Vet’s 2025 Guide to Canine Pyruvate Kinase Deficiency 🩺 Hereditary Anemia, Care & Outlook

By Dr. Duncan Houston BVSc

💡 What Is Pyruvate Kinase Deficiency?

Pyruvate kinase deficiency (PKD) is a genetic condition seen in dogs—particularly Basenjis, Beagles, West Highland White Terriers, Cairn Terriers, Dachshunds, and Pugs—where an enzyme critical for red blood cell energy metabolism fails. Without sufficient PK activity, red blood cells lack ATP, become fragile, and undergo premature destruction, leading to chronic hemolytic anemia.

🧬 Inheritance & Genetic Basis

• Inherited as autosomal recessive: dogs must receive two defective PKLR gene copies to be affected; carriers (single copy) are asymptomatic but can pass along the mutation.
• Mutation types differ between breeds (e.g., exon‑insertion in WHWTs, single‑bp deletion in Basenjis).
• Carrier frequency varies—up to 9% in WHWTs, 35% carriers, about 37% affected Beagles in some studies.

⚠️ Clinical Signs & Physical Findings

• Chronic progressive anemia: pale gums, lethargy, poor exercise tolerance—often evident by 4–12 months of age.
• Jaundice (yellow mucous membranes), dark urine, tachycardia, and sometimes gallstones from chronic bilirubin elevation.
• Splenomegaly and hepatomegaly due to red blood cell clearance.
• Secondary complications: iron overload (hemosiderosis), osteosclerosis, bone marrow fibrous transformation.

🧪 Diagnostic Approach in 2025

1. Routine Bloodwork & Lab Tests

• Complete blood count (CBC): regenerative anemia, elevated reticulocytes, low hematocrit, raised indirect bilirubin, sometimes increased serum ferritin.
• Blood smear: shows polychromasia, nucleated RBCs, echinocytes (spiculated RBCs).
• Biochemistry: assessment of liver enzymes; screen for iron overload.
• Urinalysis: signs of bilirubinuria.

2. Enzyme Assay & DNA Testing

• RBC pyruvate kinase activity assay—tests functional enzyme levels.
• Genetic tests identify breed-specific PKLR mutations—available for Basenjis, WHWTs, Beagles, Cairn Terriers, and Pugs.

3. Imaging & Tissue Evaluation

• Ultrasound or palpation confirms enlarged spleen/liver.
• Bone X-rays may reveal osteosclerosis; bone marrow biopsy can assess fibrosis in advanced disease.

📈 Disease Progression & Staging

• PKD ranges widely—from compensated, mild anemia to severe crises with collapse, ascites, or jaundice.
• Crisis triggers: stress, infections, pregnancy/lactation, drugs affecting RBCs.
• Complications appear by 4–5 years: liver failure, marrow fibrosis, and iron overload.

🩺 Management & Treatment in 2025

1. Supportive Care

• Regular blood transfusions as needed during anemia crises—monitor iron accumulation; use chelation therapy in chronic cases.
• Folate supplementation supports red blood cell production.
• Stress reduction, avoid strenuous exercise during anemia flares.

2. Bone Marrow / Hematopoietic Cell Transplantation

• The only curative option, dogs may achieve a normal lifespan post-transplant.
• Costly, requires compatible donor (siblings preferred), immunosuppression, high-risk but increasingly successful in specialized centers.

3. Splenectomy (Ancillary Therapy)

In select chronic cases, splenectomy reduces red blood cell destruction, increasing survival slightly—but does not address underlying enzyme defect.

4. Experimental & Emerging Therapies

• Gene therapy and hematopoietic stem cell editing are under investigation in humans—potential future options in dogs.
• Mitapivat, a small-molecule PK activator approved in humans (2022), shows promise—no canine use documented yet.

📅 Monitoring & Follow-up Care

• CBC every 2–3 months or during clinical decline.
• Iron panels and liver enzymes to monitor hemosiderosis.
• Repeat ultrasounds or radiographs to assess organ size & bone changes.
• Pre-transplant screening if undergoing bone marrow transplant.

🏡 Ask A Vet Home Support

• Daily logs: appetite, energy, gum color, urination, signs of jaundice.
• Medication and transfusion reminders, lab schedules.
• Alert prompts for anemia crises, discomfort, dark urine.
• Upload photos/videos: gum pallor, splenic enlargement via abdominal palpation.
• Coordinate specialist consults for HCT or transplant planning.

🔍 Key Takeaways

• PKD is a lifelong hereditary anemia with variable severity and limited treatment options.
• Supportive care—transfusions, supplements, splenectomy—can extend quality of life.
• Bone marrow transplant offers a potential cure but involves cost and risk.
• Emerging research holds promise: gene therapy, mitapivat.
• Ask A Vet tools help owners manage monitoring, treatments, and emergencies seamlessly.

🩺 Conclusion ❤️

Canine pyruvate kinase deficiency is a challenging inherited anemia—but with 2025’s supportive therapies, and potentially curative bone marrow transplantation, many dogs live meaningful lives. Future treatments like PK activators and gene therapy may unlock long-term solutions. Coupled with vigilant monitoring and support via Ask A Vet, pet owners can navigate PKD’s ups and downs and offer their companions care, comfort, and connection. 🐶✨

Visit AskAVet.com to access tools for tracking symptoms, scheduling labs, uploading images, and coordinating care with your vet—right from your phone. 📲