Understanding and Treating Red Spots on Dog Belly

You are cuddling your pup and giving him belly rubs when suddenly you notice red spots on his belly. What are these red spots and are they cause for concern? Red spots on your dog's belly could be due to a number of underlying causes ranging from a skin infection to allergies to fleas. In this article, we will discuss the most common causes of red spots on your dog's belly as well as how they are diagnosed and treated.

Dermatitis, or inflammation of the skin, can present in a variety of ways. Symptoms of a dog belly rash depend on the underlying cause, how deeply the skin is affected, and how long the problem has persisted.

Common symptoms associated with dermatitis in dogs:

• Redness and swelling

• Red pimple-like bumps

• Pruritus (aka itching)

• Scaly or flaky skin

• Blisters, crusts, or scabs

• Pain and discomfort associated with the skin

• Abnormal or foul odor

• Increased oil production

• Fluid discharge

• Alopecia (aka hair loss)

• Lichenification (aka thickening of the skin)

• Pigmentation (aka darkening of the skin)

The skin is the largest organ in the body. It normally serves as a protective barrier and helps regulate your dog's temperature. But sometimes your dog's skin can become red and inflamed. So what causes red spots on a dog's stomach?

Red spots on your dog's belly can be due to several main causes:

• Skin infections

• Allergies

• External parasites (e.g. fleas, ticks, mites)

• Immune-mediated skin diseases

• Genetic (aka congenital and inherited) diseases

• Endocrine disorders

• Environmental causes (e.g. poison ivy, insect bites)

• Skin tumors

A skin infection may manifest as red lesions on your dog's belly. If your dog's skin health is poor or the skin's barrier function is compromised, it can become infected with several types of pathogens.

When bacteria cause a skin infection, it is referred to as pyoderma, a term that reflects the presence of pus. Symptoms of pyoderma depend on how deep the infection goes. Pyoderma confined to the surface of the skin is referred to as a "hot spot." Superficial pyoderma commonly results in red bumps or pimple-like lesions, circular crusty skin, flaky skin, hair loss, and itching. Deep pyoderma is associated with more severe symptoms such as pain, a foul odor, blood, and pus.

Skin infections in dogs can also be caused by fungus, such as yeast or ringworm. Yeast infections of the skin are also referred to as yeast dermatitis or Malassezia dermatitis because they are caused by a yeast called Malassezia pachydermatitis. Dogs with yeast dermatitis typically have severely itchy skin with an unpleasant odor. The affected skin of these dogs is often characterized by hair loss, flakiness or greasiness, crusts, thickening, and hyperpigmentation.

Both bacterial and yeast skin infections are often secondary to other problems such as allergies or endocrine disorders. Additionally, these dogs often have bacterial and yeast skin infections simultaneously.

Another type of fungal skin infection in dogs is ringworm. Ringworm is characterized by circular bald and scaly lesions. Dogs with ringworm must be handled with care since ringworm is transmissible to humans.

Allergies in dogs can manifest as changes to their skin. These allergies can be due to food or the environment. Dogs can also be allergic to fleas which we will discuss later.

Dogs with food allergies are allergic to proteins such as chicken or beef. In addition to itchy skin and ears, these dogs may experience gastrointestinal upset such as diarrhea and vomiting. Unlike atopic dermatitis, dogs with food allergies experience symptoms year-round.

Dogs can also have canine atopic dermatitis, which is an allergy to environmental allergens. The most common sign of atopic dermatitis is itchy skin. This itching can vary over time and may be seasonal depending on what the specific allergen is; for example, pollen from certain plants is more common during certain times of the year.

Dogs with food allergies or atopic dermatitis often cause trauma to the skin from scratching, which makes the skin more prone to developing secondary infection. If secondary infection is present, itching increases, and skin lesions can worsen rapidly without early treatment.

External parasites can bite dogs' skin causing red spots or a rash on their belly. Fleas can cause flea allergy dermatitis and severe itching. Mites are another potential parasite and are associated with mange. Other pests like ticks, flies, and mosquitos can also bite your dog's belly, which may cause him to develop a rash. In addition to giving your dog a skin rash, these external parasites are problematic because they can transmit dangerous diseases like Lyme disease, heartworm disease, and more.

In immune-mediated skin diseases, due to a faulty immune system, a dog's cells attack his own skin, causing the layers to separate. This results in painful blisters. Examples of immune-mediated skin conditions in dogs that can result in these red blisters include systemic lupus erythematosus and bullous pemphigoid. Dogs with bullous pemphigoid may also have hives.

Dogs can inherit a variety of genetic skin disorders, some of which are present at birth while others take time to develop. The good news is that genetic skin disorders are fairly rare. Some of these congenital and inherited skin abnormalities are more common in certain breeds. For example, psoriasiform-lichenoid dermatosis is a syndrome that can cause small red lumps in the groin region and is observed in young English Springer Spaniels.

Dogs with excess sex hormone levels can develop itchy skin rashes. Such hormonal imbalances can occur in non-spayed females and intact males with testicular tumors.

Skin abnormalities can occur with other endocrine disorders, such as hypothyroidism and hyperadrenocorticism (aka Cushing's). The most common skin change observed with these disorders is hair loss but these dogs also often have secondary skin infections because their endocrine disorders suppress their immune systems.

Dogs can develop skin rashes due to contact dermatitis. Contact dermatitis is essentially an allergic reaction that occurs when an allergen or irritant touches the skin. Because dogs typically have less fur over their belly, this is a common region affected by contact dermatitis. Common culprits include plants like poison ivy and topical products like certain shampoos.

Other potential environmental causes of hives include insect bites or stings. Excessive heat and friction can also result in skin irritation and cause a rash on your dog's belly.

A red bump on a dog's belly could also be a skin tumor. There are many different types of skin tumors and they can vary widely in appearance. An example of a skin tumor that could appear red is a hemangioma, which is a benign blood vessel tumor. Unfortunately, skin tumors can also be malignant so if you notice any lumps or bumps on your dog, talk to your veterinarian as soon as possible.

Diagnosis of skin problems in dogs includes a thorough history, physical exam, and a series of diagnostic tests.

Your veterinarian will ask you several questions about the history of your dog's skin problems. Common questions will investigate the duration of the problem, age of onset, progression of symptoms, previous medications and response to treatment, and more. This type of information will help guide the diagnostic process.

Your dog's history in combination with his physical exam findings and signalment (e.g. breed, age, sex) will help determine what diagnostic tests your vet may recommend. Possible tests include skin scrapings, microscopic evaluation of skin and hair, bacterial and fungal cultures, bloodwork, urine tests, and biopsies. Note that some of these laboratory tests take several days and that reaching a diagnosis may require several visits.

Treatment options depend on the underlying cause of your dog's skin problems. For example, a skin tumor may need to be surgically removed whereas a dog with hypothyroidism may require thyroid hormone supplementation.

In addition to successfully diagnosing and treating the underlying cause, treatment must also address any secondary skin infections, which are fairly common. Secondary skin infections can be treated with topical products, systemic or oral medications, or a combination of both. Examples of topical therapies include medicated shampoos and antibiotic ointment. Some dogs also require oral medications in the form of antibiotics and antifungals. In cases of severe itching and inflammation, dogs may also be prescribed corticosteroids.

Owners need to administer treatment exactly as directed by their veterinarian. This includes completing full courses of prescribed antibiotics and following up appropriately with recheck appointments. This is crucial to successfully clear secondary skin infections and prevent antibiotic-resistant infections from developing.

Your dog may simply have a rash or red spots on her belly because of heat rash or mildly irritated skin but it could also be a sign of a more serious health issue. Therefore, if you notice a skin problem or change in your dog, consult your veterinarian as soon as possible. Early recognition and diagnosis of dog skin conditions are key to improving treatment success.