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If your dog still has a productive cough (coughing up phlegm) than she needs to be reseen by your vet. A cough often doesn't sound like our cough but more like a honk or gagging type noise. Most dogs with kennel cough recover after about 3 weeks or so. In pups it can last longer since their immune systems are not mature. Many vets will prescribe the antibiotics to help prevent any secondary bacterial infection from occurring. So it may be that she has not quite recovered from the kennel cough or a bacterial infection was present as well. I'd go ahead and have her rechecked by your vet. Your vet can go ahead recheck her and determine if she is able to receive any vaccine she is due at this point. Usually a rabies vaccine is administered between 3 and 4 months of age.
Sneezing and nasal congestion can be due to an allergic reaction to an inhaled substance. If this is the case, Benadryl can be given to your pup and the dose is 1mg per pound every 8 hours. You can read about these here.
You can read more on kennel cough here:
Canine influenza is now more prevalent as well. Read more on this here.
You could continue to monitor your dogs condition looking for colored discharge from the nose or eyes, a productive cough (coughs stuff up), stops eating or lethargy and have her reseen if she does not improve.
You can help your pup breathe easier by running a NON-medicated humidifier in the room your pup is in, or sit in a steamed up bathroom with your pup to help keep the mucous moving. Robitussin DM at a 1/4 teaspoon per 5 pounds can be used to control the cough. It should only contain dextromethorphan and Guaifenisen. and should NOT contain pseudoephedrine. Please check with your own vet first before using robitussin. Dosages can be obtained at this website. http://www.petplace.com/drug-library/dextromethorphan-robitussin-dm/page1.aspx
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