Neutering and Reproductive Disease in Small Mammals

Question 1

why do we always close rabbit spays with intradermal

Answer 1

they nibble their stiches and other rabbits do

Question 2

What is different about rabbit uterus’ compared to dogs and cats

Answer 2

have 2 cervix

Question 2

Where is the incision for rabbit ovariohysterectomy

Answer 2

between the umbilicus and pubic symphysis

Question 2

What are the 3 different castration methods in small mammals

Answer 2

scrotal (open or closed)
pre-scrotal (open or closed)
abdominal

Question 2

If you do a scrotal castration in a rabbit what must you do

Answer 2

close the inguinal canals - if open technique used

Question 3

List 4 reasons why scrotal castration in rabbits is not the preferred method

Answer 3

inceases chance of:
- wound breakdown
- infection/abscessation
- scrotal haematoma/ self trauma
- gut stasis/ ileus

Question 4

Why can you not perform pre-scrotal castration normally in some rodents

Answer 4

penis that is positioned cranial to the testicles
so would have to do 2 parallel incisions lateral to midline

Question 5

List 4 reasons why pre-scrotal and abdominal casrations are preferred

Answer 5

one incision instead of 2
wound further away from ground so infection less likely
less sensitive to skin trauma
can suture the skin closed so you can avoid using itchy skin glue

Question 6

List 8 common reproductive conditions in rabbits

Answer 6

Testicular neoplasia
Cryptorchidism
Scrotal trauma
Inguinal hernia
Uterine adenocarcinoma
Pregnancy toxaemia
Pseudopregnancy
Syphilis

Question 7

what causes syphillis in rabbits

Answer 7

Treponema cuniculi

Question 8

How is Syphilis spread in rabbits

Answer 8

copulation and close contact

Question 9

What do you see with Syphilis in rabbits

Answer 9

Crusting lesions on the mucocutaneous junction of nose, lips, eyelids, genitalia and anus.

Question 10

Lust 9 common conditions that affect guinea pig repro tract

Answer 10

Testicular neoplasia
Spermatic plugs
Inguinal hernia
Orchitis
Uterine and ovarian neoplasia
Uterine prolapse
Pregnancy toxaemia
Ovarian cysts
Dystocia

Question 11

Describe how to diagnose ovarian cysts in guinea pigs

Answer 11

easily palpated on physical exam
confirm with ultrasound

Question 12

List the clinical signs of ovarian cysts in guinea pigs

Answer 12

hair loss over flank without pruritis
pear shaped
behavious - mounting/ aggression
lethargy, reduce appetite, discomfort when handled

Question 13

why do guinea pigs need to breed before 8 months of age

Answer 13

after 8 months the pubic symphysis will be unable to separate = dystocia.

Question 14

what normally happens when guinea pig gives birth

Answer 14

In the last week of pregnancy
Relaxin from pituitary and endometrium causes fibrocartilage of the pubic symphysis to disintegrate = pubic symphysis widens to 3cm

Question 15

What is the most common mammary tumour in guinea pigs

Answer 15

benign hyperplasia

Question 16

what is the most common mammary tumour in rats

Answer 16

fibroadenoma

Question 17

when is the ferret breeding season

Answer 17

march- september

Question 18

what is important to know about ferret ovulation

Answer 18

are induced ovulators
50% of ferrets will remain in oestrus unless mated

Question 19

what does prolonged oestrus in ferrets lead to

Answer 19

oestrogen-induced bone marrow toxicosis/hyperoestrogenism.
Results in pancytopaenia and eventually death.

Question 20

List 5 clinical signs of ferret persisitent oestrus

Answer 20

Swollen vulva
Pale mucus membranes
Symmetrical bilateral alopecia of flanks and tail
Petechiae and/or ecchymoses
Lethargy and anorexia

Question 21

what is different about ferret hyperadrenocorticism

Answer 21

HAC is related to sex hormones in ferrets
NOT cushings (no excess of glucocorticoids)

Question 22

List 3 suspected causes of ferret hyperadrenocorticism

Answer 22

> 12hrs day light hours (indoor ferrets)
Early neutering (never seen in entire ferrets)*
Genetic component

Question 23

Describe the mechanism that is thought to cause ferret hyperadrenocorticism

Answer 23

1. Ferret sex hormones produced by gonads mostly , but also in adrenals
2. when gonads removed, reduction in sex hormone production and -ve feedback removed
3. More FSH/LF released and adrenals take over producing sex hormones
4. Adrenal gland hyperplasia to produce more sex hormone
5. Uncontrolled sex hormone production= Hyperadrenocorticism

Question 24

List 5 clinical signs of ferret hyperadrenocorticism

Answer 24

Symmetrical/bilateral alopecia and ‘rat tail’
Vulvar swelling in neutered jills
Sexual behaviour in neutered hobs
Pruritus
Dysuria/urinary obstruction in males (prostate)
Mammary hyperplasia

Question 25

Describe how GnRH agonist work when treating ferret hyperadrenocorticism

Answer 25

Pulse release GnRH over a long period of time.
This desensitises GnRH receptors on the pituitary so less FSH/LH is produced.
So temporarily the clinical signs may worsen before desensitisation occurs.

Question 26

Describe the surgical treatment of ferret hyperadrenocorticism

Answer 26

Try and surgically remove adrenal gland- SOUNDS COMPLICATED AND HARD
Post-operative medical treatment for HAC required if partial adrenalectomy performed.

Question 27

Decsribe how to treat ferret persistent oestrus

Answer 27

In early oestrus:
- stimulate ovulation-hCG- takes 10 days to work
- GnRH agonist implant e.g. Deslorelin- takes couple of weeks to work

For severe oestrus
May need blood transfusion
spay but must stabilise first and causes HAC risk

Question 28

List 4 reproductive control options in ferrets

Answer 28

Keep females with a vasectomised hob to induce ovulation.
Leave entire and give a yearly ‘jill jab’ to bring females out of season (proligestone injections as soon as they come into heat).
Use the hormone implant to chemically neuter on its own (deslorelin).
Surgical spay???

Question 29

List 3 reproductive control methods in male ferrets

Answer 29

Vasectomised hobs.
Use the hormone implant to chemically neuter.
Castration???