Clinical, histopathological and genetic data of ichthyosis in the golden retriever: a prospective study.

OBJECTIVES: We described epidemiological, clinical, histopathological and ultrastructural features of ichthyosis in the golden retriever breed in a prospective study. We also investigated the mode of transmission of this disease. MATERIALS AND METHODS: We examined 150 golden retrievers, 73 of which were affected by ichthyosis (35 males and 38 females). We carried out detailed clinical and histopathological examinations for 40 affected dogs. Transmission electron microscopy was performed for two of them. We used pedigree analysis with the Cyrillic software to determine the mode of transmission. RESULTS: Dermatological signs included a mild to moderate or severe generalised scaling with initially small to large whitish scales and progressively blackish scales. The ventral glabrous skin was hyperpigmented and rough, similar to sandpaper. Histopathological features were characterised by moderate to severe laminated or compact orthokeratotic epidermal hyperkeratosis without significant involvement of the stratum granulosum. Ultrastructural findings revealed laminated or compact keratin layers and numerous persistent corneodesmosomes within the stratum corneum. Analysis of the pedigree suggested an autosomal recessive inheritance. CONCLUSION: The histopathological and ultrastructural characteristics strongly suggest that golden retriever ichthyosis is a retention ichthyosis, caused by absence of corneodesmosomal degradation, transmitted through an autosomal recessive mode.

Parvovirus infection of keratinocytes as a cause of canine erythema multiforme.

Erythema multiforme major was diagnosed in a dog with necrotizing parvoviral enteritis. Skin lesions consisted of ulceration of the footpads, pressure points, mouth, and vaginal mucosa; vesicles in the oral cavity; and erythematous patches on the abdomen and perivulvar skin. Microscopic examination of mucosal and haired skin specimens revealed lymphocyte-associated keratinocyte apoptosis at various levels of the epidermis. Basophilic cytoplasmic inclusions were seen in basal and suprabasal keratinocytes. Immunohistochemical staining, performed with canine parvovirus-2-specific monoclonal antibodies, confirmed the parvovirus nature of the inclusions in the nucleus and cytoplasm of oral and skin epithelial cells. This is the first case of canine erythema multiforme reported to be caused by a viral infection of keratinocytes. This case study indicates that the search for epitheliotropic viruses should be attempted in cases of erythema multiforme in which a drug cause cannot be identified.

[Characterization of biomechanical behavior of the lumbosacral spine in dogs. Characteristics related to spondylosis and disk degeneration]. / Caractérisation du comportement biomécanique du rachis lombo-sacré chez le chien. Particularités associées à la spondylose et à la dégénérescence discale.

The in vitro and static biomechanical behaviour of vertebrae with spondylosis were compared with that of healthy vertebrae. In the dog, spondylosis predominates in the lombo-sacral spine which was chosen as an animal model for spontaneous spondylosis. Fourteen surgical specimens were take from German shepherd dogs which had been submitted to right and left lateral flexion, saggital flexion and dorsal flexion. Angular displacements were recorded with an analyser of spinal movement. Our results demonstrated diseased vertebrae have more flexibility than healthy vertebrae in the sagittal and frontal planes than but less so for dorsal flexion. In Addition, diseased vertebrae tend to move upward during lateral flexion. Exeresis of ligament and capsular structures has allowed us to demonstrate the importance of these structures in maintaining spine stability in the sagittal plane and in joint coaptation. Exeresis of the facet joints led to the demonstration of the role of these structures in the maintenance of spine stability in the transverse plane in cases of disc degeneration.