A study on clinical, ultrasonography and haematology of aglepristone-induced mid-gestation pregnancy terminations for rabbits
Aglepristone is used as a safe abortion drug for cats, dogs and rabbits. Although finding no serious side effects of it, we also have no information available about its effects on haematological parameters.
For the first time clinical and ultrasonographic features and haematological profiles were evaluated in rabbits treated with aglepristone 15 and 16 days after mating. Ten healthy New Zealand White female rabbits of 10–14 month-old were mated with fertile males and their pregnancies were confirmed by ultrasound after 15 days. Among them, 5 were treated with aglepristone (test group, n=5) while the remaining five (control group, n=5) were treated with a saline solution (0.9% NaCl). The treatment dosage was 10 mg/kg body weight, administered subcutaneously once daily on two consecutive days (day 15 and 16 after copulation). Ultrasonographic, clinical and haematological examinations were conducted daily. Aglepristone treatment induced embryonic fluid resorptions without foetal death in mid-gestation terminations. After ultrasonographic and haematological examinations done, aglepristone was confirmed to be a safe abortion drug for rabbits.
As a progesterone receptor blocker, the function of aglepristone has previously been studied in mid-term termination of pregnancy and the prevention of implantation in rabbits. Aglepristone is a synthetic steroid with anti-progesterone activity. Furthermore, it is widely used as the first licensed antiprogestin in small animal practice in most European, Latin American and Pacific countries. Although aglepristone is applied to cats and dogs, there are fully-testified side effects.
As is reported, there are anorexia, necrosis, itching at injection sites and a decline in body temperature. Transient and reversible haematological changes have been reported in 4.5% of dogs after the application of aglepristone, including neutrophilia, neutropaenia, thrombocytosis, haematocrit variation, lymphocytosis and lymphopaenia.
However, for rabbits, aglepristone’s abortifacient effects and prevention of implantation have no clinical side effects. Even in the future mating behavior, pregnancy and parturition rates, are well recorded. Embryonic or foetal development and placental growth can be testified by ultrasonographic examinations. Pregnancy can be confirmed through ultrasonography based on the detection of embryonic vesicles on the 6th day of pregnancy and heartbeat of an embryo on the 14th day after mating in rabbits.
Ultrasonography is also an important method for monitoring embryonic or foetal viability, so it is useful to determine foetal mortality in induced abortions in rabbits. Haematological examinations, in turn, are used to examine general health and physiological changes in animals. During treatment, routine haematological monitoring is suggested to enable identification and control of any toxic side effects of the medication. Although finding no serious side effects of aglepristone clinically, we alos get no information on haematological changes during aglepristone application in rabbits. This study therefore aimed at describing the clinical features and haematological profiles after aglepristone-induced abortions by monitoring the foetus, foetal membranes and embryonic vesicles ultrasonographically during the abortion process.
