So I'm home for a bit and my poor 13 year old dog is poor and old and sad. All she does is sleep. Her skin is saggy and she's thin (she was always slender, but now she's skinny) her back is slightly hunched and she walks and sits like she has arthritis (she gets medicated dog treats for this). None of that compares to how sad she looks. She doesn't want to play anymore. She's half-deaf and slightly blind. She has to be coaxed to eat dog treats even though her teeth are in good shape.

My parents said she's gradually progressed this way and it's probably just old age. I read online that mutts her size live around 13 years anyway, but I'm worried because all her mischievous spunk is gone. She's almost like a different dog.

Am I worrying unnecessarily over the natural cycle of life, or does this sound like something's legitimately wrong?