TABLE 40-1.

Drugs Used for Control of Estrus and Reproduction in the Queen

Drug	Dose	Effect	Comments
hCG	250-500 IU/cat, IM	Induce ovulation and pseudopregnancy	Effect lasts about 45 days
GnRH	25 µg/cat, IM	Induce ovulation and pseudopregnancy	Effect lasts about 45 days
Megestrol acetate (Ovaban, Megace, others)	(a)2.5 mg/cat, PO, 5 days, then once/week	Induce pharmacologic pseudopregnancy	Progestin; significant adverse effects
	(b)2 mg/cat, PO, once	Mismating
Proligestone (Delvosteron)	100 mg/cat, SC	Estrus suppression	Progestin; effect lasts about 6.5 months
Chlormadinone	2 mg/cat, PO, once/week	Estrus suppression	Progestin; not widely used
Melatonin	30 mg/cat/day, PO	Estrus suppression	Takes 30 days to achieve effect, must be given continuously
Deslorelin (Suprelorin)	6 mg, SC implant	Estrus suppression	GnRH analogue; duration of effect variable
PGF2alpha	(a)After day 33: 2 mg/cat/day for 5 days, IM or SC	Pregnancy termination after day 33 of gestation	Short-term adverse effects common: vomiting, diarrhea, panting, restlessness
	(b)After day 40: 0.5-1.0 mg/kg, twice 24 hours apart, IM or SC
Cabergoline (Galastop)	(a)1.65 µg/kg/day for 5 days, SC	Pregnancy termination after day 25-30 of gestation	Prolactin inhibitor; abortion occurs within 7-10 days; occasional vomiting reported
	(b)5-15 µg/kg/day, to effect, PO
	(c)5 µg/kg/day, PO with cloprostenol 5 µg/kg every 2 days, to effect, SC
	(d)15 µg/kg/day, PO with alfaprostol 10 µg/kg every 2 days, to effect, SC
Aglepristone (Alizin)	15 mg/kg, twice 24 hours apart, SC	Pregnancy termination after day 25 of gestation	Progesterone antagonist; abortion occurs within 5-9 days; occasional depression and anorexia reported

GnRH, Gonadotropin releasing hormone; hCG, human chorionic gonadotropin; IM, intramuscular; PGF_2alpha, prostaglandin F_2alpha; PO, by mouth; SC, subcutaneous.