Can toxins in a flea collar cause weakness in a dog's hind legs?

Yes, toxins in a flea collar can potentially cause weakness in a dog's hind legs, particularly if the collar contains harmful chemicals or if the dog has an adverse reaction to them. Symptoms may include lethargy, coordination issues, or muscle weakness. If a dog shows signs of weakness after exposure to a flea collar, it's important to remove the collar immediately and consult a veterinarian for evaluation and treatment.