Quinton marine plasma is a supplement made from cold-sterilised, filtered seawater harvested from a protected plankton bloom in the Atlantic. It exists in two forms, and this is the part most pet owners get wrong: only the isotonic form should ever be given to a dog or a cat. The hypertonic version is roughly three times more concentrated in mineral salts and is contraindicated in kidney disease, heart disease and high blood pressure — three conditions that are extremely common in the animals whose owners come looking for it. Used correctly, isotonic marine plasma is a gentle mineral and rehydration support, not a treatment.
I have been working as an animal naturopath for over fourteen years, mostly with cats in chronic kidney disease, and marine plasma is one of those products I get asked about constantly. So let me be precise about what it does, what it doesn’t do, and where the real risk sits.
What is Quinton marine plasma?
Quinton marine plasma is 100% natural seawater, cold-sterilised and either diluted with spring water (isotonic) or left at full concentration (hypertonic), used as a mineral supplement. It was developed by the French physiologist René Quinton in the early 1900s, who documented the mineral similarity between diluted seawater and the extracellular fluid that bathes our cells.
The appeal is the mineral profile rather than any single active ingredient. Seawater contains up to 78 naturally occurring elements and trace minerals — magnesium, potassium, calcium, zinc, selenium, manganese — in a dissolved, bioavailable, naturally balanced ratio. Nothing is synthesised or added.
➡ The honest version: there are no controlled veterinary trials on marine plasma in dogs or cats. What we have is a century of human use, a plausible mineral rationale, and clinical observation. I use it as support, never as therapy, and I say so to every client.
Isotonic vs hypertonic: what is the difference?
This distinction is the entire safety story of this product.
| Quinton Isotonic | Quinton Hypertonic | |
|---|---|---|
| Composition | ~29% seawater, ~71% spring water | 100% undiluted seawater |
| Mineral concentration | Matches blood plasma | ~3× higher |
| Sodium per 10 ml ampoule | ~30 mg (approx.) | ~100 mg (approx.) |
| Human use | Daily mineral and hydration support | Athletes, acute exhaustion, high physical stress |
| Use in dogs and cats | ✅ The only form I recommend | ⚠️ Not suitable — see contraindications |
Hypertonic marine plasma is marketed for fatigue, low energy and athletic recovery in people. In a dog or a cat, the mineral load is simply too high relative to body mass, and it carries specific contraindications: hypertension, cardiac disease, and advanced kidney failure.
If you already own a box of hypertonic ampoules bought for yourself, don’t split the difference by giving a smaller dose to your pet. Buy the isotonic version. It is a different product, not a stronger one.
Where to find it (EN market): Original Quinton (Laboratoires Quinton), Quicksilver Scientific Quinton Isotonic, and Water & Wellness all sell isotonic ampoules in the UK, US and AU. Look for the words isotonic or hypotonic-balanced on the box, and glass ampoules or dropper bottles rather than powders.
Can you give Quinton marine plasma to dogs and cats?
Yes — isotonic marine plasma can be given orally to dogs and cats as a remineralising and rehydrating support. It is a food supplement, not a medicine, and it does not interact with most conventional drugs. That said, “safe for most” is not “appropriate for all”, and the sodium content matters in a few specific patients.
The situations where I have found it genuinely useful:
1. Dehydration and mineral loss Cats in particular are chronically under-hydrated. In animals losing fluid through vomiting, diarrhoea or polyuria, isotonic marine plasma added to drinking water supports rehydration with electrolytes rather than plain water alone.
2. Chronic kidney disease (with caveats) This is the request I get most often. In early-stage CKD (IRIS stage 1–2) with normal blood pressure, a small daily amount of isotonic plasma can support mineral balance in a cat that is drinking and urinating heavily. In stage 3–4, or in any cat with hypertension or on a sodium-restricted renal diet, I do not use it without the vet’s agreement — the sodium is small, but it is not zero, and it belongs in the daily total. Check the IRIS staging system with your vet before deciding.
3. Gut inflammation — IBD, chronic enteritis, diarrhoea Chronic diarrhoea drains electrolytes. Isotonic plasma is well tolerated even by irritated stomachs and can be given alongside gut-repair protocols (slippery elm, colostrum, probiotics).
4. Nausea, gastritis and poor digestion It supports normal gastric acid production, which is exactly what a lot of older cats on long-term antacids are lacking.
5. Feline asthma — nebulised This is my favourite use and the one nobody expects. Isotonic marine plasma can be nebulised in place of plain saline for cats with feline asthma or chronic bronchitis, helping to loosen secretions. Discuss it with your vet first if your cat is on an inhaled steroid protocol.
6. Skin and eyes — topical For eczema, hot spots, acne and mild dermatitis, the dermatological version (cold-microfiltered seawater spray) can be sprayed directly on the skin. Isotonic plasma is also a gentle eye and nasal rinse — useful in cats with chronic rhinitis or post-herpetic nasal congestion.
How to give marine plasma to a dog or cat: practical dosing
Standard ampoules contain 10 ml. Start at the low end for a week before increasing — I have never seen a benefit from rushing this.
Cats (all sizes) ✅ ¼ ampoule (about 2.5 ml, roughly half a teaspoon) once daily ➡ Straight into the mouth by syringe, mixed into wet food, or added to the water bowl
Small dogs (under 10 kg / 22 lb) ✅ ½ ampoule (about 5 ml, 1 teaspoon) once daily
Medium dogs (10–25 kg / 22–55 lb) ✅ 1 ampoule (10 ml, 2 teaspoons) once daily
Large dogs (over 25 kg / 55 lb) ✅ 1–2 ampoules daily, split between morning and evening
Diluted in the water bowl ✅ 1 ampoule per 1 litre of fresh drinking water, changed daily. My preferred method for fussy cats and for multi-pet households.
Nebulised (feline asthma) ✅ 2–3 ml of isotonic plasma in the nebuliser chamber, 5–10 minutes, once or twice daily
Topical (skin) ✅ Spray the dermatological version directly onto clean skin, 2–3 times daily
⚠️ Give it away from meals if you are using it for digestion, and always alongside — never instead of — free access to fresh water.
Warnings and contraindications
This is the section that gets skipped in most articles about marine plasma, and it is the one that actually matters.
⚠️ Never give the hypertonic form to a dog or cat.
⚠️ Advanced chronic kidney disease (IRIS stage 3–4): vet approval first. Damaged kidneys handle sodium and mineral loads poorly, and many of these patients are on a deliberately restricted diet.
⚠️ Hypertension: common in senior cats, frequently undiagnosed. If your cat’s blood pressure has never been measured, measure it before starting.
⚠️ Heart disease, including feline HCM and canine congestive heart failure: sodium is managed carefully in these patients. Do not add anything containing it without asking.
⚠️ Congenital hyperaldosteronism, liver disease with ascites, oedema: avoid.
⚠️ Sudden diarrhoea after starting: stop and reduce. Some animals are simply sensitive to the mineral load.
When to see your vet
Marine plasma is a supplement. It does not replace diagnostics, and delayed diagnosis is the most common harm I see in natural pet care. Book an appointment if your animal has:
- Vomiting or diarrhoea lasting more than 24–48 hours
- Sudden increase in thirst and urination
- Weight loss, or refusing food for more than 24 hours (critical in cats — hepatic lipidosis develops fast)
- Laboured breathing, open-mouth breathing in a cat, or a cough that worsens
- Straining to urinate, or blood in urine
- Any skin lesion that spreads, weeps or smells
💚 My personal note
I keep isotonic ampoules in the fridge the way other people keep electrolyte sachets. The moment I find them genuinely worth their price is not in chronic disease at all — it’s the day after: after a vet visit, after fluids, after a bout of vomiting, when an animal is flat and off their food and everything I actually want to give them requires a functioning appetite.
But I will say this plainly, because I have watched too many owners spend money on the wrong thing: for a cat in kidney disease, marine plasma is nowhere near the top of the list. Phosphate control, hydration, appropriate protein and omega-3s do the heavy lifting. Marine plasma is a small supporting player. If your budget only stretches to one thing, it should not be this one.
FAQ
Can I give Quinton marine plasma to a cat with kidney failure? Only the isotonic form, and only with your vet’s agreement — especially from IRIS stage 3 onward or if your cat has high blood pressure. The isotonic version contains roughly 30 mg of sodium per 10 ml ampoule, which is a small but real addition to a sodium-controlled renal diet. Never use the hypertonic form in kidney disease.
What is the difference between isotonic and hypertonic Quinton? Isotonic is diluted seawater matching the mineral concentration of blood plasma. Hypertonic is undiluted seawater, roughly three times stronger. Only the isotonic form is suitable for dogs and cats.
How long does it take to see any effect? For hydration and appetite support, most owners notice something within one to two weeks. For skin, allow four to six weeks. If nothing has changed after two months, it isn’t working for your animal and there is no reason to keep buying it.
Can I nebulise marine plasma for my asthmatic cat? Yes — isotonic marine plasma can be used in a nebuliser in place of plain saline, typically 2–3 ml per session. It supports mucus clearance. It does not replace bronchodilators or steroids in a diagnosed asthmatic; talk to your vet before changing an existing protocol.
Does Quinton marine plasma have side effects in pets? It is generally very well tolerated. The most common issue is loose stools when the dose is too high too quickly. Reduce the amount and reintroduce slowly.
Is there scientific evidence for marine plasma in animals? No controlled veterinary trials exist. The rationale is based on mineral composition and over a century of human use. I treat it as supportive, not therapeutic, and I would encourage you to do the same.
Can I use human Quinton ampoules for my dog? Yes — there is no separate veterinary formulation. It’s the same product, dosed down by body weight. Just check that the box says isotonic.
Disclaimer
This content is for informational purposes only and does not constitute medical advice or replace veterinary consultation. The homeopathic and natural remedies mentioned have no scientifically validated efficacy. Always consult your vet before making changes to your pet’s diet or administering any remedy. Products mentioned are not intended to diagnose, treat, cure or prevent any disease.
Written by Eli, animal naturopath — 14+ years of clinical practice in integrative pet care. elicats.com
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