ITP in Dogs: Symptoms, Causes, and Treatment

ITP in dogs (immune-mediated thrombocytopenia) is a serious autoimmune condition in which a dog’s immune system mistakenly destroys its own platelets, the blood cells responsible for normal clotting. As platelet levels drop, affected dogs can develop bruising, bleeding, weakness, and, in severe cases, life-threatening blood loss. 

While ITP in dogs can occur on its own or develop secondary to infections, medications, cancer, or other diseases, prompt veterinary diagnosis and treatment are critical to improving outcomes. Understanding the signs of immune-mediated thrombocytopenia can help pet parents recognize when a dog needs urgent veterinary care. 

What Is ITP in Dogs?

Immune-mediated thrombocytopenia, also known as ITP in dogs, is a blood disease in which the dog’s immune system attacks and destroys the body’s platelets. Platelets are blood cells that stop bleeding by forming clots.  

ITP is a serious disease and is common in middle-aged dogs. 

ITP can be classified as either a primary or secondary disease.  

Due to the severity of ITP’s effects, the disease is a medical emergency and should be treated by your dog’s veterinarian or the nearest veterinary emergency hospital as soon as possible. 

Types of ITP in Dogs 

There are two types of ITP in dogs: 

1. In primary (idiopathic) ITP, there’s no known reason why the immune system is destroying the body’s platelets.  

2. In secondary ITP, the immune system destroys platelets in response to an underlying condition, such as cancer, infection, or toxin or drug exposure. 

Symptoms of ITP in Dogs

Since platelets form blood clots to stop and prevent bleeding, a platelet deficiency caused by ITP in dogs typically causes internal bleeding and bruising.  

Signs you may observe in your dog include: 

• Abnormal bruising 

  • Small pinpoint bruises found on skin and mucosal surfaces (e.g., gums, vulva, or penis) 

  • Large bruises 

• Abnormal bleeding 

  • Dark, tarry stool  

  • Bloody diarrhea or blood in the stool 

  • Bleeding from the gums 

  • Epistaxis (nosebleed) 

  • Blood spots in the eyes 

  • Hematemesis (bloody vomit) 

  • Bloody vaginal discharge 

  • Blood in the urine 

• Lethargy 

• Reluctance to exercise 

• Decreased appetite 

• Pale mucous membranes 

• Fever 

• Enlarged lymph nodes 

• Rapid or difficulty breathing 

• Anemia, which may develop from blood loss 

Causes of ITP in Dogs

ITP in dogs in is a relatively common disease that occurs most often in middle-aged, female dogs. 

While any dog breed can be affected by ITP, including mixed-breed dogs, certain breeds may have a genetic predisposition. These include:  

• Cocker Spaniels 

• Standard Poodles 

• Toy Poodles 

• Old English Sheepdogs  

• Scottish Terriers 

Primary ITP is more common than secondary ITP in dogs. 

Triggers for secondary ITP include: 

• Medications 

  • Sulfa, cephalosporin, and penicillin antibiotics 

  • Phenobarbital 

  • Fenbendazole 

• Infectious diseases 

  • Tick-borne diseases (e.g., Lyme disease,  babesiosis,  ehrlichiosis,  anaplasmosis,  Rocky Mountain spotted fever) 

  • Leishmaniasis 

  • Leptospirosis 

  • Heartworm disease 

  • Parvo 

  • Canine distemper 

  • Salmonellosis 

• Cancer, most commonly lymphoma and hemangiosarcoma 

• Disseminated intravascular coagulation (DIC) 

• Toxins (e.g., zinc and xylitol) 

• Venomous snake bites 

How Veterinarians Diagnose of ITP in Dogs

If your dog is showing signs of ITP, particularly abnormal bruising or bleeding, your veterinarian will take a complete medical history, including any medications your dog is taking and recent tick exposure.  

If your dog has a familial connection that predisposes them to ITP, it’s important to inform the veterinary team. 

Your vet will then perform a physical examination and likely recommend diagnostic testing.  

• Blood work 

• Urinalysis 

• Fecal evaluation  

Your dog’s blood can also be evaluated under a microscope to confirm low platelet numbers.  

Additional testing, such as a bone marrow biopsy and imaging, including X-rays and ultrasound, can assess for other underlying causes of ITP. 

Primary ITP is a diagnosis of exclusion, meaning that all causes of secondary ITP must first be ruled out. 

Treatment of ITP in Dogs

Treatment for ITP in dogs typically requires hospitalization for stabilization and treatment.  

Treatment may include a blood transfusion, especially if a sudden and excessive blood loss occurred, or a plasma transfusion to help increase platelet numbers quickly. 

The mainstay of ITP therapy is medication to suppress the immune system, to stop your dog’s body from destroying its platelets.  

Steroids such as prednisone are often used. 

Supportive care measures may be used, depending on your dog’s symptoms: 

• Supplemental oxygen 

• IV fluids 

• Antibiotics 

• Anti-nausea medications, such as Cerenia 

Rarely, if medications don’t control a dog’s ITP or the condition recurs repeatedly, a splenectomy—a surgical procedure to remove the spleen—may be performed. 

In ITP, a dog’s immune system attacks platelets. The spleen then removes those platelets from the body.  

If the spleen is removed, then a dog will have more platelets because the organ won't be removing them. 

Recovery and Management of ITP in Dogs

Once your dog is feeling better and returns home, they will need frequent veterinary rechecks to monitor their progress and therapy while recovering from ITP in dogs. 

Immunosuppressive medications are often continued for several months and sometimes for the rest of the dog’s life, depending on the underlying cause of the ITP. With this treatment, the goal is to find the lowest possible dose of medication to keep the immune system at bay. 

Most dogs can live a long, happy life after an ITP diagnosis, especially if the underlying cause is treated promptly and aggressively. Full recovery occurs in 70% to 90% of dogs with ITP. 

However, indications that a dog might not fully recover include: 

• Black, tarry stool 

• Increased blood urea nitrogen test (BUN) 

• Underlying illness severe enough to warrant a blood transfusion 

ITP recurrence can be as high as 30% and often occurs two to three months after the initial diagnosis. Removal of the spleen results in remission in 60% of dogs affected with recurrent ITP.  

Unfortunately, for dogs who can’t tolerate immunosuppressive medications, blood transfusions, or splenectomy surgery, ITP can be fatal or may warrant humane euthanasia. 

Prevention of ITP in Dogs

Some causes of secondary ITP can be prevented. Year-round tick prevention is especially important for dogs who spend a lot of time outside, particularly in the woods or hiking. 

Preventing exposure to infectious diseases and venomous snakes can also help decrease your dog’s risk.