Oestrus Cycle of the Bitch and Queen

Question 1

Where is prostaglandin produced from in the not pregnant female?

Answer 1

Endometrium

Question 2

How does the luteal phase of a dog differ?

Answer 2

Follicles increase in size and luteinise on the inner surface, so progesterone increases before the egg is released
Prolactin is luteotrophic and increases when progesterone starts to fall, maintaining progesterone secretions from the CL, without prolactin progesterone would drop to basal values
When the luteal phase ends the dog goes into an obligatory anoestrus

Question 3

What happens before ovulation in a dog?

Answer 3

Rise in oestrogen, LH surge seems to be induced by fall in oestrogen and increase in progesterone

Question 4

How is the fertilisation window different in a dog?

Answer 4

Later, as at ovulation the egg is immature and takes 2 days before it can be fertilised, fertilisation window is late

Question 5

Define metoestrus and dioestrous

Answer 5

Metoestrus – luteal phase during its maturational phase

Dioestrus – remaining part of luteal phase