A swollen paw on a dog usually comes from one of a handful of causes: something stuck between the toes, an insect sting, an allergic reaction, an infection, or an injury like a sprain or broken toe. Most cases aren’t emergencies, but figuring out the cause matters because the right response ranges from a simple soak at home to a same-day vet visit.
Foreign Objects Trapped in the Paw
The single most common reason for a swollen paw is a foreign object lodged between the pads or toes. Thorns, small rocks, splinters, and foxtail grass seeds are frequent culprits. Foxtails are especially problematic because their barbed shape lets them burrow deeper into tissue over time rather than working their way out. A dog with something stuck in the paw will typically limp on that leg and lick obsessively at one specific spot.
If you can see the object, you may be able to remove it carefully with tweezers. But if the area is already red and swollen, or if you can’t locate what’s causing the irritation, the object may have migrated below the skin surface. At that point, a vet needs to extract it, sometimes with light sedation. Left alone, embedded foreign bodies almost always lead to secondary infections that make the swelling worse.
Insect Stings and Spider Bites
Bee stings are a classic cause of sudden paw swelling, especially in curious dogs that step on or swat at insects. The swelling tends to appear within minutes and is usually concentrated around a single spot. If you can find the stinger, scrape it out with a credit card or stiff edge rather than squeezing it, which can push more venom into the skin. Tweezers work too if you grasp the stinger itself below the venom sac.
Most sting reactions are mild and resolve on their own within a day. Spider bites, however, can be harder to identify and occasionally cause skin tissue to die around the bite, requiring veterinary treatment or even surgery. The real danger with any bite or sting is an allergic reaction. If your dog develops facial swelling, hives across the body, vomiting, difficulty breathing, or collapses, that’s anaphylaxis and requires emergency care immediately.
Allergies and Chronic Paw Inflammation
When the swelling isn’t sudden but keeps coming back, or when multiple paws are affected, allergies are a likely cause. Dogs with environmental allergies (pollen, dust mites, mold) or food sensitivities often develop a condition called pododermatitis, which is chronic inflammation of the paw. The skin between the toes turns red, puffy, and sometimes raw from constant licking and chewing.
The licking itself creates a vicious cycle. Moisture from saliva promotes yeast and bacterial overgrowth between the toes, which makes the itching worse, which leads to more licking. You’ll often notice rust-colored staining on the fur around the paws from saliva. Contact allergies can also trigger it, sometimes from something as simple as a new floor cleaner or walking through treated grass. Figuring out the underlying allergen, whether environmental or dietary, is the only way to break the cycle long-term.
Interdigital Cysts and Lumps
If the swelling looks like a firm, raised bump between your dog’s toes, it may be an interdigital furuncle, commonly called an interdigital cyst. These are deep, inflamed nodules that form in the webbing between toes. They can rupture and drain, then refill, sometimes repeatedly over weeks or months. Short-haired breeds with stiff fur between the toes, like Bulldogs, Labradors, and Pit Bulls, are especially prone.
These lumps are often caused by ingrown hairs, friction, or bacterial infection, but they can sometimes look similar to tumors. Actual paw tumors are rare, but a vet may recommend a biopsy for any unusual or recurring lump. A skin biopsy is the only way to definitively tell the difference between a benign cyst and something more serious.
Injuries: Sprains vs. Fractures
Trauma to the paw, whether from jumping off a high surface, getting stepped on, or catching a toe in something, can cause swelling from either a soft tissue sprain or a bone fracture. Both cause limping, but there are some differences in how they present.
A sprained paw typically shows mild swelling and a reluctance to bear full weight. Your dog may walk with an unusual gait but can still get around. They might become less active or withdraw to a quiet spot. A fracture tends to produce more dramatic signs: visible bruising or discoloration under the skin, intense pain when the area is touched, and sometimes aggression or crying out from a dog that’s normally gentle. In open fractures, the bone breaks through the skin, which is unmistakable. But closed fractures can be subtle, showing only as bruising and severe tenderness. X-rays are the only reliable way to distinguish the two.
Hot pavement is another common injury source, especially in summer. Pad burns cause swelling along the bottom of the paw and may blister or peel. If the pavement is too hot for you to hold your hand on for five seconds, it’s too hot for your dog’s feet.
What You Can Do at Home
For mild swelling without signs of a fracture or severe allergic reaction, a warm Epsom salt soak can help reduce inflammation and draw out minor irritants. Mix a quarter cup of Epsom salts into a liter of warm water and soak the affected paw for up to 10 minutes. You can repeat this up to three times a day. Dry the paw thoroughly afterward, especially between the toes, since trapped moisture encourages infection.
Between soaks, keep the area clean and try to prevent your dog from licking it. A recovery cone or lightweight bootie can help. Check between the toes and pads carefully for any visible objects, cuts, or stingers. If the swelling doesn’t improve within 24 hours, gets worse, or your dog stops putting any weight on the paw, it’s time for a vet visit rather than continued home care.
Signs That Need Urgent Attention
Most paw swelling is uncomfortable but not dangerous. However, a few situations call for prompt or emergency veterinary care:
- Rapid swelling of the face or throat alongside the paw, which signals a systemic allergic reaction
- Difficulty breathing or blue-tinged gums after a sting or bite
- Visible bone or a paw that hangs at an abnormal angle
- Red streaking spreading up the leg from the paw, suggesting the infection is moving into deeper tissue
- Foul-smelling discharge from a wound or between the toes
- Swelling that persists beyond a couple of days or keeps recurring without an obvious cause
At a vet visit for paw swelling, expect a physical exam and possibly X-rays. If there’s a lump or an unusual lesion, the vet may take a cell sample (a quick needle draw from the swollen area) to examine under a microscope. These cytology tests typically cost under $50 to $70, and a biopsy runs around $90 if a tissue sample needs to be sent to a lab. Knowing the cause early usually means simpler, cheaper treatment than waiting until a minor problem escalates.