Thèses sur le sujet « Cavalier King Charle »

One hundred and sixty-five CKCS subjects, both healthy and affected by different stages of MMVD, were examined from November 2018 to June 2021 at the Veterinary Teaching Hospital in Lodi – University of Milan – Cardiology Section. Each dog was submitted to a clinical examination and echocardiographic, radiographic, and morphometric data were collected. Whole blood and plasma were collected for genetic analysis and biomarker (miRNA) evaluation. The objectives of this study were: 1) To describe breed-specific reference values for vertebral heart score (VHS), vertebral heart atrial size (VLAS), M-VLAS, and radiographic left atrial enlargement (RLAD) in healthy adults CKCS; 2) To conduct a genomic study on a population of Italian CKCS; 3) To characterize echocardiographic features of the mitral valve in this breed, focusing on dogs classified as American College of Veterinary Internal Medicine (ACVIM) B1, without clinical signs and without left atrial and ventricular enlargement; 4) To analyze the relationships and the prognostic value of morphometric variables in CKCS affected by MMVD; 5) To analyze the expression of miRNAs described in the literature as being involved in the pathophysiology of MMVD, and identified in dogs’ plasma. Results: 1) Healthy CKCS had a median VHS of 10.08 ± 0.56v, a VLAS, M-VLAS and RLAD respectively of 1.79 ± 0.3v, 2.23 ± 0.44v and 1.2 ± 0.34v; 2). The top 1% single-nucleotide polymorphisms (SNPs) of both Wright’s fixation index (FST) and cross-population extended haplotype homozygosity (XP-EHH) analyses localized 10 consensus genes on chromosomes 3-11-14-19; 3) Within class B1, older subjects showed significantly higher values of anterior mitral valve area (AMVA), width (AMVW), mitral valve annulus in diastole (MVAd) and systole (MVAs) and lower sphericity index (SI); 4) A more severe mitral regurgitant jet size and a thicker anterior mitral valve leaflet were observed in CKCS smaller than standard proposed by the Ente Nazionale della Cinofilia Italiana (ENCI) and with morphometric characteristics tending to brachycephalism; 5) miR-30b-5 was significantly higher in ACVIM B1 compared to healthy subjects (ACVIM class A) and the AUC was 0.79. According to the age of dogs, the expression of miR-30b-5p remained significantly higher in group B1<3y (2.3 folds p=0.03), B1 3-7y (2.2 folds p=0.03), and B1>7y (2.7 folds p=0.02) than in stage A. The AUCs were fair in discriminating group B1<3y and A (AUC 0.78), and B1 3-7y and A (AUC 0.78), and good in discriminating group B1>7y and A (AUC 0.82). Conclusions: 1) Findings supported previous studies recommending the use of breed-specific reference values for VHS, VLAS, M-VLAS and RLAD and provided background data for future radiographic evaluations of CKCS dogs with clinical signs of cardiac disease; 2) This genetic analysis expands the knowledge of the genetic basis of MMVD by identifying genes involved in the early onset of MMVD in CKCS; 3) This is the first study that describes measurements of the anterior mitral valve leaflet and the mitral valve annulus in the CKCS affected by MMVD at different stages. Differently aged B1 dogs have different clinical and echocardiographic patterns. Further investigations with a larger study population and an appropriate follow-up would highlight prognostic factors related to disease worsening within this heterogeneous ACVIM class; 4) The morphological study of CKCS showed that a more severe regurgitant jet size was observed in subjects with a shorter head and nose. Subjects with a smaller head stop angle had thicker anterior mitral valve leaflets. Dogs with cephalic morphology more similar to the King Charles spaniel breed, that is with a brachycephalic morphotype, showed a more severe regurgitant jet size and valvular characteristics related to worse forms of MMVD (thicker anterior mitral valve leaflet, greater mitral valve annulus and lower sphericity index); 5) miR-30b-5p increases in the plasma of asymptomatic CKCS and this can be considered a potentially promising biomarker even at an asymptomatic stage of disease, particularly at a young age.

Chronic valvular heart disease (CVHD) is common in Cavalier King Charles spaniel (CKCS) and has the potential to affect platelet activation or function. The present study objective was to determine platelet closure time, mean platelet component (MPC) concentration and platelet component distribution width (PCDW) in dogs with subclinical CVHD, and to assess the factors influencing these variables. A second objective was to assess platelet count, MPC concentration, PCDW, mean platelet volume (MPV), platelet volume distribution width (PDW), plateletcrit (PCT), mean platelet mass (MPM) and platelet mass distribution width (PMDW) in CKCS. Haematological values, closure time, murmur grade and echocardiographic variables were recorded in 89 CKCS. Associations between explanatory variables (sex, age, murmur grade, echocardiographic variables, platelet count, and haematocrit (HCT)) and outcomes (closure time, MPC concentration, and PCDW) were examined using multivariate regression analysis. Platelet indices were compared between CKCS and a group of 39 control dogs (non-CKCS). A model with 5 variables best explained variation in closure time (R2, 0.74), with greater than 60% of the variance of closure time explained by mitral valve regurgitant jet size. The model of best fit to explain variation in MPC concentration included only platelet count (R2, 0.24). The model of best fit to explain variation in PCDW included platelet count and sex (R2, 0.25). The MPC concentration, MPV, PDW, MPM and PMDW values were significantly higher, and the platelet count, PCT, PCDW and HCT values significantly lower, in the CKCS compared to control dogs. In the present study, a significant effect of mitral valve regurgitant jet size on closure time was consistent with platelet dysfunction. However, platelet activation, as determined by MPC concentration and PCDW, was not a feature of subclinical CVHD in CKCS.

O crescimento e as dimensões das estruturas oculares em cães de diversas raças têm sido objeto de estudo. Sabe-se que quanto mais longilíneo o crânio, maior o comprimento axial do bulbo ocular. O objetivo deste trabalho foi acompanhar o desenvolvimento das dimensões dos componentes oculares (comprimento axial, espessura da lente, profundidade da câmara anterior e da câmara vítrea) e relacionar as medidas com o sexo, a idade, tamanho, medidas do crânio e peso de cães da raça Cavalier King Charles Spaniel, uma raça braquicéfala. Foram realizadas 117 medidas biométricas oculares em cães variando entre 15 dias e 36 meses de idade, não sedados, sentados ou deitados em posição esternal, utilizando-se ultrassonografia modo-B com transdutor microconvexo de 8 MHz. No momento de cada medida ocular os cães foram pesados e as medidas de comprimento, altura, distâncias fronto-occipital, fronto-nasal, bizigomática e circunferência do crânio foram registradas. As estruturas oculares mostraram uma curva de rápido crescimento entre 15 dias e 4 meses de idade e uma curva suave de crescimento até os 12 meses, idade em que cessou o crescimento do cão (altura e comprimento). Os machos apresentaram medidas maiores de altura, comprimento e crânio do que fêmeas, porém não houve diferença significativa entre os parâmetros de biometria ocular de machos e fêmeas. O valor médio de comprimento axial do bulbo para cães adultos (acima de 12 meses) foi de 18,10 ± 0,48 mm, para a espessura da lente, de 7,15 ± 0,16 mm, para profundidade da câmara anterior, de 2,05 ± 0,37 mm e para a profundidade da câmara vítrea, de 8,91 ± 0,30 mm. Não houve diferença entre as medidas dos olhos direito e esquerdo. Os resultados sugerem que a curva de crescimento ocular acompanha a curva de crescimento do cão, fato semelhante ao que ocorre em diferentes espécies estudadas por outros autores. Em cães adultos, não foi observada relação entre as medidas dos componentes oculares e as medidas de altura, comprimento, peso e tamanho do crânio. Foi estabelecida uma tabela de crescimento correlacionando comprimento axial do bulbo e idade do cão com a finalidade de padronizar esses dados para a raça.
Ocular biometry and ocular growth has been studied in dogs of different breeds. It\'s already known that dogs with longer skulls have longer axial length of the eye. This study aimed to evaluate the development of ocular dimensions (axial length of the bulbus, lens thickness, anterior and vitreous chamber depth) in Cavalier King Charles Spaniels, a braquicephalic breed, and its relationship to age, gender, weight, height and lenght of the dog and dimensions of the head. Ocular dimensions were obtained from 117 measurements between 15 days and 3 years old, in standing nonsedated animals using B-mode ultrasound with an 8 MHz curvilinear probe. At the same time the dogs were weighted and height, length and head dimensions (head circumference, fronto-occipital, fronto-nasal distance and bizigomatic distances) were recorded. The ocular parameters showed a rapid growth curve from 15 days to 4 months and then a slow curve until 12 months, same age that the height and length ceased its growth. Males showed significant higher measurements of height, length and head parameters than females, but no difference in ocular biometry was found between males and females. The mean value for axial lenght for adults (over 12 months) was 18,10 ± 0,48 mm, for lens thickness was 7,15 ± 0,16 mm, for anterior chamber depth was 2,05 ± 0,37 mm and for vitreous chamber depth was 8,91 ± 0,30 mm. There was no significant difference between left and right eyes. Results suggest that eye growth curves accompanies dogs height, length, head size growth curves, what is similar to the data found in different species studied by other authors. There was no relation between eye parameters and dog\'s height, length, head size or weight in adult individuals. A table was established correlating axial length of the bulbus and age to be used as a reference for the breed.

O presente relatório é resultado do estágio curricular, 11º semestre do Mestrado Integrado em Medicina Veterinária. Este decorreu em duas instituições de referência veterinária em Barcelona (Hospital ARS Veterinária e Hospital Veterinari Montjuïc) e permitiu melhorar e integrar os conhecimentos adquiridos ao longo do curso. O relatório é composto por três partes: introdução, que situa temporal e espacialmente, relatório de casuística, que abrange todas as atividades realizadas e assistidas, e monografia. A monografia consiste na descrição de uma afeção neurológica, muito comum em Cavalier king charles spaniel, designada de siringomielia. A monografia inicia-se com uma revisão bibliográfica e termina com o relato de quatro casos clínicos acompanhados no Hospital ARS Veterinário; ABSTRACT: Small animal practice This report is the result of the traineeship in the 11th semester of the Integrated Master degree in Veterinary Medicine. It took place in two veterinary reference institutions in Barcelona (hospital ARS veterinary and hospital Veterinari Montjuïc) and contributed to improve and integrate the knowledge acquired throughout the course. The report consists in three parts: Introduction, which locates temporally and spatially, the sample report covering all activities, and monograph. The monography is the description of a neurological disorder, very common in Cavalier king charles spaniel, designated syringomyelia. The monography begins with a literature review and ends with the description of four clinical cases followed in ARS veterinary hospital.