Dog & cat health · Vet-reviewed guide

Ticks on Dogs: What They Look Like, the Diseases, and What to Do

A tick is more than a gross hitchhiker — it's a potential carrier of serious disease. How you find and remove them matters more than most owners realize.

Quick answer: Ticks on dogs are small, spider-like parasites that attach to the skin to feed on blood, and the reason they matter so much is disease: ticks can transmit Lyme disease, ehrlichiosis, anaplasmosis, and others. An attached tick looks like a small gray, brown, or black bump, often mistaken for a skin tag or wart, and it grows and darkens as it fills with blood.

Common spots are the head, ears, neck, feet, and between the toes. The two things that matter most are prompt, correct removal and knowing the warning signs of tick-borne illness, because the longer a tick stays attached, the higher the disease risk. Removing a tick the wrong way, by squeezing or twisting, can actually increase that risk, so the method matters. This guide covers how to spot ticks, the diseases they carry, and when to see a vet, and links to a step-by-step safe-removal guide.

What ticks look like on a dog

An attached tick is a small firm bump, gray to brown or black, that you feel when petting your dog.² Unfed, they can be as small as a pinhead or a sesame seed; engorged with blood, they swell to the size of a small bean and lighten in color. Look closely and you can see legs where it meets the skin, which distinguishes a tick from a skin tag. Check the head, ears, neck, armpits, groin, feet, and between the toes, especially after time outdoors.

The diseases ticks carry

This is why ticks are more than a nuisance. Depending on your region and the tick species, they can transmit Lyme disease, ehrlichiosis, anaplasmosis, Rocky Mountain spotted fever, and babesiosis.¹ Signs of tick-borne illness often appear weeks after the bite and include lameness or shifting leg pain, fever, lethargy, loss of appetite, and swollen joints or lymph nodes. Because these are delayed, it helps to note the date you found a tick.

Remove ticks promptly and correctly

The sooner an attached tick is removed, the lower the disease risk, but how you remove it matters just as much.¹ Squeezing or crushing the tick's body, or twisting it, can push infected material into the bite. See our step-by-step guide on how to safely remove a tick from a dog before you attempt it.

When to see a vet

See a vet if you cannot remove the tick fully, if the bite area becomes red, swollen, or infected, or if your dog shows any signs of illness in the weeks after a bite, such as limping, fever, or lethargy.² Vets can also run a simple blood test a few weeks after a bite to check for exposure. If treatment is needed, it must be prescribed by a vet. See how our vet prescription service works.

Prevention is the real answer

Because ticks are a year-round, disease-carrying risk, prevention beats reaction. See our flea and tick prevention guide for vet-guided options.¹