Answer

This is not considered particularly safe to use in nursing dogs.

You can read about this med here

http://www.animalshelter.org/petmeds/Urinary_TractKidneys/Cephalexin/186.html

It sounds like your dog may have allergies or possibly demodectic mange mites.

You can read about demodex here

http://www.marvistavet.com/html/body_demodectic_mange.html

Pregnancy does take a lot out of the dam but this isn't normal in a healthy dog.

Interdigital cysts can also go along with allergies.

You can read about interdigital cysts here

http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/70800.htm

http://www.itsfortheanimals.com/INTERDIGITAL-FURUNCLES.HTM

 

If you know the problem is an ear infection and that the ear drum is not perforated then there are some things you can use.

You can see if your local pet supply store carries Zymox with cortisone or find it online. I've had good luck clearing up infections with that. You can read about it here
http://animalpetdoctor.homestead.com/Zymox.html
This site goes over ear infections and has another ear cleaner mentioned that had good results
http://www.dermapet.com/articles/art-03.html
here is just the product info
http://www.dermapet.com/prod-09.html
Ear infections are a common symptom of allergies in dogs.

 

You can read about allergies and dermatitis in dogs here

http://www.lbah.com/allergy.htm

http://www.priory.com/vet/vetatop1.htm

Dogs can develop allergies to foods, even ones they eat all the time, and to inhaled items, and contact allergens such as rug cleaners, cedar beds, or chemicals including lawn chemicals or even flea bites.

You might want to try a different dog food that has no ingredients the same as what you feed now. Diets of Fish and Potato, venison, or rabbit etc. where the protein source is new and there are no grains in the food can work for many dogs for example. Another option is the hypoallergenic diet from your vet Hills ZD. Changing food does no good if you feed the same ingredients. Remember food changes have to include all treats and can take 8-12 weeks or more before you see results in skin and coat.

If this is an inhalant allergy you may find using a HEPA air filter in the room the dog uses most and wiping the dog down with a damp towel when it comes in helps reduce allergen exposure.

I'd not use the meds you have on hand without direct approval from your vet.

You may want to start introducing real food to the pups in case you have to wean them to treat mom.

Hope this helps you!