5-Hydroxytryptophan

5-HTP, or Griffonia seed extract, is a human dietary supplement used for a variety of ailments in humans. This supplement is potentially toxic in pets as it has the ability to induce serotonin syndrome.

Signs and symptoms of toxicity: sedation, agitation, tremors, seizures, hyperthermia, GI upset, difficulty walking, abdominal pain, increased sensitivity to stimuli, and temporary blindness.

Toxic consumption: For dogs, the minimum oral toxic dose is 24 mg/kg (11 mg/lb). Oral ingestion of 128 mg/kg (58 mg/lb) by a dog may be fatal.

Dogs: 5-HTP Toxic Consumption
X-Small Yorkie, Chihuahua	Small Pug, Boston Terrier, Poodle	Medium Beagle, Scottish Terrier	Large Boxer, Cocker Spaniel	X-Large Retriever, German Shepherd	XX-Large Great Dane, St. Bernard
1 – 10 lbs. (0.45 – 4.6 kg)	11 – 25 lbs. (5 – 11.4 kg)	26 – 40 lbs. (11.8 – 18.2 kg)	41 – 70 lbs. (18.6 – 31.8 kg)	71 – 90 lbs. (32.3 – 40.9 kg)	91 – 110 lbs. (41.4 – 50 kg)
> 10.8 mg	> 120 mg	> 283 mg	> 446 mg	> 775 mg	> 993 mg

References:
– Peterson, M.E. & P.A. Talcott (2013). Small Animal Toxicology, 3rd Ed., Saunders. St. Louis.