The video reminds me of my Ginger (lab/shepard mix) and Patches. Patch was about 7 weeks old and Ginger about 2 months. They grew up as sisters ending up at 78 lbs 7 lbs. Ginger would try to purr like her sister, never realy worked. Patchs was diabetic and Ginger kept an eye on her. They slept together, played together, and if one went to the vet the other had too. When Ginger passed it took 7 weeks before Patch knew it and she just stopped eating and drinking. 4 days later she too was gone.