Thrombocytopenia means a low platelet count. Platelets are tiny blood cells that plug small leaks in blood vessels, so a low count can lead to bleeding.1,2 Normal counts in most dogs are roughly 175,000 to 500,000 per microliter, depending on the lab, and some breeds such as Cavalier King Charles Spaniels and Greyhounds naturally run lower.3,2,4 The most common cause of a severely low count is immune thrombocytopenia (ITP), where the immune system destroys platelets. Tick-borne infections, cancer, some medicines and severe illness can also lower platelets.2,5 Most dogs don't bleed on their own until platelets fall below about 30,000.2,5 Most dogs with ITP recover with treatment, but it can come back.6,7
See a vet the same day if you notice any of these. Go to an emergency vet now if your dog is weak, has pale gums, is bleeding heavily, or has wobbliness or seizures:
- Pinpoint red or purple spots on the skin or gums, or new bruises2,3,8
- Nosebleeds, bleeding gums or blood in the eyes2,8
- Black, tarry stool, or blood in the urine or vomit3,2
- Pale gums, weakness or fast breathing3
- Sudden wobbliness, seizures or behavior change, which can mean bleeding in the brain7,8
What the Research Says
- New 2024 specialist guidelines. The American College of Veterinary Internal Medicine published consensus statements on diagnosing and treating ITP. The treatment statement alone drew on 288 references.5,7
- ITP is diagnosed by ruling things out. No single test proves ITP, so vets check for tick-borne disease, cancer, medicines and clotting problems first.5
- Most dogs survive. In studies, about 3 in 4 to almost all dogs survive the first weeks to months, although up to 27% die and relapse happens in 9% to 47%.6,7
- Some breeds have harmless low counts. About 30% to 50% of Cavalier King Charles Spaniels have naturally fewer, larger platelets without any bleeding problem.2
Normal Platelet Counts and Breed Differences
| Platelet count (per microliter) | What it usually means |
|---|---|
| About 175,000 to 500,000 (lab ranges vary) | Normal for most dogs3,9 |
| Below the usual range in a healthy Cavalier King Charles Spaniel, Norfolk or Cairn Terrier, or Greyhound (in Cavaliers, often 50,000 to 100,000 or lower) | Often a normal breed difference2,8,4 |
| Below 100,000, confirmed on a blood smear | Your vet will look for a cause5 |
| Below about 50,000 | Bleeding after an injury or surgery becomes more likely2,6 |
| Below about 20,000 to 30,000 | Bleeding without an injury becomes likely2,3,5 |
Platelets sometimes clump in the sample tube, which makes a machine count read falsely low, so vets check a blood smear before diagnosing low platelets.10,5 These bands are a guide only; your vet looks at the whole picture.
Causes of Low Platelets
- Immune thrombocytopenia (ITP, also called IMT): the immune system destroys platelets. It may have no known trigger (primary) or follow another disease (secondary). Middle-aged female dogs and Cocker Spaniels are overrepresented.5,2 Some dogs have IMHA and ITP at the same time.11
- Tick-borne diseases such as Ehrlichia and Anaplasma.5,12,13 See tick diseases in dogs.
- Other infections such as parvovirus, distemper and leptospirosis.3,8
- Cancer, such as lymphoma and hemangiosarcoma, and bone marrow disease, including leukemia.3,2,14
- Some medicines, including certain antibiotics and chemotherapy drugs.2,5
- DIC, a clotting crisis caused by severe illness, which uses up platelets.2,15
- Severe bleeding, toxins and venoms, such as zinc, xylitol and snake bites.3
- A brief, mild drop 3 to 10 days after some repeat modified-live vaccines.1
Rat poison causes bleeding by blocking clotting factors. Platelets may drop, but usually only mildly to moderately.16 See blood disorders in dogs.
Signs
Many dogs with low platelets show no obvious signs, so the problem is often found on a routine blood test.3,6 When signs appear, they are usually surface bleeding: pinpoint spots (petechiae), bruises, nosebleeds, bleeding gums, black stool and blood in the urine.2,8 Heavy bleeding can cause anemia, with pale gums and weakness.3 See nosebleeds in dogs.
Diagnosis
- Complete blood count with a blood smear reviewed by a pathologist5
- Chemistry panel and urine test5
- Clotting tests (PT and aPTT), to rule out clotting factor problems such as rat poison and DIC5,11
- Combined blood and DNA (PCR) tests for Ehrlichia, Anaplasma and Babesia5
- Chest X-rays and belly ultrasound to look for cancer5,11
- A bone marrow sample if other blood cell counts are also low5
- Genetic testing in healthy Cavaliers and other breeds with harmless low counts, to avoid unneeded treatment5,2
Treatment
- Treat the cause: an antibiotic for tick-borne infection, or stopping a medicine that may be responsible.2,8
- Steroids are the first treatment for ITP. A second immune-suppressing medicine may be added if there is no response in about 5 to 7 days or steroid side effects are a concern.7
- For dogs that are bleeding, a chemotherapy-class medicine or a human antibody product (IVIG) can raise platelets faster and shorten the hospital stay.7,6
- Transfusions help with life-threatening bleeding but don't fix the count.2,8
- Spleen removal is an option for some dogs that keep relapsing.7,8
- Rest and avoiding injury while counts are low, and avoiding medicines that affect clotting unless your vet approves them.2
Treatment for ITP is tapered slowly, often over 4 to 6 months or longer, with regular platelet checks. Some dogs need low-level treatment for life.2,7
Outlook
Most dogs with ITP survive with treatment.6,7 Dogs that are bleeding into the gut, lungs or brain, or that need transfusions, are at higher risk.7 ITP comes back in somewhere between 1 in 10 and almost half of dogs, often in the first few months.7 "ITP cannot always be cured, but the patient can go into remission," notes the Animal Medical Center in New York.8 Low platelets from tick-borne disease or a medicine usually recover once the cause is treated.8,2
Frequently Asked Questions
Can low platelets in dogs go back to normal?
Usually, yes, once the cause is treated. Dogs with ITP often reach remission, but they need checks because it can come back.
Is thrombocytopenia a form of leukemia?
No. Low platelets have many causes, and most aren't cancer, though leukemia and other marrow cancers can lower platelets.
What foods increase platelets in dogs?
No food has been shown to raise platelets in dogs. Treating the cause is what works. Ask your vet before giving supplements.
What is the most common cause of low platelets in dogs?
Immune thrombocytopenia (ITP) is the most common cause of severely low counts. Tick-borne diseases are common causes where ticks are widespread.
Is ITP in dogs curable?
Many dogs go into lasting remission. Some relapse and need longer or lifelong treatment.
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Sources and further reading
This article was rewritten and fact-checked on October 30, 2026 against current veterinary references and specialist guidelines:
- Cotter SM. Bleeding Disorders of Dogs. Merck Veterinary Manual (pet owner version), full review December 2017, updated June 2026.
- McQuinn E (reviewed by Carnevale J). Platelet Disorders in Animals. Merck Veterinary Manual (professional version), full review February 2025, updated March 2026.
- Weir M, Williams K, Panning A, Ward E. Thrombocytopenia in Dogs. VCA Animal Hospitals, updated October 9, 2025.
- IDEXX Laboratories. Diagnostic update: Greyhound-specific reference intervals. IDEXX, June 2025.
- LeVine DN, Kidd L, Garden OA, et al. ACVIM consensus statement on the diagnosis of immune thrombocytopenia in dogs and cats. Journal of Veterinary Internal Medicine, 2024.
- Thomason JM. Top 4 primary immune-mediated disorders in dogs. Clinician's Brief, Summer 2024.
- LeVine DN, Goggs R, Kohn B, et al. ACVIM consensus statement on the treatment of immune thrombocytopenia in dogs and cats. Journal of Veterinary Internal Medicine 2024;38(4):1982-2007.
- The Animal Medical Center. Thrombocytopenia (Low Platelet Count) in Dogs and Cats. AMC (New York), updated June 5, 2026.
- Merck Veterinary Manual. Hematology (Complete Blood Count) Reference Ranges. Merck Veterinary Manual (professional version), table, accessed October 2026.
- McQuinn E (reviewed by Carnevale J). Overview of Hemostatic Disorders in Animals. Merck Veterinary Manual (professional version), full review February 2025, updated March 2026.
- Sellon RK. Canine immune-mediated hemolytic anemia and thrombocytopenia. EVC Voorjaarsdagen, Amsterdam, 2008. Proceedings hosted by IVIS (full text requires free IVIS login).
- Palerme JS (reviewed by Carnevale J). Ehrlichiosis in Dogs. Merck Veterinary Manual (professional version), full review September 2025, updated June 2026.
- Barnes C, Williams K, Llera R, Ward E. Ehrlichiosis in Dogs. VCA Animal Hospitals, updated July 30, 2025.
- Hatamkhani A, Intile J. How to approach canine leukemias in general practice. Today's Veterinary Practice, January/February 2026.
- Guillaumin J. Disseminated intravascular coagulation. Clinician's Brief, September 2019.
- Tauer D (reviewed by Brutlag A). Anticoagulant Rodenticide Poisoning in Animals. Merck Veterinary Manual (professional version), November 2025.
About this article
Last updated : new page written using the 2024 ACVIM consensus statements on immune thrombocytopenia, the Merck Veterinary Manual, the Animal Medical Center, VCA, Clinician's Brief and IVIS-hosted proceedings; includes the research summary, platelet count table, causes, signs, diagnosis, treatment, outlook, key takeaways and FAQ.
This page is for general information and is not a substitute for an exam by your veterinarian.
