Uso clínico de hormônios na repodução de pequenos animais
Romagnoli, Stefano
The abortifacient efficacy of prostaglandin F2alpha products (PGF) involves induction of luteolysis,stimulation of uterine contraction and cervical dilation. PGF will induce luteolysis and depress progesterone (P4)concentrations to nearly non-detectable levels very easily after day 25 or 30 following just a 4-5 day course oftreatment. PGF can be used also earlier in pregnancy provided that the onset of cytological diestrus is timedprecisely and treatment course is longer than 5 days. With late abortion, the treatment must be continued untilverification of efficacy by ultrasound as partial abortion of litters can occur. Other uses of PGF includeshortening of diestrus in bitches, emptying the uterine content and improving semen quality in dogs. Antiprolactinagents include dopamine agonists (bromocriptine or cabergoline), and serotonin antagonists(metergoline). Anti-prolactin drugs can be used to control pseudopregnancy, induce abortion and the resumptionof estrus. Antiemetic (metoclopramide and domperidone) and antipsychotic drugs (chlorpromazine andsulpiride) have prolactin release properties which are widely documented in human medicine; their clinicalefficacy in the treatment of agalactia or hypogalactia is anecdotally reported also in bitches and queens.Aglepristone saturates P4 receptors causing abortion when administered at the dose of 10 mg/kg twice 24 hoursapart. The early administration of aglepristone at 0 to 25 days after mating is approximately 99% effective inprevention of pregnancy; however, care should be taken when using it without having assayed serum P4 or afterday 35 of pregnancy. Aglepristone can be used for several other purposes among which induction of parturitionand treatment of feline mammary hypertrophy. The clinical use of other hormonal drugs such as estrogens andsympatho-mimetics for conditions such as urinary incontinence and retrograde ejaculation is briefly discussed.(AU)
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