DVM 360 “How long does [a] tick have to feed to transmit an infection?” Susan E. Little, DVM, PhD, DACVM, Krull-Ewing professor of parasitology at the Center for Veterinary Health Sciences at Oklahoma State University in Stillwater, posed to her audience during a lecture at the 2025 American Veterinary Medical Association (AVMA) Convention in Washington, DC, this July.1
“The true answer is, it depends,” Little answered.
The answer to how long a tick must feed to transmit a pathogen depends on several factors. These factors may include tick species, pathogen type, tick life stage, environmental conditions such as temperature and humidity, and the type of host.
As Little would go on to explain, no studies have investigated the minimum time it takes for North American ticks to transmit pathogens to dogs. To date, the available data is extrapolated from studies on mice, guinea pigs, or dogs in other parts of the world.1 Moreover, many of these studies have been conducted using immature ticks, or nymphs, instead of adult ticks.
“Larvae feed in about 3 to 5 days…nymphs feed in about 5 to 7 days…adults feed for 7 to 14 days or longer. And so, their physiology is different. How quickly they get into that rapid feeding process that will lead to transmission varies for the different stages,” said Little.