Домашня тварина чухається, бо має блоху.

Because тварина is a feminine singular noun, and the adjective has to agree with it in gender, number, and case.

• тварина = feminine, singular, nominative
• so the adjective is домашня = feminine, singular, nominative

The dictionary form of the adjective is often given as домашній, but that is the masculine nominative singular form.

Yes, in this sentence it naturally means pet.

Literally:

• домашня = domestic, home
• тварина = animal

So домашня тварина is literally domestic animal, but in everyday usage it often corresponds to pet.

It is in the nominative singular because it is the subject of the sentence — the thing doing the action.

• Домашня тварина = the pet / domestic animal
• It is the one that чухається and має something

Чухається means scratches itself or is scratching itself.

It comes from the verb чухатися, which is a reflexive verb. In this context, the idea is that the animal is scratching its own body.

Depending on context, English might translate it as:

• scratches itself
• is scratching itself

Ukrainian present tense can cover both a general present and a present continuous meaning.

The -ся makes the verb reflexive.

So:

• чухати = to scratch something
• чухатися = to scratch oneself

In this sentence, the animal is not scratching something else; it is scratching itself. That is why the reflexive form is used.

Because блоху is the accusative singular form, and мати normally takes a direct object in the accusative.

• nominative: блоха = a flea
• accusative: блоху = a flea, as the object of has

So:

• має блоху = has a flea

This is very normal for feminine nouns ending in -а.

Because має is the 3rd person singular present form of мати = to have.

So:

• я маю = I have
• ти маєш = you have
• він / вона / воно має = he / she / it has

Here the subject is домашня тварина, which is singular, so має is the correct form.

Бо means because.

It is a very common, natural way to give a reason in everyday Ukrainian.

So:

• чухається, бо має блоху = is scratching itself because it has a flea

A more formal or longer equivalent would be тому що, but бо is extremely common in normal speech.

Yes. Ukrainian word order is fairly flexible.

This sentence:

• Домашня тварина чухається, бо має блоху.

could also be rearranged in some contexts, for example:

• Бо має блоху, домашня тварина чухається.

But the original order is the most neutral and natural for a simple statement.

In Ukrainian, changing word order often changes focus or emphasis, not the core meaning.

Yes. It is present tense, 3rd person singular.

Ukrainian present tense often covers both:

• a simple present meaning: scratches itself
• a continuous meaning: is scratching itself

The exact English translation depends on context. In this sentence, either can work.

Yes, absolutely.

• Домашня тварина чухається, бо має блоху.
• Домашня тварина чухається, тому що має блоху.

Both mean the same thing. The version with бо is shorter and more conversational. The version with тому що can sound a bit more explicit or slightly more formal.

Because Ukrainian often builds that idea into the verb by using -ся.

In English:

• The pet scratches itself

In Ukrainian:

• Домашня тварина чухається

So the reflexive ending -ся already carries the idea of self / itself, and you usually do not need a separate word.