Four Leaf Rover Bovine Colostrum Review

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Four Leaf Rover Bovine Colostrum is a single-ingredient powder of New Zealand bovine colostrum in a 1.04 oz (29.5 g) jar. We think it is a sound pick if you want one ingredient and clear origin statements, with two weak points: no stated IgG level, and a jar that lasts only about a month for dogs over 60 lb. Like all colostrum, its evidence for allergic itch is limited.

What is in the jar

Colostrum is the first milk a cow produces after calving. It carries antibodies (IgA and IgG), lactoferrin, proline-rich polypeptides (PRPs) and growth factors, which is why it is sold as a gut and immune supplement. Here is what the current label states:

• Ingredients: "New Zealand bovine colostrum", 1.97 g per teaspoon. Inactive ingredients: none.
• Net contents: 1.04 oz (29.5 g), which works out to about 15 level teaspoons. The product page also gives a 51 g item weight; that is the shipping weight, jar included.
• Flavor: unflavored, going by the label. The product page lists a "Beef" flavor, but the label lists nothing except colostrum.
• Marks on the jar: the NASC Quality Seal, plus "Hormone Free", "Grass Finished", "Nothing Artificial", "Proudly made in the USA" and "Certified Plastic Negative".
• Supply claim: a "60 DAY SUPPLY LARGE DOG" panel, which holds only for some large dogs (see how long a jar lasts, below).

Four Leaf Rover also sells probiotics, digestive enzymes and other supplements; this review covers only the colostrum. Every label detail is laid out field by field in our specs and ingredients sheet.

Sourcing claims: where each one comes from

Sourcing is the main reason people pick this product, so it helps to know which claims are printed on the label, which come from the brand's product page or website, and which appear only in retailer copy.

None of this is a red flag, and the label-level claims are more specific than most colostrum listings. The gap is potency. Without a stated IgG level you are trusting the source and the brand, not a number you can compare. If a number matters to you, our page on whole colostrum vs IgG-standardized powders explains what those percentages do and do not tell you.

What the research says about colostrum for dogs

No study has tested this specific product. Dog trials on bovine colostrum in general are few and small, and the largest dog trial and the main review come from Nestle Purina researchers. That review, published in Animals in 2025 (Effect of Bovine Colostrum on Canine Immune Health (opens in a new tab)), summarizes three dog studies:

• A 40-week trial in 24 adult dogs fed a diet with 0.1% colostrum found higher fecal IgA, a stronger response to a distemper vaccine and steadier gut bacteria.
• A study of 70 recently weaned puppies, from a different group, found better stool scores on several days compared with skim milk powder.
• A 3-week pilot in 8 adult female Beagles averaging about 8 years old, combining colostrum with probiotics, found no measurable immune benefit.

None of these measured itching or skin outcomes. "May support gut and immune health" is a fair description; allergy relief is a theory the trials have not tested. Our colostrum for dogs guide covers the research and side effects in more depth.

Dosing: the current label chart

The current label directions give one daily dose by body weight. The brand suggests giving it away from meals, though it can be mixed into a little broth or kefir.

• Get a measuring spoon set with 1/8 teaspoon. A household spoon can easily double a small dog's dose. If you start a small dog at half the chart amount, a mini "pinch" spoon helps.
• Change one thing at a time. Do not start colostrum in the same week as a new food or probiotic.
• Keep a short log. Score itching from 0 to 10 and note stool quality each day, then review at 6 to 8 weeks. Our page on how long colostrum takes to work explains that review point, and how to use it walks through a daily routine.

How long a jar lasts

At 1.97 g per teaspoon, a 29.5 g jar holds about 15 level teaspoons. The last two columns of the dosing table divide that by each label dose. For your own dog, type its weight into the calculator: it returns the label amount in grams, the days one jar should last and the number of jars an 8-week trial needs.

So the "60 Day Supply Large Dog" claim matches the 31 to 60 lb dose. A Labrador or shepherd over 60 lb gets about a month from a jar, and a giant breed about three weeks. Heaped spoons shorten all of these. If your dog is over 60 lb, budget for two or three jars before you start, rather than stopping a trial halfway. For small dogs the opposite question matters: check that the expiry date leaves room for four months of use.

Giving it to a picky dog

The powder has no added flavor, but some dogs notice it, mostly when it clumps on dry kibble. Stirring the dose into a tablespoon of warm (not hot) onion-free broth, or a spoon of wet food, solves most refusals. A paste on a lick mat works for dogs that reject anything in the bowl. Our Q&A on what to do when your dog won't eat it has the full set of methods, and raw feeders can follow the steps in adding colostrum to a raw diet.

Pros and cons

Which con matters most depends on your dog. For a large or giant breed it is the jar size. If you compare products by numbers, it is the missing IgG figure. For a food-allergic dog, the dairy proteins outweigh everything else, so read colostrum and dogs with multiple food allergies first. If itch is the main problem, the evidence gap matters most, and fish oil has more dog research behind it; see colostrum vs fish oil.

How it compares on paper

We compared what each label and brand states, nothing more. None of these products has been tested head to head in dogs.

Peak Pets' product page shows both a scoop chart and a teaspoon chart, so follow whichever is on the jar. All six powders we compared, with notes on chews and puppies, are ranked in best colostrum for dogs.

Before you buy: a pre-purchase checklist

1. Has the itch been diagnosed? Fleas, mites, skin or ear infections, food allergy and environmental allergy each need a different plan. Red, smelly, greasy or broken skin usually means an infection that needs an exam.
2. Are fleas handled? In flea-allergic dogs, VCA notes (opens in a new tab) that one bite can cause itching for days, and fleas are often not visible. Year-round prevention comes before any supplement.
3. Is a food trial running or planned? If so, wait. VCA's elimination diet guidance (opens in a new tab) asks owners to avoid treats and supplements that may contain protein during the trial; our dog food allergies guide explains why.
4. How many jars will a fair trial take? Use the jar calculator above. Over 60 lb, plan on two or three.
5. Do you have the right spoon? A set with 1/8 teaspoon, plus a mini "pinch" spoon if your dog is small and you start low.
6. How will you give it? If your dog already refuses powders, decide on broth, wet food or a lick mat before ordering, or consider a chew.

Who should skip it

• Dogs with a confirmed dairy or beef allergy, unless your vet approves.
• Dogs that get loose stool from dairy. Colostrum has less lactose than mature milk but still contains some; see colostrum and lactose-intolerant dogs.
• Dogs with kidney disease, pancreatitis or other chronic illness, or on prescription medication, where any new protein supplement needs a vet's okay. See colostrum and kidney disease.
• Pregnant dogs and dogs intended for breeding. The label caution reads: "Safe use in pregnant animals or animals intended for breeding has not been proven."
• Very young puppies, unless your vet approves; bovine colostrum does not replace the mother's colostrum.
• Dogs with sudden, severe or infected itching. Oozing, smelly skin or ears need an exam, and hot spots are covered in colostrum and hot spots.

The label also says to stop and consult your vet if your dog's condition worsens or does not improve.

Buying it on Amazon and what to check on arrival

Check who the seller is on the offer you choose: the brand's own storefront on Amazon, or Amazon itself, is safer than an unknown third-party seller, because a supplement jar that sat in a hot warehouse or was resealed is not worth the saving.

When the jar arrives:

• Seal intact. Return a jar with a broken or missing inner seal.
• Expiry date. It should cover the days your dog needs, per the jar estimates above.
• Label matches. New Zealand bovine colostrum as the only ingredient, 1.97 g per teaspoon, the NASC seal and a weight chart. Packaging is changing, so read the chart on the jar you received rather than the one in the product photos.
• Storage. Keep the lid closed, store it cool and dry, and use a clean, dry spoon so the powder does not clump.

We placed the card here because this is where most readers decide. It fits best for a dog up to 60 lb with a vet-checked allergy plan and no dairy issues. For a dog over 60 lb, compare the cost per day with a larger container first.

FAQ

Is Four Leaf Rover colostrum good for dogs with allergies?

It may support gut and immune health, which is the theory behind giving colostrum to allergic dogs, but no dog study has measured its effect on itching. Treat it as an add-on to a vet's allergy plan.

Can I put Four Leaf Rover colostrum on my dog's skin?

Some retailer product descriptions suggest mixing the powder with water into a paste for irritated skin. We found no study of topical colostrum in dogs, and open wounds, hot spots or infected skin need a vet instead.

Is it safe for dogs with a dairy or beef allergy?

Not as an assumption. Colostrum is cow's milk and contains casein and other milk proteins, and beef and dairy are the most commonly reported food allergens in dogs. Ask your vet before starting it.

Can I give Four Leaf Rover colostrum during an elimination diet?

It is better to wait until the trial is over. Vets ask owners to avoid treats and supplements containing animal proteins during a food trial, and colostrum is a milk protein.

How long does it take to see results?

Give it daily and review it at 6 to 8 weeks. That is a practical review point, not a proven timeline. Stool changes, if any, usually show before any change in skin or itch.

Can my dog take it every day long term?

The label gives a daily dose. The longest controlled dog trial with bovine colostrum ran 40 weeks with no side effects reported, but there is little data beyond that, so recheck at annual vet visits.

Is PupRx or Peak Pets better than Four Leaf Rover?

Not better overall, just different. PupRx states 25% IgG and Peak Pets states 20% immunoglobulins, so their strength is printed on the label. Four Leaf Rover states its New Zealand source but no potency figure.

All Four Leaf Rover colostrum questions

Buying questions

• Whole Colostrum vs Immunoglobulin Supplements for Itchy Dogs

Safety concerns

• Can Colostrum Cause Diarrhea in Lactose-Intolerant Dogs?
• Is Colostrum Safe for Puppies? Side Effects and Dosing
• Is Bovine Colostrum Safe for Dogs With Food Allergies (Beef or Dairy)?
• Is Colostrum Safe Long Term for Dogs With Kidney Disease?

Comparisons

• Colostrum vs Fish Oil for Environmental Allergies in Dogs
• Four Leaf Rover Colostrum vs Gut Guard for Dogs With IBD
• Colostrum vs Probiotics for Dogs
• Colostrum vs Slippery Elm for Seasonal Allergy Itching in Dogs

Results & dosing

• How Long Does Colostrum Take to Work in Dogs? (Itch and Gut)
• Is Colostrum Safe for Daily Long-Term Use in Dogs?

Problems & fixes

• Colostrum Not Working for Your Dog's Scratching? Common Reasons
• Dog Won't Eat Colostrum Powder? Mixing Tips for Picky Dogs
• Is Colostrum Making Your Dog Vomit? Causes and Fixes

Specific dogs

• Can Colostrum Help Dogs With Hot Spots and Skin Infections?
• Can You Add Colostrum to a Raw Dog Food Diet?