watchdog: 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/sbin/watchdog - from package: watchdog

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

On Debian possible default full paths are:

/usr/sbin/watchdog - from package: watchdog
/usr/lib/picolisp/bin/watchdog - from package: picolisp

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

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