Usefulness of cytological evaluation of milk in diagnosing mastitis in bitches

Abstract

The aim of this study was to evaluate the prevalence of mastitis in female lactating dogs by interpreting the milk cytology in the diagnostic protocol. Milk samples were manually collected in sterile vials from 89 lactating bitches (i.e., 157 mammary glands) aged between 10 and 168 months. Milk smears were obtained by using the squash and May-Grünwald-Giemsa (MGG) techniques. Acute mastitis episodes were consistent with increased numbers of degenerated neutrophils, erythrocytes, and engulfed bacteria. Eosinophils were present in retention mastitis inflammations. Foamy cells were present in every type of inflammation. Subclinical cases of mastitis were characterized by a reduced number of neutrophils with engulfed bacteria. The period of lactation has a great influence on the type of mastitis encountered. Our results have showed that the lactation period has influence over different types of mammary gland inflammations. In most cases, galactostasis (65%) followed by subclinical mastitis (22%) and acute mastitis (13%) were encountered. Neutrophils and phagocytosis exhibited specificity for acute inflammations, whereas eosinophils and foamy cells were consistent with cases of retention mastitis. The presence of red blood cells in most cases was correlated with acute inflammations. It seems that cytological evaluation of milk could be quite helpful in diagnosing mammary gland inflammations..