[Hormonal heat induction in anoestral blue fox vixens after recording ovarial and hormonal conditions]

An investigation on the ovarial status of blue fox vixens which had not come into oestrus until the 15 of April is described. The ovarial status was determined both by progesterone-analysis and by laparotomy and direct inspection of the ovaries. Afterwards, the vixens were treated with 100 I.U. PMSG (Antex, Leo) every second day for five treatments. One day after the last PMSG treatment, 200 I.U. HCG (Physex, Leo) was administered. Two days after the last treatment, the vixens were killed and two ovaries were reexamined. The investigation showed that 44% of the vixens had functioning corpora lutea in the ovaries by the time of the first inspection. One vixen had cystic degeneration of the ovaries, two had follicles, while the rest had inactive ovaries. The progesteron levels were in accordance with the findings by laparotomy. Thirty-one percent of the vixens with inactive ovaries responded to treatment with ovulation, and all of those with follicles ovulated, while no response of the vixens with corpora lutea could be registered.