Here's a breakdown of the causes:
1. Underlying medical conditions:
* Infectious diseases: Many infectious diseases, like equine influenza, equine herpes virus, strangles, and West Nile virus, can cause petechiae.
* Blood clotting disorders: Conditions like disseminated intravascular coagulation (DIC), a life-threatening condition where the blood clots too easily, can lead to petechiae.
* Immune-mediated diseases: Immune diseases like purpura hemorrhagica, which causes inflammation of blood vessels, can lead to petechiae.
* Endotoxemia: This occurs when bacteria release toxins into the bloodstream, often due to severe infections like colic.
* Kidney disease: Horses with kidney disease can have petechiae due to a lack of clotting factors produced by the kidneys.
* Liver disease: Horses with liver disease can have petechiae due to a decreased ability to produce clotting factors.
2. Trauma:
* Severe physical trauma: Blunt force trauma or even a severe cough can cause petechiae.
* Intravenous injections: Incorrect administration of intravenous injections can cause petechiae at the injection site.
3. Medications:
* Some medications can cause petechiae as a side effect, particularly those that affect blood clotting.
4. Other factors:
* Stress: Severe stress can trigger petechiae in horses.
* Nutritional deficiencies: Lack of vitamin K, which is essential for blood clotting, can cause petechiae.
It's important to note:
* Petechiae are often a symptom of a more serious underlying condition.
* It's crucial to consult a veterinarian immediately if you notice petechiae in your horse.
The veterinarian will conduct a thorough examination, including blood tests, to identify the underlying cause and recommend appropriate treatment.