Cat Supplement Dosage Calculator

Supplements can significantly improve quality of life for cats with arthritis, digestive issues, immune problems, or other health conditions. Our calculator provides weight-based dosages for the most common and effective cat supplements, plus brand recommendations and usage notes.

Joint Support (Glucosamine/Chondroitin)

Dosage: 20mg per pound once daily. For arthritis, hip dysplasia, joint pain. Takes 4-6 weeks to see improvement—don't give up early. 90% of cats over 12 years have arthritis (often hidden—cats mask pain). Signs: difficulty jumping, stiffness, reluctance to climb stairs, avoiding litter box.

Best brands: Cosequin for Cats (powder or capsules), Dasuquin (includes MSM for extra anti-inflammatory effect), Nutramax Welactin (combines glucosamine with omega-3s). Give with food to improve absorption and reduce stomach upset.

Fish Oil (Omega-3 EPA/DHA)

Dosage: 20mg EPA+DHA per pound once daily with food. Reduces inflammation (arthritis, IBD), supports healthy coat/skin, benefits kidney and heart health. Look for supplements listing EPA and DHA amounts—cheap fish oils may not contain therapeutic levels.

Best brands: Nordic Naturals Pet (liquid or soft chews), Grizzly Salmon Oil (pump bottle—easy dosing), Nutramax Welactin (capsules). Refrigerate after opening to prevent rancidity. Cats may have fishy breath—normal side effect.

Probiotics (Digestive Health)

Dosage: 0.5 billion CFU per pound once daily. For diarrhea, IBD, antibiotic recovery. Helps digestive health and immune function. Give 2+ hours apart from antibiotics (if using both) to prevent antibiotics from killing beneficial bacteria.

Best brands: FortiFlora (powder packets—highly palatable, cats love the taste), Purina Pro Plan Veterinary Supplements, Proviable-DC (capsules with both probiotics and prebiotics). Refrigerate probiotics for maximum potency, though some shelf-stable formulas exist.

L-Lysine (Immune Support)

Dosage: 50mg per pound twice daily. For feline herpesvirus (FHV-1), upper respiratory infections, eye issues (conjunctivitis, watery eyes). Lysine inhibits viral replication. Most effective when started at first sign of symptoms (sneezing, eye discharge).

Best brands: Vetoquinol Viralys (gel or powder—easy administration), Tomlyn L-Lysine (chews or gel), Enisyl-F (paste). Safe for long-term use in cats with chronic FHV-1. May take 1-2 weeks to see full effect.

B-Complex Vitamins

Dosage: 1mg per pound once daily. For appetite stimulation, kidney disease, stress, senior cats. B vitamins support energy metabolism and nervous system function. Especially helpful for cats recovering from illness or with poor appetite.

Best brands: Pet-Tabs (tablets), VetriScience Laboratories (B-complex formulas), Rx Vitamins. B vitamins are water-soluble (excess excreted in urine), making overdose unlikely. Give with food for best absorption.

Supplement Safety & Interactions

Always consult your vet before starting supplements. Some supplements interact with medications:

• Fish oil: May increase bleeding risk if combined with NSAIDs or blood thinners. Monitor closely if cat is on multiple medications.
• Probiotics: Give 2+ hours apart from antibiotics to maintain effectiveness of both.
• Glucosamine: Generally safe, but use caution in diabetic cats (may affect blood sugar—monitor closely).

How to Give Supplements to Cats

Mix with food: Easiest method for powders/liquids. Mix with small amount of wet food to ensure cat eats entire dose. Pill pockets: For capsules/tablets. Greenies Pill Pockets highly effective. Compounded flavors: Ask vet about compounding pharmacy—can make supplements in chicken/tuna flavors.

If cat refuses: Try different brands (flavors vary), mix with extra-tasty treats (Churu, tuna juice), or ask vet about liquid formulations. Never force pills dry—risk of esophageal damage.

When to Expect Results

• Joint supplements (glucosamine): 4-6 weeks for noticeable improvement. Continue long-term for best results.
• Fish oil: 2-4 weeks for coat/skin improvements. 4-8 weeks for anti-inflammatory effects.
• Probiotics: 3-7 days for digestive improvements (firmer stools, less diarrhea).
• Lysine: 1-2 weeks for reduction in respiratory/eye symptoms.
• B-vitamins: 1-2 weeks for appetite stimulation and energy improvement.