Melanotic

Melanotic tumors in the paraproctal tissue in some cases, because of the large size of the new-growths, cause paralysis of the sciatic nerve.

Lameness of the Horse Veterinary Practitioners' Series, No. 1 John Victor Lacroix

Melanotic tumors have been found in the brain and meninges in the form of small, black nodules in gray horses, and in one instance are believed to have induced the condition known as stringhalt.

Special Report on Diseases of the Horse Charles B. Michener 1877