Small Mammal Repro Flashcards
How do rabbit and rodent repro tracts differ to other animals? What implication does this have?
- open inguinal canals -> potential risk of herniation
- close tunic etc. when operating
Reasons for neutering small mammals?
- avoid pregnancy
- behavioural (fighting, mounting)
- smell
- avoid repro disese
What is the correct neutering technique for rabbits?
- prescrotal/scrtoal
- open/closed
> no correct, everyone has different approaches
What age can castration be performed?
4 months with both testes fully descended
What should be carried out prior to castrating rabbit?
- full clinical exam (sex, concurrent disease)
- anaesthesia
- clip and prep surgical site (skin thin and tears easily)
- technique of your choice
Outline the steps of castrating a rabbit
- Immobilise testes (prevent testes dissapearing up inguinal canal into abdomen)
- incise through skin and tunic (on testes)
- exteriorise testicle and break down attachment between tunic and skin (as open method)
- clamp tunic and place transfixing monocryl ligature proximally (as closed method)
- incise between clamps, check for bleeding and GLUE (not suture)
Main post-op complications of castrating rabbits and rodents?
- herniation (2 ligatures to prevent this)
- infection
How are rabbit spays different to other animals?
- 2 uterine hrons and 2 cervices
- no uterine body
- fat +++ in broad ligament
What age are rabbits spayed at?
5-6 months
Outline steps of spay op in rabbits
- 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)
Why should you be cautious when incising for rabbit spay?
- ceacum and bladder v close
Post spay problems?
- adhesions
- GI stasis
How may tissue adhesion risk be lowered?
- 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)
How can GI stasis be avoided?
RInitidine GI stimulant started preop
When should you start syringe feeding a rabbit post op?
- if not eating 2-4 hours after recovery
How soon after castrating a rabbit is it safe to mix him with an entire female?
6 weeks!
Should rabbits be kept in after operations?
- if quiet hospital keep in to monitor eating and poassing feaces
- if busy and stressfull send home with meloxicam
Are rabbits prone to uterine disease?
- 79% animals develop uterine adenocarcinoma in entire animals!
What type of tumour is uterine adenocarcinoma?
- slow growing so may not be noticed
- slowly metastasising (liver and lungs)
- potentially extrememly painful
- clinical signs
> lethargy
> weight loss
> aggression
If spaying an old rabbit what should be done first?
Radiograph chest to check for mets as very liekly to be there already
What is the average age of onset of uterine adenocarcinoma in rabbits?
4-5 years
What is a common problem in rodent castrates?
- 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
What age should guinaepig castration be carried out?
3-4 months
How do hystricomorphs scortums differ to other animals?
not well developed scrotum
What age can rats be castrated?
3 months
What is the post common post-op complication for rats?
- chewing off sutures!
- > build little busta colalrs
Pros of recommending spaying rodents?
- preventing pregnancy (but can castrate)
- prevents dystocia in older guinae pigs
- prevents cystic ovaries in guinaepigs
- prevents mammary tumours in rats
Cons of recommending spaying rodents?
- technically challenging op
- midline spay invasive
What is the most common repro abnormality of female guinae pigs over 2-3 years?
> cystic ovaries
- painful
- gradual onset flank alopecia
- abdomen distended
- masses palpable
Is it more difficult to spay guinaepigs with cystic ovaries?
- technically easier as overies bigger
- may be systemically ill due to anorexia
Which disease is common in rats?
- 90% rats develop mammary tumours (fibroadenomas)
- can occour in males too
- good prognosis if compeltely resected but difficult to resect witohut recurrence
How may mammary tumours be prevented?
Spaying
When do female ferrets come into oestrus?
Spring
What type of ovulators are ferrets?
Induced
What does lack of mating in ferrets cause?
Hyperoestrogenism and oestrogen toxicity
- > vulval swelling, anorexia, lethargy
- > severe anaemia, neutropenia, thrombocytopenia
- can bleed out and die
Tx of hyperoestrogenism in ferrets?
- 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)
How can you control ferret smell?
- castration (during breeding season so testicles larger and descended)
- deslorelin implants
Which species is ferret spaying similar to?
Cats
What are the disadvantages to neutering ferrets?
- disruption normal hormonal cycle predisposes to hyperadrenocorticism
- deslorelin implant should be considered at same time to prevent this
