included in submission sheets in the future to explore other possible associations.

Overweight in Swedish show dogs\u2013prevalence and association with performance in competition

BackgroundThe prevalence of overweight and obesity is increasing in companion dogs, but little is known of these conditions in show dogs. This study assessed body condition score (BCS) of show dogs of six selected popular breeds at a major Swedish dog show event and examined the association between BCS and performance in competition.ResultsAt one of Sweden’s largest dog shows, BCS of 120 dogs of six different breeds was assessed by trained animal healthcare personnel, using a 9-point BCS scale with conditional cut-off for overweight set to BCS ≥ 6. Prevalence of overweight in the cohort was 32% but all overweight dogs except one displayed only slight overweight (BCS 6) and no dog was assessed as obese (BCS 8–9). Prevalence of overweight differed significantly between breeds (P < 0.0001) with Labrador retrievers, Golden retrievers and French bulldogs showing the highest mean BCS (5.6–5.7) and highest prevalence of overweight (50–67%). Lean and overweight dogs received awards and higher show awards (certificates) to the same extent, and no significant association between slight overweight and performance in competition was found.ConclusionsPrevalence of overweight in Swedish show dogs was relatively high and in the same range as in the Swedish dog population as a whole. Dog owners, breeders and judges should be made aware of canine obesity problems and trained in BCS assessment, to better prevent canine overweight and associated health risks. This is particularly important for retriever and brachycephalic breeds, which showed high prevalence of slight overweight and have breed-specific health problems exacerbated by overweight. Owners and breeders of traditionally sturdy dog breeds should be informed that overweight dogs do not outperform lean dogs in competition.

Investigation of Mutations in Exon 12 Of β-MYH7, 16 Of MYBPC3 and 2 Of TCAP Gene in Dogs with Dilated Cardiomyopathy using PCR-SSCP Technique

Background: Dilated cardiomyopathy is the important myocardial disease and one of the most common cause of death in the medium to large size dog breeds worldwide. The disease is characterized by dilatation of cardiac chambers and thinning of walls leads to systolic failure. Mutations in some sarcomere genes leads to cardiomyopathy in humans. Sarcomere is an important multifunctional protein network involved in the signal reception and transduction. Mutations in β-MYH7, MYBPC3 and TCAP genes produce alterations in the morphology of heart (hypertrophy or dilatation). Methods: In this study twenty apparently healthy and twenty five dogs with dilated cardiomyopathy (DCM) were selected from patients reported or referred to University Veterinary Hospital and Teaching Veterinary Clinical Complex, Mannuthy (2015-2017) based on the clinical examination, radiographic, electrocardiographic, haematobiochemical and echocardiographic studies cardiac disorders (Dilated cardiomyopathy and hypertrophic cardiomyopathy) were confirmed. Result: In the present study we investigated genetic alterations of exon 12 of β-MYH7, 16 of MYBPC3 and 2 of TCAP gene in dogs by polymerase chain reaction -single stranded confirmation of polymorphism (PCR-SSCP). Polymerase chain reactions were analysed using acrylamide gel and samples with different pattern of bands were sequenced. Polymerase chain reaction-SSCP showed different migration of band pattern in the intron 1 of TCAP gene in one sample.

Heart Rate Changes Before, During, and After Treadmill Walking Exercise in Normal Dogs.

In dogs, changes in heart rate (HR) can reflect conditioning, fear, anticipation, and pain; however, these are not routinely assessed in veterinary rehabilitation patients. Knowing the expected HR changes during rehabilitation exercises can guide protocols and can optimize post-operative therapy. The primary objectives of the study were to assess HR in dogs undergoing treadmill exercise (TE) during the walk and to compare the three collection techniques of HR, namely, auscultation, a HR monitor (HR MONITOR), and a Holter monitor (HOLTER). We hypothesized that the HR would increase by 20% during TE, that HR taken after TE would not be the same as the HR during TE, and that all methods of measurement would have good agreement. HR was recorded in all methods simultaneously, in eight adult healthy large breed dogs during rest (REST), immediately before TE (PRE), during TE (WALK), and 15 and 60 s after TE (POST-15, POST-60). Statistical analyses included Spearman and Pearson correlations, Bland-Altman analyses, and a repeated measures ANOVA with Sidak's post-hoc test (significant at value of p < 0.05). Increased HR was reflected in TE during WALK, and elevations in HR during WALK were not reflected in POST timepoints. Auscultation was also not possible during WALK. Significant moderate-to-strong correlations existed among all monitoring options at each of the timepoints (rho range = 0.5–0.9, p < 0.05). There were no correlations between peak HR and age or weight. The main limitation of this study is that only healthy and large breed dogs were used. Both monitors captured the increase in HR during exercise and could guide TE regimens to minimize patient risk of injury and to maximize training effectiveness.

CT measures of adrenal gland length and caudal pole diameter are reproducible in large breed dogs: A pilot study.

Computed tomography (CT) is increasingly available to evaluate dogs with suspected adrenal disease, however, published studies describing the reproducibility of CT methods for quantifying adrenal gland (AG) measurements are lacking. This prospective, pilot, observer agreement study aimed to evaluate reproducibility and repeatability of two different methods of measurement of AGs on CT to establish a usable technique and define standard reference ranges. Multiplanar reformatted (MPR) CT images of both AGs of six large breed dogs were obtained with the MPR axis parallel to the spine and parallel to the long axis of the AG. Ten measurements were performed: maximal length and diameter at cranial and caudal poles on dorsal, sagittal, and transverse images; and minimal diameter of cranial and caudal poles on transverse images. Three observers with different levels of experience repeated these measurements three times for each dog. Intra‐ and interobserver variability were calculated through intraclass correlation coefficient (ICC). The differences in time to perform measurements between the two methods were tested with Student's t‐test. Regardless of the measurement method used, length of AGs on dorsal and sagittal MPR images had the lowest intra‐ and inter‐observer variability (ICC = 0.93‐0.99), diameter of caudal pole on transverse plane showed low intra‐ and interobserver variability (ICC = 0.77‐0.80) and diameter of cranial pole had the highest variability (ICC = 0.12‐0.61). Although length was the less variable measurement, its use may be unrealistic in daily practice. Interestingly measurement of caudal pole on transverse plane was characterized by low intra‐ and interobserver variability. No difference in time performing the measurements was noted between the two methods.

Zurich Cementless Dual Mobility Cup for Canine Total Hip Prosthesis: Implant Characteristics and Surgical Outcome in 105 Cases

AbstractDislocation after total hip arthroplasty (THA) remains a troublesome complication, and a source of frustration for the owner and the surgeon. The dislocation rate of hip prostheses in dogs is reported to range from 4 to 15%, representing the most common short-term complication. This is especially true in large and giant breed dogs, usually requiring revision surgery. With the increase in the number of THA being performed in veterinary surgery, reducing or preventing complications such as postoperative THA dislocation will be of paramount importance. The Zurich cementless dual mobility (DM) system allows impingement-free range of angulation of 80 to 132 degrees between the ceramic head and the polyether ether ketone (PEEK) cup when combined with the range of the PEEK cup in the outer metal cup. In this article, we review the use of the DM cup in THA in large and giant breed dogs, in terms of its history, biomechanics, outcomes and complications based on 105 cases.

Sociocognitive Review on Discourse of Discrimination and Hatred: Focusing on the Perception of Large Dogs Affected by the Publication of the Dog Safety Countermeasure

Sociocognitive Review on Discourse of Discrimination and Hatred: Focusing on the Perception of Large Dogs Affected by the Publication of the Dog Safety Countermeasure

An Ancient Practice but a New Paradigm: Personal Choice for the Age to Spay or Neuter a Dog.

Extensive practice and knowledge of the methods and effects of castration of male livestock and even humans has been widespread since ancient times, but only a few decades ago did neutering (including spaying) become a routine part of canine husbandry. In the US, the 6-month neuter became standard practice. Only recently, however, have some of the consequences of this major physiological alteration become evident. As the data-based study on 35 breeds reveals, there are major breed differences associated with effects of neutering, especially with early neutering, including increased risks of joint disorders and some cancers. The study of mixed-breed dogs reveals that the risk of joint disorders is increased in the large dogs. Implications of breed-specific and sex-specific effects for age of neutering have prompted the consideration of a new paradigm with regard to this practice. This involves focusing on each individual dog when deciding upon the appropriate age of neutering to avoid increasing the risk of a joint disorder or cancer above that inherent for the breed. For many breeds, particularly the smaller dogs, no effects were found for the age of neutering on joint disorders and the cancers followed. In these cases, the caregiver has a wide range of choice for neutering without increasing the dog's risk for these diseases. In the future, additional research may reveal more about other increased risks for age-related cognitive dysfunction or elevated levels of luteinizing hormone caused by gonad removal, and lead to revised guidelines.

Pediatric Craniofacial Fractures From Canine Bites.

Craniofacial fractures from canine bites are rare, but can be devastating events that lead to complex surgical management, long-term functional deficits, and psychological sequelae. The objective of this case-control study was to identify risks associated with craniofacial fractures in pediatric dog bite victims. From 2008 to 2019 at our quaternary center, all children with craniofacial fractures from dog bites were included in this study. Controls were obtained in a 2:1 ratio via a random sample of all dog bite encounters. Logistic regression was used to calculate odds ratios (OR) with 95% confidence intervals (CI). Of 3602 dog bite encounters, 114 children were included in the study with an average age of 4.8 years (interquartile range = 2.4-9.1 years) and 51 patients (45%) were female. Seventy-four children (65%) were bitten by a family-owned dog. Thirty-eight patients with 60 craniofacial fractures were identified. The following factors were significantly associated with increased risk for craniofacial fractures: Caucasian race (OR 7.3, CI 1.6-16.7), age under five (OR 4.1, CI 1.6-10.7), rural location (OR 3.9, CI 1.3-12.3), child location on the floor (OR 6.2, CI 2.4-16.2), and dogs weighing over 30 pounds (OR 19.6, CI 5.8-82.3). Nine patients (12%) required multiple reconstructive operations, and four patients (5%) developed post-traumatic stress disorder. In conclusion, toddlers in rural households with large dogs are at high risk for sustaining craniofacial fractures from bite injuries. Craniofacial surgeons, pediatricians, and emergency department physicians should use these data to lead prevention efforts in the community.

The Physiological Conundrum That is the Domestic Dog.

Across Mammalia, body size and lifespan are positively correlated. However, in domestic dogs, the opposite is true: small dogs have longer lives compared with large dogs. Here, I present literature-based data on life-history traits that may affect dog lifespan, including adaptations at the whole-organism, and organ-level. Then, I compare those same traits to wild canids. Because oxidative stress is a byproduct of aerobic metabolism, I also present data on oxidative stress in dogs that suggests that small breed dogs accumulate significantly more circulating lipid peroxidation damage compared with large breed dogs, in opposition to lifespan predictions. Further, wild canids have increased antioxidant concentrations compared with domestic dogs, which may aid in explaining why wild canids have longer lifespans than similar-sized domestic dogs. At the cellular level, I describe mechanisms that differ across size classes of dogs, including increases in aerobic metabolism with age, and increases in glycolytic metabolic rates in large breed dogs across their lifespan. To address potential interventions to extend lifespan in domestic dogs, I describe experimental alterations to cellular architecture to test the "membrane pacemaker" hypotheses of metabolism and aging. This hypothesis suggests that increased lipid unsaturation and polyunsaturated fatty acids in cell membranes can increase cellular metabolic rates and oxidative damage, leading to potential decreased longevity. I also discuss cellular metabolic changes of primary fibroblast cells isolated from domestic dogs as they are treated with commercially available drugs that are linked to lifespan and health span expansion.

Measurement of the Femoral Anteversion Angle in Medium and Large Dog Breeds Using Computed Tomography.

To promote the development of an optimally functional total hip prosthesis for medium and large dog breeds, accurate measurements of the normal anatomy of the proximal femur and acetabular retroversion are essential. The aim of the current study was to obtain precise normal values of the femoral anteversion angle using computed tomography on cadavers of mature dogs with normal hip joints of both medium and large breeds. Based on the length of their femora 58 dogs were allocated either to group I: ≤195 mm or group II: >195 mm. In the study the femoral anteversion angle (FAA) was measured on each femur using multi-slice spiral computed tomography (CT). The data were processed as multi-planar and three-dimensional reconstructions using Advantage Workstation software. The CT measurements showed that the mean ± standard deviation (SD) FAA of group I was 31.34 ± 5.47° and in group II it was 31.02 ± 4.95°. There were no significant mean difference associations between the length of the femur and the femoral neck angle in either group (P > 0.05). The data suggest that a prosthesis FAA of 31 degrees would be suitable for a wide range of dog sizes.

Técnica de placa dupla para fixação concomitante da osteotomia de nivelamento do platô tibial e ostectomia modificada em cunha de fechamento cranial da tíbia em um cão com doença do ligamento cruzado cranial e ângulo de platô tibial excessivo: relato de caso

ABSTRACT Tibial plateau leveling osteotomy (TPLO) associated to cranial wedge closing ostectomy (CCWO) has been one of the best options to manage cranial cruciate ligament (CCL) disease and excessive tibial plateau angle (TPA) in large dogs, however, the complication rate is potentially high. It is believed that a more robust fixation is necessary to stabilize them and decrease the risk of implant failure. A 6-year-old male American Pit Bull, weighing 36kg, with 90-day history of right hind limb lameness, was diagnosed with CCL disease. Due to the excessive tibial plateau angle (42°), TPLO was associated with a modified CCWO using a double plating technique. A final TPA of 12⁰ was accomplished, and a restricted level of exercises and physiotherapy were recommended. The patient was followed monthly until the fifth month postoperatively, when radiographic bone consolidation and no lameness were observed. By the date of this submission, 3 years after the procedure, the owner has reported no complications. The double plating technique for fixing TPLO and modified CCWO proved to be effective for the treatment of CrCL deficiency in a large dog with an excessive TPA.

Femorotibial joint kinematics in nine dogs treated with lateral suture stabilization for complete cranial cruciate ligament rupture.

To quantify 3-D femorotibial joint kinematics during ambulation in dogs with cranial cruciate ligament (CCL) rupture treated with lateral fabellotibial suture stabilization (LFTS). 9 adult dogs (body weight, 15 to 35 kg [33 to 77 lb]) with unilateral complete CCL rupture. Digital 3-D bone models of the femur and fabellae and tibia and fibula were created from CT scans. Lateral fluoroscopic images of stifle joints were collected during treadmill walking before surgery and 6 months after LFTS. The LFTS was performed with nylon leader material secured with knots. Gait cycles were analyzed with a 3-D to 2-D image registration process. Femorotibial joint kinematics (craniocaudal translation, internal-external rotation, and flexion and extension angles) were compared among CCL-deficient stifle joints before LFTS, CCL-deficient stifle joints 6 months after LFTS, and unaffected contralateral (control) stifle joints. Owners and veterinarians subjectively assessed lameness by use of a visual analog scale and gait examination, respectively, at each time point. At midstance phase, medial cranial tibial translation decreased from 9.3 mm before LFTS to 7.6 mm after LFTS but remained increased when compared with control stifle joint values. Following LFTS, axial rotation and stifle joint flexion and extension angles were not significantly different from control stifle joints. On the owner survey, the median walking lameness score improved from 9.3 of 10 before surgery to 0.3 after surgery. On gait examination, median walking lameness score improved from 2 of 4 before surgery to 0 after surgery. Stifle joint instability was only slightly mitigated at 6 months following LFTS performed with knotted nylon leader material in medium to large dogs with CCL rupture, despite improvement in lameness.

Outcomes and prognostic indicators in 59 paraplegic medium to large breed dogs with extensive epidural hemorrhage secondary to thoracolumbar disc extrusion.

To evaluate outcomes and prognostic factors after decompressive hemilaminectomy in paraplegic medium to large breed dogs with extensive epidural hemorrhage (DEEH) and thoracolumbar intervertebral disc extrusion (TL-IVDE). Retrospective, cohort, descriptive study. Fifty-nine client-owned dogs. Medical records and advanced imaging were reviewed for paraplegic dogs with DEEH. Ambulatory status 6 months after surgery and postoperative complications were recorded. Multiple logistic regression models were constructed to explore prognostic factors. Records of 22 dogs with and 37 dogs without pelvic limb pain perception at presentation were included. Median age of dogs was 5 years (interquartile range, 4-7), and mean weight was 26.9 kg (SD, ±9.71). Labradors and Labrador mixes were most common (17/59 [28.8%]). Recovery of ambulation occurred in 17 of 22 (77.3%) dogs with and in 14 of 37 (37.8%) dogs without pain perception prior to surgery. Progressive myelomalacia was recorded in three of 59 (5.1%) dogs, one with pain perception and two without pain perception at presentation. Postoperative complications (14/59 [23.7%]) were common. Factors independently associated with outcome included clinical severity (odds ratio [OR] 0.179, P = .005), number of vertebrae with signal interruption in half Fourier single-shot turbo spin-echo sequences (HASTEi; OR, 0.738; P = .035), and ratio of vertebral sites decompressed to HASTEi (OR, 53.79; P = .03). Paraplegic medium to large breed dogs with DEEH have a less favorable outcome after surgical decompression than paraplegic dogs with TL-IVDE. Dogs with DEEH can have severe postoperative complications. Loss of pain perception and increased HASTEi are associated with a poor outcome, while more extensive decompression improves outcome.

Could a rabies incursion spread in the northern Australian dingo population? Development of a spatial stochastic simulation model.

Australia, home to the iconic dingo, is currently free from canine rabies. However northern Australia, including Indigenous communities with large free-roaming domestic dog populations, is at increased risk of rabies incursion from nearby Indonesia. We developed a novel agent-based stochastic spatial rabies spread model to evaluate the potential spread of rabies within the dingo population of the Northern Peninsula Area (NPA) region of northern Australia. The model incorporated spatio-temporal features specific to this host-environment system, including landscape heterogeneity, demographic fluctuations, dispersal movements and dingo ecological parameters—such as home range size and density—derived from NPA field studies. Rabies spread between dingo packs in nearly 60% of simulations. In such situations rabies would affect a median of 22 dingoes (approximately 14% of the population; 2.5–97.5 percentiles: 2–101 dingoes) within the study area which covered 1,131 km2, and spread 0.52 km/week for 191 days. Larger outbreaks occurred in scenarios in which an incursion was introduced during the dry season (vs. wet season), and close to communities (vs. areas with high risk of interaction between dingoes and hunting community dogs). Sensitivity analyses revealed that home range size and duration of infectious clinical period contributed most to the variance of outputs. Although conditions in the NPA would most likely not support a sustained propagation of the disease in the dingo population, due to the predicted number of infected dingoes following a rabies incursion and the proximity of Indigenous communities to dingo habitat, we conclude that the risk for human transmission could be substantial.

Unraveling the chaotic genomic landscape of primary and metastatic canine appendicular osteosarcoma with current sequencing technologies and bioinformatic approaches.

Osteosarcoma is a rare disease in children but is one of the most common cancers in adult large breed dogs. The mutational landscape of both the primary and pulmonary metastatic tumor in two dogs with appendicular osteosarcoma (OSA) was comprehensively evaluated using an automated whole genome sequencing, exome and RNA-seq pipeline that was adapted for this study for use in dogs. Chromosomal lesions were the most common type of mutation. The mutational landscape varied substantially between dogs but the lesions within the same patient were similar. Copy number neutral loss of heterozygosity in mutant TP53 was the most significant driver mutation and involved a large region in the middle of chromosome 5. Canine and human OSA is characterized by loss of cell cycle checkpoint integrity and DNA damage response pathways. Mutational profiling of individual patients with canine OSA would be recommended prior to targeted therapy, given the heterogeneity seen in our study and previous studies.