What type of dog is the oldest in age?

There's no single "oldest" dog breed in the sense of having the longest lifespan. Dog longevity is influenced by many factors including:

* Genetics: Some breeds are genetically predisposed to live longer than others.

* Lifestyle: Diet, exercise, and overall health care can impact a dog's lifespan.

* Individual Variation: Just like people, individual dogs within the same breed can have varying lifespans.

Here are some breeds generally known for having relatively long lifespans:

* Chihuahua: Known for their playful personality and can live up to 18-20 years.

* Yorkshire Terrier: These small dogs can live up to 15-20 years.

* Pomeranian: Another small breed, Pomeranians can live up to 12-16 years.

* Shih Tzu: These friendly dogs can have lifespans of 10-16 years.

* Lhasa Apso: These Tibetan dogs are known for their hardiness and can live up to 14-15 years.

Important note: Even within these breeds, individual dogs can live longer or shorter than the average. There are also many other breeds that can live to a good age with proper care.