The present study was conducted on (40) white mice of approximately the same age (4-6 weeks) and body weight (23-25 gm) for the aim of observing the histopathological changes for male and female reproductive organs due to prolonged treatment (6 months) with anticancer chemotherapeutic agent namely methotrexate.Forty mice were divided into 4 groups (10 mice of each group 5 mice per sex). The first group (low or therapeutic dose group ) was received 0.15 mg/kg B.W. The second group ( intermediate dose group ) received 0.3 mg/kg B.W. The third group ( toxic dose group ) received 0.45 mg/kg B.W. the fourth group was a control group; it received 0.2 ml buffered physiological saline.All these groups injected intramuscularly, once weekly for 6 months. The results showed that methotrexate can cause suppression of spermatogenesis. In female, methotrexate can cause obvious pathological changes in uteri and ovaries such as reduced endometrial glands and ovarian follicles respectively

TVT, also known as infectious sarcoma, venereal granuloma, transmissible lymphosarcoma or sticker tumour is a benign reticuloendothelial tumour that affects particularly mucosa of external genital organs and rarely internal genital organs in dogs of both genders. TVT is usually transmitted by coitus but also can be transmitted by licking, sniffing, biting,and scrabbling of the tumour affected area or through damaged skin of mucosa. Transmissible venereal tumour (TVT) is usually observed in stray animals live in tropical and subtropical lands. The affected animals are usually within 9-13 months of age and with high sexual activity. Tumour is frequently located in posterior vagina and vestibulovaginal junction. The averagechromosome count of TVT cells is 59 (57- 64). TVT specific antibodies were found in blood samples of affected animalswhich suggest that they may have a role in natural regression mechanism. The primary objective of tumour treatment is total elimination by surgery, radiotherapy, immunotherapy and/or chemotherapy. Controlling of the disease is very difficult because stray dogs are carriers.

The present study was conducted on (40) white mice of approximately the same age (4-6 weeks) and body weight (23-25 gm) for the aim of observing the histopathological changes for male and female reproductive organs due to prolonged treatment (6 months) with anticancer chemotherapeutic agent namely methotrexate. Forty mice were divided into 4 groups (10 mice of each group 5 mice per sex). The first group (low or therapeutic dose group) was received 0.15 mg/kg B.W. The second group (intermediate dose group ) received 0.3 mg/kg B.W. The third group ( toxic dose group ) received 0.45 mg/kg B.W. the fourth group was a control group; it received 0.2 ml buffered physiological saline. All these groups injected intramuscularly, once weekly for 6 months. The results showed that methotrexate can cause suppression of spermatogenesis. In female, methotrexate can cause obvious pathological changes in uteri and ovaries such as reduced endometrial glands and ovarian follicles respectively

The role of L-asparaginase (L-ASP) in limiting signs of methotrexate (MTX) toxicosis was studied. Eight dogs were randomly allotted to 2 groups of 4 dogs. All dogs were given 400 IU of L-ASP/kg of body weight IM, on day 1. On day 10, group-1 dogs were given 3 mg of MTX/kg, IV, and group-2 dogs were given 6 mg of MTX/kg, IV. All dogs were given 400 IU of L-ASP/kg, IM, 24 hours later (on day 11). One group-2 dog was euthanatized on day 16 because of severe gastrointestinal signs that were unresponsive to treatment. A second dose of MTX, identical to that given on day 10, was given on day 20 to each surviving dog, followed by L-ASP on day 21. On day 67, the 7 surviving dogs were given 3 mg gf MTK/kg, IV. Adverse reactions observed were vomiting diarrhea, and weight loss. Gastrointestinal side effects of MTX were not attenuated with L-ASP and would be a serious limitation to use of MTX administered at an intermediate dose in the treatment of lymphoma in dogs.