Fireworks have six components: fuel (usually charcoal, although phosphorous has been used), oxidising agents (usually nitrates, chlorate or perchlorate), reducing agents (usually sulphur and charcoal), regulators (usually metals), colouring agents (such as barium, copper, calcium, sodium, strontium) and binders (usually dextrin).
Ingestion of a used domestic firework is unlikely to result in any significant signs as the chemical components will have been burnt or dispersed during the explosion. Unexploded display fireworks could cause more significant signs and possibly chlorate toxicosis and spent display fireworks could potentially contain a toxic dose of barium.
There are very occasional reports of poisoning from ingestion of fireworks in pets.
- Bariumpoisoning occurred in a dog that ingested the combustible material from the ends of multiple sparklers.
- Phosphorouspoisoning was reported in a small dog after ingestion of fireworks.
Barium toxicity results in severe hypokalaemia with hypertension and arrhythmias and signs are expected to occur within 6-8 hours. Chlorates cause haemolysis and methaemoglobinaemia. Phosphorous is not found in fireworks in the UK or the US, but may be in fireworks, particularly firecrackers, from elsewhere. Clinical signs of phosphorous toxicity include haemorrhagic gastroenteritis, weakness, cardiovascular collapse, hypocalcaemia and renal and hepatic injury.
Most pets, however, remain well after ingestion of fireworks, although some develop gastrointestinal upset; this is also the case in humans that ingest fireworks.Sparklers only contain a small amount of chemicals and generally only cause gastrointestinal upset but a burning sparkler has a very high temperature and will cause burns if chewed or touched.
Blast injuries, burns, eye injuries and inhalation effects may also occur from exposure to fireworks.
Treatment of pets after ingestion of fireworks is supportive. Most symptomatic pets will develop only mild, self-limiting signs. If more significant signs develop contact a poisons centre for advice.
Read the British Veterinary Association (BVA) policy on fireworks.