Small Mammal Repro

Question 0

How do rabbit and rodent repro tracts differ to other animals? What implication does this have?

Answer 0

• open inguinal canals -> potential risk of herniation

- close tunic etc. when operating

Question 1

Reasons for neutering small mammals?

Answer 1

1. avoid pregnancy
2. behavioural (fighting, mounting)
3. smell
4. avoid repro disese

Question 2

What is the correct neutering technique for rabbits?

Answer 2

• prescrotal/scrtoal
• open/closed
  > no correct, everyone has different approaches

Question 3

What age can castration be performed?

Answer 3

4 months with both testes fully descended

Question 4

What should be carried out prior to castrating rabbit?

Answer 4

1. full clinical exam (sex, concurrent disease)
2. anaesthesia
3. clip and prep surgical site (skin thin and tears easily)
4. technique of your choice

Question 5

Outline the steps of castrating a rabbit

Answer 5

1. Immobilise testes (prevent testes dissapearing up inguinal canal into abdomen)
2. incise through skin and tunic (on testes)
3. exteriorise testicle and break down attachment between tunic and skin (as open method)
4. clamp tunic and place transfixing monocryl ligature proximally (as closed method)
5. incise between clamps, check for bleeding and GLUE (not suture)

Question 6

Main post-op complications of castrating rabbits and rodents?

Answer 6

• herniation (2 ligatures to prevent this)

- infection

Question 7

How are rabbit spays different to other animals?

Answer 7

• 2 uterine hrons and 2 cervices
• no uterine body
• fat +++ in broad ligament

Question 8

What age are rabbits spayed at?

Answer 8

5-6 months

Question 9

Outline steps of spay op in rabbits

Answer 9

• make incision midway between umbilicus [may not be visualised] and pubic symphis
• > go just cranial to last pair of nipples
• exteriorise repro tract, handle gently as tissue is friable
• ligate ovaires and broad ligament (usually full hysterectomy)
• ligate blood vessels (may be more than in dog)
• transfixing ligature distal to cervices cranial to urethra (ligate as close to cervices as possible)

Question 10

Why should you be cautious when incising for rabbit spay?

Answer 10

• ceacum and bladder v close

Question 11

Post spay problems?

Answer 11

• adhesions

- GI stasis

Question 12

How may tissue adhesion risk be lowered?

Answer 12

• gentle and minimal tissue handling (don’t go back in to check pedicles)
• keep tissues moist
• appropriate suture material choice (PDS, monocryl, NOT catgut)
• NSAIDs 5d postop - start just pre-surgery (meloxicam)

Question 13

How can GI stasis be avoided?

Answer 13

RInitidine GI stimulant started preop

Question 14

When should you start syringe feeding a rabbit post op?

Answer 14

• if not eating 2-4 hours after recovery

Question 15

How soon after castrating a rabbit is it safe to mix him with an entire female?

Answer 15

6 weeks!

Question 16

Should rabbits be kept in after operations?

Answer 16

• if quiet hospital keep in to monitor eating and poassing feaces
• if busy and stressfull send home with meloxicam

Question 17

Are rabbits prone to uterine disease?

Answer 17

• 79% animals develop uterine adenocarcinoma in entire animals!

Question 18

What type of tumour is uterine adenocarcinoma?

Answer 18

• slow growing so may not be noticed
• slowly metastasising (liver and lungs)
• potentially extrememly painful
• clinical signs
  > lethargy
  > weight loss
  > aggression

Question 19

If spaying an old rabbit what should be done first?

Answer 19

Radiograph chest to check for mets as very liekly to be there already

Question 20

What is the average age of onset of uterine adenocarcinoma in rabbits?

Answer 20

4-5 years

Question 21

What is a common problem in rodent castrates?

Answer 21

• testicles very easily retracted into abdomen
  > though large fat pad present to prevent herniation
• higher chance of post-op infections (sit in their own urine/feaces, testes right next to anus)
  > give prophylactic ABx

Question 22

What age should guinaepig castration be carried out?

Answer 22

3-4 months

Question 23

How do hystricomorphs scortums differ to other animals?

Answer 23

not well developed scrotum

Question 24

What age can rats be castrated?

Answer 24

3 months

Question 25

What is the post common post-op complication for rats?

Answer 25

• chewing off sutures!

- > build little busta colalrs

Question 26

Pros of recommending spaying rodents?

Answer 26

• preventing pregnancy (but can castrate)
• prevents dystocia in older guinae pigs
• prevents cystic ovaries in guinaepigs
• prevents mammary tumours in rats

Question 27

Cons of recommending spaying rodents?

Answer 27

• technically challenging op

- midline spay invasive

Question 28

What is the most common repro abnormality of female guinae pigs over 2-3 years?

Answer 28

> cystic ovaries

• painful
• gradual onset flank alopecia
• abdomen distended
• masses palpable

Question 29

Is it more difficult to spay guinaepigs with cystic ovaries?

Answer 29

• technically easier as overies bigger

- may be systemically ill due to anorexia

Question 30

Which disease is common in rats?

Answer 30

• 90% rats develop mammary tumours (fibroadenomas)
• can occour in males too
• good prognosis if compeltely resected but difficult to resect witohut recurrence

Question 31

How may mammary tumours be prevented?

Answer 31

Spaying

Question 32

When do female ferrets come into oestrus?

Answer 32

Spring

Question 33

What type of ovulators are ferrets?

Answer 33

Induced

Question 34

What does lack of mating in ferrets cause?

Answer 34

Hyperoestrogenism and oestrogen toxicity

• > vulval swelling, anorexia, lethargy
• > severe anaemia, neutropenia, thrombocytopenia
• can bleed out and die

Question 35

Tx of hyperoestrogenism in ferrets?

Answer 35

• stabilise (blood transfusions if necessary)
• spay
• hormones tx
  > jill jab (proligestone, given in spring as breeding season starts, may need repeating 2-3x/season)
  > deslorelin implant (GnRH agonist, repeat q18-24 months, consider sedation, initial signs of oestrus will be seen, expensive)

Question 36

How can you control ferret smell?

Answer 36

• castration (during breeding season so testicles larger and descended)
• deslorelin implants

Question 37

Which species is ferret spaying similar to?

Answer 37

Cats

Question 38

What are the disadvantages to neutering ferrets?

Answer 38

• disruption normal hormonal cycle predisposes to hyperadrenocorticism
• deslorelin implant should be considered at same time to prevent this