Here is a good one from 1975 :)
https://wol.jw.org/en/wol/d/r1/lp-e/1975044?q=anal+sex&p=par#h=4
Unnatural Sexual Relations
● Over two years ago this magazine warned against perverted sex practices such as oral and anal copulation, pointing out that, like homosexuality, these were “contrary to nature.” The Christian apostle Paul says that those practicing unnatural sexual acts ‘receive in themselves the full recompense due for their error.’ —Rom. 1:21-27.
Supporting this, the July 15, 1974, “Watchtower” quoted a warning from Dr. Elmar G. Lutz that “herpes-virus,” which ranks next to gonorrhea as a leading venereal disease, could be transmitted through oral-genital sex acts.
Now, from the London “Medical News” comes yet further evidence of the rightness of the apostle Paul’s inspired statement. At the Praed Street Clinic of St. Mary’s Hospital, authorities are quoted as saying that, while male gonorrhea acquired from the rectum (as in homosexual acts) has been relatively “commonplace,” evidence now records increased rectal contamination with gonorrhea among women. Of 105 females referred to the Clinic, doctors found that almost half had “indulged in either oral or rectal coitus.” The report adds that “such figures co-relate closely with those previously obtained from overseas sources.”