Mesocephalic Dogs Research Articles

Preliminary study on intraocular abnormalities found in senior dogs by ultrasonography in a veterinary hospital in Guayaquil, Ecuador

Research on ophthalmology in veterinary medicine in Ecuador is scarce, and ocular health in older dogs should be studied. This study aimed to determine the incidence of ophthalmic abnormalities in senior dogs attending a hospital at Guayaquil and relate them to the type of lesion, breed, sex, age, and type of dog head shape. One hundred healthy senior dogs (> six years old) who underwent consultation during the study were subjected to bilateral eye ultrasonography (USG 10-MHz transducer) and examined for ocular alterations. Breed, sex, age, and head shape were also recorded. Thirty-eight animals presented with ocular abnormalities: presumed cataracts (19%), crystalline luxation (6%), presumed senile retinal degeneration (6%), retinal detachment (4%), nuclear sclerosis (4%), masses and vitreous degeneration (3%), presumed glaucoma (2%), and cysts in the anterior and posterior chambers (1%), mainly as bilateral lesions (24%). Cataracts were present in a more significant proportion in dolichocephalic dogs (8/18) than in brachycephalic (3/22) and mesocephalic dogs (8/60) (p =0.01). In addition, older animals were more affected, both unilaterally and bilaterally, and in both locations (lens or retina)(p <0.05), whereas crystalline luxation and senile retinal degeneration were significantly associated with age(p <0.05), whereas trends were observed for cataracts (p =0.065). Although ultrasound alone does not allow a definitive diagnosis, these preliminary results provide insights into the ocular abnormalities in apparently healthy senior dogs from Guayaquil (Ecuador). Unsuspected intraocular lesions might be relatively high in these patients; however, more extensive studies with complete ocular examination are recommended to confirm these results. Keywords: Aging dog; Cataracts; Retinal lesion; Ultrasonography

Preliminary study on intraocular abnormalities found in senior dogs by ultrasonography in a veterinary hospital in Guayaquil, Ecuador

Research on ophthalmology in veterinary medicine in Ecuador is scarce, and ocular health in older dogs should be studied. This study aimed to determine the incidence of ophthalmic abnormalities in senior dogs attending a hospital at Guayaquil and relate them to the type of lesion, breed, sex, age, and type of dog head shape. One hundred healthy senior dogs (> six years old) who underwent consultation during the study were subjected to bilateral eye ultrasonography (USG 10-MHz transducer) and examined for ocular alterations. Breed, sex, age, and head shape were also recorded. Thirty-eight animals presented with ocular abnormalities: presumed cataracts (19%), crystalline luxation (6%), presumed senile retinal degeneration (6%), retinal detachment (4%), nuclear sclerosis (4%), masses and vitreous degeneration (3%), presumed glaucoma (2%), and cysts in the anterior and posterior chambers (1%), mainly as bilateral lesions (24%). Cataracts were present in a more significant proportion in dolichocephalic dogs (8/18) than in brachycephalic (3/22) and mesocephalic dogs (8/60) (p =0.01). In addition, older animals were more affected, both unilaterally and bilaterally, and in both locations (lens or retina)(p <0.05), whereas crystalline luxation and senile retinal degeneration were significantly associated with age(p <0.05), whereas trends were observed for cataracts (p =0.065). Although ultrasound alone does not allow a definitive diagnosis, these preliminary results provide insights into the ocular abnormalities in apparently healthy senior dogs from Guayaquil (Ecuador). Unsuspected intraocular lesions might be relatively high in these patients; however, more extensive studies with complete ocular examination are recommended to confirm these results. Keywords: Aging dog; Cataracts; Retinal lesion; Ultrasonography

Comparative macroanatomical and scanning electron microscopy study of the eyeball in brachycephalic and mesocephalic dog breeds.

The anatomical structures forming the eyeball differ among dog breeds, both morphologically and morphometrically. This study was aimed at determining the morphometric values of the eyeball layers of different dog breeds and the morphological structures of these layers using scanning electron microscopy. Thirty-two eyeballs of 17 dogs belonging to 9 different breeds that died from traffic accidents, falling from a height, and naturally were used. These dog breeds were grouped according to their brachycephalic and mesocephalic skull structures, and morphometric measurements of the eyeballs of each group were obtained. Scanning electron microscopy was used to examine the morphological structure of the eyeball layers. The studied dogs' eyeballs comprised three layers: outer, middle, and inner. Thickness measurements obtained from three different regions of the eyeball indicated that the equatorial region was the thinnest among all dog breeds. Moreover, the cornea, which is covered by the sclera along its edges, was thicker at the corneal limbus than at the corneal vertex. A positive correlation was observed between lens thickness and the number of ciliary processes, which varied according to the dogs' head structures. Notably, depression was observed in the posterior surface of the lens in brachycephalic dogs. The morphometric values of the eyeball layers in the brachycephalic and mesocephalic dog breeds were also determined. These values will help researchers study this subject, and the determined morphometric and morphological values will contribute to the anatomy literature. RESEARCH HIGHLIGHTS: This comprehensive study investigates the morphometric and morphological variations in the eyeball layers of different dog breeds, utilizing scanning electron microscopy to analyze eyeballs. It reveals significant breed-specific differences, particularly between brachycephalic and mesocephalic dogs, regarding eyeball layer thickness, corneal structure, lens thickness, and the number of ciliary processes.

Epidemiology of heat-related illness in dogs under UK emergency veterinary care in 2022.

Dogs are exposed to increasing environmental risk for developing heat-related illness (HRI), with 2022 recorded as the hottest year to date in the UK and most of Europe. This study used VetCompass data to report the incidence risk, event fatality rate and canine risk factors for HRI in dogs presenting to Vets Now emergency care practices in the UK during 2022. From the clinical records of 167,751 dogs under care at Vets Now emergency clinics in 2022, 384 HRI events were identified. The 2022 incidence risk of HRI within the Vets Now caseload was 0.23% (95% confidence interval [CI]: 0.21%‒0.25%), with an event fatality rate of 26.56% (95% CI: 21.66%-32.25%). Multivariable analysis identified breed, age and sex/neuter status as risk factors for HRI. Brachycephalic dogs had 4.21 times the odds of HRI compared to mesocephalic dogs (95% CI: 3.22‒5.49, p<0.001). The clinical data used in this study were not primarily recorded for research and had some substantial levels of missing data (especially patient bodyweight). In order to protect canine welfare, improved long-term mitigation strategies are urgently needed to minimise HRI risk and associated fatality in UK dogs.

The mobility of the brachycephalic canine nostril in relation to the degree of nostril stenosis

Previous studies have shown that the most reliable external conformational risk factor of whether a brachycephalic dog will develop Brachycephalic Obstructive Airway Syndrome (BOAS) is the status of nostril stenosis, assessed as a static observation using the brachycephalic nostril grading scheme. The nostrils however are a dynamic structure, opening further when the dog is exercising, sniffing or panting. The hypothesis of this study was that brachycephalic dogs with open or mildly stenotic nostrils are more likely to have nostril mobility whilst dogs with moderately or severely stenotic nostrils are more likely to have immobile nostrils. A retrospective study of dogs presented for BOAS assessment at two UK referral centres between 2012 and 2020 was performed. Data extracted included nares stenosis status and nares mobility. A mesocephalic pilot control group was recruited from a third referral centre. Statistical analysis was performed with χ2, Cochran-Armitage, spearman's rho and linear-by-linear tests as appropriate.Of the 974 brachycephalic dogs included in the study: 124 had open nostrils (68.5% mobile); 212 mildly stenotic nostrils (58.5% mobile); 379 moderately stenotic nostrils (35% mobile) and 259 severely stenotic nostrils (19.3% mobile). The nostril stenotic status was significantly associated with nostril wing mobility (χ2 =135.55; P<0.0001). When considering open and mildly stenotic (considered acceptable) nostrils versus moderate and severely stenotic nostrils, mobility was 62% versus 25.5% (χ2= 135.88; P = <0.0001). All 27 mesocephalic dogs had nostril mobility. Brachycephalic dogs with moderate and severely stenotic nares have reduced nasal mobility compared to brachycephalic dogs with mildly stenotic and open nares. Data is further evidence that dogs with moderately and severely stenotic nares should not be bred.

Arterial blood gas measurements are different for brachycephalic and nonbrachycephalic dogs acclimatized to an altitude of 1,535 meters.

To define reference intervals (RIs) for arterial blood gas (aBG) measurements in healthy, nonsedated, dolichocephalic, and mesocephalic (nonbrachycephalic) dogs at approximately 1,535 m above sea level and compare these findings with healthy, nonsedated, brachycephalic dogs living at the same altitude. 120 adult nonbrachycephalic dogs and 20 adult brachycephalic dogs. Cases were prospectively enrolled from October 2021 to June 2022. Dogs were enrolled from the community or after presentation for wellness examinations or minor injuries including lacerations, nail injuries, and lameness. Physical examinations and systolic blood pressure (sBP) measurements were obtained before blood sample collection. Arterial blood was collected from the dorsal pedal artery or femoral artery. After data collection, brachycephalic dogs underwent pre- and postexercise tolerance assessments. The mean and RI values for arterial pH (7.442; 7.375 to 7.515), partial pressure of oxygen in arterial blood (Pao2; 78.3; 59.2 to 92.7 mm Hg), partial pressure of carbon dioxide in arterial blood (Paco2; 28.0; 21.5 to 34.4 mm Hg), saturation of arterial oxygen (Sao2; 98.4; 84.3% to 101.4%), HCO3 (18.9; 14.9 to 22.4 mmol/L), concentration of total hemoglobin (ctHb; 17.5; 13.4 to 21.1 g/dL), and sBP (133; 94 to 180 mm Hg) were established for healthy nonbrachycephalic dogs at 1,535-m altitude. All aBG measurements were statistically and clinically different from those previously reported for dogs at sea level. Brachycephalic dogs had significantly lower Pao2 and Sao2 (P = .0150 and P = .0237, respectively) and significantly higher ctHb (P = .0396) compared to nonbrachycephalic dogs acclimatized to the same altitude; the nonbrachycephalic RIs were not transferable to the brachycephalic dogs for Pao2. This study represents the first collation of aBG measurements for healthy nonbrachycephalic dogs acclimatized to an altitude of 1,535 m. Additionally, this study identified differences in arterial oxygenation measurements between brachycephalic and nonbrachycephalic dogs. RIs in brachycephalic dogs need to be established.

Heart rate variability and vasovagal tone index in brachycephalic dogs.

Brachycephalic breeds of dogs, most of which show signs of the brachycephalic syndrome may have greater parasympathetic stimulation than other breeds, leading to higher values of heart rate variability and vagal tone index. The aim of this study was to establish a computerized electrocardiographic study and an assessment of the vagus sympathetic balance through heart rate variability and vagal tone index of five brachycephalic breeds compared to mesocephalic dogs. Sixty dogs were used, divided into groups made up of Boxers, English Bulldogs, French Bulldogs, Pugs, Shih-Tzu and no defined breed mesocephalic dogs. Statistical analysis was carried out using the Shapiro-Wilk test, Kruskal-Wallis and Dunn's test or ANOVA and Bonferroni (p<0.05). In the evaluation of vagal sympathetic balance among all the dogs, there was a negative correlation between heart rate and HRV 10RR (r = - 0.7678; p < 0.0001), HRV 20RR (r = - 0.8548, p < 0.0001) and VVTI (r = - 0.2770; p = 0.0321). It can therefore be concluded that the dog's breed and morphology did not alter its electrocardiographic parameters or heart rate variability. The vagal tone index, which in other studies differed in brachycephalic dogs, showed no difference when compared separately in brachycephalic breeds.

The difference between two brachycephalic and one mesocephalic dog breeds’ problem-solving performance suggests evidence for paedomorphism in behaviour

Despite serious health and longevity problems, small brachycephalic breeds are becoming increasingly popular among pet owners. Motivations for choosing short-nosed breeds have been extensively investigated in recent years; however, this issue has been addressed mainly by relying on owner reports, resulting in explanations of “cute looks”, referring to the baby-schema phenomenon and “behaviour well suited for companionship”. We aimed to compare the behaviour of two brachycephalic (English and French bulldogs) and one mesocephalic (Mudi) breed in a problem-solving context. The dogs were given the task of opening boxes containing food rewards. We investigated human-directed behaviour elements over success and latency (indicators of motivation and ability). We found that both English and French bulldogs were significantly less successful in solving the problem than mudis. Both brachycephalic breeds had longer opening latencies than the mesocephalic breed. Brachycephalic breeds oriented less at the problem box and more at humans present. In summary, the short-headed breeds were less successful but oriented much more toward humans than mesocephalic dogs. Owners might interpret these behaviours as “helplessness” and dependence. The results support the hypothesis that infant-like traits may be present not only in appearance but also in behaviour in brachycephalic breeds, eliciting caring behaviour in owners.

The Anatomy of the Stomatognathic System in Different Skull Types in Dogs.

The anatomy of the stomatognathic system is important for both clinical evaluations and surgical approaches in all animal species. The aim of this study was to describe the innervation and vascularization of the stomatognathic system of the dog. Twelve dogs without a history of disease or cranial malformation were used: 4 brachycephalic, 4 mesocephalic, and 4 dolichocephalic. The dogs were dissected, and arteries, veins, and nerves related to the masticatory and swallowing components were identified. The distribution pattern of these structures in the 3 different skull types were observed. The entire blood supply of the stomatognathic system is derived from the external carotid artery, which originates from the common carotid artery, and terminates as it branches into the superficial temporal and maxillary arteries. The other main branches of the common carotid artery are the occipital, cranial laryngeal, ascending pharyngeal, lingual, facial, caudal auricular, and parotid arteries. Blood drainage was achieved via the external jugular vein, which originates from the union of the linguofacial and maxillary veins. Brachycephalic dogs had blood vessels with greater sinuosity (more deviations) when compared to dolichocephalic and mesocephalic dogs. The stomatognathic system innervation of brachycephalic skull dogs showed differences in the distribution of the facial nerve in the labial commissure and maxillary and mandibular regions. The cranial conformation of dogs demonstrated anatomical variations of the vascular and neural structures of the stomatognathic system. This data may be useful to improve clinical practice, surgical planning, and interpretation of clinical dysfunctions.

Challenges of transsphenoidal pituitary surgery in severe brachycephalic dogs.

Transsphenoidal hypophysectomy is the standard surgical technique for the excision of pituitary neoplasms. Anatomy may be more obscured in brachycephalic skull types due to the crowding of soft tissue and osseous structures. We describe the unique challenges to approach the sphenoid bone and localize the correct burr hole site in severe brachycephalic dogs. A single institution retrospective case series of brachycephalic dogs with pituitary-dependent hypercortisolism (PDH). Preoperative computed tomography enabled 3D-, and cross-sectional reconstruction to plan and dry-practice the position of the ideal burr hole in relation to the sella turcica, pterygoid hamular processes, and hard palate. Rostral burring of the caudal hard palate obscuring the direct sphenoid approach necessitated adaptations to the original transsphenoidal hypophysectomy procedure. Postoperative outcomes and complications with respect to those seen in mesocephalic dogs are described. Ten brachycephalic dogs including French Bulldogs (n = 9) and a single Dogue de Bordeaux were included. All dogs were diagnosed with PDH and had preoperative advanced imaging performed on the skull. All but one dog had an enlarged pituitary gland, with a median pituitary/brain value of 0.5 (range 0.21-0.9). A total of 11 transsphenoidal hypophysectomy procedures were performed in these 10 dogs. Rostral extension of the soft palate incision into the hard palate was performed to access the burr hole site on the sphenoid bone. Major complications included aspiration pneumonia (n = 1), severe gastroesophageal reflux (n = 1), and central nervous signs (=1). All dogs survived until discharge, with a median time to follow-up of 618 days (range 79-1,669 days). Seven dogs experienced long-term remission of PDH. Brachycephalic dogs undergoing transsphenoid al hypophysectomy benefit from meticulous presurgical planning and extension of the approach into the caudal hard palate. Advanced surgical skills can render a good outcome in a technically challenging environment.

Morphological and Morphometric Analysis of Canine Choroidal Layers Using Spectral Domain Optical Coherence Tomography.

The choroid, a multifunctional tissue, has been the focus of research interest for many scientists. Its morphology and morphometry facilitate an understanding of pathological processes within both the choroid and retina. This study aimed to determine the choroidal layer thicknesses in healthy, mixed-breed mesocephalic dogs, both male (M) and female (F), using spectral domain optical coherence tomography (SD-OCT) with radial, cross-sectional, and linear scans. The dogs were divided into two groups based on age: middle-aged (MA) and senior (SN). Thicknesses of choroidal layers, namely RPE-Bruch's membrane-choriocapillaris complex (RPE-BmCc) with tapetum lucidum in the tapetal fundus, the medium-sized vessel layer (MSVL), and the large vessel layer with lamina suprachoroidea (LVLS), as well as whole choroidal thickness (WCT), were measured manually using the caliper function integrated into the OCT software. Measurement was performed dorsally and ventrally at a distance of 5000-6000 μm temporally and nasally at a distance of 4000-7000 μm to the optic disc on enhanced depth scans. The measurements were conducted temporally and nasally in both the tapetal (temporal tapetal: TempT, nasal tapetal: NasT) and nontapetal (temporal nontapetal: TempNT, nasal nontapetal: NasNT) fundus. The ratio of the MSVL thickness to the LVLS thickness for each region was calculated. In all examined dogs, the RPE-BmCc in the dorsal (D) region and MSVL in the Tt region were significantly thicker than those in the other regions. The MSVL was thinner in the ventral (V) region than in the D, TempT, TempNT and NasT regions. The MSVL was significantly thinner in the NasNT region than in the D region. LVLS thickness and WCT were significantly greater in the D and TempT regions than those in the other regions and significantly lesser in the V region than those in the other regions. The MSVL-to-LVLS thickness ratio did not differ between the age groups. Our results reveal that the choroidal thickness profile does not depend on age. Our findings can be used to document the emergence and development of various choroidal diseases in dogs in the future.

Refractive errors inmixed breed dogs ofdifferent ages.

The purpose ofthe study was toevaluate the occurrence and range ofrefractive errors indogs ofdifferent ages. Atotal of99clinically healthy, mixed-breed mesocephalic dogs were included inthe study and divided into three different age groups according tothe current human/pet analogy chart: 40adults (23males, 17females, 1-8years old, 3-70kg), 21seniors (14males, 7females, 6-11years old, 7-42kg), and 38geriatrics (22males,16females, 8-13years old, 5-45kg). All the dogs underwent anophthalmic examination, including Schirmer tear test, tonometry, biomicroscopy, and ophthalmoscopy. Neither eye drops nor pharmacological sedatives were administered before the autorefractometry. The refractive states were assessed bilaterally using ahand-held Retinomax3 (Righton) autorefractor. The results underwent statistical analysis using Statistica v12 software (ANOVA and t-test). AP-value <0.05 was considered assignificant. Emmetropia, defined asarefractive state >-0.5D and < +0.5D, was found in36% ofthe adult, 43% ofthe senior, and 38% ofthe geriatric patients. Anisometropia was found in1% ofthe adult, 9.5% ofthe senior and 5.5% ofthe geriatric dogs when the refractive power ofthe two eyes differed ≥1.0 myopia ≤-0.5D and hyperopia ≥+0.5D were found in23% and 41% ofthe adult eye globes aswell as24% and 33% inthesenior dogs and 15% and 47% inthe geriatric dogs, respectively. The maximal values ofthemyopia intheadult and geriatric dogs were -2.5D and -2.75D, respectively. The maximal values ofthehyperopia intheadult and geriatric dogs were 1.75D and 2.5D, respectively. Nostatistically significant correlation was found between the groups. Ametropia isacommon refractive state for dogs ofdifferent ages. Themost frequent refractive state inametropic mixed-bed dogs inall age groups ishyperopia.

Evaluation of blood pressure and NT-proBNP in pugs with and without clinical signs of Brachycephalic Obstructive Airway Syndrome.

Brachycephalic Obstructive Airway Syndrome (BOAS) is a pathologic condition of the upper airways, frequently occurring in dogs of brachycephalic breeds including pugs. It has been suspected that BOAS may be associated with cardiovascular changes and an increased risk for hypertension. The cardiac biomarker NT-proBNP can help to differentiate cardiac from non-cardiac respiratory distress. A possible influence of BOAS on NT-proBNP values has not been investigated, however. The aim of the current study was to examine blood pressure and NT-proBNP levels in pugs with and without clinical signs of BOAS and compare them to values of mesocephalic dogs. For this purpose, NT-proBNP values of 42 pugs and six mesocephalic dogs and blood pressure measurements of 34 pugs and four mesocephalic dogs were explored in the present study. Pugs were examined for clinical signs of BOAS at rest and after a submaximal fitness test, and a functional BOAS grading was applied. Blood pressure (BP) was measured at the beginning and end of the study day and NT-proBNP values were obtained before and after exercise. Measured values of pugs with different degrees of clinical impairment due to BOAS were compared among each other as well as to the CG. In terms of systolic, mean, diastolic BP, and NT-pro BNP, there were no relevant differences between pugs and the CG and no obvious connection between the severity of BOAS symptoms and measured values. BP values of all groups were lower at the second measurement at the end of the study day. NT-proBNP measurements were higher after exercise. BP and NT-proBNP values in all groups were in agreement with commonly used reference ranges. In conclusion, the study adds evidence, that BP and NT-proBNP values did not differ between mesocephalic dogs and pugs with different levels of severity of BOAS but between the measurement times. Thus, in the present study, excitement and exercise seemed to have a greater influence on BP and NT-proBNP values than presence of BOAS symptoms or breed. Discovered values show that the commonly used reference ranges for BP and NT-proBNP are applicable in pugs. This indicates that NT-proBNP can be used to differentiate between cardiac and non-cardiac respiratory distress even in pugs with clinical symptoms of BOAS.

A Clinical Study on the Surgical Management of Third Eyelid Gland Prolapse in Dogs

Background: The current study was undertaken to evaluate the clinical efficacy of two different surgical methods for management of third eyelid gland prolapse in dogs. Methods: The study was conducted on 14 eyes of 11 dogs presented with third eyelid gland prolapse for surgical treatment. Two groups dogs were subjected to clinical and ophthalmic examination based on the surgical technique used i.e., Group I (n=8) in which modified Morgan’s pocket technique, Group II (n=6) in which modified orbital rim anchorage technique was used. Among the breeds brachycephalic dogs (54.54%, n=6) followed by mesocephalic dogs (45.45%, n=5). The modified Morgan’s pocket technique was adopted in 8 eyes of 7 dogs (1 bilateral, 6 unilateral) and the modified orbital rim anchorage technique was performed in 6 eyes of 4 dogs (2 bilateral, 2 unilateral). In Group I, the mean pre-operative Schirmer tear test value was 16.87±0.72 mm/min and in Group II, it was 17.33±0.67 mm/min, both values increased on 30th Post-operative day. Statistical analysis revealed that there was no significant difference between the two groups (p greater than 0.05), but there were significant differences within each group (p less than 0.05). The fluorescein dye test was repeated on 1st,7th,14th, 30th days post-operatively and found positive in the left eye of one dog with the reduced bilateral cherry eye on 7th post-operative day in group I. Third eyelid mobility was normal post-operatively in all the cases of group I. Whereas in group II, it is restricted in all the cases. Three cases regained normal contour by the 10th post-operative day whereas 5 cases by the 14th postoperative day in group I. In group II, 3 cases regained normal contour by 12th post-operative day and 3 cases regained by 14th post-operative day. One case in the group I tested positive for superficial corneal ulcer on the 7th post-operative day. One dog in group I had a recurrence after 45 days of repositioning. One dog in group II with reduced bilateral cherry eye had a recurrence in the left eye 30 days after surgery. Result: Present study, Modified Morgan’s pocket technique was considered superior over the modified orbital rim anchorage technique in view of technical feasibility and unrestricted third eyelid mobility.

Evaluation of a Treadmill-Based Submaximal Fitness Test in Pugs, and Collecting Breed-Specific Information on Brachycephalic Obstructive Airway Syndrome.

Simple SummaryIn the present study, a submaximal fitness test on a treadmill was evaluated to assess its feasibility under standardised conditions. Moreover, its effectiveness in identifying pugs with clinical signs of brachycephalic obstructive airway syndrome was examined. It was apparent that respiratory symptoms can be exposed during the fitness test, and intensified with an increased duration of exercise. This method of testing improves the clinical evaluation of the dogs and helps identify restrictions due to brachycephalic obstructive airway syndrome. Since most of the dogs could be familiarised with the treadmill, it may be a feasible option for performing fitness tests in brachycephalic dogs. Major benefits, therefore, are that each dog can be closely monitored during the entire process, and that the examination can be conducted under standardised conditions.Despite efforts of veterinarians and breeders, brachycephalic obstructive airway syndrome (BOAS) is still a common problem in pugs, underlining the need for objective tests to identify and prevent breeding with affected dogs. In the current study, a submaximal, treadmill-based fitness test was evaluated as a tool to identify signs of airway obstruction not recognisable under rest conditions. In addition to this, different body conformation and measurements were assessed regarding their association with BOAS. A total of 62 pugs and 10 mesocephalic dogs trotted with an individual comfort speed on a treadmill for 15 min. Before and during the examination, dogs were examined for signs of respiratory distress, and a functional BOAS grading was applied. The influence of body conformation on BOAS grading was tested in a univariable and multivariable logistic regression model. During exercise, more respiratory noises were observed, and existing respiratory noises became more apparent in comparison to when at rest. In the multivariable logistic regression model, no factor had a statistically significant influence on BOAS classification. Submaximal fitness testing helped to identify signs of respiratory distress not apparent under resting conditions, and could be a valuable addition for identifying dogs with BOAS. Performing testing on a treadmill facilitates continuous observation of the patients, and enables standardisation of the test regarding the test environment, as well as provides an uninterrupted, steady workload.

Who's Getting a Head Start? Mesocephalic Dogs in Still Images Are Attributed More Positively Valenced Emotions Than Dogs of Other Cephalic Index Groups.

Simple SummaryElements of a dog’s appearance in still images affect how positively human observers interpret that individual’s personality. Given that this may influence caregiving and other aspects of dog ownership, it is important to examine this phenomenon to protect dog welfare. Recently, the popularity of brachycephalic (short-muzzled) dogs has sharply risen and with it the need to assess whether this conformation affects the way in which human observers assign emotional attributes to dogs. The current study aimed to investigate whether cephalic index, a measure to quantify how long and wide a skull is, is related to how both dog owners and non-dog owning adults in the U.K. attribute emotions to still images of dogs, and in the case of dog owners, to their own dogs. Responses were received from 2451 participants. Images of breeds with less extreme skull shapes were most frequently assigned the strongest positive emotional attributions, and the inverse effect was found in more extreme skull shape categories. Results imply that the head shape of dogs may predispose humans to label those dogs with certain emotions, which could impact their behaviour towards those dogs and thus, the dogs’ welfare. These findings should prompt further investigation of morphological influences on dog–owner relationships and dog welfare.Assumptions about dogs’ personality are influenced by their appearance, which may lead to differences in ownership styles and subsequent canine welfare. The influence of canine appearance on observers’ emotion attributions to dogs remains largely unexplored. This study investigated whether canine head shape is related to how both dog owners and non-dog owning adults in the U.K. attribute emotions to still images of dogs, and in the case of dog owners, to their own dogs. Attachment, respondent personality and dog trainability were assessed as potential influences on emotional attribution in owners. Overall, 2451 participant responses were received. Still images of mesocephalic dogs were attributed primary and positively valenced emotion with more strength and frequency than other groups. Mesocephalic images were also attributed negatively valenced emotions less frequently and with less strength than other groups. Apart from empathy, no significant differences were found in emotional attribution to owned dogs of different head shapes; however, human personality influenced attribution of emotions to owned dogs. The finding that some dogs are attributed emotions more readily based on their appearance alone has applied importance, given, for example, the potential for misattribution of positive emotions to dogs in negative emotional states, and potential prejudice against dogs considered in negative emotional states.

Body mapping chart for estimation of percentage of body surface area in mesocephalic dogs.

To create a chart for estimating body surface area (BSA) for use in canine burn victims, similar to the human Rule of Nines. Prospective study, from 2016 to 2017. University teaching hospital. Nine adult, medium-sized, mesocephalic dogs (5 females, 4 males). Sedated dogs and fresh cadavers underwent full-body computed tomography (CT) scans. A 3-dimensional technique was used to calculate the surface area of specific body parts, as well as the surface area of the whole body. With the obtained measurements, a BSA chart was created. Estimates for percent of total BSA obtained with CT images were as follows: head and abdomen 14%, respectively, neck and each of the thoracic limbs 9%, thorax 18%, pelvic limbs 11% each, and pelvis including the tail 5%. The most considerable differences between dogs and people in respect to the Rule of Nines chart were noticed in the head, the pelvic limbs, as well as in the groin region in people as compared with the pelvic/tail area in dogs. The surface areas of the front legs and thorax were the only body parts that corresponded with that of human body surfaces. A chart for estimating canine body surface was created. Given the diversity of dog breeds, sizes, and body conformation, our results cannot be generalized to all dogs. Studies of more diverse populations are warranted.

Morphometrical analysis of the canine choroid in relation to age and sex using spectral domain optical coherence tomography.

This study determined the choroidal thickness of senior (SN, n = 24) and middle-aged (MA, n = 17) healthy, mixed-breed mesocephalic dogs, both males (M) and females (F), using spectral domain optical coherence tomography (SD-OCT). The dogs were divided into two groups for examination: MA dogs (4-7 years old; 6 M, 11 F) and SN dogs (8-13 years old; 12 M, 12 F). Choroidal thickness of the dogs was investigated using SD-OCT radial and linear scans. The software of the device allowed determination of the exact measurement location on the choroid. Measurements of the choroid were taken manually using the SD-OCT calliper function at distances of 5,000-6,000 μm (dorsal and ventral) and 4,000-7,000 μm (nasal and temporal) from the optic disc. Mean (µm ± SD) (MA, SN) dorsal (188 ± 28, 184 ± 33), ventral (116 ± 23, 111 ± 16), temporal (152 ± 31, 151 ± 26), and nasal (135 ± 27, 132 ± 18) choroidal thicknesses demonstrated significant differences (P < 0.02-0.001) between all areas within each group. The choroid was thickest in the dorsal region and thinnest in the ventral region. There were no significant differences based on age. Mean (µm ± SD) (M, F) dorsal (181 ± 32, 190 ± 30), ventral (117 ± 16, 11 ± 21), temporal (150 ± 26, 153 ± 30), and nasal (128 ± 20, 138 ± 23) choroidal thicknesses demonstrated significant differences (P < 0.05) between dorsal and nasal regions. The choroidal thickness in dogs depends on the area assessed independently of their age and sex.

The time required to achieve endotracheal intubation in dogs: a comparison of veterinary students and qualified veterinary surgeons

ObjectiveTo determine whether final year veterinary students take longer to perform endotracheal intubation than qualified veterinary surgeons. Study designObservational cohort study. AnimalsA total of 38 healthy mesocephalic dogs undergoing general anaesthesia for a clinical purpose unrelated to this study. MethodsTime to successful endotracheal intubation, measured from termination of intravenous induction drug administration to confirmation of endotracheal intubation, was recorded for two groups: final year veterinary students (group S) and qualified veterinary surgeons (group V). Animal age, breed and anaesthetic induction agent were also recorded. Following normality testing the groups were compared for each variable using the Student’s t test or Mann–Whitney U test where appropriate. The level of significance was defined as p < 0.05. Timed data are presented as median and interquartile range. ResultsTime to successful intubation was 54.2 (31.3) seconds in group S and 11.7 (8.5) seconds in group V, the difference being significant (p < 0.001). There was also a significant difference between groups for animal age (p = 0.036) but not for breed (p = 0.573) or induction agent (p = 0.239). Conclusionsand clinical relevance Veterinary students take longer to achieve successful endotracheal intubation of anaesthetized healthy dogs compared with qualified veterinary surgeons. To mitigate any additional risk of dogs developing hypoxaemia, it is recommended that a 55 second time limit is set after which the supervisor intervenes and takes over the intubation procedure. Preoxygenation may be used as an additional mitigation strategy.

A computed tomography–based method for the assessment of canine retrobulbar cone volume for ophthalmic anaesthesia

ObjectiveTo develop a comprehensive formula for calculating the volume of local anaesthetic solution used for retrobulbar anaesthesia in dogs with different skull morphologies. Study designRetrospective cohort imaging study. AnimalsSkull computed tomography (CT) images of 188 dogs of different breeds collected between January 2009 and December 2017. MethodsAnatomical integrity of the orbit and adjacent structures, presenting complaint, clinical signs and CT findings were verified to exclude ocular abnormalities. The volume of the retrobulbar cone of 376 eyes was calculated using CT scans of the dogs’ skulls. Additional data recorded included morphology of the skull, body weight, sex and size of the dogs, all of which were matched for possible association to the retrobulbar cone volume through univariable and multivariable linear regression models. Results of linear regression models were expressed as estimated beta coefficients with the corresponding 95% confidence intervals (95% CIs). ResultsUsing univariate analysis, the retrobulbar cone volume was positively associated with weight and male sex. In addition, brachycephalic and dolichocephalic dogs showed a larger retrobulbar cone volume than mesocephalic dogs, while sex was no longer significantly associated with the retrobulbar cone volume. In multivariate analysis, when considering all variables in the model, weight emerged as the strongest predictor (beta coefficient: 0.062 mL kg–1, 95% CI: 0.056–0.067 mL kg–1, p < 0.001). Conclusionsand clinical relevance In the veterinary literature, there is no agreement on the precise volume of local anaesthetic solution that should be used to achieve intraconal retrobulbar anaesthesia in dogs. Here we suggest a formula to calculate the retrobulbar cone volume and, accordingly, the injection volume of local anaesthetic solution for effective retrobulbar anaesthesia.