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
and cats producing litters and thus contributing to pet overpopulation. Many
American breeders also think that it may avoid their clients from having their
dog or cat reproducing later in life and somehow “stealing” their genetics.
According to many publications, this very early spaying doesn’t bear
many side effects, compared with surgical spaying later in life. Their may be
more epiphyseal fractures or an increased susceptibility to infectious diseases,
such as parvovirosis. It is necessary to adapt the pre-surgical, peri-surgical
and anaesthetic procedures due to the young age of the patient (limited time
of fast, importance of warming the animal in the course of surgery…), but the
surgical approach by itself seems to be facilitated in young bitches due to the
lack of fat around the ovaries.
2. MEDICAL PREVENTION OF OESTRUS
2.1. PROGESTINS (PROGESTOGENS)
Synthetic analogues of progesterone are the most commonly used medical
drugs for prevention or suppression of oestrus in dogs and cats (Romagnoli
and Sontas 2010). They act in blocking the production and/or the release of
GnRH from the hypothalamus. In bitches, prevention of oestrus is more frequently
done using depot administration (medroxyprogesterone acetate, delmadinone
acetate, proligestone). In queens, oral administration of megestrol
acetate every week or every 2 weeks is more frequent. Suppression of oestrus
may be performed in cats by giving daily administration of megestrol acetate
for 5 days, while in bitches we recommend - to avoid any side effect - not to
treat bitches after the 3 rd days after the beginning of proestrus (when parabasals
cells are still present on the vaginal smear).
On the contrary of what was done in the past, it is no longer recommended
to repeat administrations throughout the life of bitches and queens. This is
due to the concern about potential side effects. Although still controversial,
the main concern is the proliferation of mammary parenchyma, potentially
leading to the development of benign or malignant mammary gland tumours
after repeated administration. Skin discoloration at the site of injection, anabolic
effect, increased appetite with subsequent weight gain, insulin resistance
and suppression of adrenocortical axis are commonly reported side effects,
among others. Pyometra may occasionaly develop, especially when
progestins are administered in dioestrus, under endogenous progesterone secretion.
Proligestone, introduced more recently than the other compounds on
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