Reproduction of small animals Flashcards
Disorders of the oestrus cycle of the bitch - Abnormal length
Oestrus should occur after puberty around 6-7 months of age
Primary anoestrus occurs when there is no induction of first ostrus due to hypogonadism or hypopituitarism
Secondary anoestrus is when first oestrus has occurred but there is no subsequent oestrus. (Increased time between cycles)
-Endogenous causes: hypothyroidism, hypoadrenocorticism, obesity or luteal cysts
-Exogenous causes: Progestagens, androgens, steroids
T:Cabergoline –> dopamine receptor (D2) agonist –> INCREASED dopamine –> increased GnRH + inhibits prolactin
Split oestrus
Absence of, or depressed oestrus signs after a physiological prooestrus.
If prooestrus occurs again within 4 weeks usually next cycle is normal (hence split)
Multiple occurences: hypothyroidism, premature luteolysis
Shortened interoestrus interval
Anoestrus <2 months, usually causes repetition of oestrus however unlikely all cycles are fertile (low LH and no ovulation)
Causes: overstimulation of ovaries - follicular cysts
Premature dip in progesterone during dioestrus
Prolonged oestrus 9 days - physiological >21 days - prolonged Caused by lack of ovulation Follicular cysts Signs of oestrus >21 days (mating behaviour) Dx: Vaginal cytology T: OVH, GnRH/hCG
Induction of oestrus in bitches and queens
Indications
- Pathological anoestrus
- Hunting or show
- Cushing’s
- Hypothyroidism
- AI
Non-pharmacological - Dormitory effect (pheromones)
Pharmacological
- GnTH agonists
- Gonadotrophs - FSH/LH
- Oetrogens - endogenous gonadotrophs
- Dopamine agonist - Prolactin (Cabergolin) - given at anoestrus to induce prooestus
Deslorelin (GnRH agonist) implants - does induce oestrus, however pregnancy usually fails at day 40 due to CL regression due to reduced LH.
Prevention of the breeding in the female (medical approach)
Synthetic P4 antagonist Aglepristone - Short term: give before prooestrus - Long term: give in anoestrus - Total: just after prooestrus -Long term use can cause iatrogenic E2 + P4 --> reduces tissue sensitivity to insuln
P4 analouges
MPA (methyhydroxyprogesterone acetate) - Long acting
MA (Megestrol acetate) - Short acting
Testosterone (mibolerone - CI’ed in cats) –> lengthens anoestrus
Desloreln (GnRH agonist) –> constant secretion supresses
Unwanted mating and pregnancy termination
Indications Health -Single puppy syndrome -Mismatched breeds (small + large) -Age (<1 year, >8 tear) - dystocia
Breeding
- Incorrect partner (pedigree)
- Unwanted
Vaginal stricture + pelvic pathology
Medical
- Pregnancy ketosis/DM
- Fibroadenomatosis
Cryptorchids - termination
Pregnancy testing
- Vaginal smear - cytology
- Serum biochemistry - relaxin (28 days after ovulation)
- presence of sperm vagina (<24 hours)
Surgical
OVH
-Oestrus –> ris kof haemorrhage
-Dioestrus –> pseudopregnancy
Aglepristone (P4 antagonist)
-decreases P4 activity
Oestrogens - inhibit P4
PG’s - Luteolysis
- -> “Dinoprost”
- -> “Cloprostenol”
Stages of termination
- 30-35 days: reabsorption
- 35 days: Surgical removal of foetus (abortion)
- 45 days: Not recommended (due to ossifiction)
Drugs acting of pituitary
Dopamine agonist (cabergoline)
-Increased dopamine –>
GnRH antagonist –> decreased GnRH
CCS - decreased GnRH
Pregnancy loss (embronal and foetal mortality)
Embryonal death –> <30 days
Foetal death –> 30-35 days
Non-infectious
Hypoleuteoidism
-Embryo in P4 dependant
-Any prostaglandins –> luteolysis
Premature parturition
- Related to hypoluteolism
- Reabsorption/abortion
Myometrial activity
-Prostaglandins released –> 2nd luteolysis + foetal disstress
Mycotoxins
- Zearalenone
- Aflatoxin
- Fusarium
- Ochratoxin
Nutritional + status
-Vit B1
Stress –> cortisol –> foetal distress
Congenital disorders
- Hydrops
- Hydroallantosis
- Cerebral dysplasia
Infectious Bacterial -Brucella canis -Salmonella -Listeria -E.Coli -Mycoplasma
Viral
-Canine herpes - placental necrosis
<30 days - resorption
Last three weeks - Abortion
Canine parvo
-Absorption/stillbirth
Parasites
- Toxoplasma gondii - hydrocephalus + calcification
- Neospora caninum
Cs: If absorped before decection - no cs
Dx: Serum P4 + PM, vaginal bleeding
Abortion + dam exam
Abortion is loss of pregnancy
Embryonic death - <30 days
Foetal death - >30-35 days
Types
Abortion: Expulsion of foetus, before live
Partial abortion: Some pups live, some die
Foetal reabsorption: in first 1/2 of pregnancy usually due to inadequate hormonal support P4
Mummification: Death >45 days (ossification), skin remains and dries.
Premature/Stillbirth: Expulsion of viable puppies that died days/hours before parturition
Aetiology
Infectious - Brucella, herpes, toxoplasma, neospora, parvo
Non-infectious - Endocrine (P4), fetotoxic or teratogens
Dx: USG, vaginal cytology, serum P4, X-Ray (>45d)
foetal necropsy
Anasarca + hemoperitoneum
-merked oedema of the subcutis and hemoperitoneum are signs of sepsis
Limb deformities - varus + valgus
Canine herpes - haemorrhagic lungs, renal necrosis + petechial skin
Necrotic hepatitis - Toxoplasma
Bronchopneumonia - Bordatella bronchiseptica
Enteritis - PanLeukopenia
Dystocia in the bitch & queen (Assessment of vital functions of foetuses during(ante-) and post-partum)
Intrapartum monitoring Monitoring tools -B-Mode -Döppler US: Foetal HR -Tocodynamometry -Intrauterine Use of doppler + tocodynamometry concurrently allows for ID of labour stage + adjustment of oxytocin + Ca2+
Neonatal monitoring Spontaneous respiration -<60 seconds from expulsion -Clear nose and mouth --> CPR -Rub chest + check mm (red = good, blue = bad)
Neonatal CPR
-Back of elbow compression (120-180bpm) every second, each 6 seconds blow air into mouth and nose, do this for 20 mins.
Thermoregulation
- Post-partum body temp reduces rapid
- control environmental temp (32.2 degree)
- Increase food intake, close to mother for warmth
- Adequate bedding
- Hypothermia leads to suckling and bradycardia
Umbilicus
-Ligate + ATb
Protect from dam
-Aggression
Colostrum
-Energy, nutrients, mAb (<24 hrs is critical)
General exam
-Assess common abnormalities (Cleft palate, Umbilical hernia, atresia anii)
Dystocia of bitch (Criteria of dystocia, primary and secondary atony of uterus)
Criteria for dystocia
>72 days or >36hours from temperature drop (1 degree)
>30 mins of abdominal straining
Green discharge
After 1st puppy is delivered
- 30 mins straining from 1st puppy
- Physically stuck
- Maternal: Tremour, dyspnea, vocalisation
Uterine inertia (atony)
Most common cause of dystocia
Failure of expulsion with no obstruction
-Complete: Failure of Stage II induction
-Incomplete: Puppy’s start but not all delivered
Primary - Second phase of parturition fails to start
- Litter size
- Neuroendocrine disease (most common)
- Genetic predisposition
Second - Exhaustion of contractile forces
- Exhaustion of nutritients
- Large foetus/materal malformation
Primary - Litter size, nutritional, neuroendocrine, age, nervous
Secondary - Narrow pelvis, Neoplasia, stricture, torsion, prolapse
Dystocia of the queen
Criteria for dystocia
- Pregnancy >68 days
- Straining for >5mins
- Haemorrhagic discharge
- Foetal fluids without straining
After 1st kitten is delivered
- > 2 hours from first kitten + no care to kittens
- Physically stuck
- Maternal: Tremour, dyspnea, vocalisation
Uterine inertia (atony)
Most common cause of dystocia
Failure of expulsion with no obstruction
-Complete: Failure of Stage II induction
-Incomplete: Kitten’s start but not all delivered
Primary - Second phase of parturition fails to start
- Litter size
- Neuroendocrine disease (most common)
- Genetic predisposition
Second - Exhaustion of contractile forces
- Exhaustion of nutritients
- Large foetus/materal malformation
Primary - Litter size, nutritional, neuroendocrine, age, nervous
Secondary - Narrow pelvis, Neoplasia, stricture, torsion, prolapse
Dystocia of the bitch (obstructive dystocia, forceps delivery)
Dystocia of the bitch
- > 69 days pregnancy
- > 30 mins abdominal straining with no delivery
- No parturition within >36 hours of temp drop
- Discharge
After first puppy
- > 30 mins straining with no second pup
- Discharge
Obstructive dystocia
Absolute
-Bone abnormalities - fracture, breed, imamture
-Soft tissue - Stricture, prolapse, abscess, adhesions, stenosis
Relative
- Malposition, posture, presentation
- foetal monsters
Medical management
Foetal extraction
-Seen in canal, manual extraction
-Plenty of lube, pull caudoventrally
Forcep manipulation
- Use with care as forceps can damage the vaginal canal
- Best when only one puppy stuck
- C-Section is indicated otherwise
- Manipulate the head gently
Dystocia of the bitch (medical + surgical management)
Medical
When maternal or foetal obstruction has been ruled out
physcial/forcep manipulation
Fluids
-Correct, Volume, electrolytes, A-B, glucose
Oxytocin
- 1.1-2.2 IU/Kg induces labour by increasing frquency of contractions
- Oxytocin induced contractions require influx of Ca2+
- Calcium gluconate IV will augment oxytocin effect
Tocoylics
- Terbutaline (Betamimetic)
- Diltiazem (Ca2+ channel blocker)
Surgical
C-section
-indication: Atony, oversize, malformation
-Timing depends on: Lung development (61 days), P4 level, temp
Emergency C-Sec: Dystocia, stress, sepsis, torsion, discharge
Elective C-sec: previous C-Sec, primiparous, brachycephalics
Anaesthesiology
Pre-Med: Metaclopromide (AVOID XYLAZINE, OPIOIDS, MEDEDIMODINE)
Induction: propofol (AVOID KETAMINE)
Maintain: Iso + Sevo
Indication for volunatry and urgent C-section
Indications
- Mal-position/presentation/posture
- primary inertia (complete or incomplete)
- Any history of dystocia
- Foetal stress
Surgical
C-section
-indication: Atony, oversize, maternal malformation
Timing depends on: Lung development (61 days) P4 level <6nmol/l Temp (drops 1 degree) >24 hours from aglepristone admin --> C-Section if parturition still dystocic
Emergency C-Sec: Dystocia, stress, sepsis, torsion, discharge
Elective C-sec: previous C-Sec, primiparous, brachycephalic, large puppy syndrome (singlee pup)
Disorders of puerperium (metritis + eclampsia)
Metritis
Inflammation of uterus
<7 days PP
Risk factor for dystocia and placental retention
E.Coli (uterine commensal) –> toxin –> sepsis
Absent milk let down, vaginal discharge
Dx: Vaginal swab
T: PGF2-a, OVH
Eclampsia
Hypocalcaemia / pueperial tetany
Cs peak at 2-3 weeks PP (peak of lactation)
Demand > bone metabolism
Cs: tremour, lack of puppy care, mydriasis, low BW puppies
Dx: Blood Ca2+
T: Supplement Ca2+ (avoid giving too fast as results in arrythmia)
Disorders of puerperium (uterine prolaps, placental retention)
Uterine prolapse All or partial (horn or body of uterus) -Partial: cone shape -Complete: Y-Shape Dry --> necrotise
Straining during delivery
Excessive bleeding
Forced manual delivery
Hypocalcaemia
Visual protrusion with USG displacement
Placental retention
Larger litters = higher risk
Green placental discharge
Systemic disease
Retention –> atony, placentitis, necrosis
USG, speculum with discharge
T:Forcep removal, oxytocin (after Ca gluconate), Atb, OVH
Disorders of puerperium (Subinvolution of placental sites, disorders of maternal behaviour)
SIPS
Abnormal repair of endometrium PP (which usually occurs after placenta tears out of the uterus during birth)
Mostly young primiparous bithes
Cs; weeks of discharge PP
Dx: metritis, vaginitis, cystitis
T: OVH
Maternal behaviour disorders
Maternal bonding occurs shortly PP due to pheramones and prolactin
Facilitates
-Attentivness, nursing, grooming, protection
Anaesthetic drugs + stress can negatively affect these mechanisms and influence maternal behaviour
Maternal fear can cause cortisol and adrenaline release resulting in vasocontrcition and absent milk let down due to lower blood flow and inhibition of oxytocin reaching the mammary
Cs: infantophagia + aggression
T: Calm familiar environment + diazepam/midozolam
Disorders of the ovaries (cysts, tumours and remnant syndrome)
Cysts
Follicular - E2 producing cyst
-E2 –> prolonged proestrus + oestrus + sexual behaviour
Luteal - P4 producing post-ovulation
-P4 –> prolonged anoestrus. Risk of endometrial hyperplasia + pyometra
Dx: USG
T:
Follicular –> GnRH/LH –> ovulation
Luteal –> PGF2-a
Neoplasia Epithelial Germa cell tumors of ova Connective tissue tumors -Disorders of oestrus length, masculinisation, pyometra
Remnant syndrome -Left over tissue from a spay Cs:signs of heat (vulva oedema, standing for mounting) Dx: lab hormones level T: removal of tissue
Disorders of the tubular parts of reproductive apparatus (uterus, cystic endometrial hyperplasia/pyometra, tumours
Pyometra
Cystic hyperplasia during dioestrus (P4 is high causing thickening of the uterine lining)
bacteria invade cysts and cause purulent inflammation and endotoxin release
Usually >5years of afge within 6 weeks of oestrus
Cs: PU/PD, fever, vaginal discharge, sepsis, abdominal distention
Dog with pyometra must be bred every season or will reoccur if no OVH
Dx: USG, X-Ray
T: OVH, PGF2-a, ATb
Uterine neoplasia Usually non-spayed older dogs Leiomyo/sarco/ma Cs: increased risk for pyometra and infertility T: OVH, Chemo (doxyrubicin)
