A consonant is a speech sound that is not a vowel. It also refers to letters of the alphabet that represent those sounds: Z, B, T, G, and H are all consonants. Consonants are all the non-vowel sounds, or their corresponding letters: A, E, I, O, U and sometimes Y are not consonants.
The passage gives a brief overview of the history of mad cow disease. It details when and how it started, the spread of the disease, and the efforts taken to eradicate it.
