Objective—To determine whether cabergoline would
be safe and effective for induction of estrus in dogs
with primary or secondary anestrus.
Design—Prospective case series.
Animals—6 privately owned otherwise healthy purebred
dogs with primary or secondary anestrus.
Procedure—Dogs were treated with cabergoline (5
µg/kg [2.3 µg/lb], PO, q 24 h) until 2 days after the
onset of proestrus. Follicular development was
assessed by means of cytologic examination of vaginal
smears; ovulation was assessed by measuring
serum progesterone concentration 3 weeks after the
onset of estrus. Five bitches were mated during
Results—All dogs had normal estrus periods, and all
5 dogs that were mated whelped normal litters. Mean
duration of cabergoline treatment was 16 days. None
of the dogs had any adverse effects associated with
Conclusions and Clinical Relevance—Results suggest
that administration of cabergoline is safe and
effective for treatment for primary and secondary
anestrus in dogs. (J Am Vet Med Assoc 2002;220:
An 11-month-old healthy male Miniature Poodle was referred because of infertility. The dog was the only male at the kennel, and no other animals at the kennel were infertile.
During the preceding 2 months, the dog had mated with 4 previously fertile bitches, none of which became pregnant. Libido and sexual behavior of the dog during those matings were considered normal. Each of the matings was followed by a corresponding copulatory tie. The medical history did not reveal husbandry problems, inbreeding, or administration of any drugs that would interfere with fertility of this particular dog or the other animals
Animals—34 crossbred and purebred bitches
referred for possible pregnancy termination. Seven
additional pregnant bitches were used as controls.
Procedure—Pregnancy was assessed by ultrasonographic
examination from day 25 after mating in all
bitches. Of the 34 bitches, 25 were pregnant and
were randomly allocated to a treatment group. Group-
1 dogs (n = 12) received a combination of increasing
amounts of bromocriptine mesylate (15 to 30 µg/kg
[6.8 to 13.6 µg/lb], PO, q 12 h) and dinoprost
tromethamine (0.1 to 0.2 mg/kg [0.045 to 0.09 mg/lb],
SC, q 24 h). Group-2 dogs (n =13) received a combination
of increasing amounts of bromocriptine mesylate
(the same schedule as group-1 dogs) and cloprostenol
sodium (1 µg/kg [0.45 µg/lb], SC, q 48 h).
Both groups were treated until pregnancy termination.
Results—Treatment success was 100% in both
groups. Days of treatment required for pregnancy termination
did not significantly differ between groups
(5.0 ± 0.6 vs 3.7 ± 0.6 days, group-1 and group-2
dogs, respectively) although adverse effects only
developed in group-1 dogs. At the end of the protocols,
pseudopregnancy was observed in 3 of 12 and
6 of 13 group-1 and group-2 dogs, respectively.
Pregnancy termination was followed by a mucoid
sanguineous vulvar discharge for 3 to 10 days.
Conclusions and Clinical Relevance—Results of
this study indicate that protocols that combine the
use of bromocriptine mesylate and prostaglandins for
the termination of unwanted pregnancy in bitches are
efficient and safe. The use of bromocriptine mesylate
and cloprostenol had the best results and could be
easily used on an outpatient basis. (J Am Vet Med