RESUMO
The occipital dysplasia has been characterized by a dorsal enlargement of the foramen magnum which can vary in size and shape. Clinical signs may be present or not in animals with occipital dysplasia. The purpose of this study was to radiographically analyze the morphology and morphometry of the foramen magnum of thirty healthy dogs. This study chose to use fifteen Yorkshire terrier dogs and fifteen Toy Poodle dogs in order to characterize the radiographic aspects of the foramen magnum and contribute to the diagnosis and critical analysis of the occipital dysplasia importance. According to the foramen magnum morphology and tracings, it was possible to classify the radiographic aspects into different shapes varing from oval and quadrangular. Out of 26 (86.7 percent) animals had a dorsal enlargement and 4 (13.3 percent) showed normal foramen magnum. Animals without any clinical signs that are radiographically classified as dysplastic dogs may simply represent an anatomic variation of the foramen magnum.
A displasia do occipital é o alargamento dorsal do forame magno, o qual pode variar a sua forma e tamanho e os animais com esta alteração morfológica podem ou não apresentar manifestações clínicas. O objetivo desta pesquisa foi avaliar radiograficamente a morfologia e a morfometria do forame magno de 30 cães assintomáticos das raças Poodle toy e Yorkshire terrier, sendo 15 de cada, a fim de se caracterizar os aspectos radiográficos do forame magno e contribuir para o diagnóstico e análise crítica da relevância da displasia do occipital. O forame magno apresentou aspectos que variaram de oval a quadrangular. A presença do alargamento dorsal ocorreu em 26 (86,7 por cento) animais e a ausência em apenas quatro (13,3 por cento). Animais sem manifestações clínicas, que apresentam graus variados de alargamento dorsal e são classificados radiograficamente como displásicos, podem apenas representar variações anatômicas do forame magno.
RESUMO
This study was carried out to assess the feasibility of ultrasonographic measurements of the optic nerve sheath diameter (ONSD) in normal dogs and evaluate the effect of breed, sex, body weight and age on biometry of ONSD. The ONSDs were evaluated in 15 dogs (10-50 months old)with normal eye (7 Yorkshire terrier and 8 Maltese). Ultrasonographic measurements of the ONSD were carried out at a constant position located 5 mm behind the optic disc. Eyes were collected immediately after euthanasia, and were used for saline immersion technique and direct measurement by calipers for biometry of ONSD. In this study, there was no significant difference of ONSD between the left and the right eyes, and was no significant difference among ONSD values obtained from ultrasonographical method, saline immersion technique and direct measurement (k = 0.95). Also, there was no correlations between ONSD and sex, body weight and age, but was significant between the mean ONSD of Yorkshire terrier and Maltese (p<0.01). The mean ONSD of Yorkshire terrier was 2.10 +/- 0.22 mm and Maltese was 1.63 +/- 0.23 mm. This study suggests that ultrasonographic measurements is useful method for biometry of the ONSD in normal dogs and provides baseline information for the study of evaluating ONSD in various breeds and diagnosing several diseases with the change of the ONSD.