The main criteria that indicate what the problem might be are whether the swelling affects one or more feet.
The odds are that your dog will suffer from a foot problem at some time in their lives. Along with the swelling, your dog might also:
- limp/favor the affected leg
- lick or bite at their foor or feet
Foot or nail injuries or foreign bodies are the most common cause of lameness. At the same time, your dog’s feet might be red, smell bad, feel hot to touch, and have visible trauma.
The most common cause of swollen paws are foreign bodies. Other common causes include:
- wounds/injuries of pads or toes
- nail injuries or issues
- pad burns
- insect stings
- spider bites
- snake bites
- excessive licking such as due to allergies
- blocked lymphatic drainage
- cancer
Single foot swelling
When your dog has only one foot that is swollen, a localized issue is most likely. However, a careful examination of the affected foot is likely to provide a clue.
However, it doesn’t mean that—however frequent—foreign body or trauma is the only possibility. Some cancers, such as mast cell tumors, can lead to local swelling as well. So when looking for wounds, don’t dismiss any lumps or bumps you might find in the process.
Infections are usually secondary to another problem and can lead to swelling of one or more feet.
Foreign bodies
Foot foreign bodies can cause lameness, pain, and inflammation. In addition, the affected foot can swell either from the body’s effort to contain and remove it or from secondary infection.
For example, embedded grass awns—such as foxtails—can cause serious damage.
Wounds and injuries
Wounds and injuries are generally easy to identify when you scrutinize your dog’s foot. Typically, cuts and abrasions don’t make the foot swell. Instead, it is when the wound gets infected when you might find swelling.
A broken bone, however, such as a broken toe, is likely to swell.
Insect stings, spider or snake bites
I had my share of a dog getting stung in various places, including the feet. For example, a bee sting in the foot can result in substantial swelling and can be quite painful.
Spider bites can cause major swelling and lead to serious infections. Unfortunately, it can be hard to identify. If your dog’s swelling worsens, spreads, or if they’re in substantial pain, see a veterinarian.
Blocked lymphatic drainage
Blocked lymphatic drainage leads to edema. It can happen when a mass, tumor, or other obstruction further up the leg blocks the flow of the lymphatic fluid.
Caution: Bandaging that is too tight or children placing things like rubber bands around body parts are dangerous and can lead to edema.
Swelling of multiple feet
Allergies or adverse reactions
Allergies are a common cause of paw issues.
While exposure to some vegetation, such as poison ivy, can irritate the feet, the feet—however counterintuitive that is—can also respond to inhalant and food allergens.
As a result, the feet become inflamed, red, itchy, and swollen, especially if your dog licks them incessantly.
Pavement burns
During hot weather, pavement can become extremely hot and burn your dog’s pads. Such burns are painful and cause swelling of your dog’s feet and paws.
Infections
Both bacterial and fungal infections can make your dog’s feet swell. While with trauma or foreign body, an infection can be localized to a single foot, with systemic issues such as allergies, it is likely to invade all feet.
Along with the swelling, you might find lesions, discharge, hair loss, and excessive licking.
Tumors
While some cancers, such as mast cell tumors, are a single lump of bump, other cancers can affect multiple feet. For example, nail bed cancer is likely to present in more than one foot.
Immune disorders
The immune system can affect your dog’s feet by not working sufficiently or going off the rails. In addition, conditions that suppress immune function can lead to secondary infections.
Autoimmune conditions can cause excess inflammation. For example, even though it usually goes after the dog’s face, discoid lupus is a condition that can cause swelling of the legs and feet.
If your dog’s foot or feet as swollen doesn’t resolve, or if they are in pain, seek veterinary help.
Related articles:
Swelling (Edema) in Dogs
Further reading:
Swollen Paws in Dogs
Pododermatitis in Dogs