Menu

    1. Home
    2. About
    3. Learning Hub
    4. Clinical Reference
    5. Resources
    6. Contact

Genetic Diseases in Sheep and Goats

Introduction

Genetic diseases in sheep and goats are inherited disorders affecting skeletal development, muscle function, nervous coordination, and anatomical structures. These conditions are important in veterinary medicine because they reduce productivity, impair animal welfare, and create breeding challenges in small ruminant populations.

General Characteristics of Genetic Diseases in Small Ruminants
  • Many are breed-associated inherited disorders
  • Inheritance is commonly autosomal recessive
  • Carrier animals may appear clinically normal
  • Some conditions affect growth and survival of young animals
Importance in Veterinary Medicine
  • Economic losses due to poor growth and mortality
  • Reduced breeding value
  • Animal welfare concerns
  • Congenital deformities affecting productivity

1. Spider Lamb Syndrome (Hereditary Chondrodysplasia)

Definition

Spider Lamb Syndrome is an inherited skeletal developmental disorder characterized by abnormal bone growth resulting in long, thin, deformed limbs and spinal abnormalities.

Species and Breeds Affected
  • Suffolk sheep
  • Hampshire sheep
Etiology
  • Autosomal recessive inherited defect
  • Mutation affecting fibroblast growth factor receptor 3 (FGFR3)
Pathogenesis
  • Abnormal cartilage and bone development occur during fetal growth
  • Long bones become elongated and malformed
  • Spinal deformities develop
Clinical Signs
  • Long, thin limbs
  • Angular limb deformities
  • Kyphosis or scoliosis
  • Difficulty standing or walking
  • Facial deformities
  • Poor growth
Postmortem Findings
  • Elongated metacarpal and metatarsal bones
  • Vertebral malformations
  • Abnormal joint development
Diagnosis
  • Characteristic skeletal deformities
  • Radiographic examination
  • Genetic testing
Treatment
  • No effective treatment
  • Severely affected lambs often euthanized
Control and Prevention
  • Genetic screening of breeding animals
  • Avoid carrier-to-carrier mating
Summary for Practitioners

Spider Lamb Syndrome is an important inherited skeletal disease causing severe congenital deformities in affected sheep breeds.

2. Hereditary Splayleg

Definition

Hereditary Splayleg is a congenital neuromuscular disorder characterized by inability of newborn lambs or kids to stand properly because the limbs splay outward.

Species Affected
  • Sheep
  • Goats
Etiology
  • Inherited neuromuscular developmental defect
  • May involve genetic and environmental influences
Pathogenesis
  • Poor neuromuscular coordination and muscle weakness develop at birth
  • Limb support is inadequate for standing
Clinical Signs
  • Newborn unable to stand normally
  • Limbs spread laterally
  • Difficulty nursing
  • Weakness
  • Reduced mobility
Differential Diagnoses
  • Selenium deficiency
  • Congenital musculoskeletal defects
  • Birth trauma
Diagnosis
  • Clinical examination of neonates
  • History of familial occurrence
Treatment
  • Supportive nursing care
  • Limb taping or hobbling
  • Assistance with feeding
  • Physiotherapy
Prognosis
  • Mild cases may recover
  • Severe cases have poor prognosis
Control and Prevention
  • Avoid breeding affected lines
  • Good neonatal management
Summary for Practitioners

Early supportive care can improve survival in mild hereditary splayleg cases.

3. Goat Myotonia Congenita ("Fainting Goats")

Definition

Myotonia Congenita is an inherited muscle disorder characterized by delayed muscle relaxation following contraction, resulting in temporary stiffness or collapse.

Species and Breed Affected
  • Tennessee Fainting Goats
Etiology
  • Inherited mutation affecting chloride ion channels in skeletal muscle
Pathogenesis
  • Defective chloride channels impair muscle relaxation
  • Muscles remain contracted briefly after stimulation
  • Sudden excitement triggers temporary rigidity
Clinical Signs
  • Sudden muscle stiffness
  • Brief collapse after fright or excitement
  • Rigid limbs
  • Normal consciousness maintained
  • Muscles appear heavily developed
Important Clinical Note
  • Animals do not lose consciousness despite the term “fainting”
Diagnosis
  • Characteristic clinical episodes
  • Breed predisposition
  • Genetic testing where available
Treatment
  • Usually not required
  • Stress reduction recommended
Prognosis
  • Generally good
  • Condition is usually nonfatal
Control and Prevention
  • Selective breeding management
Summary for Practitioners

Myotonia Congenita is a classic inherited muscle disorder producing transient muscle rigidity in goats.

4. Entropion

Definition

Entropion is an inherited anatomical defect in which the eyelid rolls inward, causing irritation of the cornea by eyelashes and wool.

Species and Breeds Affected
  • Several sheep breeds
  • Occasionally goats
Etiology
  • Hereditary conformational defect
  • May be influenced by environmental factors and body condition
Pathogenesis
  • Inward rolling of eyelids causes hair contact with cornea
  • Chronic corneal irritation develops
  • Pain and secondary infections may occur
Clinical Signs
  • Excessive tearing
  • Squinting
  • Photophobia
  • Corneal ulceration
  • Cloudy cornea
  • Reduced nursing due to pain
Diagnosis
  • Clinical eye examination
  • Observation of inward eyelid rolling
Treatment
  • Eyelid eversion using sutures or clips
  • Temporary skin injections beneath eyelid
  • Surgical correction in severe cases
  • Topical antibiotics if corneal ulcers present
Complications
  • Corneal ulcers
  • Blindness if untreated
Control and Prevention
  • Avoid breeding affected animals
  • Early neonatal examination
Summary for Practitioners

Early correction of entropion is essential to prevent permanent corneal damage and blindness.

General Diagnosis of Genetic Diseases in Sheep and Goats

Diagnostic Approaches
  • Clinical examination
  • Observation of congenital abnormalities
  • Pedigree analysis
  • Radiographic imaging
  • Genetic testing where available

General Principles of Prevention and Breeding Control

  • Selective breeding programs
  • Avoid breeding affected animals and carriers
  • Maintain breeding records
  • Use genetic screening where available
Summary for Practitioners

Genetic disease prevention in small ruminants relies heavily on responsible breeding management and early identification of inherited defects.

Economic and Welfare Importance

Inherited diseases in sheep and goats can cause severe congenital deformities, impaired growth, poor production, blindness, mobility problems, and neonatal losses, leading to important economic and welfare consequences.

Summary

Important inherited diseases in sheep and goats include Spider Lamb Syndrome, Hereditary Splayleg, Myotonia Congenita, and Entropion. These disorders affect the skeletal, muscular, nervous, and ocular systems and require careful diagnosis and breeding management for long-term control.