Hello 67 firebird owner,
There are some over the counter medications that can be used in dogs - but others can be very dangerous so you have to be very careful. Read ingredients very carefully as many cold medicines have a combination of medications and this should be avoided. Be sure to avoid anything with ibuprofen or tylenol in it. I would caution you also that if the discharge seems infected there is a good chance the dog may need antibiotics - so a trip to the vet may be necessary. I would also recommend a trip to the vet if the dog is lethargic, coughing a lot, seeming to have trouble breathing, or refusing to eat anything.
If you choose to treat at home, benadryl (diphenhydramine) is a common antihistamine recommended to dogs for allergies. This can help to dry up secretions and can be helpful. The normal dosage is 1mg per pound of body weight. This is normally given every 12 hours. Here are some links to more information about the medications and sneezing in dogs.
If you need more information just reply to your question.
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