The objective of research was to determine the diagnostic value of dog prostate gland secretion cytology by special applied technique. In order to achieve the objective it was necessary to complete the following task, notably: to detect changes in the dog prostate secretion which would be indicative of pathologic processes in the gland.

The research was conducted at the premises of clinic of the Department of Obstetrics, Gynecology and Biotechnology of Animal Reproduction named after G.V. Zvereva of the Lviv National University of Veterinary Medicine and Biotechnologies named after S.Z. Gzhytsky.

10 dogs of different breeds aged from 5 to 9 years were selected for the experiment.

Dogs were put under general anesthesia before obtaining samples of the prostate gland secretion. The sterile urethral catheter was inserted into urinary bladder aseptically in order to remove urine residuals. The next step of obtaining secretion was washing the bladder with normal saline solution with complete aspiration of contents and removal of the catheter. After that another sterile urethral catheter was inserted into the prostatic urethra with palpatory control of the manipulation per rectum. Then normal saline solution was injected through the catheter, the prostate was exposing to massage and all excreted fluids were aspirated. The secretion obtained from prostatic lavage was examined under a microscope after staining and preparation of the specimen.

The research results are interpreted and diagnosis is determined based on the characteristics of cells found in the specimen. There are no prostatic parenchymal cells in prostatic secretion of healthy dogs or they form small clusters. The cells have central large nucleus with delicate chromatin pattern. Cytoplasm has granular structure. In case of hyperplasia penicillilike cell clusters as well as single cells are noticeable. Boundaries between the cells are often poorly visualized. Cytoplasm is granular, nuclei have large rounded or oval shape, usually there are no nucleoli. In case of prostatitis the specimen of prostatic excretion is neutrophils-dominated. There are a large number of prostate gland cells and their cytoplasm becomes hyperchromatic. In case of prostate abscesses there are a large number of degenerated neutrophils, cells with nucleorrhexis and vacuolated cytoplasm in the specimen. In case of neoplasms anisokariosis the nuclei of different size and shape are observed in cells. Nucleoli which are usually small and single, but can also be large, are often present in the case. Cell membranes of the neoplasms are indistinct.

In addition to microscopy the prostatic secretion was bacteriologically examined (bacterial inoculation) or polymerase chain reaction (PCR) was used for the detection of infectious agents.

The prostatic parenchymal cells of two out of 10 test specimens had a large rounded and oval nucleus with a delicate chromatin pattern; they were surrounded by a narrow corolla of cytoplasm. It suggests that lavages correspond to the physiological standard. The results from the analysis of 7 prostatic lavages showed cytoplasmic vacuolation, anisochromia of cytoplasm and epithelial cell nuclei, an increase in their size, irregular shape, vacuolation and eccentricity of epithelial cell nuclei, heterochromatization. Some cells had signs of atrophy: hypochromically stained chromatin with condensation domains, single or multiple endonuclear vacuoles were becoming visible with cytoplasm being virtually not stained. Amitotic figures and akaryocytes with foamy cytoplasm were detected. All mentioned signs enable us to diagnose prostatic hyperplasia in seven animals.

The cytology in a 9-years-old dog revealed three-dimensional structures in the form of sheet-like cell elements combined in a symplast with eccentric nuclei, large areas of vacuolated cytoplasm, cytoplasmic eosinophilia, weakly basophilic nuclei of epithelial cells, an increase in the nucleus size, heterochromatization, loop-shaped chromatin, formation of a large (> 2µm) nucleolus. These cells changes suggested that there is a neoplastic process in the prostate.

So, based on the obtained results we conclude that the use of cytological methods of research makes it possible to detect structural changes in the cells of the dog prostate secretion. The method can be helpful in diagnosing hyperplasia or neoplastic processes in the dog prostate gland.

Key words: dog, prostate, secretion, cytology.