What's the difference between neighing and whinnying?

Neighing

Definition:

Example Sentences:

(1) What seemed at first a whoa-ful tale to be reined in, has now become a bit of a mare, neigh an un-fetlocked disaster, as it gallops into one of the week's mane stories.
(2) It's neigh laughing matter Because … Much of the country is unwilling or unable to take this unpalatable equine exposé seriously.
(3) Vocalizing (neighing) and walking occurred more often before than after feeding, while eating bedding and engaging in other oral behaviors were more frequent after feeding.
(4) A colliquative Stratified tuberculoma and some lesions of caseated bronchitis and peribronchitis were found in the neigh bourhood.

Definition:

Example Sentences:

(1) Call me a boring old class war moo, but I've watched several episodes of Made In Chelsea and at no point has Fenella Flumpinton-Ding-Dong's mother pointed her towards prostitution, whinnying, "Go on darling, get your pants off, help us out."
(2) Bird's character, the sane one, is plopped into the middle of this queer ensemble to whinny and writhe.
(3) So stop pretending to be all excited about them now, you whinnying berk.
(4) When confronted by their mirror images, two animals increased their number of vocalizations, which included "whinny" sounds, barks, buzzing, and varying patterns of click trains.
(5) He had little to offer to the fast-maturing sound film, but he bawled and whinnied for a while over the equally adolescent radio networks.