26 CFR § 1.1033(d)-1 - Destruction or disposition of livestock because of disease.
(a) The destruction occurring in a taxable year to which the Internal Revenue Code of 1954 applies, of livestock by, or on account of, disease, or the sale or exchange, in such a year, of livestock because of disease, shall be treated as an involuntary conversion to which the provisions of section 1033 and the regulations thereunder shall be applicable. Livestock which are killed either because they are diseased or because of exposure to disease shall be considered destroyed on account of disease. Livestock which are sold or exchanged because they are diseased or have been exposed to disease, and would not otherwise have been sold or exchanged at that particular time shall be considered sold or exchanged because of disease.
(b) The provisions of § 1.1033(a)-2 shall be applicable in the case of a disposition treated as an involuntary conversion under this section. The details in connection with such a disposition required to be reported under paragraph (c)(2) of § 1.1033(a)-2 shall include a recital of the evidence that the livestock were destroyed by or on account of disease, or sold or exchanged because of disease.
(c) The term involuntary conversion, where it appears in subtitle A of the Code or the regulations thereunder, includes disposition of livestock described in this section. (See, e.g., section 1231 and the regulations thereunder.)