PATHOLOGY - Lambing Flashcards
What are the advantages of outdoor lambing systems?
More hygienic
Reduced mis-mothering
Ewes are more relaxed
Less labour intensive
What are disadvantages of outdoor lambing systems?
More challenging to catch ewes and lambs
Predation (crows)
Hypothermia
What are the advantages of indoor lambing systems?
Easier to catch ewes and lambs
Allows for closer monitoring
Easier to manage nutrition
Reduced risk of hypothermia
What are the disadvantages of indoor lambing systems?
More labour intensive
Increased mis-mothering
Increased risk of infectious disease
Increased risk of ewes lying on lambs
What are the four key prevention strategies to reduce complications at lambing?
Adequate nutrition
Gently tissue and animal handling with plenty of lubricant
Breeding flock selection
Strict culling policy
What are the common complications seen at lambing time?
Abortion
Metabolic disease
Dystocia
Prolapse
Metritis
Mastitis
Malignant oedema
Pre-pubic tendon rupture
When should you intervene at lambing?
If the water bag has been visible for over an hour, check the presentation of the lamb. If it is normal, wait for another hour and if nothing has happened, then intervene. If the lamb is in an abnormal presentation you should intervene immediately
What are some of the warning signs of dystocia at lambing (if you notice these you should intervene immediately)?
Ewe exhibiting signs of discomfort
Thirty minutes of unproductive straining
Birth fluids are dark/discoloured
Lamb is in abnormal presentation
What can be done to reduce the risk of infection and tissue damage when managing dystocia in ewes?
Gentle tissue and animal handling
Use plenty of lubricant
Clean and disinfect hands and equipment
What are the causes of dystocia in ewes?
Foetal malpresentation
Foetomaternal disproportion
Foetal deformaties
Maternal structural/functional abnormalities
What can cause foetomaternal disproportion?
Foetomaternal disproportion can result from the ewe having a small pelvis, which is particularly seen in younger ewes, or due to foetal oversize which can be due to breed and/or sire
What are some of the key signs of foetomaternal disproportion?
Forelimbs crossed in the birth canal
Head deviation
Shoulders struggling to fit into the birth canal
Pelvis struggling to fit into the birth canal (if in posterior presentation)
What are some of the maternal structural/functional abnormalities which can result in dystocia in ewes?
Uterine inertia
Uterine twist (not very common in sheep)
Cervical stenosis
Narrow pelvis
Abnormal bony protuberances into the birth canal
Previous trauma to the pelvis
How can you treat cervical stenosis in ewes?
Give the cervix time to relax and see what happens
Manually dilate the cervix by massaging it open
Calcium injection
Cesaerean section
What are some of the causes of foetal deformities which can result in dystocia in ewes?
Genetic
Infectious
Teratogenic plants and drugs
Which infectious agents can result in foetal deformaties in lambs?
Schmallenburg virus
Blue tongue virus
What should you advise farmers to do if they are manually extracting multiple lambs?
The best advice for farmers lambing their own ewes is to leave her to give birth to the next lamb(s) on her own, to minimise trauma from intervention. But if the lambs or discharges are stained with meconium, this is a sign of distress and the remaining lambs should be extracted manually
What are the indictors for a caudal epidural during lambing?
Ewe appears to be in pain
Significant manipulation required for lambing
Mildly disproportionate dead lamb
Episiotomy required
What are the indicators for a ewe caesarean?
No progress of active lambing within 15 minutes
Foetomaternal disproportion (lamb to big or ewe too small)
Deformed lamb
Vaginal prolpase
Unable to correct cervical stenosis
Unable to correct uterine twist
What is the post-operative care for a ewe cesarean?
Milk the colostrum from the ewe to feed to the lambs as the ewe will unlikely stand for suckling
Make sure the ewe can stand before being put in the same pen as the lambs
Monitor for vaginal discharge
Monitor for retained feotal membranes
Remove sutures at 2 to 3 weeks post-op
What are the indicators for euthanasia at lambing?
Dead lambs resulting in a systemically unwell ewe
Caesarean required but the client is unwilling
How should you decide if antibiotic treatment is necessary in ewe obstetric cases?
You should decide whether antibiotic treatment is necessary in ovine obstetric cases based on the level of intervention required and the degree of damage to the ewe reproductive tract
Which drugs are indicated if there has been minimal intervention in lambing?
If there has been minimal intervention with nothing introduced into the reproductive tract, NSAIDs can be administered in combination with monitoring from the farmer for any signs of clinical disease in the ewe
Which drugs are indicated if a clean hand has been introduced however there has been damage to the reproductive tract?
If a clean hand has been introduced however there has been damage to the reproductive tract, a one-off injection of short acting broad spectrum antibiotics is indicated
e.g. Amoxicillin or oxytetracycline
When are long acting or long course broad spectrum antibiotics indicated in ewe obstetric cases?
e.g. PenStrep or potentiated amoxicillin
Significant intervention and/or damage to the reproductive tract
Caesarean section
Clinical signs of infection
Which lamb aftercare procedures should be performed following lambing?
Check for respiration
Umbilical management
Colostrum management
Assess for meconium
Which methods can you use to resuscitate a lamb if they are not breathing post-lambing?
Ensure airway is clear of fluid
Rub the chest vigorously
Put straw up their nose
When should the umbilicus be dipped with iodine?
The umbilicus should be dipped within iodine within 15 minutes of birth and again 2 hours later if there is joint ill present on the farm
When should lambs have passed meconium?
Lambs should have passed meconium within their first 24 hours of life
Why is it so important to assess if lambs have passed their meconium?
It is important to assess if lambs have passed meconium as this is a key sign that the lamb has started to suckle and their gastrointestinal tract is functional
How do you prevent dystocia in ewes?
Nutrition
Minimise disturbance of lambing ewes
Breeding flock selection
What is the ideal body condition score (BCS) for ewes at lambing?
Body condition score (BCS) of 2.5 to 3.5
What should you select for within a breeding flock to reduce the risk of dystocia?
Make sure that farms breeding their own replacements select ewe lambs that were born to successful dams (i.e. did not require assistance lambing, no prolapse, mastitis, metritis etc.). Furthermore, it is important to have strict culling policy where you remove ewes from the breeding flock which have suffered from conditions which predispose them to similar problems in the future
What are the risk factors for vaginal prolpase in ewes?
Breed predispositions
Excessive or inadequate body condition score (BCS)
Older ewes
Short docked tails
Hypocalcaemia
Steep sloping fields
Which breed of sheep is predisposed to vaginal prolapse?
Mule ewes
What is a mule sheep?
The term Mule is used to refer to a cross between a Bluefaced Leicester ram and a Purebred hill
How do you treat a vaginal prolapse?
- Caudal epidural
- Clean the prolapsed tissue
- Use plenty of lubricant and gently push the tissue back into the body
- Do a Buhner’s stitch with uterine tape (leave an opening for urination)
- Administer NSAIDs and a broad spectrum antibiotic
- Mark ewe for culling
What is the aftercare required for a vaginal prolpase?
Continue monitoring the ewe for signs of lambing to remove the buhner’s stitch to allow the ewe to lamb
How do you prevent vaginal prolapse in sheep?
Maintain body condition score (BCS) between 2.5 and3.5
Maintain blood calcium levels
Cull ewes affected by vaginal prolapse to prevent recurrence
What is the prognosis for vaginal prolapse in sheep?
Vaginal prolapse has a high rate of recurrence and risk of complications so culling is indicated
What are some of the potential complications of a vaginal prolapse?
Abortion
Cervical stenosis
Vaginal wall necrosis
Vaginal wall infection
What should you tell the farmer to do if they call to report a uterine prolapse?
Tell the farmer to wrap the prolapse in a clean sheet or plastic and try to keep the ewe still until you arrive
How do you treat a uterine prolapse in a ewe?
- Position the ewe in sternal recumbency with her legs extended caudally
- Caudal epidural
- Clean the uterus and remove the placenta
- If there is a tear in the uterus, do an everting suture
- Gently push the uterus back in using lots of lubricant
- Ensure the uterus is completely everted as if it is not, it will prolapse again
- Administer NSAIDs and a broad spectrum antibiotic
What is the prognosis for uterine prolapse in sheep?
A uterine prolapse is unlikely to recur so there is not an indicator to cull these ewes
What are the risk factors for metritis in sheep?
Unhygienic lambing
Dead lambs
Environmental contaminants
What are the clinical signs of metritis in sheep?
Clinical signs of endotoxaemia
Red to brown purulent vulval discharge
Vulval swelling
What are the clinical signs of endotoxaemia in sheep?
Depression
Inappetence
Congested mucous membranes
How do you treat metritis in sheep?
Fluid therapy
NSAIDs
5 -7 day course of broad spectrum antibiotics
What is the prognosis for metritis in sheep?
Sheep generally respond well to metritis treatment unless they have concurrent disease such as retained foetal membranes, mastitis, vaginal rupture or peritonitis
How do you prevent metritis at lambing?
Good hygiene
Gentle tissue handling
Avoid unnecessary inteference at lambing
Administer antibiotics after difficult lambing
Environmental management
What is malignant oedema?
Malignant oedema is clostridial infection of damaged tissues in the reproductive tract resulting in severe swelling of the perineal area, purple/black/red discolouration of the tissues and an oozing blood tinged discharge and rapid death
What are the risk factors for mastitis in ewes?
Inadequate nutrition
Poor hygiene
Poor udder conformation
Udder trauma
Younger ewes
Orf infection
How does inadequate nutrition increase the risk of mastitis?
Inadequate ewe nutrition results in a decreased milk yield so the lambs are more likely to cause damage to the teats and udder when suckling as they are trying to get more milk out
What are the most common pathogens involved in ewe mastitis?
Mannheimia haemolytica
Staphylococcus aureus
What are the classifications of mastitis?
Subclinical mastitis
Acute mastitis
Chronic mastitis
Gangrenous mastitis
What is the clinical presentation of subclinical mastitis in ewes?
Subclinical mastitis presents as decreased milk yield and thus reduced lamb growth rates
What is the typical signalement of subclinical mastitis?
Subclinical mastitis is more commonly seen in older ewes, with decreased milk yield and reduced lamb growth rates more pronounced in ewes over four
What is the clinical presentation of acute mastitis in ewes?
Abnormal hindlimb gait
Depression
Inappetence
Seperation from the flock
Hot or udder
Swollen udder
Painful udder
± Discolourated udder
± Hard udder
Watery, clotted and/or blood tinged milk
(T/F) Blood tinged milk is always abnormal in ewes
FALSE. Blood tinged milk alone is not necessarily abnormal and a sign of mastitis as this can be normal soon after parturition but should be monitored
What is the clinical presentation of chronic mastitis in ewes?
Masses in the udder. These are abscesses which can rupture and reform and thus the masses may not be present every time the udder is palpated
What is the clinical presentation of gangrenous mastitis in ewes?
Abnormal hindlimb gait
Depression
Inappetence
Seperation from the flock
Cold udder
Hard udder
Purple to black discolouration of the udder
What is the main causes of death due to mastitis?
Ewes with mastitis usually die due to endotoxaemia
What is the prognosis for gangrenous mastitis?
Typically, ewes with gangrenous mastitis will die or endotoxaemia but if they do survive recovery is very slow and they will have a low body condition score for a prolonged period of time. Furthermore, the affected udder quadrant will never return to function
How do you treat mastitis?
Clean the udder
Milk the affected quadrant
Systemic antibiotics
NSAIDs
Fluid therapy
Examine and feed the lambs (as the affected ewe likely has a low milk yield or hasn’t allowed the lambs to suckle so they will need fed)
What are the benefits of milking the affected quadrant when treating mastitis?
Milking the affected quadrant can reduce the bacterial load of the udder
When are systemic antibiotics and NSAIDs indicated for the treatment of mastitis?
Systemic antibiotics and NSAIDs are indicated for the treatment of acute and gangrenous mastitis as the ewes can rapidly die of endotoxaemia
Which antibiotic is indicated in the treatment of mastitis in ewes?
Long acting amoxicillin
Which antibiotic is indicated in the treatment of severe mastitis in ewes?
Tilmicosin
Tilmicosin is a macrolide antibiotic
When is fluid therapy indicated for the treatment of mastitis?
Fluid therapy is indicated for gangrenous mastitis however once the udder is discoloured and cold this is probably not justified and euthanasia is appropriate
What are the general prognosis for mastitis is ewes?
For many ewes that have suffered from mastitis, the udder quarter is no longer productive, even in subsequent production cycles, and she has an increased risk of mastitis in the future
What is pre-pubic tendon rupture?
Pre-pubic tendon rupture is seen in late pregnancy where the pre-pubic tendon gives way under the pressure and the abdominal contents descend towards the floor under gravity, making is challenging for the ewe to move and carry out natural parturition
What are the risk factors for pre-pubic tendon rupture?
Older ewes
Multiple foetuses
What is the key clinical sign of pre-pubic tendon rupture in ewes?
Swelling of the lower abdomen, cranial to the pubis
Why do ewes with pre-pubic tendon rupture require lambing assistance?
In ewes with pre-pubic tendon rupture, the uterus becomes ventrally displaced so these ewes require lambing assistance
What is the prognosis for pre-pubic tendon rupture in ewes?
Typically pre-pubic tendon rupture will require euthanasia due to animal welfare
