Can Cats and Dogs Eat Microgreens? Safe and Toxic Types

Some microgreens make a reasonable occasional treat for cats and dogs. A few are genuinely unsafe. This guide separates the two, and is explicit about where the popular advice runs ahead of the evidence.

Disclaimer: this article is general information for owners, not veterinary advice. Talk to your vet before introducing any new food, especially if your pet is young, pregnant, elderly, or has a condition affecting digestion, the kidneys or the thyroid.

What we corrected in this article. An earlier version gave exact feeding limits (“up to 5% of a cat’s diet”, “around 10% of your dog’s diet”) and claimed that the broccoli compound sulforaphane — which it spelled “sulphorane” — has “anti-cancer” properties. We could not trace the percentages to any veterinary or scientific source, so they are gone. The anti-cancer claim is not supported by the canine research we could find, and that research is summarised honestly below. Several plants on the old avoid list also had no authoritative source behind them; they are now separated from the ones that do.

Table of Contents

Microgreens for Cats

Cats are obligate carnivores, so greens are enrichment and variety rather than nutrition they depend on. These are the varieties most often offered, with what can and cannot be said about each.

Barley grass (often sold as “cat grass”): a source of plant fiber, and the type most cats will actually chew. The frequent claim that it “helps manage furballs” is an owner observation we could not source to a veterinary reference, so treat it as anecdote rather than an established effect.
Sunflower: soft, palatable and widely offered. Its fat content is often cited as a benefit; for a treat-sized portion this is not a meaningful contribution either way.
Peas: mild and usually well accepted. We have removed the previous claim that pea microgreens “support immune health and liver function” in cats — we found no source for it.
Lettuce: mostly water, with a crunch some cats enjoy. Harmless in small amounts, and not nutritionally significant.
Catnip: catnip seedlings contain nepetalactone, the compound behind the catnip response. Whether seedlings are more potent than mature leaves is a claim we could not verify, so we no longer make it. Kittens generally do not respond to catnip until they are several months old.

How much? We are not going to invent a number. Offer a small pinch alongside a complete, species-appropriate diet, introduce it slowly, and stop if you see vomiting, loose stools or loss of appetite. For a proportion suited to your individual animal, ask your vet — that is a question about your cat’s body weight, age and health, not something a website can answer.

Microgreens Cats Should Avoid

Do not feed these — the toxicity is documented.

The allium family — onion, garlic, leek, chives, shallot, scallion. The Merck Veterinary Manual’s review of Garlic and Onion (Allium spp) Toxicosis in Animals records that absorption of the oxidant compounds in these plants causes oxidative damage to red blood cells, Heinz body formation and methaemoglobinaemia beginning within 24 hours, and states that cats are the most susceptible species, followed by dogs. This is not a dose you can judge by eye.
Nightshade seedlings — tomato, potato, pepper, eggplant. The ASPCA’s entry for the tomato plant (Lycopersicon spp., Solanaceae) lists it as toxic to dogs, cats and horses, with solanine as the toxic principle; the ripe fruit is non-toxic, but the green plant is the part you would be growing as a microgreen.
Rhubarb — the ASPCA lists rhubarb (Rheum rhabarbarium) as toxic to dogs, cats and horses, with soluble calcium oxalates as the toxic principle and kidney failure among the clinical signs.

Commonly listed as “avoid”, but we could not source it. Mustard, cabbage, radish and brussels sprout microgreens appear on avoid lists across the hobby internet, generally on the grounds that they are pungent and may cause gas or loose stools. That is a tolerance argument, not a toxicity finding, and we found no authoritative source establishing it. We are keeping them off the recommended list as a precaution and labelling the reason honestly: strongly flavoured brassicas are a plausible cause of digestive upset, and there is no reason a cat needs them.

Avocado is often listed too. The relevant hazard in avocado is persin, and it is not a microgreen crop in any case — nobody grows avocado microgreens — so it has been dropped from this list rather than repeated.

For any plant not named here, the ASPCA maintains a searchable Toxic and Non-Toxic Plants database covering dogs, cats and horses. It is the right first check.

Microgreens for Dogs

Broccoli: broccoli sprouts are a source of glucoraphanin, the precursor of sulforaphane (correctly spelled — an earlier version of this page had “sulphorane”). Sulforaphane from a broccoli sprout supplement is absorbed by dogs: Curran et al. (2018) gave a single oral dose to ten healthy dogs and measured metabolites in plasma and urine. What we will not claim is an anti-cancer effect. The one prospective canine cancer study we found — Parachini-Winter et al. (2020), seven dogs with multicentric lymphoma given oral sulforaphane for seven days — reports “no clinical response”. A cell-culture study in canine osteosarcoma lines, Rizzo et al. (2017), found sulforaphane could not induce cell death at plausible physiological concentrations and, more importantly, appeared to protect tumour cells against doxorubicin. If your dog is receiving chemotherapy, that is a reason to raise broccoli supplements with your oncologist rather than assume a benefit.
Red cabbage: the cardiovascular finding behind this entry is real but it is a mouse study, not a dog study. Huang et al. (2016) fed red cabbage microgreens to mice on a high-fat diet and found lower circulating LDL, lower liver cholesterol and reduced inflammatory cytokines. Do not read that across to dogs; we mention it because it is the source, not because it is a promise.
Kale: a palatable leafy green. We have removed the previous claims that it “reduces inflammation”, is “especially beneficial for dogs with chronic conditions”, and can “cause kidney stones in susceptible dogs” — none of the three had a source. Kale is a brassica, so the general thyroid caution below applies.
Wheatgrass: fibrous and generally well tolerated. The claim that it “supports digestion” through chlorophyll and amino acids is not something we can source; the fiber is real, the mechanism is marketing.
Mustard — mild varieties only, such as Southern Giant Curled, and only occasionally. Hot or peppery mustard varieties are best left alone; the distinction is the heat, not the plant.

How much? As with cats, we have removed the figure that used to sit here. A complete dog food is formulated to be complete; anything you add on top displaces part of it. Start with a small pinch or a teaspoon mixed into a meal, watch how your dog handles it, and ask your vet what proportion is sensible for your animal’s size and health.

Microgreens Dogs Should Avoid

The documented hazards are the same three as for cats: the allium family, nightshade seedlings and rhubarb, sourced above to the Merck Veterinary Manual and the ASPCA. Brassicas such as kale and broccoli are worth discussing with your vet if your dog has a thyroid condition.

The rest of the old avoid list — amaranth, quinoa, watercress, buckwheat, oregano, parsley and sorrel — carried no source, and we are not going to assert toxicity we cannot demonstrate. Two of them deserve a specific correction:

“Sweet pea” was wrong, or at least ambiguous. The ASPCA lists sweet pea (Lathyrus latifolius, the ornamental) as toxic to horses but non-toxic to dogs and cats. The edible pea grown for pea shoots is a different plant entirely (Pisum sativum). Listing “sweet pea” as a dog hazard confused the two.
Sorrel and other high-oxalate greens are a reasonable thing to limit, but the reason is oxalate load, not acute toxicity, and it matters most for animals with a history of urinary stones. Ask your vet if that applies to your dog.

How to Add Microgreens to Your Pet’s Diet

Wash thoroughly, start with a very small amount mixed into food, and introduce one new variety at a time so that if something disagrees with your pet you know what it was. Microgreens are an occasional supplement, never a meal replacement.

A tray left where your pet can graze is a good enrichment option, and cats and dogs do chew on greens of their own accord. You can also tuck a few into an enrichment toy to sniff out. Growing your own gives you control over what has and has not been sprayed on them.

One last piece of housekeeping: the previous version of this article ended with “microgreens have been scientifically proven to bring a lot of benefits”. The research on microgreens is mostly compositional analysis plus a small number of animal and human studies — good reason to think they are nutritious food, not proof of health outcomes in pets. We have taken the sentence out.

This article is general information for pet owners, not veterinary advice. Species-specific and animal-specific diet questions — including how much of anything to feed — belong with your veterinarian.

Sources & Links of Interest

The vendor and hobby-blog links that used to appear here have been removed. They were the only support for the feeding percentages and the anti-cancer claim, and they are not adequate sourcing for pet safety guidance.

Hayes C. Garlic and Onion (Allium spp) Toxicosis in Animals. Merck Veterinary Manual, reviewed/revised September 2024. merckvetmanual.com
ASPCA. Toxic and Non-Toxic Plants database (dogs, cats, horses), including the entries for Tomato Plant, Rhubarb and Sweet Pea. aspca.org
Curran KM, Bracha S, Wong CP, Beaver LM, Stevens JF, Ho E. Sulforaphane absorption and histone deacetylase activity following single dosing of broccoli sprout supplement in normal dogs. Veterinary Medicine and Science 2018;4(4):357–363. doi:10.1002/vms3.118
Parachini-Winter C, Bracha S, Ramsey SA, Yang L, Ho E, Leeper HJ, Curran KM. Prospective evaluation of the lymph node proteome in dogs with multicentric lymphoma supplemented with sulforaphane. Journal of Veterinary Internal Medicine 2020;34(5):2036–2047. doi:10.1111/jvim.15898
Rizzo VL, Levine CB, Wakshlag JJ. The effects of sulforaphane on canine osteosarcoma proliferation and invasion. Veterinary and Comparative Oncology 2017;15(3):718–730. doi:10.1111/vco.12212
Huang H, Jiang X, Xiao Z, Yu L, Pham Q, Sun J, Chen P, Yokoyama W, Yu LL, Luo YS, Wang TTY. Red cabbage microgreens lower circulating low-density lipoprotein (LDL), liver cholesterol, and inflammatory cytokines in mice fed a high-fat diet. Journal of Agricultural and Food Chemistry 2016;64(48):9161–9171. doi:10.1021/acs.jafc.6b03805
Our companion guide: Are microgreens safe for pets?
Other animals in this series: microgreens for hamsters and chipmunks and microgreens for birds, including chickens, parrots and budgies.