S výjimkou očkování proti vzteklině musí držitel psa všechno ohlásit.

It means with the exception of, except for, or apart from.

So:

• S výjimkou očkování proti vzteklině...
  = With the exception of rabies vaccination...

This is a fairly formal expression, and it is very common in legal or administrative language.

Both can mean except for, but s výjimkou is usually more formal and more typical of official writing.

Compare:

• s výjimkou očkování proti vzteklině = more formal, legal/administrative
• kromě očkování proti vzteklině = also correct, often a bit more everyday

In this sentence, s výjimkou fits the official tone very well.

Because s výjimkou is a fixed expression where the thing being excepted is normally in the genitive.

Here, očkování is a neuter noun meaning vaccination. Its nominative singular and genitive singular look the same:

• nominative: očkování
• genitive: očkování

So the form does not visibly change, even though the case does.

Očkování is a noun meaning vaccination or inoculation.

It comes from the verb očkovat = to vaccinate.

This type of noun is very common in Czech:

• očkovat → očkování = vaccinating / vaccination
• studovat → studování = studying
• parkovat → parkování = parking

So očkování proti vzteklině literally means vaccination against rabies.

The preposition proti usually takes the dative.

So:

• vzteklina = rabies
• dative singular: vzteklině

That gives:

• proti vzteklině = against rabies

This is a very common pattern:

• lék proti bolesti = medicine against pain
• boj proti korupci = fight against corruption
• očkování proti vzteklině = vaccination against rabies

Držitel psa means the holder of a dog or, in practical English, the dog owner/keeper.

The word psa is in the genitive singular, because Czech often uses the genitive after a noun to express of-relationships:

• držitel psa = holder of a dog
• majitel domu = owner of a house
• řidič autobusu = driver of a bus

So psa here is not the direct object. It is part of the noun phrase držitel psa.

Not exactly.

• majitel = owner, a common general word
• držitel = holder, keeper, registered holder; often more formal or legal

In everyday speech, many people might say majitel psa.
In official or administrative language, držitel psa is very natural.

So in this sentence, držitel gives the text a legal/official feel.

Because Czech often places the finite verb first and the infinitive later.

Here:

• musí = must
• ohlásit = report / declare / notify

Together they mean must report, but other sentence elements can go between them:

• musí držitel psa všechno ohlásit

This is completely normal in Czech. Compare English:

• The dog owner must report everything.

English keeps must report together more tightly; Czech is more flexible.

Ohlásit means to report, to notify, to declare, or to announce, depending on context.

In administrative language, it often means to officially report something to the authorities.

So here it means that the dog holder has the obligation to notify/report everything required.

The exact English translation depends on the wider context, but report or notify is usually best.

Ohlásit is a perfective verb, so it focuses on a completed act: making the report successfully.

That works well after musí, because the sentence is about an obligation to complete the reporting.

Compare roughly:

• ohlásit = report it, submit the report, complete the notification
• ohlašovat = be reporting, report repeatedly/habitually

In legal or administrative instructions, perfective verbs are very common because the text is usually talking about required completed actions.

Všechno means everything or all of it.

In this sentence it is the direct object of ohlásit:

• musí ... všechno ohlásit = must report everything

In practice, in legal language, everything usually means everything that falls under the rules being discussed, not literally every fact in the universe.

So the scope of všechno comes from the context.

Because držitel is in the nominative, which is the normal case for the subject.

So even though the sentence starts with S výjimkou očkování proti vzteklině, that first phrase is just an introductory exception phrase. The real subject is:

• držitel psa = the dog holder

Czech word order is flexible, so the subject does not always come first.

Yes. Czech word order is flexible, and different orders can sound more neutral, more formal, or put emphasis in different places.

For example, you could also say:

• Držitel psa musí s výjimkou očkování proti vzteklině všechno ohlásit.
• Držitel psa musí všechno ohlásit s výjimkou očkování proti vzteklině.

The original sentence sounds formal and natural, especially in official writing, because it puts the exception first:

• S výjimkou očkování proti vzteklině...

That immediately tells the reader about the one thing that is excluded.

Because Czech does not have articles like the or a/an.

So:

• držitel psa can mean the dog holder, a dog holder, or simply dog holder

You understand which one is meant from context.

In this sentence, because it sounds like a legal rule, English will usually translate it with the:

• the dog holder must report everything

But Czech itself does not need an article to express that.