Rodent Surgery Flashcards
Rodents URT anatomy ?
Have sepratae urinary and vaginal openings - can determine if discharge is from urinary or reprod tract
Scent glands ?
Ventral scent gland dwarf hamsters and gerbils vs FLNAK in syrian hamsters
What patient factos to consider in rodent surgery?
- Relatively small lung volume compared to body size
- Ideally elevate head -> reduces abdominal contnts pushing against diaphragm
Wha surgical equipment/ haemostasis considerations?
- Fine tipped equipment
- sterile cotton tip applicatos
- Artery forceps
HAEMOSTASIS in rodents?
in healthy animals total blood volume 7% of BW
- 10% of this can be drawn for blood sampling
- 0.5-0.7ml/100g max amount of blood loss
to calculate = each cotton tipped applicator holds 0.1ml blood
What initial assessment of rodents?
- Full CE
- Sabilise & get BW
- Pre-op assess - RR & HR
- Rodents don’t vomit => unnecessary to withold food &fasting inc risk of GI disturbanceds
- Minimise stress
Pain in rodents?
- Newcastle grimace scale - rats and mice
- Hunched? hiding?
-Belly pressing? - contracted abd muscles
- loss of appetite
- Chage of HR, RR and deph
surgical skin prep in rodents?
Iodine/chlorhex & good contact time
- Warm surgical scrub first
- Avoid excess alcohol due to evaporative losses
Iv placement where?
- caphalic/saphenous in GP
- Tail vein in rats
Intraosseous placement where?
- Femur -> through trochanteric fossa
- Tibia -> through tibial crest
What is fluid mainenance rate for most rodent species?
3-4ml/kg/hr
During surgery - considerations?
- HYPOTHERMIA! - warm theatre, bubble wrap, warm fluids,
- Prevent HYPOXIA! - oxygen admin
Post op considerations?
● Monitor & supportive care.
● Maintain body temperature
● Analgesia essential
○ Traumatising surgical site
● Fluid and nutritional support
○ Assist feeding ASAP.
● Therapeutic laser therapy
● Phovia
What reasons for skin surgery?
- Lump removal - neoplastic /cystic
- Absess surgery - thick, caseous material within a thick capsule
- wound management
- Scent gland hyperplasia/ neoplasia
Describe Trichofolliculoma in Guinea pigs
- usually located over the dorsum, may ischarge keratinous or haemorrhagic material from a central pore
- Surgical approach similar to lump removal
- excision curative
Describe Ventral sent gland tumour surgery in gerbils and dwarf hamsters ?
- In gerbils, neoplasia (SCC, adenomas, adenoCs)
- wide excision aroudn scent gland
- Most rodents have moderate to extensive amount of loose skin
Pregnancy prevention ?
- Sexual maturity in mice/ rats/ gerbils = 6-8 weeks
- sexual maturity in GP = 4-6 weeks (female) and 9-10 weeks (male)
Disease prevention for reproductive management ?
- significant reduction in mammary tumours developing if ovariectomy performed in rats before 90 days
What non surgical options of reproductive management?
- separation of sexes but welfare implications & fighting in same sex!
- Medical management (implants -> NOT effective, CI in GPs) & Hormonal injections (not effective)
What surgical approaches to neutering?
- Traditional, ventral abdominal midline
- Flank (GP and rats) -> bilat or unilar
- Combination approaches
What considerations for elective neutering ?
- Small nodular ovaries
- Ovaries locate dinf at
- Confilcting advice in lit regarding type of uterus tat some rodents have - clinically no difference
What advantages of Flank approach?
- Less invasive
- Quick recovery time
- Less risk of infection
- Less risk of suture disruption and complications
- Less risk of evisceration secondary to dehisence
- Bilat or unilat