Pregnancy failure in companion animals Flashcards
What occurs during proestrus?
- 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
What occurs during oestrus?
- The female accepts the male for mating
- glands secrete mucus
- endometrium becomes congested and hyperaemic
- Cervix relaxes
What occurs during dioestrus?
It is the longest phase of the oestrus cycle
The corpus luteum is present and secretes large amounts of progesterone
What is the duration of diestrus directly related to?
the time that the corpus luteum remains functional
How does diestrus end?
diestrus ends with regression or luteolysis of the corpus luteum
What are the physical changes of diestrus?
- Uterine glands undergo hyperplasia and hypertrophy
- Cervix becomes constricted
- secretions of the tract are scant and sticky
- vaginal mucosa becomes pale
What occurs during anoestrus?
- 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
Name three reproductive disorders of growth
- Hyperplasia of the genital tract
- unilateral aplasia of the uterine horns
- bilateral aplasia leading to no pregnancy
What is cystic endometrial hyperplasia?
- 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
What are the clinical signs of brucella canis?
- infection can result in abortion
- most of which occur in the last trimester between days 45-55 with no premonitary signs
What is the duration of diestrus related to?
Directly related to the time that the corpus luteum remains functional
How long does diestrus last in the bitch?
60 days (the length of gestation)
How long does diestrus last in the cat?
CL degeneration is protracted (45 days in non pregnant queen)
What ends diestrus?
regression or luteolysis of the Corpus Luteum
What causes an early return to pro-oestrus?
Failure of follicle to mature = no ovulation = no luteal phase = early return to pro-oestrus
What is hyperplasia of the vaginal wall a response to?
elevated oestrogens
How does vaginal hyperplasia vary?
mild hyperplasia to a large mass obstruction
What is the most common site for a vaginal hyperplasia?
ventral vaginal wall
What is the most common reason an animal may fail to conceive?
dogs/ cats
- Repetitive and prolonged exposure to progesterone
- increased no of endometrial glands
- Hyperplasia progresses -> cystic
- Causes infertility
- may then predispose to pyometra
Cystic endometrial hyperplasia
What are some reasons why an animal may fail to maintain a pregnancy?
- Resorbed
- aborted (foetal loss)
- Mummified
- Macerated (liquified)
- Stillborn (may not be viable)
What are the clinical signs of Brucella canis?
- 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.
Why are antibiotics not useful with brucella canis?
B canis sequesters intarcellularly
Where do herpesvirus inhabit in the bitch?
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
When does pregnancy toxaemia usually occur?
- Usually late gestation
- bitches with a larger no of puppies usually at a larger risk
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