Garden plants that are toxic to cats or dogs
These plants are moderately or severely toxic to cats or dogs. If a pet may have eaten part of one, call your vet or a pet poison line straight away.
285 plants:
- Ackee (akee, isin) Blighia sapida · cats: severe, dogs: severe (unripe fruit, seeds, pink raphe, pod, water used for cooking)
- Adam's needle (yucca) Yucca filamentosa · cats: moderate, dogs: moderate (leaves, roots)
- African nightshade (managu) Solanum scabrum · cats: moderate, dogs: moderate (unripe berries)
- African redwood (kosso) Hagenia abyssinica · cats: moderate, dogs: moderate (flowers)
- Aloe vera Aloe vera · cats: moderate, dogs: moderate (leaf latex, whole plant)
- Alpenrose (rusty-leaved alpenrose) Rhododendron ferrugineum · cats: severe, dogs: severe (leaves, flowers)
- Angel's trumpet Brugmansia x candida · cats: severe, dogs: severe (all parts, flowers, seeds, sap)
- Apricot Prunus armeniaca · cats: moderate, dogs: moderate (kernels, leaves, bark)
- Arabica coffee Coffea arabica · cats: moderate, dogs: moderate (seeds, fruit, leaves)
- Areca nut palm (betel nut palm, mak) Areca catechu · cats: moderate, dogs: moderate (nut, fruit)
- Arnica (mountain tobacco) Arnica montana · cats: moderate, dogs: moderate (flowers, roots, all parts)
- Arrowhead vine (syngonium) Syngonium podophyllum · cats: moderate, dogs: moderate (all parts, sap)
- Augustine’s rhododendron (blue rhododendron) Rhododendron augustinii · cats: severe, dogs: severe (leaves, flowers, nectar (honey))
- Australian finger lime Citrus australasica · cats: moderate, dogs: mild (leaves, peel, seeds)
- Baseball plant (living baseball) Euphorbia obesa · cats: moderate, dogs: moderate (milky latex)
- Bay laurel Laurus nobilis · cats: moderate, dogs: moderate (leaves, berries, essential oil)
- Bearded iris Iris germanica · cats: moderate, dogs: moderate (rhizomes, leaves)
- Bigleaf hydrangea Hydrangea macrophylla · cats: moderate, dogs: moderate (leaves, buds, flowers)
- Big-leaf rhododendron Rhododendron sinogrande · cats: severe, dogs: severe (leaves, flowers, nectar (honey))
- Bilimbi (cucumber tree) Averrhoa bilimbi · cats: moderate, dogs: moderate (fruit)
- Bird cherry Prunus padus · cats: moderate, dogs: moderate (seeds, leaves, bark)
- Bitter aloe (Cape aloe) Aloe ferox · cats: moderate, dogs: moderate (latex)
- Black walnut Juglans nigra · cats: unknown, dogs: moderate (moldy hulls, moldy nuts)
- Bleeding heart Lamprocapnos spectabilis · cats: moderate, dogs: moderate (all parts, roots, foliage)
- Bloodroot Sanguinaria canadensis · cats: severe, dogs: severe (rhizome, sap)
- Blue false indigo Baptisia australis · cats: moderate, dogs: moderate (all parts, seeds)
- Blue flag iris Iris versicolor · cats: moderate, dogs: moderate (rhizome)
- Bog rosemary Andromeda polifolia · cats: severe, dogs: severe (leaves, all parts)
- Boldo Peumus boldus · cats: moderate, dogs: moderate (leaves)
- Boxwood Buxus sempervirens · cats: moderate, dogs: moderate (leaves, stems)
- Burning bush Euonymus alatus · cats: moderate, dogs: moderate (fruit, seeds, leaves)
- Bur oak Quercus macrocarpa · cats: mild, dogs: moderate (acorns, leaves)
- Burrawang (cycad) Macrozamia communis · cats: severe, dogs: severe (seeds, all parts)
- Bush lily (clivia) Clivia miniata · cats: moderate, dogs: moderate (all parts, rhizome)
- Butterfly weed Asclepias tuberosa · cats: moderate, dogs: moderate (sap, leaves, all parts)
- Buttonbush Cephalanthus occidentalis · cats: moderate, dogs: moderate (leaves, bark)
- Cacao Theobroma cacao · cats: moderate, dogs: severe (seeds, cocoa products)
- Caladium (angel wings) Caladium bicolor · cats: moderate, dogs: moderate (all parts, tubers)
- California buckeye Aesculus californica · cats: moderate, dogs: moderate (seeds, leaves, flowers (nectar))
- Calla lily (arum lily) Zantedeschia aethiopica · cats: moderate, dogs: moderate (all parts)
- Camphor tree Cinnamomum camphora · cats: moderate, dogs: moderate (leaves, berries)
- Canary Islands dragon tree Dracaena draco · cats: moderate, dogs: moderate (leaves)
- Candelabra tree (naboom) Euphorbia ingens · cats: severe, dogs: severe (milky latex, all parts)
- Candlenut (kukui) Aleurites moluccanus · cats: moderate, dogs: moderate (raw nuts)
- Cardboard palm Zamia furfuracea · cats: severe, dogs: severe (seeds, all parts)
- Cardinal flower Lobelia cardinalis · cats: moderate, dogs: moderate (all parts)
- Carolina allspice (sweetshrub) Calycanthus floridus · cats: moderate, dogs: moderate (seeds)
- Cashew Anacardium occidentale · cats: moderate, dogs: moderate (raw nut shell, shell oil)
- Cassava Manihot esculenta · cats: severe, dogs: severe (raw roots, leaves, stems)
- Ceibo (cockspur coral tree) Erythrina crista-galli · cats: moderate, dogs: moderate (seeds, bark)
- Century plant (agave) Agave americana · cats: moderate, dogs: moderate (sap, leaves)
- Cherry laurel Prunus laurocerasus · cats: severe, dogs: severe (leaves, seeds, bark)
- Chilean potato vine Solanum crispum · cats: moderate, dogs: moderate (berries, leaves)
- Chinaberry (Persian lilac) Melia azedarach · cats: severe, dogs: severe (fruit, bark, leaves)
- Chinese evergreen Aglaonema commutatum · cats: moderate, dogs: moderate (all parts, sap)
- Chinese monkshood (Carmichael’s aconite) Aconitum carmichaelii · cats: severe, dogs: severe (all parts, especially the roots, sap through broken skin)
- Chinese wisteria Wisteria sinensis · cats: moderate, dogs: moderate (seeds, pods, all parts)
- Chives Allium schoenoprasum · cats: moderate, dogs: moderate (all parts)
- Chokecherry Prunus virginiana · cats: severe, dogs: severe (leaves, pits, bark)
- Christmas rose Helleborus niger · cats: severe, dogs: severe (all parts, roots, sap)
- Cider gum (eucalyptus) Eucalyptus gunnii · cats: moderate, dogs: moderate (foliage, leaf oil)
- Cinnabar rhododendron Rhododendron cinnabarinum · cats: severe, dogs: severe (leaves, flowers, nectar (honey))
- Clove Syzygium aromaticum · cats: moderate, dogs: moderate (oil)
- Coast live oak Quercus agrifolia · cats: mild, dogs: moderate (acorns, leaves)
- Comfrey Symphytum officinale · cats: moderate, dogs: moderate (leaves, roots)
- Common bluebell Hyacinthoides non-scripta · cats: moderate, dogs: moderate (bulbs, all parts)
- Common columbine Aquilegia vulgaris · cats: moderate, dogs: moderate (seeds, roots, all parts)
- Common coral tree (lucky-bean tree, umsinsi) Erythrina lysistemon · cats: moderate, dogs: moderate (seeds, bark)
- Common ivy Hedera helix · cats: moderate, dogs: moderate (leaves, berries, sap)
- Common milkweed Asclepias syriaca · cats: moderate, dogs: moderate (all parts, milky sap)
- Common privet Ligustrum vulgare · cats: moderate, dogs: moderate (berries, leaves)
- Common rue Ruta graveolens · cats: moderate, dogs: moderate (sap, leaves)
- Coral aloe Aloe striata · cats: moderate, dogs: moderate (yellow latex under the leaf skin)
- Cork oak Quercus suber · cats: mild, dogs: moderate (acorns, leaves)
- Cotton (upland cotton) Gossypium hirsutum · cats: moderate, dogs: moderate (seeds)
- Croton Codiaeum variegatum · cats: moderate, dogs: moderate (sap, leaves, seeds)
- Crown flower (giant milkweed, dok rak) Calotropis gigantea · cats: severe, dogs: severe (milky sap, leaves, all parts)
- Crown of thorns Euphorbia milii · cats: moderate, dogs: moderate (sap (latex), stems)
- Daffodil Narcissus pseudonarcissus · cats: moderate, dogs: moderate (bulbs, all parts)
- David’s lily (Lanzhou lily) Lilium davidii · cats: severe, dogs: none (all parts, pollen, vase water)
- David's peach (mountain peach) Prunus davidiana · cats: moderate, dogs: moderate (seeds, leaves, bark)
- Daylily Hemerocallis fulva · cats: severe, dogs: none (all parts, pollen, flowers)
- Deadly nightshade (belladonna) Atropa belladonna · cats: severe, dogs: severe (all parts, berries, roots, leaves)
- Delphinium Delphinium elatum hybrids · cats: severe, dogs: severe (all parts, young leaves, seeds)
- Desert rose Adenium obesum · cats: severe, dogs: severe (sap, all parts)
- Dumb cane (dieffenbachia) Dieffenbachia seguine · cats: severe, dogs: severe (all parts, especially stems, sap)
- Dusty miller (silver ragwort) Jacobaea maritima · cats: moderate, dogs: moderate (all parts)
- Dutchman’s breeches Dicentra cucullaria · cats: moderate, dogs: moderate (all parts, especially tubers)
- Easter lily Lilium longiflorum · cats: severe, dogs: mild (all parts, pollen, vase water)
- Eastern Cape giant cycad Encephalartos altensteinii · cats: severe, dogs: severe (seeds, all parts)
- Eastern cyclamen (spring cyclamen) Cyclamen coum · cats: moderate, dogs: moderate (tubers)
- Elder (elderberry) Sambucus nigra · cats: moderate, dogs: moderate (raw berries, leaves, stems, bark, roots)
- Elephant foot yam (suran, buk) Amorphophallus paeoniifolius · cats: moderate, dogs: moderate (raw corm, leaves, sap)
- English holly Ilex aquifolium · cats: moderate, dogs: moderate (berries, leaves)
- English oak Quercus robur · cats: moderate, dogs: moderate (acorns, young leaves, bark)
- English yew Taxus baccata · cats: severe, dogs: severe (needles, seeds, bark)
- Epazote Dysphania ambrosioides · cats: moderate, dogs: moderate (seeds, essential oil, leaves)
- European plum Prunus domestica · cats: moderate, dogs: moderate (pits, leaves, bark)
- Fairy Lake cycad Cycas fairylakea · cats: severe, dogs: severe (seeds, all parts)
- Flame lily (gloriosa) Gloriosa superba · cats: severe, dogs: severe (tubers, all parts)
- Flaming Katy (florist’s kalanchoe) Kalanchoe blossfeldiana · cats: severe, dogs: severe (all parts, especially flowers)
- Flamingo flower Anthurium andraeanum · cats: moderate, dogs: moderate (all parts)
- Florist’s cyclamen Cyclamen persicum · cats: moderate, dogs: moderate (tuber, all parts)
- Flowering tobacco Nicotiana alata · cats: moderate, dogs: moderate (leaves, all parts)
- Four o'clock flower Mirabilis jalapa · cats: moderate, dogs: moderate (seeds, roots, tubers)
- Foxglove Digitalis purpurea · cats: severe, dogs: severe (all parts)
- Fumewort (bird-in-a-bush) Corydalis solida · cats: moderate, dogs: moderate (tubers, all parts)
- Garden chrysanthemum Chrysanthemum x morifolium · cats: moderate, dogs: moderate (flowers, leaves)
- Garden lupin Lupinus polyphyllus · cats: moderate, dogs: moderate (seeds, pods, all parts)
- Garland flower (rose daphne) Daphne cneorum · cats: severe, dogs: severe (all parts, especially berries and bark, sap)
- Garlic Allium sativum · cats: moderate, dogs: moderate (bulbs, leaves)
- Garlic chives Allium tuberosum · cats: moderate, dogs: moderate (leaves, bulbs)
- Gelam (cajuput tree) Melaleuca cajuputi · cats: moderate, dogs: moderate (essential oil)
- Giant taro (elephant ear) Alocasia macrorrhizos · cats: moderate, dogs: moderate (all parts raw, sap)
- Glacier buttercup Ranunculus glacialis · cats: moderate, dogs: moderate (all parts)
- Golden chain tree (laburnum) Laburnum × watereri · cats: severe, dogs: severe (seeds, pods, all parts)
- Golden dewdrop (sky flower, duranta) Duranta erecta · cats: moderate, dogs: moderate (berries, leaves)
- Golden pothos (devil’s ivy) Epipremnum aureum · cats: moderate, dogs: moderate (leaves, stems)
- Grapefruit Citrus x paradisi · cats: moderate, dogs: mild (leaves, peel, seeds)
- Grapevine Vitis vinifera · cats: unknown, dogs: severe (grapes, raisins)
- Great blue lobelia Lobelia siphilitica · cats: moderate, dogs: moderate (all parts)
- Grecian windflower Anemone blanda · cats: moderate, dogs: moderate (all parts, sap)
- Grierson’s rhododendron Rhododendron griersonianum · cats: severe, dogs: severe (leaves, flowers, nectar (honey))
- Griffith’s spurge Euphorbia griffithii · cats: moderate, dogs: moderate (milky sap, all parts)
- Guaraná Paullinia cupana · cats: moderate, dogs: moderate (seeds)
- Heartleaf philodendron Philodendron hederaceum · cats: moderate, dogs: moderate (all parts, sap)
- Heavenly bamboo (nandina) Nandina domestica · cats: moderate, dogs: moderate (berries, leaves, stems)
- Heliotrope Heliotropium arborescens · cats: moderate, dogs: moderate (all parts, seeds)
- Hellebore (Lenten rose) Helleborus x hybridus · cats: severe, dogs: severe (all parts, roots)
- Henry’s lily Lilium henryi · cats: severe, dogs: none (all parts, pollen, vase water)
- Hippeastrum (amaryllis) Hippeastrum hybrids · cats: moderate, dogs: moderate (bulbs, all parts)
- Holm oak Quercus ilex · cats: mild, dogs: moderate (acorns, leaves)
- Hops Humulus lupulus · cats: mild, dogs: severe (cones, spent hops)
- Horse chestnut Aesculus hippocastanum · cats: moderate, dogs: moderate (conkers (seeds), leaves, bark)
- Hosta Hosta spp. · cats: moderate, dogs: moderate (leaves, flowers, roots)
- Hyacinth Hyacinthus orientalis · cats: moderate, dogs: moderate (bulbs)
- Indian coral tree Erythrina variegata · cats: moderate, dogs: moderate (seeds, bark)
- Italian clematis Clematis viticella · cats: moderate, dogs: moderate (all parts)
- Ivy-leaved cyclamen Cyclamen hederifolium · cats: moderate, dogs: moderate (tubers)
- Japanese andromeda (pieris) Pieris japonica · cats: severe, dogs: severe (all parts, nectar)
- Japanese anemone Anemone hupehensis · cats: moderate, dogs: moderate (all parts, sap)
- Japanese flowering cherry Prunus serrulata · cats: moderate, dogs: moderate (seeds, leaves, bark)
- Japanese iris Iris ensata · cats: moderate, dogs: moderate (rhizomes, leaves)
- Japanese pagoda tree (Chinese scholar tree) Styphnolobium japonicum · cats: moderate, dogs: moderate (seeds, pods, bark)
- Japanese plum Prunus salicina · cats: moderate, dogs: moderate (pits, leaves, bark)
- Japanese wisteria (fuji) Wisteria floribunda · cats: moderate, dogs: moderate (seeds, pods, bark)
- Javanese rhododendron (vireya) Rhododendron javanicum · cats: severe, dogs: severe (leaves, flowers, nectar)
- Jícama Pachyrhizus erosus · cats: moderate, dogs: moderate (seeds, pods, leaves, stems)
- Kaffir lime Citrus hystrix · cats: moderate, dogs: moderate (leaves, peel, essential oils)
- Karaka Corynocarpus laevigatus · cats: severe, dogs: severe (raw kernels)
- Karoo cycad Encephalartos lehmannii · cats: severe, dogs: severe (seeds, all parts)
- Kermes oak Quercus coccifera · cats: mild, dogs: moderate (acorns, leaves)
- Key lime Citrus x aurantiifolia · cats: moderate, dogs: mild (leaves, peel, sap)
- Kola nut Cola nitida · cats: moderate, dogs: moderate (seeds)
- Konjac (devil’s tongue) Amorphophallus konjac · cats: moderate, dogs: moderate (raw corm, all parts)
- Korean rhododendron (jindallae) Rhododendron mucronulatum · cats: moderate, dogs: moderate (leaves)
- Kōwhai Sophora microphylla · cats: severe, dogs: severe (seeds, all parts)
- Krantz aloe (candelabra aloe) Aloe arborescens · cats: moderate, dogs: moderate (yellow latex under the leaf skin)
- Kumquat Citrus japonica · cats: moderate, dogs: mild (leaves, peel, seeds)
- Labrador tea Rhododendron groenlandicum · cats: moderate, dogs: moderate (leaves)
- Lacy tree philodendron Thaumatophyllum bipinnatifidum · cats: moderate, dogs: moderate (all parts, sap)
- Lantana Lantana camara · cats: severe, dogs: severe (unripe berries, leaves)
- Larkspur Consolida ajacis · cats: severe, dogs: severe (all parts, seeds, young leaves)
- Late tulip (species tulip) Tulipa tarda · cats: moderate, dogs: moderate (bulbs)
- Leek Allium ampeloprasum (Porrum group) · cats: moderate, dogs: moderate (all parts)
- Lemon tree (dwarf) Citrus limon · cats: moderate, dogs: moderate (peel, leaves, essential oils)
- Lily Lilium · cats: severe, dogs: mild (all parts, pollen, vase water)
- Lily of the valley Convallaria majalis · cats: severe, dogs: severe (all parts, berries, water from vase)
- Lulo (naranjilla) Solanum quitoense · cats: moderate, dogs: moderate (leaves, unripe fruit)
- Macadamia Macadamia integrifolia · cats: unknown, dogs: moderate (nuts)
- Madagascar palm Pachypodium lamerei · cats: severe, dogs: severe (sap, all parts)
- Madagascar periwinkle Catharanthus roseus · cats: severe, dogs: severe (all parts, leaves, seeds)
- Madonna lily Lilium candidum · cats: severe, dogs: mild (all parts, pollen, vase water)
- Male fern Dryopteris filix-mas · cats: moderate, dogs: moderate (rhizome, fronds)
- Mammee apple (mamey de Santo Domingo) Mammea americana · cats: unknown, dogs: moderate (seeds, resin, bark)
- Mandarin orange Citrus reticulata · cats: moderate, dogs: mild (leaves, peel, seeds)
- Marsh marigold Caltha palustris · cats: moderate, dogs: moderate (all parts)
- Martagon lily (Turk’s cap lily) Lilium martagon · cats: severe, dogs: none (all parts, pollen, vase water)
- Mayapple (American mandrake) Podophyllum peltatum · cats: severe, dogs: severe (leaves, roots, unripe fruit, seeds)
- Mediterranean spurge Euphorbia characias · cats: moderate, dogs: moderate (milky sap, all parts)
- Mini monstera (Rhaphidophora tetrasperma) Rhaphidophora tetrasperma · cats: moderate, dogs: moderate (all parts, sap)
- Morning glory Ipomoea purpurea · cats: moderate, dogs: moderate (seeds)
- Mother of thousands (devil’s backbone) Kalanchoe daigremontiana · cats: severe, dogs: severe (all parts)
- Mountain aloe (Marloth’s aloe) Aloe marlothii · cats: moderate, dogs: moderate (yellow latex under the leaf skin)
- Mountain laurel Kalmia latifolia · cats: severe, dogs: severe (leaves, flowers, nectar, honey)
- Muscadine grape Vitis rotundifolia · cats: moderate, dogs: severe (fruit, raisins)
- Myrtle spurge (donkey-tail spurge) Euphorbia myrsinites · cats: moderate, dogs: moderate (milky sap)
- Nanking cherry Prunus tomentosa · cats: moderate, dogs: moderate (pits, leaves, stems)
- Narrow-leaved paperbark (tea tree, source of tea tree oil) Melaleuca alternifolia · cats: severe, dogs: severe (essential oil)
- Nepalese paper plant (lokta daphne) Daphne bholua · cats: severe, dogs: severe (all parts, especially berries and bark, sap)
- Night-blooming jessamine (dama de noche) Cestrum nocturnum · cats: moderate, dogs: moderate (berries, leaves, all parts)
- Night-scented lily (giant upright elephant ear) Alocasia odora · cats: moderate, dogs: moderate (all parts, sap)
- Nodding onion Allium cernuum · cats: moderate, dogs: moderate (bulbs, leaves)
- Northern red oak Quercus rubra · cats: mild, dogs: moderate (acorns, leaves)
- Nutmeg Myristica fragrans · cats: moderate, dogs: moderate (seeds)
- Oleander Nerium oleander · cats: severe, dogs: severe (all parts, smoke from burning)
- Ombú Phytolacca dioica · cats: severe, dogs: severe (leaves, berries, sap)
- Onion Allium cepa · cats: moderate, dogs: moderate (bulbs, leaves)
- Oriental poppy Papaver orientale · cats: moderate, dogs: moderate (all parts, latex)
- Ornamental allium Allium giganteum · cats: moderate, dogs: moderate (bulbs, leaves)
- Ornamental rhubarb (Chinese rhubarb) Rheum palmatum · cats: moderate, dogs: moderate (leaves, roots)
- Paddle plant (flapjacks) Kalanchoe thyrsiflora · cats: severe, dogs: severe (all parts, especially flowers)
- Panda plant (pussy ears) Kalanchoe tomentosa · cats: severe, dogs: severe (all parts, especially flowers)
- Panicle hydrangea Hydrangea paniculata · cats: moderate, dogs: moderate (leaves, buds, flowers)
- Parry's agave Agave parryi · cats: moderate, dogs: moderate (sap, leaves)
- Pasque flower Pulsatilla vulgaris · cats: moderate, dogs: moderate (all parts)
- Peace lily Spathiphyllum wallisii · cats: moderate, dogs: moderate (all parts, sap)
- Peach Prunus persica · cats: moderate, dogs: moderate (pits, leaves, bark)
- Pencil tree (firesticks, milk bush) Euphorbia tirucalli · cats: moderate, dogs: moderate (milky latex)
- Pennyroyal Mentha pulegium · cats: moderate, dogs: moderate (essential oil, leaves in quantity)
- Persian lime Citrus x latifolia · cats: moderate, dogs: mild (leaves, peel, sap)
- Persian silk tree (mimosa) Albizia julibrissin · cats: mild, dogs: moderate (seeds, pods)
- Pig’s ear (round-leaved navelwort) Cotyledon orbiculata · cats: moderate, dogs: moderate (leaves)
- Poison bulb (giant crinum lily, phlap phlueng) Crinum asiaticum · cats: moderate, dogs: moderate (bulb, leaves, all parts)
- Poppy anemone (kalanit) Anemone coronaria · cats: moderate, dogs: moderate (all parts)
- Portugal laurel Prunus lusitanica · cats: moderate, dogs: moderate (leaves, seeds)
- Puawānanga (New Zealand clematis) Clematis paniculata · cats: moderate, dogs: moderate (all parts)
- Red spider lily Lycoris radiata · cats: moderate, dogs: moderate (bulbs, all parts)
- Regal lily Lilium regale · cats: severe, dogs: mild (all parts, pollen, vase water)
- Rhododendron Rhododendron · cats: severe, dogs: severe (all parts, nectar)
- Rhubarb Rheum x hybridum · cats: moderate, dogs: moderate (leaf blades, roots)
- Robusta coffee Coffea canephora · cats: moderate, dogs: moderate (seeds (beans), unripe fruit)
- Sacred lily (omoto) Rohdea japonica · cats: moderate, dogs: moderate (all parts, berries)
- Sago cycad Cycas revoluta · cats: severe, dogs: severe (seeds, all parts)
- Satin pothos (silver vine) Scindapsus pictus · cats: moderate, dogs: moderate (all parts, sap)
- Satsuki azalea Rhododendron indicum · cats: severe, dogs: severe (all parts, nectar)
- Sausage tree (worsboom, muvevha) Kigelia africana · cats: moderate, dogs: moderate (fresh fruit)
- Sessile oak Quercus petraea · cats: mild, dogs: moderate (acorns, leaves)
- Shallot Allium cepa var. aggregatum · cats: moderate, dogs: moderate (bulbs, leaves)
- Shirui lily Lilium mackliniae · cats: severe, dogs: none (all parts, pollen, vase water)
- Siamese cassia (khi lek) Senna siamea · cats: unknown, dogs: moderate (leaves, pods, seeds)
- Siamese cycad Cycas siamensis · cats: severe, dogs: severe (seeds, all parts)
- Siberian iris Iris sibirica · cats: moderate, dogs: moderate (rhizomes, leaves)
- Smooth hydrangea 'Annabelle' Hydrangea arborescens · cats: moderate, dogs: moderate (leaves, buds, flowers)
- Snake’s head fritillary Fritillaria meleagris · cats: moderate, dogs: moderate (bulbs, all parts)
- Sneezeweed (helenium) Helenium autumnale · cats: moderate, dogs: moderate (all parts)
- Sorghum Sorghum bicolor · cats: moderate, dogs: moderate (young leaves, regrowth)
- Sour cherry Prunus cerasus · cats: moderate, dogs: moderate (pits, leaves, stems)
- Soursop (guanábana) Annona muricata · cats: moderate, dogs: moderate (seeds, leaves)
- Southern live oak Quercus virginiana · cats: moderate, dogs: moderate (acorns, young leaves)
- Southernwood (lad’s love) Artemisia abrotanum · cats: moderate, dogs: moderate (leaves, flowers, oil)
- Spanish broom Spartium junceum · cats: moderate, dogs: moderate (seeds, all parts)
- Spiny monkey orange (umhlala) Strychnos spinosa · cats: moderate, dogs: moderate (seeds, unripe fruit, roots)
- Spiral aloe Aloe polyphylla · cats: moderate, dogs: moderate (yellow latex under the leaf skin)
- Spring pasque flower (lady of the snows) Pulsatilla vernalis · cats: moderate, dogs: moderate (all parts, sap)
- Sugar apple (sweetsop) Annona squamosa · cats: moderate, dogs: moderate (seeds)
- Sugar palm (aren) Arenga pinnata · cats: moderate, dogs: moderate (raw fruit flesh)
- Swamp milkweed Asclepias incarnata · cats: moderate, dogs: moderate (all parts, milky sap)
- Sweet cherry Prunus avium · cats: moderate, dogs: moderate (pits, leaves, stems)
- Sweet orange Citrus x sinensis · cats: moderate, dogs: mild (leaves, peel, seeds)
- Sweet pea Lathyrus odoratus · cats: moderate, dogs: moderate (seeds, pods)
- Swiss cheese plant Monstera deliciosa · cats: moderate, dogs: moderate (leaves, stems, unripe fruit)
- Swiss cheese vine (Adanson’s monstera) Monstera adansonii · cats: moderate, dogs: moderate (all parts, sap)
- Tansy Tanacetum vulgare · cats: moderate, dogs: moderate (leaves, flowers, oil)
- Taro Colocasia esculenta · cats: moderate, dogs: moderate (all raw parts)
- Tasmanian blue gum Eucalyptus globulus · cats: moderate, dogs: moderate (leaves, eucalyptus oil)
- Thomson’s rhododendron Rhododendron thomsonii · cats: severe, dogs: severe (leaves, flowers, nectar (honey))
- Tiger lily Lilium lancifolium · cats: severe, dogs: mild (all parts, pollen, vase water)
- Ti plant (cordyline) Cordyline fruticosa · cats: moderate, dogs: moderate (leaves, roots)
- Tree aloe (Barber’s aloe) Aloidendron barberae · cats: moderate, dogs: moderate (yellow latex under the leaf skin)
- Tree echium (giant viper's bugloss) Echium pininana · cats: moderate, dogs: moderate (leaves, seeds)
- Tree rhododendron (lali gurans, burans) Rhododendron arboreum · cats: severe, dogs: severe (leaves, flowers, nectar (honey))
- Tulip Tulipa gesneriana · cats: moderate, dogs: moderate (bulbs, leaves)
- Ume (Chinese plum) Prunus mume · cats: moderate, dogs: moderate (unripe fruit, pits, leaves)
- Upright myrtle spurge (gopher spurge) Euphorbia rigida · cats: moderate, dogs: moderate (milky sap)
- Virginia creeper Parthenocissus quinquefolia · cats: moderate, dogs: moderate (berries)
- Wallflower Erysimum cheiri · cats: moderate, dogs: moderate (seeds, foliage)
- Wax begonia Begonia semperflorens-cultorum · cats: moderate, dogs: moderate (all parts, tubers)
- Welsh onion (scallion) Allium fistulosum · cats: moderate, dogs: moderate (leaves, bulbs)
- White cobra lily Arisaema candidissimum · cats: moderate, dogs: moderate (all parts, especially the tuber)
- White oak Quercus alba · cats: mild, dogs: moderate (acorns, leaves)
- Wild almond Brabejum stellatifolium · cats: severe, dogs: severe (nuts (raw))
- Wild garlic (ramsons) Allium ursinum · cats: moderate, dogs: moderate (bulbs, leaves)
- Winter aconite Eranthis hyemalis · cats: moderate, dogs: moderate (all parts, especially tubers)
- Winter daphne Daphne odora · cats: severe, dogs: severe (all parts, berries, sap)
- Wintersweet Chimonanthus praecox · cats: moderate, dogs: moderate (seeds)
- Wood anemone Anemone nemorosa · cats: moderate, dogs: moderate (all parts)
- Wood's cycad Encephalartos woodii · cats: severe, dogs: severe (all parts)
- Wormwood Artemisia absinthium · cats: moderate, dogs: moderate (leaves, essential oil)
- Yerba mate Ilex paraguariensis · cats: moderate, dogs: moderate (leaves)
- Yesterday-today-and-tomorrow (manacá) Brunfelsia pauciflora · cats: severe, dogs: severe (berries, seeds, all parts)
- Yoshino cherry (Somei-yoshino) Prunus × yedoensis · cats: moderate, dogs: moderate (seeds, leaves, bark)
- Yunnan rhododendron Rhododendron yunnanense · cats: severe, dogs: severe (leaves, flowers, nectar (honey))
- Yuzu Citrus junos · cats: moderate, dogs: mild (leaves, peel, seeds)
- ZZ plant (Zanzibar gem) Zamioculcas zamiifolia · cats: moderate, dogs: moderate (all parts, sap)
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.