Mammary tumours constitute more than half of neoplasms in female dogs from different countries. Genome sequences are associated with cancer susceptibility but there is little information available about genetic polymorphisms of glutathione S‐transferase P1 (GSTP1) in canine cancers. The aim of this study was to find single nucleotide polymorphisms (SNPs) in GSTP1 of dogs (Canis lupus familiaris) with mammary tumours compared to healthy dogs and to determine the association between GSTP1 polymorphisms and the occurrence of these tumours. The study population included 36 client‐owned female dogs with mammary tumours and 12 healthy female dogs, with no previous diagnosis of cancer. DNA was extracted from blood and amplified by PCR assay. PCR‐products were sequenced by Sanger method and analysed manually. The 33 polymorphisms were found in GSTP1: 1 coding SNP (exon 4), 24 non‐coding SNPs (9 in exon 1), 7 deletions and 1 insertion. The 17 polymorphisms have been found in introns 1, 4, 5 and 6. The dogs with mammary tumours have significant difference from healthy in SNPs I4 c.1018 + 123 T > C (OR 13.412, 95%CI 1.574–114.267, P = .001), I5 c.1487 + 27 T > C (OR 10.737, 95%CI 1.260–91.477, P = .004), I5 c.1487 + 842 G > C (OR 4.714, 95% CI 1.086–20.472, P = .046) and I6 c.2481 + 50 A > G (OR 12.000, 95% CI 1.409–102.207, P = .002). SNP E5 c.1487 T > C and I5 c.1487 + 829 delG also differed significantly (P = .03) but not to the confidence interval. The study, for the first time, showed a positive association of SNPs in GSTP1 with mammary tumours of dogs, that can possibly be used to predict the occurrence of this pathology.

For timely diagnostics and successful treatment of mammary tumors in human and animals a necessary search of compounds that can be the biomarkers of this disease is needed. The aim of our work was to measure the activity of glutathione peroxidase (GPx) in blood plasma and erythrocytes of dogs and cats with mammary tumors and healthy animals for establishment of intercommunication between enzyme's activity and tumors. For researches took away blood at three groups of animals: 1) four healthy females of dogs (Canis familiaris) – the German Shepherd dogs by age 3, 6, 7 and 7; 2) four females of dogs with mammary tumors – the Russian Spaniel dog by age 8, Boxer dog by age 9 and the German Shepherd crossbred dogs by age 11 and 12; 3) four females of cats (Felis catus) with mammary tumors – crossbred cats by age 6, 8 and 10 and the Persian crossbred cat by age 13. Activity of GPx was determined by decrease of reduced glutathione in a presence of hydrogen peroxide for time unit with a count on the gramme of protein in blood plasma, or haemoglobin in erythrocytes. In the sick dogs’ erythrocytes the activity of GPx presents 30.45 ± 3.08 mmol GSH/min×g haemoglobin and it is more than for the healthy animals of 27.84 ± 5.24 mmol GSH/min×g haemoglobin, these differences aren't statistically reliable however. This index is the highest for the sick German Shepherd crossbred dog aged 11 and presents 38.5 mmol GSH/min×g haemoglobin. In sick dogs’ activity of GPx in blood plasma is 7.45 ± 1.60 mmol GSH/min×g protein and it is statistically reliable less than the healthy animals of 12.77 ± 1.18 mmol GSH/min×g protein. This index is the lowest for the the 12 years old sick German Shepherd crossbred dog and it is 3.41 mmol GSH/min×g protein. In sick cats activity of GPx in erythrocytes is 41.57 ± 4.10 mmol GSH/min×g haemoglobin, and the greatest it is in the sick crossbred cat age 10 – 52.52 mmol GSH/min×g haemoglobin. The activity of the enzyme in blood plasma of sick cats is 11.58 ± 1.99 mmol GSH/min×g protein and this index is similar to the healthy dogs. Activity of GPx of the erythrocytes of dogs and blood plasma of cats with mammary tumors did not differ from healthy dogs. The activity of GPx of sick dogs only in blood plasma is less than in healthy ones. It can be the consequence of this “exhaustion” of the enzyme and its involving in the process of neutralizing of active forms of reactive oxygen species in those tissues of organism where oxidizing stress develops. Next to the study of expression on the future it is necessary to pay attention to the study of polymorphism of GPx.

For dog’s mammary tumors diagnostics scientists need researches, which can adopt and use methods developed for humans. The aim of this research paper is to set the inter relation between the parameters of nuclear morphometry (nuclear area, diameter, perimeter) and histopathological type of mammary tumors of dogs. Animals aged from 6 to 12 (medium meaning 9.2 ± 1.6 years). According to histopathological research 3 tumors were benign and 25 were malignant, 18 of them – malignant epithelial neoplasms (3 tubular carcinomas, 13 tubulopapillary carcinomas, 1 cystic-papillary carcinoma, 3 colid carcinomas, 1 micropapillary carcinoma), 3 malignant epithelial neoplasms of special type (mucinous, lipid-rich, spindle cell carcinomas) and 4 malignant mesenchymal neoplasms (chondrosarcoma). Nuclear morphometry parameters (nuclear area, perimeter and diameter) of benign tumours (20.48 ± 1.22, 19.13–21.50 µm2; 19.27 ± 0.10, 19.17–19.36 µm and 5.09 ± 0.16, 4.92–5.22 µm) were probably smaller than in malignant tumours, for example in simple carcinoma (38.61 ± 5.61, 29.26–46.16 µm2; 26.42 ± 2.32, 22.10–29.60 µm and 6.96 ± 0.52, 6.03–7.62 µm), tubular (37.89 ± 7.30, 29.94–46.16 µm2, 26.34 ± 2.83, 22,98–29,60 µm and 6.90 ± 0.70, 6.16–7.62 µm), tubulopapillary (40.22 ± 3.48, 34.38–44.75 µm2, 27.02 ± 1.49, 24.41–28.97 µm and 7.12 ± 0.31, 6.58–7.52 µm), colid (43.57 ± 5.54, 37.71–48.73 µm2, 28.05 ± 1.88, 26.54–30.15 µm and 7.41 ± 0.47, 6.91–7.85 µm), other malignant epithelial neoplasms (39.99 ± 5.15, 29.94–48.73 µm2; 26.85 ± 2.03, 22.98–30.15 µm and 7.09 ± 0.50, 6.16–7.85 µm) and malignant epithelial neoplasms of special types (45.89 ± 4.12, 43.41–50.65 µm2; 29.92 ± 0.21, 29.68–30.06 µm and 7.60 ± 0.34, 7.41–8.00 µm). However, there was not statistically significant difference in comparison between benign tumours and sarcomas (25.95 ± 5.21, 21.64–33.00 µm2; 21.85 ± 1.79, 20.21–24.05 µm and 5.68 ± 0.56, 5.21–6.42 µm). Among the different groups of malignant neoplasms lower rates were in sarcoma, the other groups had no difference. Taking into consideration the indicators of nuclear morphometry (nuclear area, diameter and perimeter) different types of neoplasms can be differentiated: benign from malignant tumours and sarcomas from malignant epithelial neoplasms (tubular, tubulopapillary, cystic-papillary, colid, micropapillary, mucinous, lipid-rich and spindle cell carcinomas).

28 Hayes JD, Mantle TJ. Use of immuno-blot techniques to discriminate between the glutathione S-transferase Yf, Yk, Ya, Yn/Yb and Yc subunits and to study their distribution in extrahepatic tissues. Evidence for three immunochemically distinct groups of transferase in the rat.

Львівський національний університет ветеринарної медицини та біотехнологій імені С. З. Ґжицького, вул. Пекарська, 50, м. Львів, 79010