من ساعة ما الكلب اتطعم، هو كويس.

In Egyptian Arabic, من ساعة ما is a very common expression meaning since or ever since.

So the sentence pattern is:

• من ساعة ما + clause
• since + clause

In your example:

• من ساعة ما الكلب اتطعم
  = since the dog got vaccinated

You can think of ساعة here not as the literal hour, but as part of a fixed expression meaning something like from the time that.

In this expression, ما helps introduce the clause that follows. It is part of the set phrase من ساعة ما.

So learners should usually memorize it as one chunk:

• من ساعة ما = since / ever since

It is similar to other Egyptian expressions like:

• بعد ما = after
• قبل ما = before
• أول ما = as soon as

Here, ما does not mean what. It is just a connector in the expression.

اتطعم is the Egyptian Arabic form meaning got vaccinated or was vaccinated.

It comes from the verb طعّم which means to vaccinate.
The form اتطعم often gives a meaning like:

• got vaccinated
• received the vaccine
• sometimes loosely, was vaccinated

So:

• الكلب طعّموا = they vaccinated the dog
• الكلب اتطعم = the dog got vaccinated

This اتـ pattern is very common in Egyptian for verbs meaning something like become X, get X done, or be affected by the action.

Not in this sentence.

An English speaker might notice that the root looks related to taste/food, but here طعّم / تطعيم in modern everyday usage commonly refers to vaccination.

So in this sentence, اتطعم should be understood as:

• got vaccinated

not:

• ate
• was fed

Context usually makes this clear.

هو here means he, and it makes the sentence sound complete and natural:

• من ساعة ما الكلب اتطعم، هو كويس.
• Since the dog got vaccinated, he’s fine.

In Egyptian Arabic, pronouns like هو are often used before adjectives or noun predicates:

• هو كويس = he is fine
• هي تعبانة = she is tired
• أنا جاهز = I am ready

Could people sometimes drop the pronoun in casual speech if the meaning is obvious? Yes, in some contexts, but هو كويس is the clearer and more standard choice here.

Because الكلب is grammatically masculine.

In Egyptian Arabic, adjectives usually agree with the noun in gender:

• masculine: كويس
• feminine: كويسة

So:

• الكلب كويس = the dog is fine
• القطة كويسة = the cat is fine

Even if the dog is biologically female, everyday speech often follows the grammatical form of the noun being used. Since كلب is a masculine noun, كويس is the expected form.

Egyptian Arabic often puts time expressions or background information first, especially when the speaker wants to emphasize the condition or time frame.

So this order:

• من ساعة ما الكلب اتطعم، هو كويس

feels very natural and means something like:

• Ever since the dog got vaccinated, he’s been fine.

If you started with هو كويس, that would shift the focus more onto he is fine, and then add the timing afterward.

Both kinds of ordering are possible in Arabic, but the version you have is very natural for introducing the time frame first.

Yes, literally it is something like he good.

In Arabic, the verb to be is usually omitted in the present tense.

So:

• هو كويس = he is fine
• أنا تعبان = I am tired
• هي هنا = she is here

But in past or future contexts, Arabic does use forms of كان:

• كان كويس = he was fine
• هيكون كويس = he will be fine

So the missing is is completely normal in present-tense Arabic sentences.

A natural Egyptian-style pronunciation would be approximately:

• min saʿit ma l-kalb ittaṭʿam, huwa kuwayyis

A few helpful notes:

• من is often pronounced min
• ساعة here is often closer to saʿa or saʿit before the next word in connected speech
• الكلب is il-kalb or el-kalb depending on how you write Egyptian pronunciation
• اتطعم often sounds like ittaṭʿam
• كويس is commonly pronounced kuwayyis / kwayyis

You do not need a perfect phonetic rendering at first; the key is recognizing the chunking:

• من ساعة ما | الكلب اتطعم | هو كويس

Because the sentence is talking about the dog, a specific dog already known in the conversation or context.

• كلب = a dog
• الكلب = the dog

So:

• من ساعة ما كلب اتطعم would sound incomplete or unnatural in this context
• من ساعة ما الكلب اتطعم clearly means since the dog got vaccinated

If the speaker meant a dog, they would usually phrase the sentence differently.

It is most commonly used when something started in the past and continues up to now, which is exactly the idea of since.

For example:

• من ساعة ما وصل، وهو ساكت
  = Since he arrived, he’s been quiet

• من ساعة ما اتخرجت، وأنا بدور على شغل
  = Since I graduated, I’ve been looking for work

So yes, it most naturally connects to something that happened before the current situation.

In your sentence:

• the dog got vaccinated first
• now the dog is fine
• that condition has held since that earlier event

That is why من ساعة ما fits well here.