Držitel psa má ohlašovací povinnost.

Držitel literally means holder or keeper. In legal or administrative Czech, it is often used for the person who officially has responsibility for something.

It is similar to owner, but not always exactly the same:

• majitel = owner
• držitel = holder / registered keeper / person in possession

So in a legal sentence like this, držitel psa can sound more official than everyday majitel psa.

Also, držitel is a masculine animate noun.

Because Czech usually expresses of by using the genitive case, not by adding a separate word.

So:

• držitel psa = holder of a dog
• majitel auta = owner of a car
• správce budovy = manager of a building

English uses a separate word (of), but Czech often uses a noun followed by another noun in the genitive.

Because pes changes form here.

• pes = nominative singular, the basic dictionary form
• psa = genitive singular

After držitel, the thing being held/owned goes into the genitive, so pes becomes psa.

This is a normal pattern with masculine animate nouns.

A quick mini-paradigm:

• pes = dog
• bez psa = without a dog
• majitel psa = owner of a dog
• vidím psa = I see a dog

So the form psa is not random; it is a regular case form.

Má is the 3rd person singular form of the verb mít = to have.

So:

• mám = I have
• máš = you have
• má = he/she/it has

In this sentence, držitel psa má... means the dog holder/keeper has...

It is a noun phrase made of:

• ohlašovací = reporting / notification-related
• povinnost = obligation / duty

So the whole phrase means something like a reporting obligation or a duty to report/notify.

This is quite typical official Czech: instead of using a full verb phrase, Czech often uses an adjective + noun structure.

Compare:

• ohlašovací povinnost = reporting obligation
• more everyday wording: musí to ohlásit = must report it

It comes from the verb ohlašovat = to report, announce, notify.

The adjective ohlašovací is a derived form meaning roughly:

• used for reporting
• related to reporting
• requiring reporting

So ohlašovací povinnost is literally an obligation connected with reporting/notification.

This type of adjective is very common in formal Czech:

• platební povinnost = payment obligation
• evidenční povinnost = record-keeping obligation
• ohlašovací povinnost = reporting obligation

It is the direct object of má, so grammatically it is in the accusative.

However, the form looks the same as the nominative:

• nominative: ohlašovací povinnost
• accusative: ohlašovací povinnost

That is normal here.

Why?

• povinnost is a feminine noun of the kost type, and its singular nominative and accusative are identical.
• ohlašovací also has the same visible form here.

So even though the phrase is functioning as an accusative object, you do not see a spelling change.

A useful comparison:

• má povinnost = has an obligation
• má novou povinnost = has a new obligation

In novou povinnost, the adjective novou clearly shows the accusative, but in ohlašovací povinnost, the form happens to stay the same.

Because Czech has no articles.

So Czech does not normally have separate words for:

• a
• an
• the

Whether something is a dog holder, the dog holder, or dog holders in general depends on context.

That is why:

• Držitel psa can mean the holder of a dog, a dog holder, or even any dog holder, depending on the situation.

In legal language, it often has a general meaning: any person who is the holder of a dog.

It is definitely formal / official / administrative Czech.

A native speaker would expect this kind of wording in:

• laws
• municipal regulations
• forms
• official notices

In everyday speech, people would usually say something more direct, for example:

• Majitel psa to musí nahlásit.
• Když máte psa, musíte to ohlásit.

So the original sentence is grammatical and natural, but it belongs to a bureaucratic or legal register.

Yes, Czech word order is fairly flexible, but the original order is the most neutral for an official statement.

Neutral version:

• Držitel psa má ohlašovací povinnost.

Other orders are possible, but they change emphasis:

• Ohlašovací povinnost má držitel psa.
  This emphasizes ohlašovací povinnost.

• Má držitel psa ohlašovací povinnost?
  This makes it a question.

In administrative writing, the neutral subject + verb + object order is usually preferred because it is clear and straightforward.