Nightshade

Symptoms reported in cats

Most serious first.

1. 1
   Vomiting, diarrhea (sometimes bloody), and significant abdominal pain 2–24 hours (typically the initial sign) · Solanine interacts directly with the cell membranes, specifically causing destruction, irritation, and inflammation to the intestinal epithelial cells7. This leads to violent lower gastrointestinal problems and tense abdominal walls.
2. 2
   Lethargy, depression, confusion, dilated pupils, ataxia, tremors, stupor, seizures 2–24 hours (typically follows gastrointestinal symptoms as the toxin is absorbed into the bloodstrea · Solanine inhibits the enzyme acetylcholinesterase in the brain and impairs mitochondrial function, severely disrupting the central nervous system3. Cats are exceptionally sensitive to these toxins because their specific liver metabolism (lack of glucuronidation) slows detoxification, resulting in more severe and prolonged neurological effects than in dogs.
3. 3
   Abnormally slow heart rate (bradycardia) 2–24 hours · Bradycardia is an uncommon, secondary sign in cats, occurring at higher toxic doses due to overstimulation of the parasympathetic nervous system.
4. 4
   Excessive drooling (hypersalivation), burning sensation, and coughing 2–24 hours · This is caused by the direct irritating effect of the plant material on the mucous membranes, as well as the overstimulation of the parasympathetic nervous system.

Important notes

Nightshade (Solanum nigrum and related Solanum species), also called Black Nightshade or Common Nightshade, is a toxic plant for cats found in gardens, roadsides, and as a weed worldwide. Like all members of the nightshade family (Solanaceae), it contains steroidal glycoalkaloids — primarily solanine and solasonine — with the highest concentrations in unripe berries, leaves, and stems.

• Toxic compounds: solanine and solasonine (steroidal glycoalkaloids); unripe green berries and green plant parts most concentrated; ripe black berries slightly less toxic
• Mechanism: glycoalkaloids inhibit acetylcholinesterase (disrupting nerve signalling) and disrupt cell membranes, causing GI and neurological effects
• Symptoms: drooling, vomiting, diarrhea, abdominal pain, lethargy, weakness; severe ingestion may cause tremors, bradycardia, or CNS depression
• Unripe berries are the greatest risk — they resemble edible berries and may attract curious cats
• Contact your vet if your cat ingests any part of the plant, especially unripe berries