Why Does My Dog Have Purple Spots On His Ear?

Vasculitis in dogs is an inflammation of the walls of the blood vessels. This abnormal disorder causes serious skin conditions. This pathology has an endless number of causes, processes and consequences, which we will gradually discuss in this article. Vasculitis is located on the skin, however it can also involve the different organs or can be associated with other diseases. We will gradually discuss these in this article. It's also important to mention that this disease may appear in any dog, of any breed or any age. Although there are suspicions of certain breeds that are more prone to vasculitis, none of these claims have been scientifically proven.

In human medicine, this pathology is widely studied and classified in a very efficient way. However, it is classified differently to canine vasculitis due to various differences. As far as veterinarians are concerned, we can break this pathology down into three main classifications that are not mutually exclusive. In other words, a vasculitis can belong to one, several or all the classifications to be correctly specified.

Classification of vasculitis according to its affected vessels

Within this group we find cutaneous vasculitis and systemic vasculitis. Cutaneous vasculitis typically affects the skin and, therefore, its symptoms can be seen on this organ. It usually occurs due to the proliferation of certain cells that end up causing inflammation of the vessels, resulting in skin lesions. These vasculitis can be classified at microscopic level according to the cells causing the clinical picture:

• Neutrophilic vasculitis: an edema of endothelial cells and abundant neutrophils on the vessel wall may be witnessed microscopically. Some vasculitis that may or may not be neutrophilic are: dermatomyositis, drug reactions (iatrogenic), Scottish terrier vasculitis, etc.
• Lymphocytic vasculitis: they rarely occur in animals and can end up being chronic. They are produced by a lymphocyte-mediated immune reaction. Some examples of lymphocytic vasculitis in dogs could be: rabies vaccine- induced panniculitis and vasculopathy of the German shepherd.
• Eosinophilic vasculitis: this type of vasculitis is mediated by immunoglobulins E. The most common examples are: reactions by ectoparasite bites and eosinophilic granuloma complex.
• Granulomatous vascultis: do not usually occur primarily, but may be the consequence of neutrophilic vasculitis. The most common examples are: sterile idiopathic panniculitis and again drug reactions.
• Systemic vasculitis: responds to inflammation of many vessels throughout the body, unlike cutaneous vasculitis, although the signs can also be seen on the skin. It is usually more serious and manages to deteriorate the patient's quality of life much more.

Classification of vasculitis according to its cause

The latest research sought out ways to further simplify the classification of the types of vasculitis in dogs. This resulted in being able to group pathologies into two large groups:

• Infectious vasculitis: this type refers to the many pathologies that are capable of causing vasculitis in dogs. The most common infectious vasculitis are those that appear as a consequence of canine ehrlichiosis, systemic lupus erythematosus, leishmaniasis, etc.
• Non-infectious vasculitis: these pathologies are not caused by a disease, therefore, they are not classified as infectious. In most cases, their cause is unknown (this is the case for idiopathic vasculitis). In some cases it may be due to misuse of medications (as in iatrogenic vasculitis).

It should be clear that both can also be cutaneous or systemic, remember that, as mentioned above, the classifications are not mutually exclusive. There are many canine vasculitis. After explaining the two ways of classifying them, we will now elaborate on the most common below.

As we have previously mentioned, these pathologies are associated with an abnormal response from the immune system against the body itself. According to microcopic findings, the classification of vasculitis almost always responds to immune-mediated diseases. Most of the time these vasculitis do not have a known cause, so they are called idiopathic.

In order to correctly diagnose your dog, a veterinarian will need to effectively link clinical signs with any clinical case, while taking into account the dog's anamnesis.

Once your veterinarian suspects vasculitis, they will try to find its cause. To do this, they will draw blood to carry out a hematology test. These tests provide valuable information for the veterinarian. For example, if there are hemotropic agents present, they will try to eliminate the hemoparasites. Or perhaps your veterinarian will have an x-ray done so as to observe if there are heartworms. Wood's lamp can also be useful to detect fungi in skin lesions. In complicated cases, a skin biopsy may be necessary.

The treatment for vasculitis in dogs will depend on each individual case and its underlying cause. For example, immune-mediated cutaneous vasculitis will be treated with immunosuppressive drugs and, if needed, with a supportive treatment that stabilizes the patient. Many times the patient arrives unbalanced for having days without eating food due to the pain and discomfort that these pathologies generate. Glucocorticoids are generally indicated and collaborate greatly in these cases.

In the case where vasculitis was caused by an infection, veterinarians will generally use antibiotics and non-steroidal analgesics. Most dogs who suffer from cutaneous vasculitis must also take anti-inflammatory drugs and immunosuppressive medications to control the abnormal immune response. The types of medication depend on the severity of the skin condition and whether or not internal organs have been affected.

When vets can’t find or treat the underlying cause of the condition, medication may need to be given for the rest of the dog's life.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

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