In veterinary there are numerous pathologies of which the tutor is not aware because they are not very frequent or too characteristic. Vasculitis in dogs is a condition that, although easy to define, is very difficult to diagnose and classify, making it very difficult for the animal caretaker to describe it to the veterinary practitioner.
In this article on our site, we will classify the types of vasculitis in dogs so that we can guide all the people who live with dogs to suspect this pathology in case their best friend presents it.
What is vasculitis in dogs?
As we said in the introduction, vasculitis is very easy to define and is nothing more than the inflammation of the blood vessels (capillaries, venules and arterioles of medium and large caliber). This pathology has endless causes, processes and consequences, which we will gradually comment on in this article. Vasculitis can be localized to the skin, it can also involve different organs or it can be associated with other diseases, either causing them or as a direct consequence of them.
Vasculitides in dogs are usually relatively frequent in these animals and no breed or age is predisposed. However, it has been reported that Rottweillers, Shetland Sheepdogs, Jack Russell Terriers and Dachshunds may be more sensitive, but this is not scientifically proven.
Types of vasculitis in dogs
In human medicine, this pathology is widely studied and is classified in a very efficient way, however, there are very important differences that prevent it from being classified exactly the same in veterinary medicine. In general terms, as far as canines are concerned, we can break down this pathology into three major classifications that are not mutually exclusive, that is, a vasculitis can belong to one, several or all of the classifications in order to be correctly specified.
Classification of vasculitides according to the vessels they affect
Within this group we find cutaneous vasculitis and systemic vasculitis. The cutaneous vasculitis is typical of the skin, so all the signs will be reflected in said organ. It usually occurs due to the proliferation of certain cells that end up causing the inflammation of the vessels, resulting in the characteristic skin lesions. It can be classified at the microscopic level according to the cells causing the clinical picture:
- Neutrophilic vasculitis: endothelial cell edema and abundant neutrophils in the vessel wall can be seen at a microscopic level. Some vasculitides 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 an immune reaction mediated by lymphocytes. Some examples of lymphocytic vasculitides in dogs could be: rabies vaccine-induced panniculitis and German Shepherd vasculopathy.
- Eosinophilic vasculitis: this type of vasculitis is mediated by immunoglobulin E. The most common examples are: reactions due to ectoparasite bites and complex eosinophilic granuloma.
- Granulomatous vasculitis: These 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 an inflammation of many vessels throughout the body, unlike cutaneous vasculitis, although the signs can also be seen on skin. It is usually more serious and manages to deteriorate the patient's quality of life much more.
Classification of vasculitides according to their cause
The latest research has sought a way to further simplify the classification of the types of vasculitis in dogs, an issue that resulted in being able to group the pathologies into two large groups:
- Infectious vasculitis: many pathologies are capable of causing vasculitis in dogs, and this type of vasculitis is called infectious vasculitis. They may or may not enter the classification that we have already named, of course. The most common infectious vasculitides are those that appear as a consequence of canine ehrlichiosis, systemic lupus erythematosus, leishmaniasis, etc.
- Non-infectious vasculitis: these pathologies are not the result of a disease, so they are not classified as infectious. Many times it is not known for sure how they appear (this is the case of idiopathic vasculitis). In some cases it may be due to misuse of medications (as in iatrogenic vasculitis).
It must be taken into account that both infectious and non-infectious vasculitides can also be cutaneous or systemic, remember that, as mentioned above, the classifications are not mutually exclusive.
In dogs there are many vasculitides that we can find, but after understanding the classification, we can name the most common below.
Atrial vasculitis in dogs
This type of vasculitis is usually cutaneous and can be both infectious and non-infectious. It is characterized by hair loss, bleeding, crusting and thickening of the pinna and the vertex of the ear, which ends up being the most affected. Its causes are so varied that any race and any age can be affected by this particular vasculitis. If not treated in time, there may be necrosis at the level of the vertex of the ear, a situation that requires otoplasty (surgery).
The discomfort that the dog suffers from this vasculitis leads to constant scratching, which usually aggravates the situation and, in some cases, can form an otohematoma. The most frequent causes of this vasculitis in dogs can be:
- Mushrooms
- Parasitic diseases
- Arthropod sting
- Autoimmune diseases
- Iatrogenic
Necrotizing vasculitis in dogs
It is characterized by the death of the affected tissue, resulting in secondary infections by opportunistic bacteria. It is rarely primary, most of the time it is a consequence of another type of vasculitis that, when it becomes chronic, ends up necrotizing the tissue due to the poor oxygenation it receives under these conditions.
The most common causes that can lead to necrotizing vasculitis in dogs are:
- Ectoparasites
- Autoimmune diseases
- Iatrogenic
Immune-mediated vasculitis in dogs
As we have already mentioned, these pathologies are associated with an immune system response against the body itself. The classification of vasculitis according to microscopic findings almost always responds to immune-mediated diseases. Most of the time these vasculitides have no known cause, so they are given the surname idiopathic
Symptoms of vasculitis in dogs
The signs and symptoms of vasculitis in dogs will be logically associated with the classification in which it is found. However, we should not break it down too much in this case, since most of the time they are very similar. Localized vasculitides (such as cutaneous ones) have very characteristic signs that can differentiate them from systemic vasculitides.
Symptoms of cutaneous vasculitis in dogs
- Ulcers
- Necrosis
- Purple spots
- Blisters
- Crusts
- Alopecia
- Spotted lesions on the mouth, nose and vertex of the ear
- Fever
- Inappetence
- Depression
Symptoms of systemic vasculitis in dogs
- Skin lesions
- Lethargy
- Fever
- Pain
- Depression
- Inappetence
- Uveitis
- Anorexy
Canine Vasculitis Diagnosis
The correct anamnesis that the veterinarian should always take will give him the path to gradually arrive at a diagnosis. Relating the clinical signs with the laboratory results in an effective way is the key for this and any clinical case.
When vasculitis is suspected, the veterinary practitioner must find the cause. To do this, he will draw blood to perform a hematologyand a blood chemistry, which are tests indicated in these cases, since they provide valuable information for the veterinarian. The elimination of hemoparasites is also indicated in this case, since we know that some hemotropic agents are the cause of infectious vasculitis. The diagnostic imaging is also important, as heartworms cause systemic vasculitides and the adult larvae may be noticeable on an X-ray. The use of Wood's lamp never hurts when it comes to skin lesions, helping us with the diagnosis of fungi. However, in these very complicated cases, a skin biopsy is also indicated.
How to cure vasculitis in dogs? - Treatment
The treatment of vasculitis in dogs will also depend on the cause. Immune-mediated cutaneous vasculitides, of course, will be treated with immunosuppressive drugs and with supportive treatment that stabilizes the patient if necessary. Many times the patient arrives decompensated for having days without eating food due to the pain and discomfort that these pathologies generate. Generally, the glucocorticoids are indicated and are very helpful in these cases.
In addition to the above, if canine vasculitis is caused by an infection, it must be treated in order to effectively reverse the problem. The use of antibiotics and nonsteroidal analgesics is indicated depending on the case.
