Através da técnica de Densitometria Óptica Radiográfica consegue-se aferir o conteúdo mineral do osso com auxílio de imagens radiográficas, demonstrando ser uma metodologia precisa, confiável e de baixo custo. Procurou-se comparar os valores da densidade mineral óssea em gatos castrados precocemente - antes da puberdade - e gatos inteiros. O grupo experimental foi composto de 59 animais, separados em fêmeas e machos, castrados e inteiros. As densidades ópticas foram medidas por meio do programa de processamento de imagens ImageLab. Foram estudadas as correlações entre os valores de DMO, peso e sexo. Os gatos machos apresentaram valores de DMO e peso maiores que as fêmeas (P<0,001). Quando separados em machos castrados e inteiros e fêmeas castradas e inteiras, os gatos machos inteiros apresentaram maior valor de DMO, independentemente do peso. Entre as fêmeas não houve diferença significativa com os valores de DMO para os animais castrados e inteiros já os gatos machos castrados apresentaram valores de DMO semelhantes ao das fêmeas castradas demonstrando que com a castração precoce há uma diminuição da densidade mineral óssea. A correlação entre peso e a DMO se mostrou mais importante nos animais inteiros que nos castrados demonstrando que a interdependência entre peso e DMO varia com a ação hormonal. Os valores médios de DMO obtidos foram de 3,7±0,44mmAl para o grupo total de fêmeas, sendo de 3,69±0,56mmAl para as fêmeas castradas e 3,72±0,25mmAl para as fêmeas inteiras. Foram de 4,39±0,5mmAl Para o grupo total de machos, sendo de 4,52±0,38mmAl para ao machos inteiros e de 3,92±0,4mmAl para os machos castrados.

Radiographic Optic Densitometry has proven itself to be a precise, reliable, and low-cost methodology that enables analysis of bone mineral content with the aid of radiographic images. A study was conducted in which the bone mineral density of cats sterilized in pre-pubescence was compared to that of non-sterilized cats. The experimental group was composed of 59 animals, which were then divided into male and female groups, as well as into sterilized and non-sterilized groups. The optic densities of these animals were measured by the image processing program software, ImageLab. The correlations between the values of BMD, weight and sex had been studied. The male cats had presented higher values of BMD and weight than female cats (P<0,001). When comparisons were made between spayed and non-spayed females and neutered and non-neutered males, the non-neutered male cats had presented higher value of BMD, independent of their weight value. As for the females, there were no significant differences in the values of BMD between spayed and non-spayed females. However, the neutered male cats presented similar values of BMD as spayed females. This illustrates that sterilization causes a reduction in bone mineral density. The correlation between weight and the BMD was more significant in the non-sterilized animal group than in the sterilized group, demonstrating that the interdependence between weight and BMD varies according to hormonal action. The average values of obtained BMD were 3,7±0,44mmAl for the whole female group, and more specifically, 3,69±0,56mmAl for spayed females and 3,72±0,25mmAl for the non-spayed females. As for the male group, the average BMD value for the whole group was 4,39±0,5mmAl. However, the average BMD value was 4,52±0,38mmAl for the non-castrated males and 3,92±0,4mmAl for the castrated males.