If you've read the back of a container of sunscreen, you know it can contain many ingredients. Generally, the primary reported issue for a pet who has ingested sunscreen is gastrointestinal upset; occasionally, those signs may be severe and include diarrhea, bloody vomiting, and potentially dehydration.
Sunscreen generally contains two primary ingredients you should know about: salicylates and zinc oxide.
Many sunscreens contain salicylates, often more than one kind, at various concentrations.
Salicylates have several effects in the body that may result in respiratory alkalosis and compensatory metabolic acidosis. On rare occasions, pets may experience hepatoxicity, hyperthermia, and seizures. Gastric ulcerations are also possible with exposure to salicylates.
While these more serious effects are not commonly reported when sunscreens are ingested, more caution may be warranted when large amounts or higher concentrations of salicylates are ingested.
Besides sunscreen, zinc oxide is also commonly found in diaper rash creams. The most common sign reported is vomiting—and because it often occurs soon after exposure due to the irritating nature of zinc oxide, pets may decontaminate themselves this way.
On rare occasions, allergic reactions are reported with ingestion of zinc oxide—typically manifesting in facial swelling and pruritis. Luckily zinc oxide is not absorbed well from the gastrointestinal tract, so zinc toxicity is not common with ingestions of diaper creams and sunscreens.
Sometimes the biggest concern regarding sunscreen exposure is not the active ingredients but the actual tube itself. Foreign body obstruction is a concern if a pet ingests a large portion of the tube.