Selección contra displasia de cadera canina en el ovejero alemán / Breeding against canine hip dysplasia in the german shepherd dog

RESUMEN La displasia de cadera canina o displasia coxo-femoral (DCF) es un desorden progresivo e incapacitante en perros de razas grandes, como el Ovejero Alemán. La selección de reproductores libres de displasia es la única forma de reducir su incidencia. Se han desarrollado varios métodos de diagnóstico basados en el examen radiográfico, en base a los cuales se seleccionan los reproductores para la cría. La DCF tiene una base hereditaria poligénica e influencia ambiental, con una heredabilidad media a baja (alrededor de 0,20 a 0,40), por lo que el progreso de la selección fenotípica ha sido lento. En Argentina la prevalencia de la displasia en la raza sigue siendo alta (>25%) y es imposible prever su incidencia en la progenie del plantel de cría. Algunos países han implementado la selección basada en el valor estimado de cría, obteniendo un importante avance. Los estudios de asociación del genoma completo han revelado numerosos marcadores asociados a la DCF y se han encontrado varios genes candidatos que señalan la posibilidad de implementar una selección genómica en un futuro cercano.

ABSTRACT Canine hip dysplasia (CHD) is a progressive and disabling disorder in large dog breeds, such as the German Shepherd dog. Breeding sires and dams free of dysplasia is the only way to reduce its incidence. Several diagnostic methods have been developed based on radiographic examination, on the basis of which dogs are selected for breeding. CHD has a polygenic hereditary basis and environmental influence, with a median to low heritability (ca. 0,20 to 0,40), so the progress in phenotypic selection has been slow. In Argentina, the prevalence of dysplasia in German Shepherd dogs remains high (> 25%) and it is impossible to predict its incidence in the offspring of the breeding stock. Some countries have implemented a selection based on the estimated breeding value, obtaining an important advance. Genomewide association studies have revealed numerous CHD-associated markers and several candidate genes have been found that point to the possibility of implementing genomic selection in the near future.

Anatomy of the diaphyseal nutrient foramen in the long bones of the pectoral limb of German Shepherds / 대한수의학회지

This study investigated the anatomy of the nutrient foramen (NF) in German Shepherds by recording the number, site, position, and direction of penetration of the nutrient canal (NC) in the humerus, radius, and ulna of 50 individuals. The site index of the nutrient foramen (SI) was calculated as the ratio of the length to the NF site from the proximal end to the greatest length of the bone. The NF diameter was measured using different sized needles. Most humeri had only one NF on the caudal surface, particularly on the lateral supracondylar crest, or distal cranial surface. All radii had one NF, usually on the caudal surface, while most ulnae had one NF located on either the cranial or lateral surfaces. The SI and NF diameters were 58.0~59.5% and 0.73~0.78 mm in the humerus, 30.4~30.9% and 0.74~0.76 mm in the radius, and 29.3~29.8% and 0.67~0.68 mm in the ulna, respectively. With the exception of the relatively proximal NF of the radius, the direction of penetration followed Berard's rule. This study provides novel information on the location and diameter of the NF and direction of the NC in the long bones of the pectoral limb of German Shepherds.

Anatomy of the diaphyseal nutrient foramen in the long bones of the pectoral limb of German Shepherds / 대한수의학회지

This study investigated the anatomy of the nutrient foramen (NF) in German Shepherds by recording the number, site, position, and direction of penetration of the nutrient canal (NC) in the humerus, radius, and ulna of 50 individuals. The site index of the nutrient foramen (SI) was calculated as the ratio of the length to the NF site from the proximal end to the greatest length of the bone. The NF diameter was measured using different sized needles. Most humeri had only one NF on the caudal surface, particularly on the lateral supracondylar crest, or distal cranial surface. All radii had one NF, usually on the caudal surface, while most ulnae had one NF located on either the cranial or lateral surfaces. The SI and NF diameters were 58.0~59.5% and 0.73~0.78 mm in the humerus, 30.4~30.9% and 0.74~0.76 mm in the radius, and 29.3~29.8% and 0.67~0.68 mm in the ulna, respectively. With the exception of the relatively proximal NF of the radius, the direction of penetration followed Berard's rule. This study provides novel information on the location and diameter of the NF and direction of the NC in the long bones of the pectoral limb of German Shepherds.

Left costocervical vein malformation with anomalous ramification of aortic arch in a dog

This report describes coexistence of anomalous branches of the aortic arch and the costocervical vein malformation in a German shepherd dog. The first branch of the aortic arch was a bicarotid trunk that divided into the left and right common carotid arteries. The next branch to leave the aortic arch was a common trunk for the right and left subclavian arteries, a bisubclavian trunk, which was immediately bifurcated. The right subclavian artery passed over the esophagus forming a deep groove, so-called incomplete vascular ring on the dorsal wall of the esophagus. Although the esophagus was constricted by the right subclavian artery dorsally and by the trachea ventrally, no clinical symptoms of esophageal obstruction and dysphagia were observed. The left costocervical vein coursed caudoventrally, passed over the aortic arch, and entered the left ventricle. This vessel was much smaller than the right costocervical vein and was partially occluded at its origin.