We've all been there — is that a tick, or something else? If you come across an unusual lump or bump during grooming or while checking for pests, it's important to identify and know the difference between a tick or skin tag on dog. Although in many cases a tick, a mole, or a skin tag is obvious, small ticks and dark-colored skin spots may require the use of a magnifying glass, good lighting, and close observation to determine the difference.

Tick or mole on dog
The first thing to do is determine if you are looking at a tick or mole on your dog. A tick is a pest that is part of the arachnid family. It has eight legs and a hard shell, and is usually brown or gray. Depending on the type, a tick may be as small as the head of a pin or as large as half an inch long. A tick's body shape changes from flat before feeding to round and engorged when it is filled with blood.
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To look at a suspected tick more closely, part the dog's hair at the site of the suspected tick and look for legs along the side of the body, near the attachment point. Use a flashlight or bring your pet into a well-lit area, and ask a helper to hold the pet or the light for you.
After you've determined that you definitely have a tick on your dog, you may wish to remove the tick yourself. This is usually an easy process to do at home, but you may need a helper to either hold the dog, or a light — or to remove the tick while you hold the dog.
Moles are black or brown bumps that are generally small and benign. They are dark in color because of melanin, a pigment that we are all familiar with in human or canine skin that usually darkens with sun exposure. Moles should always be checked out by a vet if they appear to be growing or have a concerning appearance.
What is a skin tag?

A skin tag is an unexplained growth on a dog's skin that looks similar to a wart. Unlike a wart, however, a skin tag is thin and flat, almost as if the skin has been permanently pinched together. Dark-colored skin tags may look similar to ticks that are not yet engorged with blood, but they cannot be removed with tweezers and pinching or pulling them is painful for the dog and can cause bleeding. After examining the suspected tag to make sure you can find no signs that it is a tick, such as the presence of legs, feel the skin tag, taking care not to squeeze it. It should feel like living skin and not hard and smooth like a tick.
When to seek veterinary help
If you are still unsure whether the spot in question is a tick or a skin tag, schedule a visit to your veterinarian. Don't pull on it or try to remove it until you are sure. Skin tags should not be removed at home; fortunately, they generally don't need to be removed or treated at all.
Think about other concerns
Other skin problems such as cancerous lesions can also appear at first glance to be an insect or a small bump, but could turn out to be melanoma, squamous cell carcinoma, or other kinds of skin cancer. A veterinarian will determine whether a blemish is cancerous, and what treatment options are available for your dog.
Ticks carry diseases such as Lyme disease — a bacterial infection transmitted by the black-legged tick — or anaplasmosis which is another tick-borne disease caused by a bacteria called anaplasma phagocytophilum. Anaplasmosis comes from the bite of a deer tick. Your veterinarian will be able to help treat these diseases with antibiotics. There are also preventative vaccines against Lyme disease.