Three ways to support financially, in order of usefulness for the organization.
Sponsorship first. You send a fixed amount each month, tied to a named dog you receive updates about. It is a shelter's most precious resource because it is predictable: it allows commitment to long care and to keeping unadoptable dogs for life. Some organizations exist entirely on this model.
Then the recurring donation, even a small one. It allows planning, unlike an emergency fundraiser. Finally the one-off donation, useful but volatile.
What your money actually funds: sterilization, daily food, care for severe cases, fuel for the teams. Sterilization is the highest-yield action because it reduces the number of dogs to rescue the following year.
In-kind donations are accepted by many organizations: blankets, food, veterinary supplies. Always ask for their needs list before sending anything.
Three signals to check before donating, anywhere. The destination account belongs to the organization. Their posts show follow-up over time, with identifiable dogs. The organization is willing to say what a given amount funds.
Three signals that should stop you. Permanent emergency as the only mode of communication. Refusal to state where the money goes. A recently created account collecting large amounts.
Datcha collects no donations and takes nothing from the listed organizations.