The SVPA (Société vaudoise de protection des animaux) is situated by Chalet-à-Gobet, direction Moudon.

www.svpa.ch
"Le meilleur moyen de savoir quels animaux sont disponibles au placement est de téléphoner directement au refuge, au 021/784 8002, pendant les horaires d'ouverture, qui sont de 9h. à 12h. et de 13h.30 à 17h, du lundi au samedi compris. "

N.B. You will have to pay for your dog; the amount covers the expenses for the vet, vaccinations, food etc). I think it is between 100.- and 200.- CHF

Another way is to look in free adds websites (romandie.com or scout 24 or anibis or zannonces) or to put an add. But anyone can give or sell any dog. Difficult to know if there is a problem, if the dod has been mistreated etc...