09/03/2026
Tick season, unfortunately, does not end when summer does.
In New Hampshire, adult deer ticks are often more active in the autumn. That is when many horses pick them up in the mane and tail, under the jaw, and in the groin. Lyme disease gets most of the attention, but anaplasmosis is the one that can make a horse look suddenly and obviously sick.
A few things worth knowing:
1. Pull ticks as soon as you find them. There is no guaranteed safe window for transmission of disease agents. The risk goes up the longer a tick is attached, and some tick-borne diseases can start transferring sooner than the old "wait a day" rule. Daily checks always matter because you cannot know when that tick crawled on.
2. Fever and swollen legs are a reason to call. A horse who is dull, off feed, running a fever, or stocking up in the limbs may have anaplasmosis. That is not a "wait until Monday" situation.
3. Lyme is common to be exposed to here but less common to actually cause disease. A positive blood test by itself does not necessarily mean the lameness, the crankiness, or the "not quite right" is Lyme disease. Those clinical signs have a lot of other causes that are worth ruling out.
4. Prevention is barn-level, not just an on-horse spray. Keep brush back from fence lines where you can, check horses after any time in the woods or tall grass, and talk with us about what prevention makes sense for your horses and your property.
If you find a tick, pull it, or if you have a horse who seems off as the weather cools, reach out. We’re always happy to look and make a plan!