The toxic level of nicotine in dogs is 5 milligrams of nicotine per pound of body weight, so in her case about 150mgs. In dogs a toxic amount can be deadly. One cigarette contains 15 to 25 milligrams of nicotine depending on the brand.
The butt of a cigarette is the most dangerous part as they have a deceptively large amount of toxins relative to the size of the butt as smoking concentrates some of the nicotine in the cigarette butt. The butt alone can contain from 4 to 8 milligrams depending on the length of the butt and the content of the original cigarette.
The signs of toxicity that you will see will be dependent upon the amount and type of nicotine ingested relative to your dogs body weight.
The signs of toxicity depend upon the dose and generally begin within one hour of ingestion.
Many dogs will vomit naturally after ingestion. When large amounts are consumed, the effects can be life-threatening, but even small amounts can induce symptoms. Without treatment, nicotine toxicity can cause paralysis of the breathing muscles and your dog may die from an inability to breathe, sometimes within a few hours.
If your dog exhibits any of the following symptoms, call your veterinarian.
- Stumbling and/or incoordination
- Hyperactivity or Lethargy
- Fast breathing or difficulty breathing
- Dilated pupils (center black part of eye very large)
- A very fast or slow heart rate or a very irregular heart beat rhythm
I understand that she only ate part of a cigarette, and that may not be enough to be toxic in a 33 pound dog, but given how serious nicotine toxicity is in dogs I do recommend inducing vomiting and being proactive to avoid a possible toxicity.
Please let me know if you have any further questions.