Bleach is one of the most effective antimicrobial agents for cleaning your dog's pen. Following some guidelines prevents irritation to the dog's esophagus, upper airway and gastrointestinal tract. Proper use of bleach also prevents corrosion of metal in the pen. Always remove your dog from the pen before spraying the environment with bleach.
Diluting the bleach to 1 part bleach and 32 parts water makes it safe to use. Be sure to rinse the pen thoroughly with water to remove excess bleach. Failing to rinse the pen causes the chemical fumes to irritate the dog's upper airway resulting in coughing, difficulty breathing and retching. Be sure the pen is dry before allowing your dog to enter because a dog can ingest bleach by licking a wet spot. A small amount of bleach ingestion is unlikely to be fatal since it induces vomiting, which reduces the toxin absorption. Other than vomiting, symptoms of bleach toxicity include drooling, sore throat and abdominal pain. Seek veterinary attention if you think your dog ingested bleach.