Trumpets in Bible times were made of metal or bone and formed into an instrument at least two feet long. They had a high sound that could be regulated to some degree, but they were used more for signaling than for making music. Rams’ horns, also called shofar, were signaling instruments used to assemble the army (Judg 3:27; 1Sam 13:3) or sound an alarm (Job 39:24-25; Jer 6:1; Amos 3:6). They are the most commonly mentioned instrument in the Bible, with seventy-two references.
SOUNDS OF JOY
References to horns have a particular connection with health, joy, prestige, and strength. When Hannah dedicated the miracle child Samuel to God she began her prayer, “My heart finds joy in the LORD. My head is lifted to the LORD. My mouth mocks my enemies. I rejoice because you saved me” (1 Sam 2:1). Her phrase “my head is lifted” literally means “my horn is exalted.” She was praising the strength and honor that God had bestowed on her. Later, when David wanted to express the prestige he had graciously received from God, he exclaimed, “But you make me as strong as a wild bull, and soothing lotion is poured on me” (Ps 92:10), which literally means, “you have lifted my horn.”

TOOL OF GOVERNMENT
The trumpet was used to call the Hebrew nation to assembly. It was most commonly used as a warning of and summons to war (Judg 3:27; 1 Cor 14:8). This association was so strong that in Jeremiah 4:21 the ram’s horn is used as a symbol for war itself: “How long must I see the battle flag and hear the sound or rams’ horns?” Sometimes trumpets announced danger (Amos 3:6). It was as alarming noise that would have gotten the attention of every Israelite.
When the people of Israel entered the Promised Land, their first obstacle was the mighty walled city of Jericho. God told them to take the city by marching around it while blowing rams’ horns. On the seventh day, as the rams’ horns echoed from the massive walls, the walls collapsed, and the city was taken (Josh 6:1-21).
The mere sound of the horn was a symbol of God’s power. He was the true King of Israel, more powerful than any earthly king, so his trumpets call is able to conquer obstacles and remove kings.
The sound of the trumpet also alerted the people to come to the Tent of Meeting and await instruction (Num 10:2-8). Certain signals told them to break camp or to assemble for religious occasions. The trumpet was used to announce the moving of the ark of the covenant and the beginnings of Sabbaths and religious festivals (2 Chron 29:28).
HEAVENLY TRUMPETS
When a new king was announced, the shofar spread the news (2 Sam 15:10; 1 Kings 1:34; 2 Kings 9:13). This use combined the symbolism of warfare and religious events because the king was considered God’s leader for the nation. In the last days a trumpet will announce the true King, Jesus, returning in glory at the second coming. “It will happen in an instant, in a split second at the sound of the last trumpet. Indeed, that trumpet will sound, and then the dead will come back to life. They will be changed so that they can live forever” (1 Cor 15:52; 1 Thess 4:16). The sound of the trumpet will get the attention of God’s people and signal the beginning of a new era in the kingdom of God.
Even now trumpets are in heaven-John said that he “heard a loud voice behind me like a trumpet” (Rev 1:10) when he was ushered into heaven. In Revelation 8, a trumpet announces each new event in the end times. No better auditory symbol for these end times events could there be than trumpet, which was used throughout the history of Israel as an alarm of danger and a summons to action.
so, are there pets in Rev. 8 shofar, since they announce judgement?
The first thing we have to remember is that the book of revelation is a book full of symbolism so if you read about a beast coming out of the waters then it’s symbolize something else. I didn’t see any pets reading the chapter but pets are the least important thing in God’s eye’s WE are made in his image not dog’s, cats, or any other animal so ALL DOGS DO NOT GO TO HEAVEN neither does any other animal. Animals goes back to the ground from whence they came. But always keep in mind that revelation is a book of symbols and you need other books to simply read and understand that chapter. I can refer you to some if you like. God Bless