Diseases of the Newborn

Lesson 1: Perinatal and Postnatal diseases Lesson 2: Physical and environmental causes of diseases Lesson 3: Diseases of cloned offspring Lesson 4: Neonatal infection Lesson 5: Care of clinically ill newborns

Perinatal and Postnatal diseases

Overview

Perinatal period: from late pregnancy to immediately after birth (usually the last 3rd trimester until ~1 week postpartum).

Postnatal period: from birth up to weaning.

Diseases during this time are a major cause of calf, lamb, piglet, foal, and kid mortality.

Common Perinatal Conditions:

Stillbirths - due to dystocia, prolonged parturition, or hypoxia.

Congenital anomalies - e.g., cleft palate, atresia ani, heart defects.

Birth trauma - fractures, nerve paralysis (brachial plexus, femoral nerve).

Common Postnatal Conditions:

Failure of passive transfer (FPT) - inadequate colostrum intake → immunodeficiency.

Neonatal diarrhea (scours) - caused by E. coli, Rotavirus, Coronavirus, Cryptosporidium.

Respiratory disease - aspiration pneumonia, early exposure to pathogens.

Case Example

A calf born weak, fails to stand within 2 hours, and has not suckled → diagnosed with Failure of Passive Transfer. Blood IgG testing confirms low levels.

Discussion Questions
  • Why is colostrum management critical in preventing postnatal diseases?
  • What management practices can reduce perinatal mortality in calves and lambs?

Physical and environmental causes of diseases

Physical Factors:

Hypothermia - newborns lose body heat rapidly due to wet coat, low fat stores, and large surface area.

Trauma - difficult births, rough handling, trampling by dam or herd mates.

Environmental Factors:

Cold stress - outdoor lambing/calving in winter without shelter.

Heat stress - foals born in high summer → dehydration and weakness.

Unsanitary conditions - dirty pens, bedding → exposure to pathogens causing diarrhea or septicemia.

Pathophysiology

Stress > increased cortisol > immunosuppression.

Poor environment > higher pathogen load → overwhelms immature immune system.

Case Example

Piglets born in an outdoor system in cold weather show hypothermia and high mortality. Heat lamps or creep boxes were missing.

Discussion Questions

How do environmental stressors predispose neonates to infections?

What housing modifications improve newborn survival in different livestock species?


Diseases of cloned offspring

Background

Cloning in livestock (especially cattle) is still experimental. Cloned offspring show higher morbidity and mortality compared to naturally conceived animals.

Common Problems in Cloned Neonates:
  • Large Offspring Syndrome (LOS): oversized calves/lambs > dystocia, respiratory distress.
  • Organ malformations - kidney, heart, or liver defects.
  • Immune dysfunction - abnormal development of immune system, poor adaptation.
  • Perinatal mortality - high losses within the first 24–48 hours.
Mechanisms

Errors in nuclear reprogramming during somatic cell nuclear transfer (SCNT).

Epigenetic abnormalities affecting gene expression (e.g., insulin-like growth factor pathway).

Case Example

A cloned calf born at 65 kg (double the normal birth weight) suffers from dystocia, pulmonary edema, and dies within 48 hours.

Discussion Questions
  • What are the ethical considerations of using cloning in livestock production?
  • How can veterinary care be adapted to manage cloned offspring more effectively?

Neonatal infection

Types of Infections:

Septicemia - E. coli, Actinobacillus, Streptococcus → systemic illness, high mortality.

Enteric infections - scours due to bacteria, viruses, or protozoa.

Respiratory infections - aspiration pneumonia, environmental pneumonia.

Navel ill (omphalophlebitis): bacterial infection through umbilicus > septic arthritis or liver abscesses.

Risk Factors:
  • Failure of passive transfer (FPT).
  • Contaminated environment.
  • Prematurity or weak neonates.
Case Example

A foal presents with swollen joints, fever, and lethargy at 7 days old. Blood cultures grow Streptococcus zooepidemicus. Diagnosis: septic arthritis secondary to failure of passive transfer.

Discussion Questions
  • How does colostrum failure predispose neonates to septicemia?
  • Why is umbilical cord care important in newborn management?

Care of clinically ill newborns

Principles of Neonatal Care:
  • Warmth - provide heating pads, lamps, or blankets.
  • Hydration - IV or oral fluids to correct dehydration.
  • Nutrition - tube feeding colostrum or milk if unable to suckle.
  • Antimicrobials - early use in septic neonates (based on culture/sensitivity when possible).
  • Nursing care - frequent repositioning to avoid sores in recumbent neonates.
Supportive Therapies:
  • Oxygen therapy for respiratory distress.
  • Plasma transfusions in foals/calves with FPT.
  • Pain management when appropriate.
Case Example

A lamb with hypothermia and diarrhea is treated with warming box, IV fluids, and oral electrolytes. Recovery within 48 hours highlights importance of supportive care.

Discussion Questions
  • What are the most critical first steps when managing a weak newborn calf or foal?
  • How can veterinary students distinguish between a septic neonate and one suffering from simple dehydration?