Project Description

Pseudoephedrine and phenylephrine are popular ingredients in OTC decongestant products (e.g. Claritin-D, Mucinex-D, Benadryl-D, Sudafed, and Sudafed-PE). These medications are often used to treat nasal and chest congestion.


Note that either pseudoephedrine or phenylephrine can be found in cough/cold formulations, allergy and asthma medications, hemorrhoid creams, and diet pills. If your pet has ingested any medication it is important to determine all ingredients in order to assess the risk of toxicity.

It is also important to note that, when purchasing an antihistamine for your pet, you do not choose a combination product that contains one of these ingredients.

Signs and symptoms of toxicity: hyperactivity, agitation, vomiting, increased heart rate, increased blood pressure, increased production of saliva, tremors, seizures, decreased appetite, and dilated pupils. Signs may occur within 30-60 minutes of ingestion but can be delayed with ingestion extended-release products.

Toxic consumption:
Phenylephrine: There is no established toxic threshold for pet consumption. All incidents of accidental exposure should be reported immediately.

Pseudoephedrine: Clinical signs of toxicity may be seen with doses of 5-6 mg/kg and death may occur with ingestion of doses 10-12 mg/kg of body weight.

Dogs: Pseudoephedrine Toxic Consumption
Yorkie, Chihuahua
Pug, Boston Terrier, Poodle
Beagle, Scottish Terrier
Boxer, Cocker Spaniel
Retriever, German Shepherd
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
> 2.2 mg > 24 mg > 58 mg > 92 mg > 161 mg > 206 mg
Cats: Pseudoephedrine Toxic Consumption
Most Cats Large Cats
1 – 10 lbs.
(0.45 – 4.6 kg)
11 – 25 lbs.
(5 – 11.4 kg)
cat1 fat cat
> 2.2 mg > 24 mg

– Bischoff K. Toxicity of over-the-counter drugs. In: Gupta RC, ed. Veterinary Toxicology: Basic and Clinical Principles. New York: Elsevier, 2007;p.363.
– Osweiler, G, et al. (2011). Blackwell’s five-minute veterinary consult clinical companion. Small Animal Toxicology. [Kindle version]. Retrieved from