A study of macrolides concludes there is a 1 in 10 million to 1 in 3 billion chance of treatment failure from antibiotic resistance related to the use of common animal antibiotics, depending upon the bacteria. To put that into context, you are far more likely to die from a dog bite or lightning strike than from treatment failure related to the use of antibiotics in animals.

Sources:

• Public health consequences of macrolide use in food animals: a deterministic risk assessment.
• National Safety Council: Risk of dying from a dog bite is 1:116,448 and from lightning strike is 1:164,968.

A comprehensive 2016 review of 50 studies published in Critical Reviews in Food Science and Nutrition concluded there is an established connection between animal antibiotic use and antibiotic resistance in animals, but no established causal relationship between animal antibiotic use and human resistance related to campylobacter.

Source:

“Effect of Antimicrobial Use in Agricultural Animals on Drug-resistant Foodborne Campylobacteriosis in Humans: A Systematic Literature Review,” M.A. McCrackin, Kristi L. Helke, Ashley M. Galloway, Ann Z. Poole, Cassandra D. Salgado & Bernadette p. Marriott, Critical Reviews in Food Science and Nutrition, Volume 56, 2016 – Issue 13, Pages 2115-2132.