Clinical and Endocrine Short-Term Effects of GnRH Analogue Deslorelin in Prepubertal Bitches: Does A “Flare-up” Occur?


Kaya D., Aslan S., Kaya S., Kuru M., Kaçar C., Schäfer-Somı S.

KAFKAS UNIVERSITESI VETERINER FAKULTESI DERGISI, vol.19, no.2, pp.299-304, 2013 (SCI-Expanded) identifier

Abstract

Long-acting GnRH agonists have been used both in canine estrus induction and prevention. The objective of the study was to investigate the clinical and endocrine short-term effects of a deslorelin implant (4.7 and 9.4 mg) in terms of initial “flare-up” in prepubertal bitches. Fourteen healthy, cross-breed prepubertal female dogs, aged 4 months, were used in the study. An implant containing 9.4 mg (G1, n= 5) and 4.7 mg (G2, n= 4) deslorelin (Suprelorin®) or a placebo (sodium chloride 0.9%, G3, n= 5) was inserted subcutaneously. Estrus was monitored once daily by physical and sexual behavioral changes. Vaginal cytology, serum progesterone (P4) and estradiol 17β (E2) concentrations were monitored weekly for the first five weeks throughout the treatment. None of the bitches in the treatment (G1 and G2) and control (G3) group showed any signs of estrous throughout the study period. No local reactions were observed at the implantation site. Two bitches showed an increase in serum P4 concentrations (> 1.0 ng/ml) in G1 (2/5; 40%), however, only one of these two animals (P4= 6.37 ng/ml) showed an increase in serum E2 concentrations up to 37 pg/ml. No marked increase in serum P4 and E2 concentrations were observed during the first 13 weeks of treatment in G2. These data demonstrate that in prepubertal bitches, insertion of a deslorelin implant does not cause a “flare-up effect” which commonly occurs in anestrus adult bitches during the first month after implantation. However, further studies are needed to demonstrate that the “flare-up” effect of deslorelin implant in bitches especially during later prepubertal stages.