Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to diagnose canine corneal ulcers [title] Be mindful of your dog rubbing her eye. [step] Ulcers can be difficult to see with the naked eye. Since corneal ulcers are painful, your first clue that there is a problem is that the dog's eye will bother her because it hurts.

Ending1: [substeps] If your dog's canine corneal ulcer is located under a flap of skin, toward the eye, then seek immediate medical treatment. Bring her to a vet if you suspect your dog has herpes simplex virus, or if you have seen any possible symptoms. Ending2: This is because the ulcer is cutting off circulation to the painful eye. [substeps] Your dog will grind her teeth, contort her face, or squint her eyes, and probably you will not understand why this action is happening at all. Ending3: A typical sign of a painful eye is rubbing at the eye. [substeps] Your dog might do this by rubbing the affected side of the face along the ground or rubbing at the eye with a paw. Ending4: However, watch closely to see if this symptom develops while the eye is closed. [substeps] Your dog may start to rub her eye due to pain, which may well occur in her eyes, or because of an emotion.

Answer format: ending1/ending2/ending3/ending4