dogtail-logout: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/dogtail-logout - from package: dogtail

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/dogtail-logout - from package: python-dogtail

You may install the required package with command apt-get install {package}

Error in other languages:
dogtail-logout: bevel nie gevind nie
dogtail-logout: comandă negăsită
dogtail-logout: comando não encontrado
dogtail-logout: commande introuvable
dogtail-logout: command not found
dogtail-logout: käsku ei ole
dogtail-logout: không tìm thấy lệnh
dogtail-logout: komanda nerasta
dogtail-logout: Kommando nicht gefunden.
dogtail-logout: kommandot finns inte
dogtail-logout: komut yok
dogtail-logout: nie znaleziono polecenia
dogtail-logout: níor aimsíodh an t-ordú
dogtail-logout: no se encontró la orden
dogtail-logout: no s'ha trobat l'ordre
dogtail-logout: opdracht niet gevonden
dogtail-logout: parancs nem található
dogtail-logout: perintah tidak ditemukan
dogtail-logout: príkaz nenájdený
dogtail-logout: příkaz nenalezen
dogtail-logout: команда не найдена
dogtail-logout: командата не е открита
dogtail-logout: 命令找不到
dogtail-logout: コマンドが見つかりません