A smart pet clothing with full hardware and software support for internet of things is proposed. The hardware comprises three parts: a special pet sensor, an analog front-end circuit for detecting electrocardiogram (ECG) and breath signals, and a micro printed circuit board with signal communication. The software also consists of three parts: an algorithm for biosignal processing, an application (app) as graphical user interface (GUI), and a web server for healthcare. The algorithm is used to calculate the heart rate (HR), HR variability (HRV), high-to-low-frequency ratio determined by HRV analysis, breath rate, and basic emotion analysis. The app is developed for building a user-friendly GUI and communication platform between the hardware device and the cloud server. The web server not only provides detailed information to the veterinarian and the pet owner but also runs a convolutional neural network algorithm on big data to identify abnormal ECG signals. The analog front-end circuits with ECG and breath detectors, an ARM Cortex M0 MCU, and Bluetooth and power modules are integrated into a device with the size of a coin that can be placed in an approximately 32 mm χ 32 mm × 24 mm box. The mechanism can be easily worn on clothing for monitoring pet health and mood.