Reflexes

Hindlimb

  • Quadriceps (patellar) reflex

    • L4-L6 and femoral nerve

  • Cranial Tibial Reflex

    • L6-L7 and peroneal branch of the sciatic 

  • Gastrocnemius Reflex

    • L7 - S1 and tibial branch of sciatic

  • Flexor withdrawal response

    • Absent in LMN but present with UMN

Forelimb

  • Biceps Reflex

    • C6-C8 and musculocutaneous nerve

  • Triceps Reflex

    • C7-T1 and radial nerve

  • Extensor carpi radialis reflex

    • C7-T1

  • Crossed extensor reflex

    • Can be elicited with an UMN lesion

    • Normal in young animals

  • Cutaneous trunci reflex

    • Can be from C8-L4

    • Lesion is within 2 vertebrae of absent reflex

    • Not always lost with an injury

Cranial nerves

  • Pupillary Light Reflex

    • Sensory: Optic (CN2)

    • Motor: Parasympathetic oculomotor (CN3)

  • Mydriasis

    • Parasympathetic denervation of CN3

    • Dysautonomia

    • Intraocular

    • Hernia

  • Miosis

    • Sympathetic denervation (Horner’s)

    • FeLV

    • Carbamate or organophosphate poisoning

  • Physiologic Nystagmus

    • Sensory component: Vestibular CN 8

    • Motor component of CN 3, 4, 6

  • Menace Response

    • Sensory Pathway: CN 2

    • Motor Pathway: CN 7

  • Palpebral Reflex

    • Sensory: CN 5 (trigeminal)

    • Motor CN 7 (facial)

  • Corneal Reflex and Retractor Bulbi Reflex

    • Sensory: CN 5 (trigeminal)

    • Motor: CN 7 (facial) CN 6 (abduces

  • Gag Reflex

    • Glossopharyngeal and vagus (CN 9 and 10)