Neutering and Reproductive Disease in Small Mammals Flashcards
Why would you perform an ovariohysterectomy in small mammals?
- Prevent unwanted litters e.g. siblings, pelvic closure in guinea pigs.
- Protect against common diseases of reproductive tract
- Allow for rabbit pairing (male and female) and for groups of animals to live together e.g. singular male guinea pig with many females.
Why would you perform castration in small mammals?
- Prevents unwanted litters
- Prevent spraying
- Can help with aggression?
- Allow for rabbit pairing (male and female) and for groups of animals to live together e.g. singular male guinea pig with many females.
- Protect against common diseases of reproductive tract?
Why would you not want to perform an ovariohysterectomy or castration in small mammals?
- Risk of general anaesthetic?
- Ferrets -> related to disease!
How do you perform an ovariohysterectomy in rabbits and guinea pigs?
- Abdominal approach between the umbilicus and pubic symphysis (Incision 2cm long, midway between umbilicus and pubic symphysis.)
- Careful tissue handling, especially with the gut – adhesions easily formed.
- Haemostatic clips or suture to ligate.
- Always use intradermal sutures to close skin – they nibble and their friends nibble!
- Monofilament suture for ligatures, muscle, sub cut and skin. Avoid skin glue if possible.
- The surgery itself is the same method as cats and dogs.
- Rabbits have two cervix but this doesn’t change what you do.
- They can be hard to locate the uterus if they are young. Tip is to look for the fat attached to the reproductive tract – more dense than other body fat.
What methods are available for castrating small mammals? Which one should you use for each species?
- Scrotal (open or closed)
- Pre-scrotal (open or closed)
- Abdominal
How do you perform scrotal castration in small mammals? Why is it not a preferred method?
- Similar to a cat, except that the inguinal canals must be closed if an open technique is used.
- 1 to 1.5cm incision made through the skin and vaginal tunic ventrally on both sides of the scrotum, parallel to penis.
- Testis is removed from the tunic and ligatures placed.
- The large testicular fat pad is removed as well with the testes.
- Skin glue to close, sutures difficult in scrotal tissue.
Disadvantages - It increases the chances of some post op complications:
* Wound breakdown
* Infection/Abscessation
* Scrotal haematoma/self trauma
* Gut stasis/ileus
How do you perform pre-scrotal castration in small mammals?
- Similar to a dog, except open inguinal ring!
- Single midline incision cranial to the scrotum and each testicle is pushed up to it.
- Except, some rodents have a penis that is positioned cranial to the testicles. In these cases a pre-scrotal technique cannot be performed with a single midline incision like in rabbits. Instead, two parallel incisions are made slightly lateral to the midline.
How do you perform abdominal castration in small mammals?
- One midline incision going through linea alba (at the cranial pole of the bladder)
- Testicle is pushed up into the abdomen from the scrotum. The testicle is then visualised from the abdomen and exteriorised.
- The tail of the epididymis is dissected from the everted hemiscrotal sac to exteriorise.
- Tunic closure is the same with all three techniques.
Why are pre-scrotal and abdominal castration techniques preferred?
It reduces the chances of some post op complications because:
* One incision instead of two.
* Wound is further away from the ground so infection is less likely.
* Less sensitive skin so self-trauma less likely.
* Can suture the skin closed so you can avoid using itchy skin glue.
What clinical signs are associated with reproductive disease in small mammals?
- Changes to body shape, weight loss
- Pain e.g. gut stasis, reluctance to move or inappetence
- Discharge or genitalia changes e.g. puss discharge, swollen vulva, crusts, blood.
- Fur loss/changes
- Changes to urination e.g. blocked or dysuria (prostate)
- Swellings/masses e.g. enlarged mammary glands, neoplasia, hernias
- Prolonged labour e.g. dystocia
- Behaviour changes e.g. sexual behaviour, aggression.
What are common reproductive conditions in rabbits?
- Testicular neoplasia
- Cryptorchidism
- Scrotal trauma
- Inguinal hernia
- Uterine adenocarcinoma
- Pregnancy toxaemia
- Pseudopregnancy
- Syphilis
What clinical considerations are important to take into account with uterine adenocarcinomas in rabbits?
- Commonly accepted to have an 80% incidence in does > 4 yrs old.
- Metastasise by direct contact, blood and lymph
- Endometrial hyperplasia/endometritis/pyometra might be present
- Endometrial venous aneurisms causes potentially life-threatening bleeding
What is this an example of?
Uterine adenocarcinoma
What causes syphilis in rabbits? How is it spread? What clinical signs are associated?
- Caused by the spirochete, Treponema cuniculi.
- Spread during copulation and close contact.
- Crusting lesions on the mucocutaneous junction of nose, lips, eyelids, genitalia and anus.
What are common reproductive conditions in guinea pigs?
- Testicular neoplasia
- Spermatic plugs
- Inguinal hernia
- Orchitis
- Uterine and ovarian neoplasia
- Uterine prolapse
- Pregnancy toxaemia
- Ovarian cysts
- Dystocia
