Hypertypes in dogs: proposals to keep them out of the breeding way

Le phénotype de nombreux chiens ne correspond pas à celui de leur standard, qui devrait définir l’archétype racial idéal, notamment dans des populations canines en vogue. En élevage, une sélection globale en consanguinité large est la règle, la consanguinité étroite devant rester exceptionnelle. A partir de cette situation, la sélection dans la race doit s’appuyer sur un standard bien rédigé et correctement interprété. L’émergence d’hypertypes au sein des deux structures devrait être contenue par de bonnes pratiques d’élevage et un encadrement strict de la politique de sélection des associations de races. La profession vétérinaire, à différents niveaux - praticiens, sociétés savantes, institutions - souffre d’un déficit d’implication et de faire-savoir dans la lutte contre la production d’hypertypes canins ; certaines mesures simples devraient permettre de modifier les comportements des responsables de la filière, des éleveurs, des juges, des vétérinaires, du public, et de ce fait réduire les effets néfastes de comportements gravement préjudiciables à la santé et au bien-être du chien de race.Many dogs do not correspond phenotypically to their standard guidelines, which should describe the ideal of the breed type, especially in populations brought into fashion. Breeders must follow a « global selection way » under line breeding, close inbreeding must remain out of the ordinary. Then, selecting in a breed supposes a well written and correctly interpreted standard. Hypertype production may occur in both structures and should be avoided by respecting good practices either in breeding or in conducting selection in a breed. For many reasons, and at many levels - practitoners, continuing education and professional associations/colleges - veterinarians are not sufficiently involved and do not communicate enough against the production of canine hypertypes ; some simple pratical actions should be able to modify the behaviour of all the stakeholders - kennel clubs, breeders, judges, veterinarians, public - and thereby to reduce a considerable prejudice on dogs health and welfare

First reports of autochthonous eyeworm infection by Thelazia callipaeda (Spirurida, Thelaziidae) in dogs and cat from France

Thelazia callipaeda (Spirurida, Thelaziidae) is a small nematode living in the conjunctival sac of domestic and wild carnivores, rabbits and humans causing lacrimation, epiphora, conjunctivitis, keratitis and even corneal ulcers. The first autochthonous cases of thelaziosis affecting four dogs and one cat living in South Western France (Dordogne area) are reported and described. Nematodes recovered from the animals were morphologically identified as T. callipaeda and a partial region of the cytochrome oxidase c subunit 1 gene (cox1) was amplified by PCR from nematode specimens (from two dogs and the cat). In each case, this was shown to have an identical sequence to the haplotype 1 (h1) of T. callipaeda. So far, the arthropod acting as intermediate host of T. callipaeda eyeworms has not been identified in France although it might be Phortica variegata (Steganinae, Drosophilidae) as recently described in Italy

Progressive Retinal Atrophy in the Border Collie: A new XLPRA

<p>Abstract</p> <p>Background</p> <p>Several forms of progressive retinal atrophy (PRA) segregate in more than 100 breeds of dog with each PRA segregating in one or a few breeds. This breed specificity may be accounted for by founder effects and genetic drift, which have reduced the genetic heterogeneity of each breed, thereby facilitating the identification of causal mutations. We report here a new form of PRA segregating in the Border Collie breed. The clinical signs, including the loss of night vision and a progressive loss of day vision, resulting in complete blindness, occur at the age of three to four years and may be detected earlier through systematic ocular fundus examination and electroretinography (ERG).</p> <p>Results</p> <p>Ophthalmic examinations performed on 487 dogs showed that affected dogs present a classical form of PRA. Of those, 274 have been sampled for DNA extraction and 87 could be connected through a large pedigree. Segregation analysis suggested an X-linked mode of transmission; therefore both XLPRA1 and XLPRA2 mutations were excluded through the genetic tests.</p> <p>Conclusion</p> <p>Having excluded these mutations, we suggest that this PRA segregating in Border Collie is a new XLPRA (XLPRA3) and propose it as a potential model for the homologous human disease, X-Linked Retinitis Pigmentosa.</p

Éthique vétérinaire et sélection du chien de race

Relationships between canine and humans have induced the emergence of an ancestral morphotype, then of primary canine breeds, from which the process of selection has created the modern breeds, as they exist actually. Breed standards have established breed phenotypes but their interpretation may facilitate the development of deviating types, from which a loss of genetic variability may result by breeding, as a consequence of an inappropriate selective pressure. The veterinarian is well-founded to contribute in keeping the necessary genetic diversity in populations of dogs ; he must take care of welfare and health in purebred dogs, keeping in mind that an harmonious interspecific dependency between dogs and humans enforce a necessary reasonable morphological breeding selection, as well as a broadening of natural behavioural abilities in each group of breeds.La cohabitation du chien et de l’Homme s’est traduite par l’émergence d’un morphotype canin ancestral, puis de races primaires, à partir desquelles la sélection a créé les races modernes que nous connaissons actuellement. Les standards en définissent les phénotypes, mais leur interprétation peut privilégier la production de certains morphotypes raciaux déviants, inductrice d’un appauvrissement de la variabilité génétique par pression sélective inappropriée. Le vétérinaire a toute légitimité pour s’impliquer dans le maintien de la nécessaire diversité génétique des effectifs ; il a le devoir de veiller au bien-être et à la santé du chien de race, en rappelant qu’une dépendance interspécifique harmonieuse du chien et de l’Homme impose à ce dernier de pratiquer une sélection morphologique raisonnable et de favoriser l’épanouissement des aptitudes comportementales naturelles dans chaque groupe de races.Chaudieu Gilles. Éthique vétérinaire et sélection du chien de race. In: Bulletin de l'Académie Vétérinaire de France tome 174, 2021. pp. 46-54

Les tests génétiques chez le chien

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Dog olfactory receptor gene expression profiling using samples derived from nasal epithelium brushing

International audienceDogs have an exquisite sense of olfaction. In many instances this ability has been utilized by humans for a wide range of important situations including detecting explosives and illegal drugs. It is accepted that some breeds have better senses of smell than others. Dogs can detect many volatile compounds at extremely low concentrations in air. To achieve such high levels of detection, the canine olfactory system is both complex and highly developed requiring a high density of olfactory receptors capable of detecting volatiles. Consequently the dog genome encodes a large number of olfactory receptor (OR) genes. However, it remains unclear as to what extent are all of these OR genes expressed on the cell surface. To facilitate such studies, a nasal brushing method was developed to recover dog nasal epithelial cell samples from which total RNA could be extracted and used to prepare high quality cDNA libraries. After capture by hybridization with an extensive set of oligonucleotides, the level of expression of each transcript was measured following next generation sequencing (NGS). The reproducibility of this sampling approach was checked by analyzing replicate samples from the same animal (up to 6 per each naris). The quality of the hybridization capture was also checked by analyzing two DNA libraries; this offered an advantage over RNA libraries by having an equal presence for each gene. Finally, we compared this brushing method performed on living dogs to a nasal epithelium biopsy approach applied to two euthanized terminally ill dogs, following consent from their owners.Comparison the expression levels of each transcript indicate that the ratios of expression between the highest and the least expressed OR in each sample are greater than 10,000 (paralog variation). Furthermore, it was clear that a number of OR genes are not expressed.The method developed and described here will allow researchers to further address whether variations observed in the OR transcriptome relate to dog ’life experiences’ and whether any differences observed between samples are dog-specific or breed-specific

Screening for a Canine Model of Choroideremia Exclusively Identifies Nonpathogenic CHM Variants.

International audienceChoroideremia is an X-linked, progressive photoreceptor degeneration disorder due to mutations in CHM. In addition to an atrophy of the outer retina, affected individuals present with a characteristic atrophy of the choroid. To search for a canine model, we screened the CHM gene of 37 dogs (22 breeds) with various forms of retinal dystrophies. We found 21 variations in 13 breeds (17 detected in only one breed and 4 shared by two or more) with 43% segregating in the same pedigree, a Great Dane female and a female offspring. Of particular interest were an exonic missense variation and a 3-bp intronic deletion near a splice acceptor site. However, although not detected in unrelated healthy Great Danes, these variants were nonpathogenic since they did not segregate with the disease phenotype in the pedigree. These results suggest that a CHM dog model may not be viable, as is the case for mouse and zebrafish

Cani-DNA, un CRB qui a du chien! Réseau de collecte de prélèvements de chiens par les vétérinaires pour la recherche biomédicale et la diversité génétique

National audienceThe Cani-DNA BRC* collects samples from dogs used as spontaneous genetic and preclinical models of rare and complex human genetic diseases. Since 2012, a partnership has been established between the CNRS and the four National Veterinary Schools (ENV: Alfort, Nantes, Lyon, Toulouse) and the biotech company Antagene (Lyon). Sample collection is open to interested parties, with the voluntary participation of dog owners, breeders and pedigree clubs, and is based on a national veterinary network including practitioners, histopathology laboratories, clinics and specialized hospitals, oncology and imaging centers, the CHUVs* of the National Veterinary Schools and the AFVAC* Association. Samples and associated genealogical, phenotypic and clinical data are collected by qualified veterinarians (DVM) to implement the centralized Cani-DNA database (LIMS Modul-Bio) and perform DNA and RNA extractions from them. The BRC performs quality controls and stores the corresponding samples at -20 °C. These nucleic acid samples are then distributed to the scientific community at local, national and international levels for mutually beneficial research projects in veterinary and human medicine and for programs on genetic diversity. In 2021, Cani-DNA contained 33,000 DNA samples extracted from blood, including 18,500 DNA samples stored at the Rennes site, 10,000 at the four ENVs and 4,500 at Antagene. In addition, 6,200 tissue samples are available (for 2,000 dogs), in particular for comparative oncology projects. These resources concern approximately 300 breeds of dogs and more than 100 canine genetic diseases homologous to human genetic diseases.Le CRB* Cani-DNA collecte des prélèvements de chiens comme modèles spontanés génétiques et précliniques de maladies génétiques humaines rares et/ou complexes. Depuis 2012, un partenariat a été établi entre le CNRS et les quatre Écoles Nationales Vétérinaires (ENV : Alfort, Nantes, Lyon, Toulouse) et la société de génétique animale Antagene (Lyon). La collecte est réalisée par Cani-DNA, ouverte vers la société, avec la participation volontaire de propriétaires, d’éleveurs de chiens ou de clubs de races, et repose sur un réseau vétérinaire national incluant des praticiens, des laboratoires d’analyses histopathologiques, des cliniques et hôpitaux spécialisés, des centres de cancérologie et d’imagerie, les CHUV* des Écoles Nationales Vétérinaires et l’association AFVAC*. Les prélèvements (sang, plasma et tissus) accompagnés de leurs données généalogiques, phénotypiques et cliniques sont réalisés par des vétérinaires diplômés (DVM), réceptionnés par le CRB qui renseigne la base de données centralisée Cani-DNA (LIMS Modul-Bio) et réalise les extractions d’ADN et d’ARN à partir de ces prélèvements ; le CRB réalise les contrôles qualité et assure le stockage des échantillons correspondants, à -20 °C. Ces échantillons d’acides nucléiques sont ensuite distribués à la communauté scientifique, locale, nationale et internationale pour des projets de recherche apportant un bénéfice mutuel en médecine vétérinaire et humaine et pour des programmes sur la diversité génétique. En 2021, Cani-DNA compte 33 000 échantillons d’ADN extraits à partir de sang, plasma et tissus dont 18 500 ADN stockés sur le site rennais, 10 000 dans les quatre ENV et 4 500 à Antagene. De plus, 6 200 échantillons de tissus sont disponibles (pour 2 000 chiens), plus spécifiquement pour des projets de cancérologie comparée. Ces ressources concernent environ 300 races de chiens et plus d’une centaine de maladies génétiques canines, homologues de maladies génétiques humaines

Illustration of a Border Collie pedigree segregating PRA constructed by the Cyrillic 2

1 software. This pedigree is constituted of 80 dogs, 33 dogs are affected (30 males and 3 females).<p><b>Copyright information:</b></p><p>Taken from "Progressive Retinal Atrophy in the Border Collie: A new XLPRA"</p><p>http://www.biomedcentral.com/1746-6148/4/10</p><p>BMC Veterinary Research 2008;4():10-10.</p><p>Published online 3 Mar 2008</p><p>PMCID:PMC2324077.</p><p></p

Note technique sur la reprise progressive des activités de médecine préventive à la levée du confinement le 11 mai – Gestion des protocoles vaccinaux

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