Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to protect your cat or kitten from parasites [title] Apply topical insecticides. [step] Use an effective, veterinarian recommended product that is appropriate for the age of your kitten. Be aware that different spot on products contain different active ingredients, not all of which are effective or safe.

Ending1: Most vets think that topical insecticides will repel parasites. [substeps] Never apply a topical insecticide to your cat. Ending2: If you are unsure, check with your veterinarian or find an online product that will apply to your cat and/or kitten-all on the same label. [substeps] Cats with parasitic infestations should be very cautious and avoid getting the product, as it can produce dangerous fumes and cause allergic reactions. Ending3: [substeps] Apply the product to the back of the cat's neck where they can't reach it to rub off. This is usually a good method for any cat, but if it proves ineffective or the cat manages to get it off, then you should consider using another product--the flea collar method, spray, or shampoo. Ending4: [title] Use flea-borne disease-fighting products. [step] Most common flea repellents and sprays should be applied twice per month.

Answer format: ending1/ending2/ending3/ending4