У кошки есть свой лоток, и мы меняем наполнитель каждое утро.

Russian very often expresses possession with the pattern:

у + possessor in the genitive + есть + possessed thing

So:

• у кошки есть свой лоток = literally at the cat there is its own litter box
• natural English translation: The cat has its own litter box

This structure is usually more natural in Russian than кошка имеет....
The verb иметь exists, but it is less common in everyday speech for ordinary possession.

So for simple X has Y, Russian often prefers:

• У меня есть книга = I have a book
• У собаки есть мяч = The dog has a ball
• У кошки есть свой лоток = The cat has its own litter box

Because у in this meaning requires the genitive case.

The base form is:

• кошка = cat

In the genitive singular, it becomes:

• кошки

So:

• у кошки = of the cat / at the cat / the cat has

This is part of the standard possession pattern in Russian:

• у мамы
• у брата
• у кошки

Here есть means something like there is / there exists and helps express possession.

So:

• У кошки есть свой лоток = The cat has its own litter box

In the present tense, Russian sometimes omits есть, especially when the meaning is obvious:

• У кошки свой лоток

That can also mean The cat has its own litter box.

However, including есть is very normal and often makes the idea of existence/possession clearer. In a teaching sentence like this, keeping есть is especially helpful.

Свой is a reflexive possessive adjective meaning one’s own.

Russian usually uses свой when the possessor is the same as the subject or the main reference point of that clause.

Here:

• У кошки есть свой лоток = The cat has its own litter box

Using свой emphasizes that the litter box belongs to the cat itself, not to someone else.

If you said её лоток, it could also mean her/its litter box, but свой is often preferred when referring back to the same owner and when the meaning is its own.

Compare:

• Кошка любит свой лоток = The cat likes its own litter box
• Кошка любит её лоток = The cat likes her/its litter box; this can sound like it belongs to someone else

Because свой has to agree with the noun it describes, and the noun is лоток.

• лоток is masculine singular
• so the adjective must also be masculine singular nominative
• therefore: свой лоток

Compare:

• своя миска = its own bowl (миска is feminine)
• своё место = its own place (место is neuter)
• свои игрушки = its own toys (plural)

Because лоток is the thing that exists/is had in the possession structure.

In the pattern:

у + genitive possessor + есть + nominative thing possessed

the possessed item is normally in the nominative case.

So:

• у кошки = possessor, genitive
• есть
• свой лоток = thing possessed, nominative

This is why it is лоток, not лотка or лотокa in some other case.

Наполнитель is in the accusative case because it is the direct object of the verb меняем (we change).

The dictionary form is:

• наполнитель = filler/litter

Since наполнитель is a masculine inanimate noun, its accusative singular looks the same as the nominative singular:

• nominative: наполнитель
• accusative: наполнитель

So even though the form does not change, the function does:

• мы меняем наполнитель = we change the litter/filler

Менять is the imperfective verb, and it is used here because the sentence describes a habitual, repeated action:

• мы меняем наполнитель каждое утро = we change the litter every morning

Russian typically uses the imperfective for:

• repeated actions
• habitual actions
• ongoing processes

A perfective verb would suggest a single completed action, not a regular routine.

So:

• меняем = we change / we are in the habit of changing
• good with каждое утро = every morning

Каждое утро means every morning.

The adjective каждый (every/each) agrees with утро:

• утро is neuter singular
• so каждый becomes каждое

That gives:

• каждое утро

This expression is commonly used in the accusative to indicate repeated time, but for neuter inanimate nouns like утро, the accusative form looks the same as the nominative:

• nominative: каждое утро
• accusative: каждое утро

So the form stays the same.

It is a time expression, not the main object.

In:

• мы меняем наполнитель каждое утро

the parts are:

• мы = subject
• меняем = verb
• наполнитель = direct object
• каждое утро = adverbial expression of time

Russian often uses the accusative for expressions of time such as:

• каждый день = every day
• каждую неделю = every week
• каждое утро = every morning

Yes, Russian word order is relatively flexible.

This sentence:

• У кошки есть свой лоток, и мы меняем наполнитель каждое утро.

is neutral and natural.

But some rearrangements are possible depending on emphasis:

• Каждое утро мы меняем наполнитель.
• Наполнитель мы меняем каждое утро.

These all mean roughly the same thing, but the emphasis changes:

• putting каждое утро first highlights the time
• putting наполнитель first highlights what is being changed

The original order is a straightforward, neutral choice.

Literally, лоток can mean tray or box-like container, but in the context of a cat, it usually means a litter box or cat tray.

So:

• кошачий лоток = cat litter box
• у кошки есть свой лоток naturally means the cat has its own litter box

Context is doing a lot of work here.

In general, наполнитель means filler or filling material.

But with a cat and a litter box, it specifically means cat litter.

So:

• менять наполнитель = to change the cat litter

This is a good example of a word whose exact English translation depends on context.

Yes. Russian often omits subject pronouns when the verb ending already shows who is doing the action.

• меняем already means we change

So:

• мы меняем наполнитель каждое утро
• меняем наполнитель каждое утро

Both are possible.

Including мы can add emphasis or clarity, especially if the speaker wants to contrast we with someone else:

• Мы меняем, а не они = We change it, not they

Without that emphasis, omitting мы is often perfectly natural.