Zycosan Injection for Dogs and Cats: What to Expect
By Pet Health Supplies Delivered to Your Door. — PETRX.com | Published: 2026-10-22
Category: Buying Guides
Zycosan (pentosan polysulfate sodium) is an FDA-approved equine arthritis injection. Learn what it means for dogs and cats, how it works, and key decision rules for pet owners.
Quick answer
Zycosan (pentosan polysulfate sodium) is FDA-approved for controlling osteoarthritis in horses, but it is sometimes used off-label in dogs and cats. This guide explains what to expect, how it works, and the key decision rules for pet owners considering this joint injection.
How Zycosan Works in Joints
Zycosan contains pentosan polysulfate sodium, a semi-synthetic polysulfated xylan with heparin-like properties. It is believed to help protect cartilage, reduce inflammation, and improve joint fluid quality. In horses, it is given as an intramuscular injection, and the same route is used off-label in dogs and cats.
Off-Label Use in Dogs and Cats
Zycosan is not FDA-approved for dogs or cats. Your veterinarian must prescribe it off-label based on their clinical judgment. Some vets use it for chronic osteoarthritis, hip dysplasia, or joint stiffness when other treatments have not provided enough relief. Always discuss the risks, benefits, and monitoring plan with your vet before starting.
What to Expect During and After Injection
The injection is given into the muscle, usually in the hindquarters. Some pets may experience mild soreness at the injection site. A typical course involves a series of injections (often 2–4) spaced a week apart, followed by maintenance doses. Improvement in mobility and comfort may take several weeks. Your vet will advise on the schedule and any needed blood work.
Decision rules for pet owners
- Consult your veterinarian first: Zycosan is a prescription product. Your vet must determine if off-label use is appropriate for your pet’s specific condition, age, and health status.
- Understand the dosing schedule: A typical protocol for dogs and cats is 2–4 intramuscular injections given one week apart, then maintenance every 3–6 months. Your vet will tailor the plan. Ask your vet for a written schedule and note any missed doses.
- Monitor for side effects: Possible side effects include injection site pain, bruising, or rare allergic reactions. Because pentosan has heparin-like activity, bleeding risk is a concern in pets with clotting disorders. Report any unusual bleeding, swelling, or behavioral changes to your vet immediately.
- Set realistic expectations: Improvement is gradual and may take 2–4 weeks after the first injection. Zycosan helps manage symptoms but does not cure arthritis. Combine with weight management, joint supplements, and appropriate exercise.
Product facts
- Zycosan Injection (Pentosan Polysulfate Sodium) 250mg/mL, 7.5mL: Zycosan (pentosan polysulfate sodium injection) 250 mg/mL is FDA-approved for controlling clinical signs of osteoarthritis in horses. It is a prescription intramuscular injection. This equine approval means the product has undergone safety and efficacy testing in horses, but its use in dogs and cats remains off-label, requiring veterinary oversight.
Zycosan Injection (Pentosan Polysulfate Sodium) 250mg/mL, 7.5mL
Is Zycosan right for your pet?
Best for
- Dogs and cats with moderate to severe osteoarthritis who have not responded well to oral joint supplements or NSAIDs
- Pets that cannot tolerate long-term NSAID use due to kidney, liver, or gastrointestinal issues
Not ideal for
- Pets with known bleeding disorders or those on anticoagulant therapy
- Pets with a history of allergic reactions to heparin or similar compounds
