Can pets harbor ticks, even in the winter?

A dog with ticks sitting in the woods in the winter season.

A recent study utilized TickSpotters, a photograph-based crowdsourced surveillance program to identify a variety of tick species found on domestic pets throughout the year. The findings revealed that ticks, although typically thought to pose a health risk in the spring and summer, are present in colder months, including in the winter.


In their article, “An analysis of companion animal tick encounters as revealed by photograph-based crowdsourced data,” Kopsco and colleagues found, “The percentage of reports of ticks found on companion animals is more than doubled in the fall and winter seasons from what was reported in the spring and summer seasons.”¹

Between January 1, 2014 and December 31, 2018, TickSpotters received  5,132 specimens from domestic animals (stated or assumed to be pets). The majority of ticks were found on dogs or cats.

50% of the ticks had been attached for 2.5 days or longer.

“Prior to uploading a photograph of the specimen to the system, instructions were provided to participants on how to take a photograph of the specimen with a size reference, proper lighting and clear focus to ensure the image highlighting the necessary anatomy to facilitate correct identification by researchers,” the authors write.

A variety of tick species were identified. Blacklegged ticks comprised 4 out of 10 of the tick species. American dog ticks, lone star ticks, and brown dog ticks were also found.

Additional findings:

  • Majority were adult ticks (9 out of 10);
  • 50% of the ticks had been attached for 2.5 days or longer;
  • Nearly 50% of the ticks were found in non-endemic states;

For example, 7.6% were from the East and West south central (AL, KY, MS, TN, AR, LA, OK, TX), 4.6% were from the Mountain area (AZ, CO, ID, MT, NM, NV, UT, WY), and 12.9% were from the Pacific area (AK, CA, HI, OR, WA).

  • More than half of the tick bites occurred in the Fall or Winter;

29% of all submissions occurred in the Fall (September-November), while 34% of all ticks  submitted occurred in the Winter months (December-February).

Since the duration of tick attachment on pets was more than 2 days, the authors raised the concern that pets are “not being checked regularly or thoroughly enough for ticks, or that owners are less inclined to continue use of effective tick prevention products when they believe tick activity is lower.”

Nearly 50% of the ticks were found in non-endemic states.

The authors also raised a concern for humans. “A recent survey of pet owners found that people whose pets had a tick encounter within the past 6 months were more likely to encounter a tick themselves.”

“Crowdsourced data reveal that mostly adult ticks are detected on pets, and they are found at a point in the blood-feeding process that puts pets at heightened risk for disease transmission.”

The authors suggest, “Our findings emphasize the importance of more broadly publicizing these ticks’ seasonal activity.”

  1. Kopsco HL, Duhaime RJ, Mather TN. An analysis of companion animal tick encounters as revealed by photograph-based crowdsourced data. Vet Med Sci. 2021 Aug 20. doi: 10.1002/vms3.586. Epub ahead of print. PMID: 34414695.

1 Reply to "Can pets harbor ticks, even in the winter?"

  • Christine Powell
    10/13/2021 (11:55 pm)

    Fascinating and eye-opening for those new to tick talk. Will be sharing widely.

Join the Lyme Conversation
(Note: comments are moderated. You will see your comment after it has been reviewed.)

Some html is OK