16.8.4: Neutering in small mammals Flashcards
What suture material should you use in a rabbit and how should you close the skin?
- Use a monofilament suture material for ligatures, muscle, subcut and skin
- Avoid skin glue if possible
- Do intradermals rather than skin sutures - the rabbit and its friend may nibble at visible sutures
What should you remember when doing a scrotal castration in small mammals?
- If open technique: the inguinal ring is large so must be closed to prevent abdominal contents falling through
- Remove the large testicular fat pad alongside the testes
- Skin glue has to be used to close the skin because scrotal skin is hard to close
- This is not the preferred method of castration
What is the preferred method of castration in small mammals? Why is this?
Pre-scrotal or abdominal castration
Reduced chances of some post-op complications compared to scrotal castration e.g.:
* 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
Clinical signs of reproductive disease in small mammals
- Changes to body shape
- Pain e.g. gut stasis, reluctance to move or inappetence
- Discharge or genitalia changes e.g. pus, discharge, swollen vulva, crusts
- Fur loss/ changes
- Weight loss
- Changes to urination e.g. blocked or dysuria (prostate)
- Swellings/ masses e.g. enlarged mammary glands, neoplasia, hernias
- Prolonged labour e.g. dystocia
- Behavioural changes e.g. sexual behaviour, aggression
Common conditions in rabbits
- Testicular neoplasia
- Cryptorchidism
- Scrotal trauma - common between fighting males
- Inguinal hernia
- Uterine adenocarcinoma
- Pregnancy toxaemia
- Pseudopregnancy
- Syphilis
Prevention and treatment of uterine adenocarcinoma
- Ovariohysterectomy
- May need to wait to correct anaemia (due to bleeding) before taking to surgery
Clinical considerations before taking a rabbit with uterine adenocarcinoma to surgery
- Metastasises by direct contact, blood and lymph -> taken thoracic rads before surgery!
- Endometrial hyperplasia/ endometritis/ pyometra might be present
- Endometrial venous aneuryisms can cause potentially life-threatening haematuria
- Rabbits bleeding a little on the outside can bleed a lot on the inside. At the very least, take a PCV.
Causative agent and clinical signs of Syphilis
Treponema cuniculi (spirochete)
* Spread during copulation and close contact
* Presenting signs: crusting lesions on the mucocutaneous junction of the nose, lips, eyelids, genitalia, anus; can look similar to myxomatosis
* Zoonotic but not a major risk to humans
Common conditions in guinea pigs
- Testicular neoplasia
- Spermatic plugs
- Inguinal hernia
- Orchitis
- Uterine and ovarian neoplasia
- Uterine prolapse
- Pregnancy toxaemia
- Ovarian cysts
- Dystocia
Signalment and clinical signs of ovarian cysts
Signalment and diagnosis
* Common in entire female guinea pigs; can happen at any age
* Easily palpated on physical exam (care not to rupture); can confirm with ultrasound
* May have repeated history of ileus/ gut stasis over a few months
Clinical signs
* Hair loss over flanks without pruritus and with normal skin
* Pear shape
* Behaviour -> mounting, aggression
* Lethargy
* Reduced appetite
* Discomfort when handled
Causes of dystocia in guinea pigs
- If owner does not breed before 8 months old, pubic symphysis will be unable to separate -> dystocia
- Also caused by obesity, large foetuses, uterine inertia
Common conditions in chinchillas
- Fur ring -> paraphimosis
- Spermatic plugs
- Inguinal hernia
- Uterine neoplasia
- Pyometra
- Dystocia
Common conditions in gerbils
- Cystic ovaries
- Neoplasia
Common conditions in hamsters
- Cystic ovaries
- Neoplasia
- Pyometra (some creamy vulval discharge is normal following oestrus)
Common conditions in rats
- Pyometra
- Neoplasia e.g. mammary
Common conditions in hedgehogs
- Pyometra
- Neoplasia
What is the most likely cause of mammary masses in guinea pigs?
Benign hyperplasia most likely (if female). If male, more likely to be malignant.
What are the most common forms of mammary tumours in rats and how do they present?
Most common type = fibroadenomas
* Found anywhere on the body, even the spine
* Can become very large, ulcerate, and infiltrate locally -> poor QOL
* Ideally remove when they are small. These do not tend to metastasise
What forms of mammary tumours are most common in mice and gerbils?
Adenocarcinomas
* Highly malignant
* Metastasis common
* Poor prognosis
Are most mammary tumours in hamsters benign or malignant?
Benign
Common conditions in ferrets
- Testicular neoplasia
- Prostate hyperplasia
- Ovarian neoplasia
- Pyometra
- Pregnancy toxaemia
- Persistent oestrus
- Hyperadrenocorticism
Pathogenesis of persistent oestrus in ferrets
- Ferret breeding season = March-September
- Jills are induced ovulators and about 50% of them will remain in oestrus unless mated
- Prolonged oestrus results in oestrogen-induced bone marrow toxicosis / hyperoestrogenism
- This results in pancytopaenia and eventually death
Clinical signs of persistent oestrus in ferrets
- Swollen vulva
- Pale mucus membranes
- Symmetrical bilateral alopecia of the flanks and tail
- Petechiae and/or ecchymoses
