Page 665 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

640 CHAPTER 3

VetBooks.ir Table 3.1 Havemeyer system for classification of laryngeal neuropathy

ENDOSCOPIC FINDING HAVERMEYER SCALE LANE SCALE US SCALE
Symmetrical at rest, full synchronous movement Grade I 1 1
Some asynchronous movement, full abduction easily attained Grade II.1 2 2a
Some asymmetry at rest, full abduction attained and maintained Grade II.2 3- to 3 2b
Asymmetry at rest, full abduction attained but not maintained Grade III.1 3 to 3+ 3
Asymmetry at rest, full abduction not attained Grade III.2 4- to 4 3
Asymmetry with little arytenoid movement Grade III.3 4+ 3
Total paralysis of the arytenoid Grade IV 5 4

3.77 3.78

Fig. 3.77 Dynamic overground endoscopy showing
symmetrical full abduction of the arytenoid cartilages.

Fig. 3.78 Grade III.2 recurrent laryngeal neuropathy,
showing asymmetry of the arytenoid cartilages,
in a horse shortly before undergoing overground
endoscopy.

arytenoid cartilage towards, or even across, the mid- Management
line can be observed in significant cases (Fig. 3.79). The management of RLN depends on the degree
This is often preceded by collapse of one or both of the neuropathy and the athletic potential of the
vocal cords. horse. Generally, the maximum demand for air is