Neurology Case of the Month: Tetraparetic Yorkie

Written on June 21, 2012 by Staff Veterinarian

Signalment: 1 1/2 yr MC Yorkie Mix

History: Referred to MVRH for evaluation following an acute onset of ataxia on all 4 legs progressing rapidly to nonambulatory tetraparesis over the course of 24 hours. No known toxin exposure or ingestion of trash or carcasses. Two days prior to admission he’d fallen off the back of the couch.

Neurological exam:

Mental status: BAR
Nonambulatory without support
Cranial nerves:
Weak palpebral (blink) reflex bilaterally, remainder WNL
Postural reactions:
Normal CP x 4 with support
Spinal reflexes:
Absent patellar reflex bilaterally
Reduced in all 4 legs
Spinal pain:
Muscle tone:
Reduced x 4
Muscle atrophy:
Pain sensation:
Normal x 4
Cutaneous trunci:
Normal bilaterally

What is your neurolocalization? What are the top differential diagnoses? (SCROLL DOWN TO SEE ANSWERS)







Neurolocalization = Diffuse lower motor neuron


The top 4 differential diagnoses are:

  • Tick Paralysis
  • Coonhound Paralysis / Acute Idiopathic Polyradiculoneuritis
  • Botulism
  • Acute fulminant myasthenia gravis


The RDVM had removed an engorged tick prior to referral. We shaved the entire dog to be sure that we located and removed any other ticks that were attached to the dog. Frontline was given to help reduce future tick exposure. Additional diagnostics that were planned if there was no improvement by the following day included: routine blood tests, thoracic radiographs to look for megaesophagus, and possibly electrodiagnostics (EMG, nerve conduction studies, etc.) and CSF analysis.


Tick Paralysis


Removal of engorged ticks. By the following morning, the patient was walking without assistance and without any treatment other than removal of a tick by the RDVM. This is highly suggestive that the patient truly had Tick Paralysis. The other conditions listed above would not improve that quickly.


The prognosis for recovery from Tick Paralysis in the United States is excellent as long as the offending tick is removed.

For additional information concerning diffuse LMN diseases, download the June 2007 IVGI newsletter.

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