Pregnancy failure in companion animals

Question 1

What occurs during proestrus?

Answer 1

• Marked increase in reproductive activity
• Follicular growth
• Uterus enlarges slightly
• endometrium becomes congested and oedematous, glands show secretory activity
• vaginal mucus becomes hyperaemic
• the bitch shows external evidence -> vulval oedema

Question 2

What occurs during oestrus?

Answer 2

• The female accepts the male for mating
• glands secrete mucus
• endometrium becomes congested and hyperaemic
• Cervix relaxes

Question 3

What occurs during dioestrus?

Answer 3

It is the longest phase of the oestrus cycle
The corpus luteum is present and secretes large amounts of progesterone

Question 4

What is the duration of diestrus directly related to?

Answer 4

the time that the corpus luteum remains functional

Question 5

How does diestrus end?

Answer 5

diestrus ends with regression or luteolysis of the corpus luteum

Question 6

What are the physical changes of diestrus?

Answer 6

• Uterine glands undergo hyperplasia and hypertrophy
• Cervix becomes constricted
• secretions of the tract are scant and sticky
• vaginal mucosa becomes pale

Question 7

What occurs during anoestrus?

Answer 7

• The genital system is quiescent
• Follicular development is minimal and corpora lutea have regressed/ are non-functional
• physically- secretions are scant and the cervix is constricted

Question 8

Name three reproductive disorders of growth

Answer 8

• Hyperplasia of the genital tract
• unilateral aplasia of the uterine horns
• bilateral aplasia leading to no pregnancy

Question 9

What is cystic endometrial hyperplasia?

Answer 9

• repetative and prolonged exposure to progesterone results in an inapproprate increase in size and number of endometrial glands
• can cause infertility
• may predispose to pyometra

Question 10

What are the clinical signs of brucella canis?

Answer 10

• infection can result in abortion
• most of which occur in the last trimester between days 45-55 with no premonitary signs

Question 11

What is the duration of diestrus related to?

Answer 11

Directly related to the time that the corpus luteum remains functional

Question 12

How long does diestrus last in the bitch?

Answer 12

60 days (the length of gestation)

Question 13

How long does diestrus last in the cat?

Answer 13

CL degeneration is protracted (45 days in non pregnant queen)

Question 14

What ends diestrus?

Answer 14

regression or luteolysis of the Corpus Luteum

Question 15

What causes an early return to pro-oestrus?

Answer 15

Failure of follicle to mature = no ovulation = no luteal phase = early return to pro-oestrus

Question 16

What is hyperplasia of the vaginal wall a response to?

Answer 16

elevated oestrogens

Question 17

How does vaginal hyperplasia vary?

Answer 17

mild hyperplasia to a large mass obstruction

Question 18

What is the most common site for a vaginal hyperplasia?

Answer 18

ventral vaginal wall

Question 19

What is the most common reason an animal may fail to conceive?

dogs/ cats

Answer 19

• Repetitive and prolonged exposure to progesterone
• increased no of endometrial glands
• Hyperplasia progresses -> cystic
• Causes infertility
• may then predispose to pyometra

Cystic endometrial hyperplasia

Question 20

What are some reasons why an animal may fail to maintain a pregnancy?

Answer 20

• Resorbed
• aborted (foetal loss)
• Mummified
• Macerated (liquified)
• Stillborn (may not be viable)

Question 21

What are the clinical signs of Brucella canis?

Answer 21

• Infections can result in abortions and stillbirths in bitches, and epididymitis, prostatitis, orchitis and sperm
  abnormalities in males.
• Litters can contain both live and dead pups.
• Most abortions occur during the last trimester, between day 45-55 with no premonitory signs. Followed by
  mucoid to grey/green vaginal discharge for weeks.

Question 22

Why are antibiotics not useful with brucella canis?

Answer 22

B canis sequesters intarcellularly

Question 23

Where do herpesvirus inhabit in the bitch?

Answer 23

Inhabits the URT
Mlae to female venereal contact is not a significant means of transportation
Infection of the pregnant bitch before day 30 leads to resorption

Question 24

When does pregnancy toxaemia usually occur?

Answer 24

• Usually late gestation
• bitches with a larger no of puppies usually at a larger risk
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