Small Animal Reproduction Flashcards
Describe the negative feedback system that occurs on the hypothalamus during sperm production.
- GnRH from hypothalamus to anterior pituitary
- Anterior pituitary produces FSH and LH
- FSH to testes Sertoli cells to produce sperm
- LH to testes Leydig cells to produce testosterone
What does testosterone do?
- Contributes to secondary male characteristics – stature, shape
- Sex behaviours – mounting, marking, roaming, competitive aggression towards other male dogs around females in heat
What are the key features of reproductive pattern in bitches?
- Mono-oestrous with an obligatory anoestrus
- Puberty – onset variable, mean 9 months age, little dogs begins earlier than larger dogs
- Fertility – peak reached at 2 years age
When are the phases of oestrous cycle in bitches?
- Pro-oestrus – 6 to 11 days
- Oestrus – 5 to 9 days
- Ovulation on day 3
- Luteal or progesterone (metoestrous is earlier and dioestrous is later) dominated phase – 56 to 60 days
- Anoestrus – months
Describe pro-oestrous in bitches.
- Rising levels of FSH inducing oestrogen secretion
- Haemorrhagic vaginal discharge and swelling of the vulva
- Attractive to males
- Playful behaviour but aggressive if dog attempts to mount
- Increased urine making
- Anxiety/agitation
What are the behavioural signs during oestrous in bitches?
- Bitch allows dog to mount
- Bitch presents her perineum to the dog and ‘stands’ with the tail deviated to one side
- Roaming/seeking/escaping to find a mate
- Competitive aggression towards other females
What happens during oestrous in bitches?
- Phase of increasing FSH levels, oestrogen spike which turns the anterior pituitary to secreting LH
- LH surge induces progesterone secretion from the ruptured follicle
- Ovulation occurs on average on day 3
- Vaginal discharge becomes clear, vulva stays swollen
How can you subjectively tell the optimal time to mate in bitches?
- Start of pro-oestrus to standing oestrus
- Maximal fertility is from the day of ovulation to up to 4 days after ovulation
- Vulvar softening
- Vaginal impedometry
How do you objectively tell the optimal time to mate in bitches?
- Hormone concentrations – oestrogen, LH, progesterone
- Vaginal cytology
- Vaginoscopy
When should you mate dogs?
- After ovulation – 48 hours for eggs to mature before they can be fertilised
- 12 hours after ejaculation fresh sperm cells are able to fertilise an egg
- Canine sperm cells can live for up to five days
- 2 matings (24 – 48hours apart) are recommended
Name the 2 surgical options for oestrous suppression in bitches.
Ovariectomy
Ovariohysterectomy
Name the 3 medical options for medical oestrous suppression.
Progestogens
Androgens
GnRH agonists
How does progestogen suppress oestrous?
Synthetic analogue of progesterone to trick bitch into thinking she is in luteal phase
How do androgens suppress oestrous?
Such as testosterone. Testosterone have no licensed preparations and are not used widely. Progesterone has severe side effects in bitches.
How do GnRH agonists suppress oestrous?
Only 60% of bitches respond to implant at pre-puberty at 12-16 weeks.
Name the 2 surgical options for management of male dog fertility.
Castration
Vasectomy
Name a medical management of male dog fertility.
Deslorelin acetate implant is a GnRH agonist
Describe how a Deslorelin implant affects male dogs.
Infertility is achieved from 6 weeks up to at least 6 months after initial treatment. Treated dogs should therefore still be kept away from bitches on heat within the first 6 weeks after initial treatment.
Describe how Deslorelin implant affects pre-pubertal bitches.
Temporary infertility to delay the first oestrus in intact and healthy sexually immature female dogs. Should be administered between 12 and 16 weeks of age.
How do Deslorelin implants affect male cats?
Temporary infertility and suppression of urine odour and of sexual behaviours such as libido, vocalisation, urine marking, and aggressiveness in intact male cats from 3 months of age
What are the causes of misalliance?
- Non-breeding female
- Wrong mate
- Under sized bitch/large dog
- Immature bitch
- Concurrent medical condition
What is the medical management option of misalliance?
Aglepristone (Alizin) is licensed. Most effective 10-14 days after mating – wait until end of oestrus
What are the physical and behavioural signs of pseudocyesis?
Physical – mammary glands, lactation
Behavioural – nest building, nursing
Describe the clinical presentation of pseudocyesis.
- Nest making and digging
- Listless/depressed
- Poor appetite or excessively hungry
- Collects toys to mother or ‘nurse’ them
- Restlessness
- Competitive aggression towards other dogs
How can pseudocyesis be managed?
- Prolactin inhibitor as prolactin drives clinical signs so may have to give early in luteal phase
- Surgical neutering once pseudocyesis resolved as neutering during these phases has much higher risks during surgery
- Will recur
What are the key characteristics of reproduction in queens?
- Seasonally polyoestrous related to daylight length – anoestrus (UK) is generally between Sept/Oct and Feb in the UK
- Puberty 5-11 months
- Peak fertility - 2-8 years
- Litter size 3-5
What are the properties of oestrous cycles in queens?
- No distinctive pro-oestrous
- Waves of follicle development – behaviour can appear continuous
- Induced ovulation – stimulation of vagina results in GnRH release and LH surge
- Inter-oestrous period variable, particularly if the luteal phase is not initiated by mating 8-15 days
What are the oestrous behaviours in queens?
Vocalisation
Restlessness
Rolling
Rubbing
Squat/submissive posture
What is the pregnant and non-pregnant luteal phase in queens?
Non pregnant luteal phase 25-45 days and pregnant luteal phase 65 days
How long does the corpus luteum secrete progesterone for in pseudopregnancy?
30-40 days
When is on the onset of puberty in toms?
5-11 months
What are the testosterone driven male secondary characteristics in toms?
Cheek pads
Stature
Urine pheromones
Roaming/aggressive behaviours
How is pregnancy diagnosed by abdominal palpation in queens?
From day 14 but peaks at 21 day for discrete lumps in uterus. Pinking of the nipples
How can pregnancy be diagnosed from a relaxin assay?
Commercially available, can from 24 days but advised at 30 days
How can pregnancy be diagnosed from imaging?
Ultrasound - from day 15-17
Radiography from day 35
What is the ovulation, implantation and gestation period of queens?
- Ovulation 24 - 36 hours after mating
- Implantation 14 days after mating
- Gestation 63-65 days
- Larger litters associated with shorter pregnancy length
How does pseudocyesis in queens differ to that in bitches?
- Unlike the bitch no increases in prolactin or relaxin
- Minimal clinical signs – mammary gland enlargement only
How long does each phase of parturition take in queens?
1 = 6-12 hours
2 = 4-16 hours, 42h if disturbed
3 = generally 10-15 minutes following kitten
How does cryptorchidism affect toms?
- Significance is the persistence of male behaviours – roaming, urine spraying
- May remain fertile
How is cryptorchidism in toms diagnosed?
Check for testosterone dependent penile spines. Testosterone assays possible but not commonly performed
How is cryptorchidism in toms treated?
No treatment proven to induce retained testicles to descend. Removal usually advisable - testes often remain functional
What is ovarian remnant syndrome in queens?
- Causes are surgical failure/re-vascularisation dropped remnant
- Common sites – ovarian pedicle, but can be cementum or peritoneal wall
- Retained tissue may be greater risk of neoplasia
How is ovarian remnant syndrome diagnosed?
- Signs of oestrous
- Vaginal cytology during oestrous
- Induce ovulation with GnRH, document progesterone levels 10-14 days after intramuscular injection
- Exploratory laparotomy – most rewarding if CL present, visible yellow tissue
How is abortion induced in queens?
Synthetic progestin. Rarely used and not advised due to high incidence side effects. No product licensed for abortion in cats
When does cystic endometrial hyperplasia and pyometra occur?
Often within 2 months of oestrous
What is the clinical presentation of cystic endometrial hyperplasia and pyometra?
Entire female
Vulval discharge
Abdominal distension
Anorexia, depression, dullness, pyrexia
PUPD less common
How is cystic endometrial hyperplasia and pyometra diagnosed?
- Leucocytosis and left shift, anaemia
- Hyperproteinaemia with hyperglobulinaemia
- Radiograph
- Ultrasonography
How is pyometra in queens treated?
- Surgical ovariohysterectomy
- Medical – PGF2 alpha or/in addition to Aglepristone
- With supportive care
What are the possible stages that could be of issue to fertility and abortion?
- Failure of oestrous – age, breed, oestrous signs
- Failure of mating – mating behaviour, male problem?
- Failure of ovulating – blood sample for progesterone 3-10 day safter mating, can ovulation be induced medically?
- Failure of fertilisation – PD positive?
- Failure of pregnancy – screen for infectious disease
- Failure of parturition – dystocia
When should you intervene in stage 1 of parturition in queens?
- Reduction in rectal temperature more than 12 hours previously and no signs of parturition
- Prolonged signs beyond 12 hours for no obvious stress related cause
- Passage of red-brown fluid from zonal placental separation
- Ultrasound suggestive of foetal death
- Dam dull/depressed/dehydrated
When should you intervene in stage 2 of parturition in queens?
- When active straining does not produce a kitten in 30 minutes
- When active straining ceases for greater than 2 hours or is infrequent over 4 hours
- Head/tail/leg visible during contractions but not progressing
- Passage of red-brown discharge without a foetus
- Depression/dullness of queen
What are the possible interventions for dystocia in queens?
Manual
Medical – oxytocin and calcium gluconate
Surgical – caesarean
What is the pattern of reproduction in queens?
Induced ovulators, polyoestrous and seasonal long day breeders
How does a cat in oestrous behave?
Sudden development of vocalisation and restlessness
When will a female cat first come into oestrous?
In spring as long as she is approaching 6 months
What is the optimal time after mating to palpate the abdomen and detect pregnancy in cats?
28 days
What blood test is performed in determine whether a female cat is spayed or to determine whether there is an ovarian remnant?
Progesterone levels after GnRH stimulation
If a queen is repeatedly diagnosed as pregnant by abdominal palpation but subsequently the pregnancies fail, which tests are most likely to be appropriate to find the cause of the infertility?
Routine haematology, FeLV and FIV screen
When should you intervene in stage 1 of pregnancy?
Prolonged signs beyond 12 hours, passage of red-brown fluid, dam dull and anorexic
When should you intervene in stage 2 of pregnancy?
Passage of red brown fluid without a kitten, dam dull and anorexic, when active straining does not produce a kitten in 30 minutes, when the queen stops strains for over 2 hours despite there being more kittens to be born
What are the clinical signs of prostatic disease?
Dysuria/stranguria
Urinary incontinence
Haematuria
Straining to pass faeces
Abnormally shaped faeces
Abdominal pain
Pyrexia
What is benign prostatic hyperplasia?
Palpable symmetrical prostatomegaly. Can see asymmetry due to combination of atrophy and hyperplasia
What are the clinical signs of benign prostatic hyperplasia?
Dysuria/stranguria
Urinary incontinence
Haematuria
Straining to pass faeces
Abnormally shaped faeces
(Pain
Pyrexia)
How is benign prostatic hyperplasia treated?
Delmadinone acetate injection
Deslorelin implant)
Osaterone acetate tablets
Surgical castration
What is the cause of prostatitis?
Bacterial infection
How is prostatitis diagnosed?
- Pain is the distinguishing sign to differentiate BPH from prostatitis
- Ultrasound shows changes consistent with BPH
- Cytology and culture of FNA or prostatic wash to see free bacteria or degenerative neutrophils
How is prostatitis treated?
Underlying BPH, antibiotics
What are the clinical signs of prostatitis?
(Dysuria/stranguria
Urinary incontinence
Haematuria
Straining to pass faeces
Abnormally shaped faeces)
Pain
Pyrexia
What is the cause of prostatic abscess?
Progression of prostatitis
How are prostatic abscesses diagnosed?
- Unwell, pain
- Doughy feel on palpation
- Loculations within parenchyma and hyperechoic/echo-dense fluid
- History/clinical exam
- Prostatomegaly
- Ultrasound
- Cytology/biopsy
- Culture and sensitivity
What are the clinical signs of prostatic abscess?
(Dysuria/stranguria
Urinary incontinence
Haematuria
Straining to pass faeces
Abnormally shaped faeces)
Abdominal pain
Pyrexia
What is needed to treat prostatic abscesses?
Antibiotics and castration alone ineffective, needs some kind of surgical drainage
Name 2 surgical drainage methods to treat prostatic abscesses.
Marsupialisation
Omentalisation
What is marsupialisation?
Involves a surgical procedure that creates an opening from a gland to the outside to allow drainage – so the infected prostatic fluid would drain through the body wall.
What is omentalisation?
Omentum acts as biological drain and has great vascular supply to bring nutrients to site.
Outline the approach to prostatic omentalisation.
- Dorsal recumbency
- Urethral catheter
- Caudal laparotomy
- Omental release
- Expose prostate and isolate with swabs so as not to spread infection
- Stab incision into the lateral aspect
- Digit exploration of cavities to break down pockets of cystic tissue and flush as much out as possible
- Forceps draw omentum into the ventral prostate
- Wrap the omentum around the urethra
- Secure with absorbable monofilament sutures
What causes prostatic cysts?
Retention cysts
Para-prostatic cysts
Associated with BPH/prostatitis/neoplasia
How are prostatic cysts diagnosed?
- Not painful – differentiating sign
- Signs more chronic
- Cyst may contain urine – ultrasound
- Biopsy to rule out neoplasia
Why is medical treatment mot typically chosen for prostatic cysts?
Leads to refill
How can prostatic cysts be treated surgically?
- If parenchymal and small, castration may be enough
- If not very large, perhaps drainage and castration might avoid more invasive surgery
- If it is possible to fully resect the cyst then omentalisation may not be required
Outline the approach to prostatic cyst resection and omentalisation.
- Dorsal recumbency
- Urethral catheter – do not want to damage this
- Caudal laparotomy
- Omental release
- Expose prostatic cyst
- Isolate with moistened lap swabs – assume there is infection so give pre-operative antibiotics and pack with swabs to prevent abdominal spread
- Resect as much of the cyst and capsule as possible
- Secure omentum to remaining capsule
What are the clinical signs of prostatic neoplasia?
Weight loss
Lethargy
Pain due to metastasis
Prostate painful firm and immobile.
Straining to pass faeces
Abnormally shaped faeces
Abdominal pain
Pyrexia
Caudal abdominal mass
How is prostatic neoplasia diagnosed?
- Prostatic signs and cancer signs, asymmetrical prostatomegaly
- Radiographs – metastatic, sometimes to bone of pelvis/lumbar spine
- Suction biopsy not FNA
How is prostatic neoplasia treated medically?
Meloxicam - pain relief and slows down growth
How can prostatic neoplasia be treated surgically?
- Cystostomy tube or urethral stenting
- Prostatectomy
Only increase MST by 6-9month, both can result in urinary incontinence
Name 3 developmental conditions of the scrotum and testes.
Anorchism/monarchism
Testicular Hypoplasia
Cryptorchidism
What may neoplasia of the scrotal skin and testicles present as?
- Asymmetrical enlargement/difference in architecture or texture
- With/without male feminising syndrome (development of mammary tissue) if functional tumour
- Cryptorchid – around 10 times risk for neoplasia
How is neoplasia of the scrotal skin and testicles treated?
- Closed castration
- Chemotherapy for the few cases with metastasis
What may Sertoli tumours present as?
- Feminising syndrome due to oestrogen secretion - alopecia, gynaecomastia, galactorrhea, pendulous prepuce, attractive to males
- Bone marrow hypoplasia and pancytopaenia
How may interstitial cell tumours present?
Almost always benign
How do seminomas present?
- Normally benign
- Androgen secretion more common
What causes orchitis and epididymitis?
Usually ascending infection (prostatitis, UTI) but can also be secondary to bites and/or via haematogenous spread
How may orchitis and epididymitis present?
Acute pain and swelling
Can result in abscess (testes/scrotum)
How is scrotal or testicular trauma managed?
- Remove damaged/necrotic tissue typically means debridement
- If testicle is exposed = castration
What is scrotal or testicular torsion associated with?
Associated with enlarged, neoplastic and abdominal testicles
Name 6 congenital abnormalities of the prepuce and penis.
Intersex
Hypospadia
Persistent penile frenulum
Congenital phimosis
Congenital paraphimosis
Preputial agenesis
What is the cause of ischaemic necrosis of the penis and prepuce?
Drug-related thrombosis
What is hypospadias?
- Failure of fusion of the urogenital folds and incomplete formation of penile urethra
- Abnormal termination of urethra
What are the clinical signs of hypospadias?
UTI
Urine scalding
Incontinence
What are the clinical signs of penile and preputial neoplasia?
Swelling/mass
Discharge
Prolapse
Haematuria/dysuria
How is penile and preputial neoplasia treated?
Amputation partial or complete, adjunctive therapies
How are penile lacerations treated?
- Minor lacerations heal by second intention
- Minor wounds in penile urethra managed with catheter
- More serious trauma will require primary reconstruction or partial or total penile amputation
Which breeds are predisposed to urethral prolapse?
Brachycephalics
What is the aetiology of urethral prolapse?
UTI or sexual excitement
What are the clinical signs of urethral prolapse?
Urethral mucosa protrudes from tip of penis, haemorrhage, may have dysuria
How is urethral prolapse treated?
Treat underlying cause and perform urethropexy
What are the clinical signs of phimosis?
Inability to urinate normally, impedes mating
How is phimosis treated?
Surgical correction to enlarge orifice
How is paraphimosis treated medically?
- Reduce size of penis and protect from trauma – sedatives, flush penis, lubricate
- Prevent recurrence – may need temporary purse-string
How is paraphimosis treated surgically?
- Narrowing of preputial orifice
- Enlargement of preputial orifice
- Preputial lengthening (preputioplasty)
- Phallopexy – keeping penis sutured back in so it can’t extrude out of prepuce only for non-breeding dogs.
- Penile amputation
What is the aetiology of priapism?
Parasympathetic stimulation via the pelvic nerve, typically secondary to spinal cord injury, thromboembolic occlusion or mass lesion
How is pregnancy diagnosed in the bitch?
- Abdominal palpation – day 28 in the bitch (and day 21 in queens)
- Ultrasound scan from day 20
- Blood samples – acute phase proteins or the hormone relaxin from day 21
- X-rays from 42 days when skeletons start to ossify
Why are behavioural signs not a reliable method of diagnosing pregnancy in the bitch?
Bitches have a progesterone dominated phase whether mated or not, mammary development, abdominal thickening, nest making.
What is the duration from time of service and duration of ovulation in the bitch?
Duration from time of service very variable (56-72 days)
Duration from ovulation 63 days (or fertilisation 61 days
How does litter size affect gestation length?
Large litters shorter gestation/born earlier
Small breed shorter gestation/born earlier
Why is it challenging to determine time of pregnancy in the bitch?
Oocysts are immature after ovulation and 1-2 days after ovulation mature and are viable for 2-5 days and perm is viable for 4-6 days. So makes it hard to determine time of pregnancy.
How can pregnancy in the bitch be medically terminated?
Antiprogestin
Antiprolactin - luteolytic
Prostaglandin
What are the possible problems during pregnancy in the bitch?
- Foetal death – stress, infection
- Premature parturition – still birth puppies, unknown
- Gestational diabetes – anti-insulin effects of progesterone mediated through growth hormone, often resolved at parturition. Needs managing occasionally if PUPD for example, caesarean as soon as puppies are healthy enough
- Pregnancy toxaemia – rare, characterised by ketosis, characterised in ruminants by poor nutrition in pregnancy. More common in large breeds with larger litters.
- Eclampsia
How are overdue pregnancies in the bitch managed?
- Assessment mammary glands – is lactation established?
- Abdominal ultrasound to confirm pregnancy and assess foetal heart rate (150bpm) and movement
- Plasma progesterone – abrupt decrease signals parturition, not done often
- Monitor daily around 68-69 days – check foetal viability
- 70 day limit regardless
Which behavioural changes can be used to predict parturition in the bitch?
- Restless
- Nesting behaviour 24-49 hours before whelping
- Shiver as body temperature drops
- Sudden drop in rectal temperature 10-14 hours before due to loss of progesterone which can be thermogenic.
How can the effects of relaxin be used to predict parturition in the bitch?
Changes in appearance perineum is subtle, appearance of abdominal musculature
How can diagnostic imaging predict parturition in the bitch?
Ultrasound – foetal size, head diameter
Radiography – ossification times for different areas if it was vital to predict time of parturition
What are the different presentations of puppies being born and their risks?
- Puppies present with their head towards the back of the dam, spine relative to maternal spine
- Up to 40% of deliveries are caudal with hindlegs behind
- Breech is generally normally presented and delivered okay, barring a few complications
- Lateral or ventral deviation of the neck is when issues start to arrive as head and shoulders must come through cervix at the same time.
What are the behavioural signs associated with stage 1 of labour in the bitch?
Restlessness
Nest-making
Shivering
Inappetance
Hiding/seeking reassurance
Panting
Occasional vomiting up to 24 hours
What are the behavioural signs of stage 2 and 3 of labour in the bitch?
Active and visible contractions of the abdomen
Recumbency or standing 10-30 minutes from onset of active straining to birth
Time between puppies/kittens up to 4 hours
What are the characteristics of dystocia in the bitch?
- Rectal temperature drop and return to normal with no evidence of labour
- Gestation is longer than 70 days
- Green vaginal discharge (placental separation) but no other signs of labour
- Strong contractions for longer than 30 minutes, with no pup produced
- Weak contractions for more than 4 hours with no pup produced
- More than a gap of 4 hours between pups
- Parturition has lasted 24 hours
- Systemic illness in the bitch
- Bitch in severe discomfort
What are the possible maternal causes of dystocia in the bitch?
Uterine inertia pelvic canal abnormalities
Intrapartum compromise, such as hypoglycaemia, hypocalcaemia, sepsis, shock.
What are the possible foetal causes of dystocia in the bitch?
Oversize
Malposition and malposture
Anatomical abnormalities
Malpresentation
How can dystocia cases in the bitch be managed?
- Oxytocin – increases frequency of contractions
- Calcium gluconate – increases the strength of contractions
- Dextrose infusion – for exhaustion/hypoglycaemia
- Manipulation
What are the indications for a caesarean section in the bitch?
- Failure to respond to medical management or manipulation
- Pelvic abnormality evident
- Foetal distress evident
When is foetal stress evident through heart rate?
Heart rate of less than 150bpm is consistent with stress
Less than 130bpm is foetus having poor survival if not delivered within 2-3 hours
Less than 100bpm foetus requires immediate intervention
What are the post-parturient care measures taken in puppies?
- Gentle body stimulation (rubbing) if doesn’t respond quickly to bitch licking or bitch disinterested
- Clear the airway
- Clamp and cut umbilicus
- Maintain body temperature
- Encourage suckling
When is haemorrhage normal and abnormal in bitch parturition?
Normal after each foetal delivery. Haemorrhagic discharge after whelping is abnormal
How is acute metritis characterised in the bitch?
Foul smelling vaginal discharge, green/black discharge if placental retention
What are the clinical signs of acute metritis in bitches?
Depression
Anorexia
Pyrexia
Dehydration
How is acute metritis treated in bitches?
Oxytocin if under 24 hours from end of parturition IVFT, antibiotics (amoxy-clav first line)
Ovariohysterectomy
Distinguish the aetiologies and treatments for uterine prolapse and rupture in the bitch.
Prolapse – excessive traction or straining, manual replacement, laparotomy and OVH
Rupture – large litters, multiparous dam, excessive oxytocin use, laparotomy and OVH
What is eclampsia?
- Hypocalcaemia
- Typically post-partum due to lactation demands
What are the predisposing factors of eclampsia in bitches?
- Small breeds and primiparous bitches at risk
- Inappropriate Ca supplementation in pregnancy, upsets homeostatic mechanisms needed for calcium release, hypoglycemia and hypothermia during parturition
What are the clinical signs of eclampsia in bitches?
Restlessness
Salivation
Facial pruritis
Progresses to:
Stiffness/ataxia
Recumbency/leg rigidity
Tachypnoea and tachycardia
Hyperthermia
How is eclampsia in bitches treated?
- Slow, intravenous calcium
- Oral supplementation then required
- Pups should be removed for 24 hours and fed artificially, then supplemented
What is agalactia?
Absence of milk - mammary disorder
Distinguish primary and secondary agalactia?
Primary = failure of mammary gland development
Secondary = failure of milk let down
What is agalactia associated with?
Presence metritis/retained membranes
Other maternal illness primiparous dams
Post-caesarean
Extreme stress
How should agalactia be managed in bitches?
- Oxytocin parenterally
- Supplement feed puppies
What are the clinical signs of mastitis in bitches?
Pyrexia
Anorexia
Dehydration
Painful firm mammary glands/gland/abscess, watery/blood stained/purulent secretions
How is mastitis treated in bitches?
- Warm compresses, stripping, massage, allow pups to suckle
- Amoxycillin clavulanate or trimethoprim/sulfadiazine empirically
- Pain relief – paracetamol
- If need to stop lactation – cabergoline
What are the reasons for castration in cats and dogs?
- Population control
- Management/behavioural modification - prevent roaming, male aggression, unwanted sexual behaviour, spraying in tom cats
- Infectious disease control
- Compliance with legal requirements (XL Bully legislation
- Prevention/treatment of disease - testicular disease, perineal rupture, perianal adenoma, prostatic diseases
- Control of hereditary diseases
What are the possible adverse effects of castration in dogs and cats?
- Weight gain
- Behavioural – nervous dogs may get worse after castration so may choose to not castrate and work with a behaviourist instead
- Consider temporary chemical castration trial
- Some evidence of increased risk of development of bladder and prostate cancer
- Delayed closure of growth plates with early neutering
What are the possible surgical complications of castration?
- Scrotal bruising/swelling
- Haemorrhage
- Infection and wound dehiscence from self-trauma
Distinguish open and closed castration.
Open – incise and peel away the vaginal tunic, ligatures placed around exposed blood vessels and vas deferens
Closed – tunic left intact, ligatures placed around outside of tunic (incorporating more tissue)
When is closed castration indicated in dogs?
Closed for testicular tumours. Closed is simpler, reduced risk of peritoneal contamination or herniation
When is open castration indicated in dogs?
Preferable for larger dogs - more secure ligatures
Outline the procedure of an open castration in dogs.
- Push testicle cranially out of the scrotum, hold firmly in a ‘claw grip’ and incise the skin over the top of the testicle.
- Incise through the fascia. Need careful control of depth of incision, and being able to identify different tissue types.
- Push the testicle through the skin incision.
- Incise through vaginal tunic. Control depth so that don’t cut into testicle itself.
- Break down the ligament of the epididymis (where vaginal tunic attaches) using haemostat/swab.
- Fully exteriorise the testicle by applying caudal and outward traction.
Outline the procedure of closed castration in dogs.
- Push testicle cranially out of the scrotum, hold firmly in a ‘claw grip’ and incise the skin over the top of the testicle.
- Incise through the fascia. Need careful control of depth of incision, and being able to identify different tissue types.
- Push the testicle through the skin incision.
- Break down the external fascia and fat using haemostat/swab
- Fully exteriorise the testicle by applying caudal and outward traction
What is the most important reason to push up the testicle and make your incision directly on top of the testicle, instead of incising skin first and then pushing up testicle afterwards?
Avoid accidentally cutting too deep and damaging structures under the pre-scrotal skin, such as the urethra.
Where are the ligatures during a canine castration placed?
Place 4 clamps. Tie 2x ligatures in the crush of the most proximal clamps. Cut between the 2 most proximal clamps
What must be considered with cutting between the most proximal clamps during a canine castration?
Check your ligated cord isn’t bleeding before releasing it. For open castrations, consider closing or ligating the tunic.
How is a castration in dogs closed?
- An intradermal pattern (less irritant) or external cruciate sutures (cheaper)
- Synthetic monofilament
- Non-absorbable
- Cutting/reverse cutting needle
Outline the procedure for an open feline castration.
- Incise over the testicle with scalpel blade, through the scrotum and the vaginal tunic. Keep your incision parallel to the intratesticular septum/raphe.
- Break down the ligament on the tail of the epididymis and strip the fascia away from the testicle.
- Break off the vas deferens close to the testicle to separate it from the blood vessels.
- Tie the vas deferens in a knot with the blood vessels (use a square knot with at least 4 throws). Cut the testicle off with the scalpel and tug the scrotum so the knot returns inside.
- Repeat for second testicle.
- The 2x scrotal incisions are left open, not sutured closed. Check that there’s no subcutaneous tissue poking through, then press the tissue edges together in apposition. Check the accuracy of your incisions – they should be parallel to the intratesticular raphe & similar length.
Why do we need to suture the skin closed for dog castrates but not for cat castrates?
- Smaller incision
- Tension skin in under. Pre-scrotal position in taught and stay open if not closed. Scrotal skin lacks tension so will stay in that position
What is the advantage and disadvantages of closed feline castration?
Advantage – quicker
Disadvantages – only 1 throw so less secure, uses a surgical instrument so added costs of autoclaving.
When does lack of testicular descent require surgery in cats and dogs?
Some testicles will descend late – still not present by 6m then surgery
How are cryptorchids classified by location?
Pre-scrotal, inguinal or abdominal
Why must cryptorchid testicles be removed?
Potentially a 10x increased risk of neoplasia
What is the inguinal surgical technique to cryptorchid castration?
- Stabilise and incise skin over testicle
- Ensure correctly identified testicle – often will be smaller/softer/abnormally shaped
- Ligate and close as normal
Similar to routine castration just needs additional incision at site of retained testicle.
What are the 2 possible approaches to abdominal cryptorchid castrations?
Ex-lap
Laparoscopy - best option, if available, as less morbidity than ex-lap
What are the advantages of laparoscopic removal of abdominal cryptorchid testes?
Less invasive
Less morbidity/tissue trauma
Less pain
Faster recovery
Improved visualisation
What is scrotal ablation?
Removal of the scrotum with the testes
When is scrotal ablation indicated?
- Old dog with very pendulous scrotum (risk of trauma)
- Testicular and/or scrotal neoplasia
- Trauma
- Treatment of haematoma/seroma/abscess following routine castration
Outline the approach to scrotal ablation in cats and dogs.
- Incise around the base of the scrotum (skin and fascia)
- Control haemorrhage
- Perform routine open or closed castration on the testicles
- You will need to break down the scrotal septum that separates the two testicles
- Routine closure of wound
What is the outcome of a vasectomy in cats and dogs?
Inhibits male fertility, but has no effect on behavioural patterns (roaming, aggression, marking) and no reduction in hormonally associated diseases, so is not recommended compared to castration
What is the approach to vasectomy in cats and dogs?
- Pre-scrotal incision
- Incise into vaginal tunic
- Locate ductus deferens, ligate and resect a small segment
What is the post operative care needed for male reproductive tract surgery?
- Post operative analgesia
- Prevention of self-trauma at incision site
- Restricted exercise – dogs: 10 day rest, short lead walks only. Cats: 3 days keep indoors and prevent jumping
Where should you make your incisions for routine canine castration?
Ventral midline cranial to the scrotum
30kg 2yo Rottweiler, closed castration – what suture is best for the ligatures?
Modified miller’s knot, absorbable monofilament, size 3M/2-0. Could also do surgeon’s knot, absorbable multifilament, size 3.5M/0.
You’re about to perform feline castration using the open hand-tie technique – what equipment do you need to prepare?
Scalpel blade only
What is an ovary sparing hysterectomy?
Surgical removal of uterus and cranial cervix only, ovaries left intact and functional
What are the advantages of an ovary sparing hysterectomy?
- Can perform on paediatric patients without affecting pubertal maturation
- Will still experience routine oestrous cycles and display enlarged vulva and be attracted to males but no bleeding
- Prevents pyometra, unsure about reduced risk of mammary cancer
What are the indications for bitch spays?
- Population control
- Control of hereditary diseases
- Owner convenience – not attracting attention from male dogs, not having to deal with oestrous bleeding
- Therapeutic procedure
Why may a bitch spay be a therapeutic procedure?
- Treatment and/or prevention of pyometra, glandular hyperplasia, torsion, prolapse, abortion, ovarian cyst, neoplasia
- Prevention of pseudopregnancy
- Reduced incidence of mammary tumours
management of diabetes and epilepsy
What have bitch spays been linked to increase risk of?
Urinary incontinence
Joint disease
Neoplasia
When should a bitch be spayed?
- Perform during anoestrous, avoid seasons as the uterus is more friable and at greater risk of haemorrhage
- Typically perform before 1st season at 6 months or 3 months after the end of a season.
- 3 months after end of season is to avoid false pregnancy, as prolactin usually settled down by then. Do not spay if still having a false pregnancy.
Why may a queen be spayed?
- Population control
- Behavioural: calling, roaming, fighting. Consider effect on injuries and disease transmission
What is the surgical landmark when doing a routine midline ovariohysterectomy?
Incise just caudal to the umbilicus.
What are the advantages of longer and shorter incisions when doing a spay?
Longer incision = easier to exteriorise and ligate, less trauma to tissues, less stressful to you
Shorter incision = quicker to close.
Which ligament do we have to stretch/break to help us exteriorise the ovary?
Suspensory ligament
Why must you first warn the anaesthesiologist when exteriorising the oavry in a spay?
In order to exteriorise the ovary, you need to stretch or break down the suspensory ligament – you may need to do this blind
Outline a midline ovariohysterectomy approach to a bitch spay.
- Dorsal recumbency
- Incision caudal to the umbilicus
- Locate uterus
- Work along the uterine horn until you find the ovary.
- Break the suspensory ligament to exteriorise the ovary
- Ligatures
- Cut with a scalpel between the clamps/just proximal to the ovary. Ensure you’re cutting away from yourself and away from your patient
- Grasp the pedicle with rat toothed forceps, release the final clamp, and gently lower the pedicle into the abdomen whilst checking for bleeding.
- Ligatures on the uterine body - 1 circumferential constricting ligature placed first most proximally. Then 1 transfixing ligature.
- Close
How should clamps and ligatures be applied in a bitch spay?
- 4x clamps (grey lines) proximal to ovary. Apply deepest first
- Tie ligature loosely where the clamp is then move the clamp and tighten in the crush
- Cut between the 2x most distal clamps
- Need to make a hold in the broad ligament through which you then apply clamps. Choose an avascular area.
What may have to be done to the broad ligament before ligation in a bitch spay?
Broad ligament can be fatty and vascular. You need to reduce some of this bulk so that you are not having to ligate the whole thing for your cervical pedicle.
How is a bitch spay closed?
- Linea alba – absorbable monofilament simple continuous or simple interrupted
- Subcutaneous – absorbable monofilament or multifilament in simple continuous
- Skin – either external nylon sutures or most common in practice is intradermals with an absorbable monofilament and swaged on reverse cutting needle
How do you identify the incision side of a flank approach to a cat spay?
Make a triangle between the wing of the ilium and the greater trochanter
What are the differences between a midline bitch spay and a flank cat spay?
- Everything is smaller – often only use single ligatures and no transfixing
- More chance of operating during or close to season – uterus can be friable. Ligate without clamping. Care when tightening ligatures not to shear through the tissue
- Smaller suture materials – 3-0 often ok
- Closure for flank – close muscles (don’t need to separate layers), subcutaneous layer, then skin (intradermal)
What are the advantages and disadvantages for a laparoscopic ovarioectomy for a cat spay?
More expensive
Faster return to normal activity
Reduced post op discomfort
What is the approach to a laparoscopic ovarioectomy?
- 2 or 3 ports (holes) into abdomen, through which instruments (forceps, cauteriser, camera) are inserted
- Abdomen inflated with CO2, camera provides magnification
- Blood vessels are cauterised rather than ligated
What analgesia is required for a spay?
- Opioid
- Local anaesthetic line block before skin incision, and/or splash block onto ligated pedicles
What is the post-operative care required for a spay?
- 5-day course of analgesia
- Buster collar or medical t-shirt
- Gentle tissue handling and suturing
- Restricted exercise
- Post-operative checks at 2 and 10 days, advice before reducing calorie intake to prevent weight gain
How long should spay patients be exercise restricted?
Traditional spay dogs: 10 days strict rest, no walks – only outside for toileting (on lead)
Lap spay dogs: less restrictive, can treat more like dog castrates
Cats: 10 days keep indoors and prevent jumping
What is needed for surgical preparation before a caesarean on a bitch or queen?
- Care with anaesthetic/analgesic agents
- Pre-oxygenate
- Anti-emetic
- Position to reduce emesis and aspiration
- Surgical clip and place IV catheter and give IVFT before give pre-med
- Keep in sternal/lateral for as long as possible
- Intubate
Why is speed important in a caesarean?
Aim to deliver pups as quickly as possible after induction of GA
How is a caesarean section done in a bitch or queen?
- Midline laparotomy – long incision from cranial to the umbilicus to near the pubis.
- Take care when incising the linea alba to avoid the distended uterus underneath
- Gently exteriorise uterus and pack lap-swabs around and under it to reduce spillage.
- No need to break suspensory ligament – already stretched
How is the incision from a caesarean in a bitch or queen closed?
Intradermal skin sutures recommended to avoid irritation to neonates
What are some surgical diseases of the ovaries?
Ovarian cysts
Neoplasia
Ovarian remnant syndrome *
Ovarian granuloma
Torsion
Name 2 ovarian congenital malformations.
Ovarian hypoplasia
Congenital ovarian cysts
What are the clinical signs of follicular cysts?
Persistent pro-oestrous (oestrogen) or none
What are the clinical signs of luteal cysts?
Persistent anoestrous (progesterone) or none
How are ovarian cysts treated surgically?
Ovariectomy
Ovariohysterectomy
What are the possible types of ovarian neoplasia?
Benign (haemangioma)
Malignant (haemangiosarcoma)
Metastatic lymphosarcoma with secondary metastasis to the ovary
What are the clinical signs of ovarian neoplasia?
Functional and non-functional. GCT secrete oestrogen so in constant oestrous.
How are ovarian tumours treated?
1 in 3 metastatic. Mostly the epithelial tumours so for these chemotherapy is recommended post OVE
What is the signalment for ovarian remnant syndrome?
Recent OVE/OVH, with/without haemorrhage at time of surgery
What is the aetiology of ovarian remnant syndrome?
- Human error – most commonly right sided
- Ectopic ovarian tissue – only reported in cats
- Auto-transplantation – touch ovary and then touch something else in the abdomen can transplant tissue
How is ovarian remnant syndrome investigated?
Vaginal swab
Imaging
Bloods for progesterone
Oestradiol
LH
How is ovarian remnant syndrome treated surgically?
Remove the ovarian tissue. Open or laparoscopic. May be worth waiting showing clinical signs if intermittent as can be difficult to find/imaging has not identified the exact site.
Name 6 developmental surgical diseases of the female reproductive tract.
Incornuate uterus
Hypoplasia
Agenesis
Segmental aplasia
Septate uterine body
Congenital uterine cysts
Name 4 metabolic surgical diseases of the female reproductive tract.
- Mucometra (Hydrometra) rare but may be unrecognised as similar appearance to pyometra
- Pyometra with/without rupture
- Cystic endometrial hyperplasia
- Prolapse, associated with parturition
What are the species differences in neoplasia of the female reproductive tract in small animals?
- Various tumours, very rare in dogs, more common in cats
- Uterine adenocarcinoma very common in rabbits and a very important reason to recommend spay
What is the signalment of pyometra?
Typically within 2 months of oestrous, post-oestrous, middle aged and entire. Tell clients if there is a 6 week or a 3 week and followed by another 3 week oestrous, signs of pyometra
What is the aetiology of pyometra?
Cystic endometrial hyperplasia, ascending bacterial infection. E.coli, Streptococcus invading a uterus with hyperplastic endometrium. Depends on how perfuse vaginal discharge is and if cervix is open/closed whether or not septicaemia is caused.
What are the possible clinical signs of pyometra?
PUPD
Lethargy
Abdominal distension
Vulval discharge
Collapse/septicaemia – seen with MODS/SIRS and uterine rupture leading to peritonitis
Closed or open cervix
Or none
How is pyometra diagnosed?
- Bloods to check secondary, systemic effects on renal function, lymphopaenia/anaemia and immune system
- Radiographs or ultrasonography (easiest if cervix closed). Look for signs of peritonitis
How does pyometra treated differ when the cervix is closed or open?
- Closed cervix = stabilise, assess for risk of rupture and take to surgery promptly
- Open cervix = surgery can definitely wait for stabilisation
What is the surgery and the risk of surgery for treating a pyometra?
Ovariohysterectomy. Everything can be very friable so rupture during surgery a risk which can lead to peritonitis
How can pyometra be medically managed?
Combination of antibiotics and prostaglandins, dopamine agonists or progesterone receptor blockers. Recommended to breed immediately post-pyometra
What are the possible complications of pyometra?
Endotoxaemia - peritonitis, uveitis, myocarditis
Peritonitis from rupture
MODS/SIRS
How can pyometra be cured?
Full ovariohysterectomy
What are the most common types of uterine neoplasias in small animals?
Leiomyoma
Adenocarcinoma is most common malignancy
Uterine tumours very common in rabbits
How is a uterine prolapse treated in small animals?
Ovariohysterectomy laparotomy
What are 3 possible aetiologies of uterine rupture in small animals?
- Huge pyometra leading to peritonitis
- Large litters with thinning of uterine wall
- Excessive use of ecbolics (Oxytocin)
List the surgical diseases of the small animal vagina.
- Persistent hymen/vaginal strictures (uncommon)
- Rectovaginal fistulae (rare)
- Vaginal Prolapse
- Vaginal hyperplasia
- Juvenile vaginitis
What can vaginitis be secondary to in small animals?
Anatomical abnormalities
Trauma
UTI
Ectopic ureters
Uterine disease
How can vaginal prolapses be differentiated from type 3 vaginal hyperplasia?
Being unable to pass a finger between vaginal wall and the prolapse.
What is the aetiology of vaginal hyperplasia?
Vaginal oedema during follicular phase with fibroplasia cranial to the urethral papilla
How can vaginal hyperplasia be treated medically?
- Analgesia – epidural if any straining
- Protect tissue from trauma
- Topical antibiotics
- With/without urinary catheter if there is an issue with papilla
- Replace tissue
How can vaginal hyperplasia be treated surgically?
- Temporary vulval suture(s)
- OVE/OVH
- Vaginal resection rarely required
What can indicate vaginal neoplasia on a clinical exam?
Perineal bulging
Vulval discharge
So rule out things like perineal hernia, pyometra
How can benign vaginal neoplasia be treated surgically?
- Episiotomy to expose the vagina
- Urethral catheter identifies and protects the urethra from damage during surgery
- Vaginectomy
- With/without OVE/OVH
How does a vaginectomy differ between intraluminal and extraluminal masses?
Intraluminal mass – within vaginal wall, dissect away
Extraluminal – pedunculated mass on a stalk, ligation of the pedicle sufficient as benign
What are the indications for an episiotomy in small animals?
- Excise vaginal masses
- Repair lacerations/strictures of vagina/vestibule
- During parturition
What is the approach to an episiotomy?
- Midline incision
- Non-crushing forceps either side
- Full thickness incision
- Close in 3 layers: a) vaginal mucosa closed with simple continuous pattern, b) vaginal muscle and subcutaneous in 2nd layer, c) perineal skin in 3rd
What are the surgical diseases of the vulva?
- Developmental – juvenile vulva
- Inflammatory – vulval fold pyoderma
- Traumatic
What is the aetiology of juvenile vulva?
Failure of development of external genitalia, associated with early spay and obesity
What are the clinical signs of juvenile vulva?
Local dermatitis
UTI
How is juvenile vulva treated?
Episioplasty/vulvoplasty
List the surgical diseases of mammary glands in small animals.
- Supernumerary nipples, inverted nipples, nipple hyperplasia
- Asymmetry
- Pseudopregnancy
- Fibroepithelial hyperplasia
- Tumours
- Oestrogen-secreting gonadal tumours
- Mastitis (surgery only if gangrenous)
- ORS
What are the small animal species differences in mammary anatomy?
Cats – 4 pairs
Dogs – 5 pairs (3rd is the extra)
Describe mammary blood supply in small animals.
Blood supply comes from either cranial or caudal. In cats also have anastomoses between left and right sides
- Lateral thoracic
- Internal thoracic
- Cranial superficial epigastric
- Caudal superficial epigastric
Describe mammary lymphatic supply in small animals.
Lymphatics also run either cranially or caudally. Axillary LN and superficial inguinal LNs.
How are fibro-adenomatous hyperplasias treated?
- Stabilise medically but can self-resolve
- OVE/OVH with/without mastectomy
- Best to remove endogenous progesterone as well
What are some red flags of mammary neoplasia in small animals?
- Rapid growth
- Local infiltration/fixation
- Inflamed excessively
- Size
- Lymph node involvement
- In cats, if more large number of glands involved
What is a mammectomy?
Lump and some normal mammary tissue but not the whole gland
What is a simple mastectomy?
- Isolated to one gland
- If mass is central or most of gland affected
How is a regional masectomy done?
- Lateral 1-2cm margins
- Deep margin to fascia of rectus sheath (no need to remove unless tumour is invasive/fixed)
- Control bleeding coming from caudally or cranially according to which gland(s) affected
What is a radical masectomy?
- Lymph nodectomy – drain
- In cats radical mastectomy also going to require body wall resection if have curative intent
What are the species differences when surgically removing mammary neoplasia in small animals?
If a dog, remove when its under 2cm
If a cat take it out as early as possible