Table 1.

Modified Frankel scale used to describe the degree of neurologic impairment for dogs with intervertebral disc herniation.

Grade	Clinical signs
0	Paraplegia with absent superficial and deep pain sensation (also termed “deep pain negative” throughout the literature); there is an absence of behavioral response (e.g., vocalizing or orienting movement of the head toward stimulus) when clamping of a hemostat or other instrument to the skin of the limb/paw (superficial) and when applying the same stimulus while clamping the bone of the digit (deep). There is no observable voluntary movement of the hind limbs
1	Paraplegia with absent superficial but intact deep pain sensation; behavioral response (e.g., vocalizing or orienting movement of the head toward stimulus) is absent when clamping the skin (superficial) but present when clamping the bone of the digit (deep). There is no observable voluntary movement of the hind limbs. Note that some studies group this subset of dogs with either grade 0, or grade 2 depending on study design
2	Paraplegia with intact superficial and deep pain sensation (also termed “deep pain positive” throughout the literature); there is presence of a behavioral response (e.g., vocalizing or orienting movement of the head toward stimulus) to both superficial and deep noxious stimuli. There is no observable voluntary movement of the hind limbs
3	Non-ambulatory paraparesis; there is movement of one or both hind limbs, but the animal is unable to take 10 consecutive unassisted weight-bearing steps
4	Ambulatory paraparesis; the animal can take 10 consecutive unassisted weight-bearing steps with the hind limbs but displays an ataxic or paretic gait
5	Paraspinal hyperesthesia only; the animal has a normal hind limb gait but has posture or physical examination findings indicative of paraspinal hyperesthesia
6	Normal