68° Congresso Nazionale SCIVAC: Le domande più frequenti in ...

68° CONGRESSO NAZIONALE SCIVAC 11-13 Marzo 2011 - Milano
LE DOMANDE PIÙ FREQUENTI IN RIPRODUZIONE CANINA E FELINA
Tutto quello che i vostri clienti osano spesso chiedere e a cui voi non sapete rispondere
14 th EVSSAR Congress - Advances in Feline Reproduction - March 11 th 2011
quently induce oestrus in anoestrous animals. In the past, only injectables
forms were available on the market, and the daily administration process did
not make it pratical enough for routine use. At the beginning of the 21 st century,
biocompatible implants allowing daily delivery of these drugs were developed
and used in the mare, the cow and the bitch (Trigg 2001). Promising
results were obtained, as Kutzler (2005) and Volkmann et al (2006) reported
heat and ovulation induction in all treated animals with implants delivering
25μg per day of the GnRH agonist deslorelin. Heats were induced 3 to 5 days
after implant administration. Moreover, pregnancy results that were obtained
(5/8 -62%- bitches from Kutzler et al, 9/13 -69%- from Volkmann et al)
opened interesting perspectives for the future. However, these results were
mainly obtained in anoestrous beagle bitches housed in research colonies, and
few data from the field are actually available.
In a recent study conducted in our clinical division (Fontaine et al. 2010),
32 bitches consulting for heat induction were observed. Two groups were differentiated:
group 1 (G1), where bitches were implanted 80 to 160 days after
the last heats were observed (G1; n=8) and group 2 (G2, n=24) where bitches
were implanted in late anoestrus 200 to 590 days after.
Oestrus induction was obtained in all 32 bitches, 4.3±1.4 days after implantation
[from 2 to 7 days]. Ovulation was observed in 25/32 bitches
(78.1%) 11.8+/-2.1 days after implantation. Statistical analysis showed no
difference in age and size of ovulating and non ovulating bitches. 3/8 bitches
(37.5%) implanted in G1 did not ovulate, whereas it only concerned 4/24
bitches (16.7%) implanted in G2. Pregnancy was diagnosed in 18/24 bitches
(75%). No statistical difference concerning the age, the size and the time of
implantation of pregnant and non pregnant bitches could be enlightened.
3.2. IN THE QUEEN
In the queen, hormonal protocols of oestrous induction are not ideal at the
moment, as dopaminergic compounds seem to have a weak and inconstant
efficacy, gonadotropins (although widely used) may bear undesired side effects
and GnRH agonists implants are still being studied. Queens being highly
sensitive to light, manipulation of photoperiod seems nowadays to be one
of the most effective and safe way to induce oestrus in anoestros queens, especially
in the non-breeding season. Catteries having sufficient lightening 14
hours a day (enough to read a newspaper without effort) help the queens to
cycle all year long.
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