Their saliva is making some farmers allergic to their own cattle and sheep. When Clark Giles first heard about ticks making people allergic to meat, he found the notion so unbelievable, he considered it “hogwash.” Then, in 2022, it happened to him. Following a spate of tick bites, he ate a hamburger and went into sudden anaphylaxis. His lips became numb, his face swollen, and his skin a “red carpet from my knees to my shoulders,” he says. Eventually, Giles—who raises sheep on a homestead in Oklahoma—had to give up eating not just beef but pork, and, yes, even lamb.
From there, his allergy started to manifest in stranger ways. During lambing season, the smell of afterbirth left him with days of brain fog, fatigue, and joint aches. To touch his sheep, he now needs nitrile gloves. To shovel their manure, he now needs a respirator. And Giles doesn’t even have it the worst of people he knows: A friend with the same allergy was getting so sick, he had to give up his sheep altogether. This unusual allergy is most often caused by the lone-star tick, whose saliva triggers an immune reaction against a molecule, alpha-gal, found in most mammals besides humans. The allergy is also known as alpha-gal syndrome, or AGS. In recent years, the lone-star tick has been creeping northward and westward from its historical range, in the southeastern United States. (Oklahoma is in fact right on the edge; ticks are more prevalent in its east than its west.) Alpha-gal syndrome, too, is suspected to be on the rise. Farmers who spend their days outdoors are particularly exposed to lone-star ticks, and repeated bites may cause more severe reactions. And so, Giles is among a group of farmers who have become, ironically, allergic to the animals that they raise.