Disorders of the puerperium Flashcards
Define puerperium
The period after parturition when the reproductive tract returns to its non-pregnancy condition so that the female can become pregnant again. Aim for the shortest time possible
What normally happens during the puerperium? 4
Involution
Endometrial regression
Elimination of contaminants of the reproductive tract
Resumption of ovarian cyclical activity
What disorders can affect the normal puerperium? 4
Dystocia
Uterine prolapse
RFM
Uterine disease
Define involution - discuss timings
Reduction in size of uterus and cervix after calving
Greatest decrease in first few days after parturition
Diameter of gravid horn will halve in 5 days whereas the length will be halved by 15 days pp.
By 8-10 days pp, whole uterus should be palpable per rectum
Complete involution within 25-50 days (changes after 50 days are minimal)
Difficult to find hand through cervix by 10-12 hours pp and by 96 hours pp only 2 fingers can be admitted through the cervix
Reduction in external diameter of cervix is also appreciable when palpated per rectum (15cm at 2 days, 9-11cm at 10 days, 7-8cm by 30 days and 5-6cm at 60 days pp).
In case of normal involution, by 25 days pp the diameter of the cervix starts to exceed that of the previously gravid uterine horn.
What are the physiological changes that occur during involution?
Shift from hypertrophy (due to increase in collagen and smooth muscle) to atrophy (due to loss of smooth muscle and degradation)
Reduction in size of the myofibrils
Prostaglandins may control involution, so their (and possibly oxytocin) exogenous use may be used to accelerate involution
How does the endometrium regenerate?
Uterine caruncles undergo degenerative changes probably due to vasoconstriction and ischaemia and this results in necrosis and sloughing of caruncular tissue. This is considerably reduced by 25 days pp.
Lochial discharge (necrotic sloughing, blood, foetal fluids) Occurs at day 2-9 pp, yellowish-reddish/brown. Variable volume. Normally doesn't have a foetid odour.
Systemic response (APPs) occurs
Endometrial epithelium covers the caruncular and inter-caruncular surfaces with centripetal growth of cells from the uterine glands (UGs).
List bacterial pathogens that may be found in the uterine lumen - 5
Arcanobacterium pyogenes E. coli Streptococci Staphylococci Fusobacterium necrophorum
Lochia provides an ideal growth medium.
How are uterine bacteria eliminated?
Phagocytosis - main mechanism Physical expulsion (contractions and secretions)
By about 5 weeks, 50% will be sterile and by 8-9 weeks, most animals will have a sterile uterine lumen.
What happens leading up to resumption ovarian cyclical activity?
Gestation: pituitary refractive to GnRH pp (P4)
7-10 days pp, plasma FSH increases, associated with 1st pp follicular wave
Ovulation will only occur if the follicle produces enough oestradiol to stimulate adequate LH secretion.
Suckling delays ovarian cyclical activity.
Luteal phase may be normal length OR much shorter due to poor preovulatory development of the follicle leading to inadequate luteinisation of the CL.
What does the fate of the dominant follicle depend on? 2
If it has developed LH-R (granulosa cells)
If it has developed proteases
Why does dystocia affect the normal puerperium?
By breaking host defence mechanisms (e.g. physical barrier of vulva and cervix)
Causes physical deformity (vulva/cervix)
Causes tissue damage (more prone to contamination)
Uterine inertia
Lack of sterility due to obstetrical interventions.
Predisposes RFM and uterine disease.
When does uterine prolapse occur? How often? Predisposition? Survival rate? Physiological risks?
0.1-0.6% calvings, within first 24 hours pp
PREDISPOSITION:
Pluiparous cows > heifers
Grossly protracted and assisted parturitions
SURVIVAL: 75-80%
PHYSIOLOGY: abdominal straining and flaccid uterus –> hypocalcaemia
What are the risk factors for uterine prolapse? 7
Prolonged dystocia Foetal traction Foetal oversize Extreme laxity of perineum and vulva Hypocalcaemia Paresis RFM
Treatment - uterine prolapse
Protect and support the prolapse Calciu borogluconate Relieve ruminal tympany Restrain the cow Epidural (to stop abdominal strain) Clean uterus 'Frog-leg' position (eases manipulation) Gentle replacement Ensure total inversion (Stitch the vulva) ABs + NSAIDs Oxytocin
What is the incidence of RFM?
Overall = 6-8 %
With dystocia = 25-40%
Explain how the placenta becomes separated and expulsed.
PLACENTAL MATURATION: changes in P4 and E2 concentrations, changes in collagenase and proteases/glucosaminidases, reduction in number of binucleate cells in the trophectoderm
Exsanguination of the foetal side of the placenta and collapse of the trophectodermal villi
Distortion of the placentomes (uterine contractions)
Lack of antioxidants, stress, oxidative injury and the role of PGF and PGE synthesis
IL8, leukocyte migration and collagenases
Reasons for RFM
Failure of maturation of placenta (i.e. premature calving)
Failure of detachment of foetal and maternal villi of the placentome
Inadequate uterine contractions due to hypocalcaemia or dystocia
Predisposing factors - RFM
Abortion Stillbirth Multiple birth Dystocia, premature calving Infectious placentitis (Brucellosis, Salmonellosis etc) Hypocalcaemia Hydrallantois Increasing age of the dam Prolonged gestation Micronutrient deficiencies - Se, Vit E and A
Clinical features - RFM
Morbidity - lack of appetite, reduced milk yield
Mortality - 1-4% mainly related to metritis/toxaemia
Duration of retention depends on myometrial contractions (caese 36 hours after parturition)
Fertility - no effect on own if mating 60 days pp, along with metritis –> increases days open, services per conceptions and the calving to first oestrous interval.
Treatment - RFM
Traction (NOT recommended anymore)
Wait until at least 5 days pp before vet exam
If pyrexic, depressed appetite and milk yield, treat for metritis.
ABs - PN or intrauterine
Hormones - prostaglandins or oxytocin (evidence not convicing regarding efficacy)
Collagenase infusion into stumps of umbilical arteries of retained membranes
What are the 3 types of uterine disease? What determines whether or not they occur? 3
Pathogen species, degree of colonisation and magnitude of immune response determines whether the infection results into:
ENDOMETRITIS
METRITIS
PYOMETRA
Why does uterine infection develop? 2
Physical barriers (vulva and cervix) Immune defence system
What pathogenic bacteria may be implicated in uterine disease? 6
Arcanobacterium pyogenes Fusobacterium necrophorum E. coli Prevotella species (formerly bacteroides) Clostridium spp Mannheimia haemolytica
Incidence - endometritis
6-43%
Doesn’t affect general health but does affect fertility
Endometritis - pathogens
Opportunists - E.coli with subsequent overgrowth of A.pyogenes, F. necrophorum, Prevotella species
Clinical signs - Endometritis
mucopurulent discharge in clinical cases
no systemic illness
neutrophils in uterine luminal fluid
Diagnosis - endometritis
Rectal palpation
Poorly involuted uterues
Presence of discharge around cerivcal os (vaginoscope)
Metricheck to collect discharge (to look for presence of neutrophils in vaginal swabs)
How many neutrophils should be present in a cervical swab?
20-33 days pp = >18%
33-49 days pp = >10%
>50 days pp = >5%
Treatment - endometritis
Stimulation of oestrous in cyclic (PGF2a) and acyclic cows (3-5mg E2 or use of GnRH)
Intrauterine cephapirin (Metricure, Intervet)
Clinical signs of puerperal metritis
Systemic illness
purulent feotid fluid in uterine lumen
Distended, fluid-filled atonic uterus
Elevated rectal temperatures (40-41 degrees)
Dullness, depression, milk drop, inappetence
Within a few days of parturition, usually follows severe dystocia, uterine inertia, RFM
Sore, swollen and inflamed vagina and vulva
Systemic toxaemia: fast weak pulse, rapid respiration ,dehydration, sluggish CRT, diarrhoea
Pyaemia: concurrent peritonitis, mastitis
Treatment - puerperal mastitis
Case dependent, overall poor prognosis
SUPPORTIVE: stabilise circulatory system, fluids and NSAIDs
PARENTERAL ANTIBIOTICS: Bactericidal (cephalosporins, ceftiofur, broad-spectrum penicillins) or bacteriostatic (oxytetracycline)
CONTRADINDICATIONS: oestrogens increase absorption of endotoxins
UTERINE LAVAGE: (after stabilisation of circulation) followed by ABs (like oxytetracycline)
What equipment is needed for uterine lavage? 3
Wide bore stomach tube
Funnel
Normal saline
Define pyometra
accumulation of purulent material in the uterus in the presence of an active persistent CL
What happens in pyometra?
Clinical signs?
Diagnostic techniques? 2
Uterine horns - large, distended
Cervix - closed
CLINICAL SIGNS:
Sequel to chronic endometritis
No signs of ill health
Absence of cyclicity
DIAGNOSIS:
Differentiate from normal pregnancy by rectal palpation (thickness of uterine wall, slipping of allantochorion, uterine caruncles) and transrectal ultrasonography (speckled echotexture of uterine contents versus black anechoic appearance of normal foetal fluids)
Treatment - Pyometra
PGF2alpha + intrauterine cephapirin (an AB)
How much do RFM cost a farmer?
Direct costs = £84
Total costs = £300-475
How much does uterine disease (endometritis) cost a farmer ?
Direct costs = £71
Total costs = £166
Average herd spends £833 per 100 cows
