Lecture 20

What species have the highest incidence rates of dystocia?

Cattle, with rates of 3% - 25% of births, especially in heifers.

What economic impacts does dystocia have?

Millions in losses due to reduced performance and increased culling, along with associated labour and veterinary costs.

What are some causes of dystocia

Foetal-pelvic disproportion, ineffective labour, malpresentation, uterine torsion, insufficient dilation, foetal abnormalities

What is foetal-pelvic disproportion?

A condition where there is a disproportion between foetal size and maternal pelvic dimensions, accounting for 50%-70% of dystocias in beef cattle and 15-30% in dairy

What accounts for 20%-45% of dystocias in cattle?

Malpresentation, where the foetus is not positioned correctly for birth.

What causes foetal malpresentation

Perhaps:

• Foetal maturity, strength, and coordination play a role, especially in posterior presentations.

• Foeto-pelvic disproportion

What is the preferred presentation of a neonate

Anterior longitudinal, dorso-sacral, with head and front legs first

What is ineffective labor?

Weak or ineffective contractions that can be primary or secondary, causing 10%-20% of dystocias in cattle, but is the most common cause of dystocia in pigs, dogs and cats

• Primary: Failure to initiate proper contractions/pushing due to factors like hypocalcaemia, debility obesity.

• Secondary: Initially good contractions that weaken due to exhaustion, obstruction, or other complications (like twins).

What genetic factors can be selected to influence dystocia?

Foetal birth weight, double muscling, gestational length, and maternal pelvic internal diameter.

What nutritional management strategy can help prevent dystocia?

Preweaning growth in heifers, and careful management of gestational nutrition.

Can you describe:

... a logical approach to examination of an animal with dystocia ... how you would assess foetal viability ... factors that will influence your choice of correction method ... how you would correct foetal malpresentations

1. Evaluation of history with consideration of age, condition of patient, expected parturition timing, foetal viability, owner preference of patient priority

2. Foetal viability can be assessed via ultrasounds, heart rate monitoring (especially in dogs), manual palpation in larger animals

3. Factors that influence my choice include: 

   1. What options do you have

   2. Which patient is your priority

   3. What facilities and assistance is available

   4. What does the client think

4. Correction via manipulation, traction, caesarean or foetotomy

What are the options for management of dystocia?

Manipulation, traction, foetotomy, caesarean section, and euthanasia.

What are basic considerations for manipulation techniques in dystocia management?

Maintain hygiene and lubrication, assess cow and calf viability, and manage maternal straining.

How would you perform a manipulation

• Adjust calf position and posture if it is safe and feasible.

• Avoid attempting to convert posterior presentations to anterior, as it is rarely successful.

• Minimise the effective diameter of the calf/foal/lamb

• Employ appropriate stimulation of contractions if needed

• Can use equipment for larger animals such as chains, ropes, snares, eye hooks etc.

When are traction techniques used

Applied when no physical obstruction exists, and the foeto-pelvic disproportion is assessed and is fine. Mum just might not be pushing

What are some considerations for traction techniques

• Correct malpresentations before applying traction.

• Estimates of necessary force must be based on careful assessment—“not too hard” is the guiding principle.

• Use equipment properly

• Equipment should be correctly positioned for effective delivery.

• Dilate the cervix

When is a foetotomy indicated?

When the foetus is dead or correcting difficult flexions is necessary.

What circumstances indicate a caesarean section?

• Inability to extract the foetus vaginally due to conditions like foetopelvic disproportion or uterine torsion.

• Required for live, viable foetuses, valuable foetuses, or certain cases of foetal monsters.

• Elective pre-parturient

• Dead foetuses

What ethical considerations may lead to euthanasia in dystocia cases?

Animal welfare and cost implications showing euthanasia might be the most humane option.