Table 1 Use of the key abnormality method to make a diagnosis when presented with a recumbent calf

1. Understand structure and function relevant to recumbency in a calf

 The nervous system

  • Central nervous system (CNS) (cerebral cortex/cerebellum)

  • Peripheral nervous system (peripheral nerve damage)

   • Femoral nerve (noting that most will stand with assistance)

 The musculoskeletal system

  • Muscle weakness (dehydration/metabolic acidosis/anoxia/malnutrition)

  • Muscle pathology (myopathy)

  • Skeleton (fractures/pain)

2. Ascertain the history/signalment

 Take a detailed history based on the signalment of the animal in question and directed towards determining whether the most common causes of disease

 Take a generic history followed by key, case-specific questions.

  • Key information includes age, signalment, the timeline of clinical signs and the progression of disease

  • Key, case-specific questions

   • Has the calf been recumbent since birth?

   • Was the calf able to stand at birth but subsequently became recumbent?

   • Was there dystocia?

   • What is the herd bovine viral diarrhoea (BVD) status?

3. Perform a general clinical examination

 Determine which body system(s) are primarily involved by:

  • Establishing the most likely location of any lesions

  • Establishing the type of lesions

 Key systems of interest in the recumbent calf are:

  • The central and peripheral nervous system

  • The musculoskeletal system

 General clinical examination

  • Is the calf dull, depressed?

  • Is the calf bright, alert and reactive?

  • Can the calf stand once it is assisted to rise?

  • What is the hydration status?

  • Is there a suck reflex?

  • Mucous membranes?

  • Hypopyon present?

 If central and peripheral nervous system is implicated continue to full neurological examination. If musculoskeletal system is implicated continue to full musculoskeletal examination

4. Consider and rank differential diagnoses

 Rank differential diagnoses in order of probability of occurrence. Apply clinical knowledge, experience and rational thinking. Common diseases should be at the top of your list of differential diagnoses.

  a. Calf recumbent since birth

   i. Calf is dull and/or depressed

    • History of severe dystocia, absence of suck reflex

     • Most probable diagnosis: Post-dystocia cerebral anoxia with metabolic acidosis

      (less common diagnoses: hydrocephalus, umbilical haemorrhage)

   ii. Calf is bright, alert and reactive

    • History of severe dystocia (assess lower and upper motor neuron function to help localise spinal cord segment involved)

     • Most probable diagnosis: Spinal cord trauma

    • History of severe dystocia, musculoskeletal lesions

     • Most probable diagnosis: Fracture of femur, metacarpal, first phalanx (P1)

    • History of severe dystocia, genuflexion, laxity of patella and neurogenic atrophy of the quadriceps femoris

     • Most probable diagnosis: Femoral nerve paralysis (particularly if bilateral)

    • Intention tremor (head bobbing), if able to stand a wide-based stance

     • Most probable diagnosis: Cerebellar hypoplasia (BVD)

    • Obvious pelvic asymmetry when standing

     • Most probable diagnosis: Hip dislocation

      (less common diagnoses: hip dislocation, vitamin E/selenium myopathy)

  b. Calf became recumbent approximately 10 days after birth

   i. Calf is dull and/or depressed

    • Diarrhoea and varying degrees of metabolic acidosis (assess hydration)

     • Most probable diagnosis: Enterotoxigenic Escherichia coli (ETEC)/rotavirus diarrhoea

    • Petechiation and/or hypopyon

     • Most probable diagnosis: Septicaemic colibacillosis

      (less common diagnosis: metabolic acidosis in the absence of diarrhoea)

   ii. Calf is bright, alert and reactive

    • CNS implicated following neurological examination

     • Most probable diagnosis: Spinal abscess

      (less common diagnosis: congenital heart defect)