Which clinical sign is associated with organic pentavalent arsenic exposure?

• A. Neuro signs and sitting-dog posture
• B. GI signs only
• C. Respiratory distress
• D. Skin rashes and lesions

Answer: (A)

Organic pentavalent arsenic exposure is most classically linked to neurotoxic effects, including signs of weakness and impaired coordination that can produce a distinctive sitting-dog posture. This posture reflects hind limb weakness and altered gait from neuropathic involvement, which is a hallmark feature of organoarsenical toxicity seen in veterinary toxicology texts.

The other options don’t fit this specific exposure pattern as well. GI signs can occur with arsenic exposure in general but aren’t the defining feature of organic pentavalent forms. Respiratory distress isn’t the primary presentation for this exposure, and skin rashes or lesions are more typical of chronic inorganic arsenic toxicity, not the acute neuro-dominant picture used to identify organic pentavalent arsenic effects.

So, the neurologic signs, especially the sitting-dog posture, best indicate organic pentavalent arsenic exposure.