Generic Name: paroxetine
Brand Names: Paxil, Paxil CR

Paroxetine, a selective serotonin receptor inhibitor (SSRI), is commonly prescribed to treat depression in human medical practice. It is also used in veterinary practice to treat a wide range of behavioral issues. However, paroxetine can be toxic to your pet if ingested in significant quantities.

paroxetine

It is important to realize that, even at therapeutic doses, your pet may show signs of fatigue, excitation, nervousness, or loss of appetite.

Please note that other SSRIs (such as citalopram, escitalopram, fluoxetine, and sertraline) carry similar toxicity risks.

Signs and symptoms of toxicity: fatigue, agitation, tremors, increased saliva production, vomiting, loss of appetite or refusal to eat, seizures, aggression, weakness, diarrhea, decreased heart rate, and difficulty walking.

Toxic consumption:
Doses of 1 mg/kg may cause mild sedation in dogs while signs of toxicity may be seen with doses of 10 mg/kg.

Dogs: Paroxetine 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)
dog1 dog2 dog3 dog4 dog7 dog6
Paroxetine > 4.4 mg > 49 mg > 117 mg > 185 mg > 322 mg > 413 mg

 
References:
– Osweiler, G, et al. (2011). Blackwell’s five-minute veterinary consult clinical companion. Small Animal Toxicology. [Kindle version]. Retrieved from Amazon.com
– Wismer TA. Antidepressant drug overdoses in dogs. Vet Med 2000; 95:520-525.