The words "Dog" and "Dogs" are mentioned 40 times in the KJV of The Bible, but all of these are in proverbs and sayings not to a particular dog.
A specific dog breed, Greyhound, is mentioned in Proverbs 30:31 at least according to the American Standard Version, English Revised Version, and few others (major translations KJV and NIV don't translate this verse using Greyhound).
A few notable verses:
Proverbs 26:11
As a dog returneth to his vomit, so a fool returneth to his folly.
Matthew 15:27
And she said, "Yes, Lord, yet even the little dogs eat the crumbs which fall from their masters' table."
Answer
There are several biblical references to the word Dog or Dogs
You are most likely thinking of the altercation between David and the Philistine (geber/giant) known as Goliath. The account is written in 1 Samuel chapter 17. You will find Goliath refers to the word dog in verse 43.
Additional Answer:
In the New King James Version, there are 40 verses with the word dog(s). Please rephrase the question with the specifics you wish answered. Here is a notable verse used by Christ as a metaphor for His teachings to the Apostles:
Dogs are mentioned in the Bible. There is a verse referencing that even the dogs get the scraps from the masters table.
Greyhound
Dogs are mentioned but there are no references to any specific dogs.
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