Why My Dog’s Nail Turned Black?

My dog nail turned black. Photo of a black dog nail.

If you’ve realized that one or two of your dog’s nails turned black and are wondering what’s going on, you’re in the right spot! Here’s what you need to know!

There are a few common reasons for your dog’s nail to turn black. The most likely one is a fungal or bacterial infection in the nail itself. Other common causes include trauma to the nail or the toe, having a detached nail, aging, or symptoms of some sort of allergy, growth, or tumor. In rare cases, it can indicate an autoimmune disease. Learning how to tell what is (and isn’t) is essential!

Do dogs’ nails change color?

As your dog grows up and ages, nails can change color. From puppyhood to adulthood to senior years, nails will adapt and change. Some start as white, then go brown, and then black. Others start beige, go white, and then black. It depends on genetics, amongst other things! More on this below.

Why would a dog’s nails turn black?

As mentioned above, there are several reasons for a dog’s nail to turn black. Understanding how to distinguish between them helps you treat them properly! Top causes include:

  • Infection
  • Trauma
  • Aging
  • Allergies
  • Growth/tumor
  • Autoimmune disease

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There are all sorts of bacterial and fungal infections possible. They are commonly picked up in various locations, including dog parks, the sidewalk, backyards, and more. When they set into an infection, it will turn the nail black. You may also notice that the nail looks misshapen or has dark spots on it. These are signs that it’s an infection

Many dogs will also favor a leg that isn’t injured because their toe/foot will be itchy or might even be painful. They will pick at it more, either by licking or scratching it. If caught early, it shouldn’t spread past one or two toenails. It should be treated sooner rather than later, though, since it can create more serious health conditions if it’s left unattended!


This is similar to what happens with humans. With an injury to the nail or the toe itself, the nail will bruise, causing a dark spot or dark nail. The color will move along the nail bed as it grows out, and normal nails will come back.

A damaged nail may start red, then go brown, purple, and black. This is often okay on its own, but if the cuticle separates from the nail bed, it can be painful for your dog. If you notice that your dog is uncomfortable or the nail looks like it’s hanging on by a thread, you’ll want to have your vet look at it to help decide whether to take it off and wrap it to allow it to heal properly or to make another recommendation.


As dogs get older, their nail color will darken in many cases. This is especially likely if your dog has one or two black or beige nails, to begin with (more on that below). In this case, it’s nothing to be alarmed about since it’s like when your dog starts to go grey.

If a nail goes black because of aging, it will often get thicker, too. Your dog won’t notice any change and will not pick at it or otherwise pay attention to it. You might be tempted to cut the nail off, but keep in mind that the nail is not dead — it still has a quick and still protects your dog, so it’s needed!


It seems strange since dog allergies often come in the form of vomiting or hives, but it’s true! If a dog has environmental allergens, its nails can take on stripes or dramatically change color. It could be an allergy flare-up, or it could be long-term allergies.

This is not dangerous since it’s just discoloration of the nail. However, a vet can confirm and give your dog a test to figure out what is causing the allergic reaction!


When a nail’s growth gets disturbed, it can discolor. When a dog has a growth on its paw, toe, or even nailbed, this would count as a growth disturbance. Growths are often benign, but it’s good to have them checked out by your vet just to make sure.

Autoimmune disease

When a dog has symmetrical lupoid onychodystrophy (SLO), one of the symptoms or signs of it is that the nails will discolor. They can also split or crack or simply fall off. However, most will know that they have SLO before this, so your vet will be well aware of how to treat it!

Why are my puppy’s nails turning black?

Some puppies will have different colored nails at first. They may start beige and then go black. Some dog breeds commonly have black nails (like Rottweilers, for example). In this case, their nails will naturally darken to black as they grow out of their puppy years.

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

This is due to genetics! Just like their fur pattern can change and do things like giving them odd socks or making unique fur colors around their eyes, their nails can be multicolored. Some may grow out of this with their nails going yellow or white, and some may have different colored nails for their whole lives!

What to look for if your dog’s nail turns black

As mentioned above, there are signs that you can look for that your dog is dealing with a health problem rather than a discoloration. These include:

  • Picking at the nail
  • Not putting weight on the foot or limping
  • Showing signs of distress
  • Discharge
  • Odor
  • The black spreading to other nails

We all want to think that the discoloration is just a simple color change, but it’ll be essential to make sure that it is as harmless as that. All of these signs above show that something more serious will require an expert’s opinion!

Dog nail turning black after injury: what does it mean?

If your dog hurts its foot during a swim in the lake or perhaps gets a little too excited digging a hole, trauma to the nail can happen. If it turns black, it means that there is a blood bleed underneath or the nail is dying (temporarily) and will fall off as it separates from the nail bed itself.

What is the treatment for a dog’s black nail?

In cases where your dog has an infection, it would be a topical ointment. You must keep your dog from licking this, as it’s not safe for them to ingest. Most will cover the nail with wrapping.

Keeping the nail covered is also the treatment for when the nail is damaged or separating/has separated from the nailbed. The goal is to allow it to heal without getting infected!

How to cut a dog’s black nails

In this case, it depends if the black coloring is new or standard. In cases where their nail is newly black, you’ll want to visit your vet to see what the underlying issue is. Even if your dog seems fine, it’s still a critical step to helping keep your dog’s health a priority. Typically, a vet should be the only person to cut a black nail since an aged/unhealthy nail can be brittle and shatter easily.

However, if your dog has naturally occurring black nails, you’ll want to use your classic clippers or rotary grinders. Make sure you ask for tips for safely cutting nails from your vet. Since black nails cloak the quicks, you’ll need to learn how to cut their nails safely!

How to prevent black dog nails

It’s impossible to prevent black nails due to genetics or aging. These are the natural processes of your dog. They are also harmless.

In a situation where it’s an allergy, you can help keep your dog’s nails safe by limiting their exposure to the allergen. 

As far as bacteria and trauma, the best thing you can do is always keep an eye on your dog when he’s playing outside to help keep him from damaging his nail. When he comes in, you should have a “paw cleaning station” set up so that you can clean off any dirt or bacteria to help limit infections!


A dog’s nails can change color due to aging or genetics. Random darkening of their nail can be from an infection, trauma to the toe/nail, allergies or an autoimmune disorder, and even a growth or a tumor.

Knowing which you’re dealing with is essential, so make sure you know how to tell “normal” changes from “abnormal” changes.

A dog can have a black toenail for many reasons. Understanding which ones are serious and harmless is essential for your dog’s health and your peace of mind as a responsible pet parent!

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Andre Neves

Hi, I'm Andre and I'm the owner of Sula the Border Collie. I love writing about this amazing dog breed here. I joined the Council to be able to reach and educate more people on the joy of having a pet dog.