Why does my dog have some black nails and some white?

If you’ve ever paused mid-photo because one paw seems to wear a tuxedo while the others look bleached, you’re not alone. Mixed nail color in dogs is common and usually harmless, but it can also be a clue that something needs your attention. This article walks through what causes black and white nails, when to relax and when to act, and what practical steps dog owners can take to keep paws healthy and comfortable.

What mixed black-and-white nails reveal about your dog

People notice nails when they’re close to the camera, during grooming, or when a dog walks funny. For many owners the question is purely cosmetic — black nails on a white-coated foot can look striking — but there’s more to consider. Nail color often mirrors the genetics that determine skin and coat pigment, so mixed colors across feet are commonly normal in multi-colored dogs. Still, changes that come on suddenly, are associated with pain, or occur after an injury may suggest infection, bleeding under the nail, or in rare cases a growth. Those are the times I tell owners it’s worth getting a professional opinion.

Bottom line: why some nails are dark and others light

In brief: some dog nails are black because melanin (the same pigment in skin and fur) is present in the nail matrix; other nails are white because that pigment is absent. Genetics and local skin color are the main drivers of this pattern. Outside influences — recent trauma that causes bleeding under the nail, fungal or bacterial staining, or topical chemicals — can also make nails dark or discolored. If a nail’s color shifts rapidly, becomes tender, bleeds, or your dog favors the paw, you should consider veterinary evaluation.

From genes to melanin — how nail color develops

Nails grow from a band of tissue called the nail matrix, and the color of a nail is likely linked to whether melanocytes in that matrix deposit melanin as the nail plate forms. Where the skin and hair are pigmented, the underlying nail matrix often has pigment too, which is why you’ll commonly see darker nails on darker-coated limbs. Pigment may provide a degree of protection, for example against ultraviolet light, although the practical protective role in nails is modest compared with skin or fur. As the nail grows, pigment laid down in the matrix is carried outward in the nail plate, which is why a change in color at the base is reflected along the length over time.

When nail color shifts: aging, injury, or illness

Some differences are present from birth: white-pawed dogs with patchy color will often have pale nails where the skin is pink and dark nails where the skin is pigmented. As a dog ages, nails may darken or accumulate brownish stains simply from environmental contact or minor, repetitive trauma. In contrast, a sudden dark spot beneath the nail usually points to a subungual hematoma — a bruise under the nail — after a crush or stub. Fungal or bacterial infections can produce discoloration and a crumbly texture, and repeated contact with soil, plant tannins, or dyes can stain the nail surface. Chemical exposures like certain disinfectants or topical medications sometimes change nail appearance as well.

Signs that a nail color change could signal trouble

Not every color difference is a problem, but there are clear signals that something may be wrong. If a nail changes color quickly and the dog shows pain or limps, suspect trauma with bleeding under the nail or an infection. Persistent drainage, an unpleasant smell, swelling around the claw fold, or a nail that separates and won’t heal are all reasons to seek care. New, rapidly growing dark streaks or masses at the toe raise concern for unusual causes such as benign growths or, rarely, tumors arising from pigment cells. Recurrent infections or nails that repeatedly crack and remodel can reflect an underlying skin condition or immune issue and deserve veterinary attention.

Practical steps owners can take right away

When you first notice mixed or changing nail color, a calm, methodical check is the best approach. Gently inspect each nail: look for cracks, lifting of the nail plate, swelling at the base, or debris in the nail folds. Photograph the nails from several angles and note the date — photos give you a baseline to compare if things change. Test for pain by offering gentle pressure near the nail; withdrawal, yelping, or guarding indicates discomfort. Ask whether your dog has had recent trauma, stepped on rough terrain, or been exposed to chemicals. If the nail is bleeding, apply gentle pressure with clean gauze and use styptic powder if available. When color change is sudden, painful, accompanied by swelling or discharge, or the dog is lame, make an appointment — even a triage phone call — with your veterinarian.

Preventing nail problems and teaching good nail habits

Most nail problems are easier to prevent than to fix. Keep nails trimmed to an appropriate length so they don’t catch or split; dogs that habitually overgrow nails are more likely to suffer trauma. Teach your dog to tolerate handling of the feet early and practice short, positive sessions with clippers or a grinder so nail care becomes routine rather than stressful. Avoid walking in places with sharp debris and consider booties for hikes on rocky trails or for salty, icy sidewalks that can damage paw skin. Regularly check paws after outdoor activities and condition dry paw skin with a veterinarian-safe balm to reduce cracking that can invite infection.

Essential tools and products for healthy nails

• Quality nail clippers or guillotine-style trimmers and a low-speed rotary grinder to smooth edges — practice on relaxed dogs and go slowly to avoid the quick.
• A bright flashlight or headlamp and a small magnifier to inspect the nail base and look for debris, cracking, or discoloration that is not obvious in normal room light.
• Styptic powder or cornstarch, clean gauze, and mild antiseptic wipes for immediate first-aid if a nail bleeds; keep these in your first-aid kit for walks or trips.
• Soft protective booties for rough hikes or winter walks and a veterinarian-formulated paw balm to help prevent cracks and moisturize dry paw pads and cuticles.

At the vet: what they’ll check and likely recommendations

When you bring a dog with nail concerns, the veterinarian will take a history (how quickly the change happened, recent injuries, prior nail problems) and perform a focused exam. They may trim or remove a portion of the nail to inspect the bed, flush debris, or obtain samples. In cases of suspected infection or unusual growth, they may recommend cytology, fungal culture, or biopsy. X-rays can be useful when there is persistent lameness to check for bone involvement under the nail. Most traumatic bruises and minor infections respond to local care and a short course of topical or oral medications, while persistent or atypical lesions receive a more targeted workup.

Keeping track: follow-up, monitoring, and when to return

If your veterinarian recommends home care, watch the photographed baseline for improvement or worsening and recheck the nail in a few days. Some bruises or fungal changes take weeks to show visible improvement because the new healthy nail must grow out. If pain, swelling, odor, or discharge continues despite treatment, or if new nails become affected, return for reassessment. I typically advise owners to bring the dog in sooner rather than later for changes that are rapid or painful — early intervention often prevents more involved procedures later.

Final takeaways for worried pet parents

Mixed black and white nails are usually a normal reflection of your dog’s genetics and coloring. Where concern arises is with abrupt changes, pain, or signs of infection. A careful home inspection, clear photos, and a sensible timeline for veterinary review will keep you ahead of most problems. With simple preventive care and a calm approach to handling, nail issues are commonly manageable and don’t have to interrupt your walks or photo sessions.

References and further reading

• Merck Veterinary Manual. “Nail Disorders” section. Merck & Co., Inc. A practical clinical overview of causes of claw and nail problems in small animals.
• American Veterinary Medical Association (AVMA). “Trimming Your Pet’s Nails” — Pet care guidance on safe nail trimming and first aid for bleeding nails.
• Miller, W. H., Griffin, C. E., & Campbell, K. L. Muller and Kirk’s Small Animal Dermatology, 8th ed. — Chapter sections on nail anatomy, pigment disorders, and subungual disease.
• American College of Veterinary Dermatology (ACVD). Clinical resources and owner information about canine skin and nail health, including infection and neoplasia guidance.