Green Spot on Dog’s Skin? 4 Reasons Why It’s There!

Seeing a pustule on ourselves is not a big deal. However, if we see one on our dogs, as pet parents, we are obviously concerned. Why do dogs get pustules or green spots and what can be done about it are two of the things we wonder. 

Green spot on dog’s skin – now what? If your dog has a green spot or pustule, you need to carefully evaluate the situation and, if necessary, see your trusted veterinarian. Defined as small and pus-filled skin lesions, pustules can be a nuisance or an indicator of a more serious underlying condition. Whether your dog’s pustule falls in the first or second category is something the vet needs to determine. 

In this article, we will talk about green spots or pustules on dogs. We will discuss the reasons why dogs get them and give useful tips on how pet owners can manage them at home. We will also emphasize the importance of seeing the vet when necessary. 

What Are Green Spots or Pustules in Dogs? 

The popular term for pustules in dogs is green spots. From a more professional medical standpoint, pustules are defined as small and circular elevations of the epidermis filled with pus. 

They can appear anywhere on the body and, based on the underlying issue, can be more densely distributed in certain places. Developing a pustule or two every now and then is not a big issue. However, if your dog is prone to getting pustules or showing additional signs and symptoms, chances are there is a more serious issue. 

Why Do Dogs Get Pustules/Green Spots?

There are many reasons why dogs get pustules, and some of them are more severe than others. Let’s take a closer look at the potential causes of pustules in dogs. 

Cause number 1: Pyoderma

Pyoderma is a specific type of skin infection usually caused by Staphylococcus intermedius. In fact, whenever a dog gets pustules, it is assumed the culprit is this bacterium. Pyoderma often develops secondary in dogs with skin allergies. Other risk factors increasing the dog’s chances of developing pyoderma are:

  • External parasites (ticks, fleas, lice, mites)
  • Fungal and yeast infections of the skin
  • Hormonal imbalances (Cushing’s disease and hypothyroidism)
  • Compromised immune system
  • Certain medications (generally immune-suppressing drugs)
  • Some genetic conditions and anomalies. 

The pustules are yellow, itchy, and oozing, and usually concentrated in the trunk area. Luckily, canine pyoderma is not a contagious condition. The treatment is based on a long course of antibiotics (between 8 and 12 weeks). The most commonly prescribed antibiotics are amoxicillin, cephalexin, and clindamycin, and, in more severe cases, enrofloxacin. The vet will prescribe a suitable antibiotic based on sensitivity tests.  

Cause number 2: Skin fold dermatitis

Skinfold dermatitis is a widespread condition among certain dog breeds such as English Bulldogs, French Bulldogs, and Pugs. In such cases, the pustules are located on or near the skin folds and, if left untreated, tend to progress. Keeping your dog’s skin folds as clean as possible is helpful for preventing skin fold dermatitis. 

Cause number 3: Cutaneous lymphoma

While lymphoma is a common issue in dogs, cutaneous lymphoma, in particular, is relatively rare. Cutaneous lymphoma is a specific type of cancer that manifests with skin irritations, redness, itchiness, ulcers, and nodules. A dog with cutaneous lymphoma does not respond to any skin treatment. The lack of positive treatment response is a good indicator of cutaneous lymphoma. In case of fewer lesions, the vet will suggest surgical removal. However, if the skin lesions are widespread, it is best to combine surgery and radiation. 

Cause number 4: Pemphigus type of issues

Pemphigus is an autoimmune disorder that develops in several forms. Here are the common forms in dogs:

  • Pemphigus foliaceus – common in Akitas and usually affects the pads or, more precisely, the area around the nails. 
  • Pemphigus vegetans – usually triggered by the sun and manifesting with draining and oozing pustules. 
  • Pemphigus Vulgaris – fluid-filled and easily rupturing blisters in the mouth, nostrils, and around the anal region. 
  • Pemphigus erythematosus – crusty patches and skin scaling followed by hair loss, especially around the nose. 
  • Bullous Pemphigoid – causes welts, then fluid-filled sacs that become itchy and are located in the mouth, armpits, and groins. 

What Is the Green Mark on My Dog?

If instead of a pustule (green spot), you are referring to a green mark, especially on the dog’s belly, it means your dog is spayed. After being spayed, female dogs are marked with a special green dye on the surgical incision. The dye incorporates itself into the skin. Over time, the color may slightly fade, but it remains visible enough. 

So, if your dog is adopted and with not a very clear history and you happen to find a green mark on her belly, you can rest assured she is spayed at a certain point in her life. In such cases, the green mark is completely normal and expected, and there is nothing you should do about it. 

What Do I Do if My Dog Has a Green Spot?

The most important thing not to do is pop the pustules. Yes, it is true that popping pustules is fun and, for an unknown reason, a rewarding experience. However, you need to refrain from doing so. 

Popping the pustules will aggravate the issue and can lead to more serious skin infections. Plus, the presence of pustules is a symptom – they are not a diagnosis per se. Therefore, popping them will not solve the problem. On the contrary, it can only make things worse. 

If your dog is developing pustules on a regular basis and experiencing related skin issues, it is best advised to call the vet and schedule an appointment. The vet will perform a thorough physical examination and, based on the findings, set a diagnosis and craft a treatment plan. 

Summing Up: Green Spot on Dog’s Skin

A green spot on a dog’s skin indicates a pustule, or simply put, a pus-filled skin lesion. Pustules are disgusting to look at, but they must not be popped. 

If dealing with pustules, it is best to seek veterinary help. Some pustule-related issues are easy to deal with, while others require a more prolonged and tenacious treatment approach. 


  • Brad

    Hi I'm Brad, the founder of Having been a vet of 6 years I work alongside our team to provide valuable insight into your dog's health. I have a frenchie myself named Senzu who is my pride and joy!

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