Why Do Dogs Toenails Turn Black?

As a caring pet parent, you need to know what's happening when your dog's toenails start to turn black or change color. Infections in this area are typically secondary to another underlying disease. In addition, proper maintenance with regular nail trims and the right nail clipping technique can help prevent common issues like hangnails and ingrown toenails.

Here you’ll learn how to handle black toenails in dogs and ways to prevent it.

Do dogs toenails change color?

A Dog paw in a human hand

Sometimes black toe nails is a sign of concern but other times this is perfectly normal.

The problem with canine nail discoloration can be a serious one and affects many dogs.

There are many types of paw and nail disorders that may lead to the discoloration of the nail. Causes range from mild to serious. Some require treatment but others do not. 

Discoloration can happen with one or more toenails or even be partially affect the nails.


Make it a habit to regularly check your dog's paws and that claws are regularly trimmed and healthy to prevent claw problems.

Why are my dogs nails black?

There are many causes of nail discoloration in canines, ranging from simple to complex.

Some dogs are genetically predisposed to having black toenails and this is perfectly normal. 

Untreated claw trauma caused by either excessive running on hard terrain like asphalt, concrete and gravel, or the use of infected nail clippers can contribute to nail discoloration. 

Brown or rust-colored nails could be as a result of a bacterial claw or fungal claw disease.  In bacterial infections the most common inciting cause is trauma. However infections of the nail bed could also be a sign of a systemic health condition such as hypothyroidism, diabetes or immune-mediated diseases and onychodystrophy among others. In this case, a complete physical examination and consideration of systemic disease is essential.

Excessive licking of the paws can also result in discoloration of the toenails, especially when the dog has an over-acidic system.

The diet and nutrition of a dog also affects its nail color. This happens when a diet is not appropriate for a dog's age or breed, leading to a nutrient deficiency. That's why you should monitor your dog's reaction to certain foods or food supplements it isn't used to.

Dirty environments may also play a role in nails turning black because of parasites and bacteria found especially in excessively wet or dry environments.

Ageing can also lead to discoloration of a dog's toenails. That's because canine nails undergo changes over time, like growth rate, shape, thickness, texture and color. As your dog gets older, it's possible for the nails to gradually turn black.

Here is a summary of the most common reasons for abnormal discoloration in your dog's nail:

  • Genetics
  • Breed disposition
  • Exposure to the environment
  • Injury during nail clipping
  • Nail bed infection
  • Age
  • Bacteria
  • Parasites
  • Trauma
  • Food hypersensitivity
  • Fungus

See Your Vet

If you suspect dog nail bed infection, contact your vet about starting treatment. These can be dangerous if left without proper medical care. 

Symptoms of nail discoloration in dogs

Overgrown dark claws in small dog

You may be able to detect and prevent nail discoloration in dogs by knowing it’s symptoms. The most common being:

Pain When Walking: When a dog's feet or nails are sore, the dog assumes an awkward posture and difficulty walking. It's typically an inflammation of the dog's fold and the dog becomes hypersensitive to touch underneath the paws. So if you find your dog walking with difficulty or posing oddly, it might be a sign of infection.

Rashes or Redness of Skin Tissue: Any of these appearing around a dog's nails is most likely a sign of some underlying health problem. And neglecting it normally leads to other complications like nail discoloration.

Deformed Nail Plates: It is also a sign of infection. This can affect one or more nails depending on the severity or type of infection. 

Paw Licking: When a dog excessively licks its paw, this can be a sign of infection. Dogs do this when they feel itching around the area. And itching is often a symptom of bacterial or fungal infection. In severe cases, the dog scratches its paws against the wall or floor, or even chew it. Dogs lick parts of their body in an attempt to provide treatment for a wound as their saliva contains bacteria-killer and pain relieve elements. But over-licking may do more harm than good when the problem is systemic, like kidney or heart diseases. Use a properly-fitted Elizabethan collar for a guaranteed way to prevent paw-licking of an infection.

Smelly Nails and Pus: In severe conditions of an infection, a dog's toenails can smell and develop pus. Take him or her for an examination by a vet right away. Because neglect can lead to more serious conditions like pneumonia or bone diseases.

Nail chewing is a symptom that your dog might have the hookworm infection that results from some nutrient deficiency. Another symptom of black toenails is a splitting nail.

How to treat a dog's nail turning black?

The exact cause and reason for the discoloration in your dog's nails can sometimes be hard to specifically diagnose.

If nailbed diseases are the primary cause for the canine claw turning black, the best treatment is prevention. There are several steps you can take to that effect. And if prevention fails, you must act immediately to nib any developing problem in the bud after a mild or severe symptom appears.

Your vet will be able to diagnose and suggest the most suitable treatment for your dog for nailbed infections, usually, different antibiotics and anti-fungal drugs being the most common treatment. 

If food hypersensitivity is a possible cause for the discoloration, monitor your dog's reaction to any change in diet. Allergy to foods can cause black nails in dogs. Your pet may have to be put on an elimination diet in order to determine foods that could be causing the discoloration. 

Another preventive measure is to regularly and properly nail trim your dog’s nails. Owners are often apprehensive about trimming their pet’s nails at home. However, overgrown nails can break and get infected.

Stop quick bleeding quickly with Miracle Care Kwik Stop Styptic Powder.

In case of an accidental clipping of the "quick" (vascular part of the nail) when trimming a dog's nails, especially black nails that the "cut line" is hard to determine, make sure you have styptic powder like  Kwik Stop® on hand to stop the bleeding. It costs at under $5 for 0.5-oz jar in most pet retail outlets.

Shop Kwik Stop on Chewy

Also keep your dog from licking or chewing its nails using a dog cone when you have applied treatment so they don't lick off the medicine.

Trauma to the claws is usually resolved using a treatment of daily antiseptic soaks and the removal of the broken nail. 

Finally, clean your dog's feet regularly to remove the specks of dirt and saliva that also stain nails.

How do you cut a dog’s nails that are black?

How do you trim a dog's nails

There are a few telltale signs to help you know when it’s time to trim. 

If your pup’s nails are touching the ground. Postural changes is another one. Most common sign of overgrown nails is the click-click sound of your dog's nails as she walks on hardwood or tile flooring.

Nails should be trimmed weekly

For more advice on dog grooming at home, check out this post: the ultimate guide to dog grooming at home.

To start trimming, here are the most popular and most recommended tools for the job:

  • Dog nail grinder/sander (i.e. a Dremel) or scissors-style clippers
  • Flashlight (some nails may be dark)
  • Paw balsam (optional)
  • Styptic powder or cornstarch
  • A treat (or many treats & patience!

Keep it positive

It would much easier if you have two people involved – one that does the petting and treat giving while the other trims the nails. This would make the nail trimming experience more positive for your canine friend. 

1. Make your dog comfortable

Get your dog in a comfortable position (keep them busy with lots treats) and hug him close to your body.

2. Get your dog's body position right

Slightly extend the leg you will be working on from behind the elbow (or knee depending on the leg).

3. Define the cutting edge and trim

It is important to cut below the quick! Start to clip one nail at a time below the quick by making very small cuts to the nail and examining the nail after each small trim. Always cut parallel to the bottom.

4. Avoid injuries

To avoid any injury be aware at all times, of your dog’s body language. If he or she is starting to become too stressed or agitated, release him or her, give a treat, take a break and praise them! Safety first! Pick up from where you left off later on.

How to see the quick in my dog's black nails?

Black nails are notoriously hard to trim safely because of the concealed “quick”.

You need to be aware of the "quick" and know its exact location when trimming a dog's nails. A dog's "quick" has nerves and blood, and is highly sensitive.

Groomers recommend looking at the cross section of the nail (front/underneath) that’s visible once the first cut is made. With white nails, the start of the quick is white or pink which is close to the nailbed, while in black nails, it’s grey or black. If you shine a flashlight behind the nail the quick will become visible.

What if there's bleeding after dog nail trimming?

Don't panic if you accidentally cut the quick! Just try and stop the bleeding using styptic powder or cornstarch on the wound.If you don't have any on hand, use ice-cubes. Keep any dirt away from getting in contact with the wound. 

If you can't stop the bleeding in 30 minutes, contact your vet.

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