It is very difficult to tell from pictures and even more so if the pups are less than a year old. Your youngest pup (only 4 months old) has not lost the puppy hair yet -- so you won't really know for sure. The silky coats usually thin a great deal (most noticeable on top of head) especially when the color is getting ready to break.
One way to tell is to look at eye shine. This is not fool proof, as some say their dogs do not follow the general rule. Shine a flashlight into the pups face when they are outside at dark or look at the photos where a flash was used. If the eye shine is reddish/orangish then the coat is most often cotton. If the eye shine is greenish then the coat is usually silky. There is actually a genetic link to why this is true. The component that makes the greenish eye shine possible is genetically linked to silky coats.
Puppy eye shine is most always blue -- your 4 month old may still be blue and you will have to wait to get a clear red/green deviation. |