REPRODUCTION - Canine and Feline Fertility Flashcards
(125 cards)
When do bitches reach sexual maturity?
Female dogs reach maturity at approximately 6 months old, however larger breed dogs tend to reach maturity closer to 12 - 18 months old
How long is proestrus in the bitch?
Proestrus is approximately 7 - 9 days in the bitch, however this can range from 3 - 17 days so it is important to ask the owners about their previous seasons
What are the signs that a bitch is in proestrus?
Vulval swelling
Hyperaemia
Excessive licking of themselves
Serosanguinous vaginal discharge
Attractive to male dogs, however the bitch won’t stand to be mated
Which endocrine changes occur during proestrus in the bitch?
Proestrus is characterised by rapid follicular development and an increase in oestrogen for until 2 days before oestrus. Oestrogen levels will begin to decline at the end of proestrus. Progesterone will be low but will begin to rise at the end of proestrus
How long is oestrus in the bitch?
Oestrus is approximately 7 - 9 days in the bitch, however this can range from 3 - 21 days so it is important to ask the owners about their previous seasons
What are the signs that a bitch is in oestrus?
Vulval swelling (however oedema is reduced)
Wrinked vaginal folds (see using speculum)
Straw coloured vaginal discharge
Attractive to males
Will put tail to one side and stand to be mated
Which endocrine changes occur during oestrus in the bitch?
Luteinisation begins before ovulation, resulting in a decline in oestrogen and rapid rise in progesterone which triggers the luteinising hormone (LH) surge in the bitch, which defines the onset of oestrus. Ovulation occurs 2 days after the LH surge, and the primary oocyte has to mature into the secondary oocyte, which takes another 2 - 3 days. Thus the optimal fertile period in the bitch is 4 - 6 days after the LH surge
What is luteinisation?
Luteinisation is the process by which the granulosa and theca cells convert to luteal cells in response to reduced oestrogen synthesis and begin elevated progesterone production, which is essential in the remodelling and lysis of the follicular wall, a process required for ovulation to occur
How long is metoestrus in the bitch?
Metoestrus is approximately 56 - 58 days (2 - 3 months)
What are the signs that a bitch is in metoestrus?
Vulval swelling subsides
Won’t stand to be mated
May see gradual mammary gland development
Increasing abdominal distension
This is when you would check for puppies as she may be pregnant
Which endocrine changes occur during metoestrus in the bitch?
Progesterone will continue to rise, peaking approximately 3 weeks afte the LH surge. Progesterone levels will slowly decline for the rest of metoestrus. The bitch undergoes passive luteolysis due to decreased LH in the bloodstream resulting in the corpus lutea no longer being supported in progesterone production. Prolactin levels will begin to increase in the second half of metoestrus
How long is anoestrus in the bitch?
Anoestrus can be 4 - 9 months
Which endocrine changes occur during anoestrus?
Progesterone declines to basal levels
When are bitches at optimal fertility?
Female dogs are at optimal fertility from the day of ovulation to 4 days after ovulation
Which methods can you use to determine if a bitch is at optimal fertility?
Count 9 - 14 days from the onset of proestrus
Behavioural changes
Vaginal cytology
Measure hormone concentrations
How will a vaginal smear appear on cytology if the bitch is in proestrus?
Erythrocytes
Intermediate cells
Parabasal cells
Less than 80% superficial epithelial cells
No neutrophils
How will a vaginal smear appear on cytology if the bitch is in oestrus?
Erythrocytes
Over 90% cornified superficial epithelial cells
Parabasal cells at the end of oestrus
No neutrophils
How will a vaginal smear appear on cytology if the bitch is in metoestrus?
Neutrophils (will appear on the first day of metoestrus)
Less than 80% cornified superficial epithelial cells
Intermediate cells
Parabasal cells
Sperm (if she has been mated)
How will a vaginal smear appear on cytology if the bitch is in anoestrus?
Parabasal cells
Few neutrophils
Maybe few superficial epithelial cells
No erythocytes
Which hormone concentration is typically measured to determine bitch fertility?
Serum progesterone concentrations
Which tests are available for measuring progesterone concentrations in the bitch?
IDEXX in house test (in house)
Ovucheck premate ELISA (in house)
Send to laboratory
What are the pros and cons of in house vs laboratory measurements of serum progesterone concentrations?
In house tests are cheaper and immediate, however less accurate than laboratory tests
How often should you be measuring serum progesterone concentrations?
You can begin measuring serum progesterone concentrations 7 - 9 days after the onset of proestrus (owners will start to notice the physical and behavioural changes), and blood sample and test every 24 - 48 hours depending on the temperament of the bitch. When the test indicates ovulation, mate within 24 - 48 hours
What concentration is serum progesterone at ovulation in the bitch?
Serum progesterone is at 5 - 8ng/ml in the bitch at ovulation