HealthAnatomyWhy Are My Dogs Nails Turning Black?

Why Are My Dogs Nails Turning Black?

Although there are several reasons for a dog’s nail to turn black (including trauma, aging, autoimmune disease, and genetics), the most common reason is a fungal or bacterial infection. With proper treatment, the infection should clear in 4-6 weeks. To prevent future infections, trim your dog’s nails once per month. 

If you are like most dog owners, your dog means the world to you and you take photos of him constantly. As you go through these photos, you may have noticed something strange about your dog’s nails. They used to be light, but now some (or even all) of them have turned black.

What causes this? And should you be concerned?

Dog nails can turn black for a variety of reasons, including:

  • Nail Fungus
  • Infection
  • Trauma
  • Autoimmune Disease
  • Aging
  • Genetics

In this article, we will go over each into detail on the possible reasons your dog’s nails have turned black. Some reasons require medical attention, some are completely natural.

Nail Fungus

When your dog’s claws display abnormal nail color because of a fungal infection, usually only one or two nails are affected at a time. The two strains of fungi that are responsible for most fungal infections in dogs are Dermatophytes and Malassezia. The infection can take hold in nearly any crevice on your dog’s claw, from the nail bed to the claw folds to the actual nail itself.

Symptoms of a Fungal Infection

Common symptoms of fungal infections on dog nails include discoloration, brittle nails, licking and biting of the paws, and itchy paws.

If you suspect that your pup might have a fungal infection on their nail, it is best to seek immediate attention as delaying treatment may allow for the infection to spread to other, previously unaffected areas.

To diagnose your dog, your veterinarian will conduct a simple test where they will scrape (and sometimes biopsy) the infected area to view under a microscope. If your vet determines that there is indeed a fungal infection, they will prescribe the correct course of action for your dog.

Treatments for Fungal Infections

Treatments for fungal infections include foot soaks, antifungal spray, and antifungal therapy.

Antifungal therapy includes preventative and restorative maintenance, where all loose, brittle nails are removed before the treatment is applied. The treatment can take course over several months, during which excellent hygiene is required to completely eradicate the issue.

During this time, you will need to trim your dog’s nails frequently to remove any infected sections while undergoing sequential fungal testing until the results are clear.

This is a fastidious process, but it brings about the best results for your dog’s nails.

Bacterial Infection

Other than fungal infections, nail infections can be caused by different forms of bacteria. Some forms of bacteria will turn your dog’s nails red or black.

Treatments for Bacterial Infections

Topical medications are typically the treatment of choice for infections caused by bacteria. Depending on how severe the infection is, your veterinarian might prescribe a round of oral antibiotics or other medication to resolve the infection.


Just like a human’s finger nail can become visibly discolored after a traumatic event, so can your dog’s.

If your dog’s paw was accidentally stepped on, smashed in a door, or caught in the carpet, it’s possible that one or more of their claws may become discolored after the incident.

Nails can even fall off due to trauma, so be mindful if your dog is favoring their paw after a traumatic event.

Autoimmune Disease

Nail discoloration is a marked symptom of SLO (symmetrical lupoid onychodystrophy), an autoimmune disease that affects a select handful of breeds. This autoimmune disease causes a considerable amount of pain for dogs; their nails will split and even fall off because of the condition.

When diagnosed, your vet will take the autoimmune disease and all accompanying symptoms into account when creating your dog’s treatment plan.

The following breeds are the ones most affected by SLO:

  • Rottweiler
  • Greyhound
  • West Highland White Terrier
  • German Shepherd
  • Welsh Corgi
  • Schipperke
  • Labrador Retriever
  • Schnauzer
  • Gordon Setter
  • Charles Spaniel
  • Bearded Collie
  • German Shorthair Pointer
  • Akita
  • Cavalier King


As mentioned earlier, changes in your dog’s physical appearance are to be expected as they age. While most people typically think of a dog’s coat showing more white or gray, another way that dogs show their age is through their nails. Over time, the nails can naturally turn yellow or black as the dog ages due to no external factors.

Genetics and Hyperpigmentation

Perhaps the least concerning of all the possible causes for your dog’s nails turning black, genetics and hyperpigmentation can also account for this phenomenon.

Hyperpigmentation occurs when there is a large deposit of melanin, causing the black nail. Hyperpigmentation and genetics are combined in the cases of some specific breeds that have dual nail colors.

When these dogs are puppies, their claws are white, but as they age, they turn black naturally. In this case, it is important that you are familiar with the breed of your dog, so you know what to expect as they grow older.

How Can I Prevent My Dog’s Nails from Turning Black?

The best way to prevent your dog’s nails from turning black is to regularly trim them (this will prevent infections and trauma). If you choose to trim their nails at home, be sure to research appropriate trimming methods. You will need to pay special attention while trimming their nails, as you can cause further injury by cutting too close to the quick or the dog’s nail bed.

In the nail bed is a vein that is easily nicked but will bleed profusely and can lead to an infection. If you choose to trim your dog’s nails at home, keep a styptic powder on hand to staunch any bleeding that can occur if you nick the quick.

There’s a reason groomer’s and veterinarians keep styptic powder nearby when they trim dog’s nails; it is easy to accidentally injure your dog while trying to trim them.

Most importantly, remember to always clean and bandage the area as promptly as possible to curb the likelihood of infection and keep your dog’s nails looking pristine.

A Nail Turning Black Should Be Taken Seriously

As you can see, there are a variety of reasons your dog’s nails have suddenly turned black. There is a high likelihood that the color changed because of an infection, whether that be fungal or bacterial. The other likely reason is that some sort of trauma happened to their paw; just like humans, their nails can turn black and unfortunately fall off if the damage is severe enough.

The easiest way to keep your dog’s nails from turning black is to regularly trim their nails. Trimming your dog’s nails can be a stress-inducing task, so if you do not believe that you can cut them without injuring the dog, there is no shame in going to a groomer.

If you trim your dog’s nails incorrectly, you risk exposing them to infection, drawing blood, or otherwise injuring your dog. If you choose to trim your canine companion’s nails at home, keep a styptic powder handy so that you can easily stop the flow of blood should you accidentally nick them.

Your dog’s nails turning black should be a cause for concern, but it is easily manageable. As with any other medical condition, determining the cause of the change should be your priority; from there, you will be able to determine the best course of action for your dog. If you have further questions, refer to your preferred veterinarian for their professional opinion.

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