La bestkuracisto steriligos la katon post la vakcino.

It means veterinarian.

It is a compound:

• best- = animal
• kuracisto = doctor, healer, medical professional

So bestkuracisto is literally an animal doctor.

In Esperanto, compounds are very common. The last part is usually the main idea, so a bestkuracisto is a kind of kuracisto.

Steriligos is the future-tense verb.

You can break it down like this:

• steril- = sterile
• -ig- = make something become, cause to be
• -os = future tense

So steriligos means will make sterile or simply will sterilize.

The dictionary form is steriligi.

The -n marks the direct object.

Here:

• la bestkuracisto = the subject, the one doing the action
• la katon = the object, the one receiving the action

So la katon means the cat as the thing being sterilized.

This -n ending is called the accusative ending, and it is one of the most important features of Esperanto grammar.

Because Esperanto verbs do not agree with person or number.

The ending -os always means future tense, no matter who the subject is:

• mi steriligos = I will sterilize
• li steriligos = he will sterilize
• ŝi steriligos = she will sterilize
• ili steriligos = they will sterilize

So steriligos stays the same.

Esperanto has only one article: la, meaning the.

There is no separate word for a or an.

So:

• la bestkuracisto = the veterinarian
• la katon = the cat
• la vakcino = the vaccine / the vaccination, depending on context

If the noun is not definite, Esperanto often just leaves out the article.

Post means after.

So post la vakcino means after the vaccine or, in context, often after the vaccination.

A learner should notice that:

• vakcino literally means vaccine
• vakcinado more literally means vaccination, the act or procedure

So if you want to be very precise about the event, post la vakcinado may be clearer. But in context, post la vakcino can still be understood.

Because after a preposition like post, Esperanto normally uses the basic noun form, not the accusative.

So:

• post la vakcino = after the vaccine / vaccination

The -n ending is not used here because la vakcino is not the direct object of the verb. It is part of a prepositional phrase.

Not completely.

The neutral order is:

• La bestkuracisto steriligos la katon post la vakcino.

But Esperanto word order is fairly flexible because the -n on katon shows that it is the object.

For example, you could also say:

• Post la vakcino, la bestkuracisto steriligos la katon.

That version is very natural too, and it emphasizes the time a bit more.

By itself, kato usually means cat in a general sense.

If you want to specify sex, you can say:

• katino = female cat
• virkato = male cat

So la katon here does not necessarily tell you whether the cat is male or female. It just says the cat.

Yes, it is a normal general word for making an animal unable to reproduce.

English often uses different everyday words:

• spay for females
• neuter for males

Esperanto often uses the broader verb steriligi without forcing that distinction.

If someone wants to be more specific, other words may be used depending on context, but steriligi is a very natural general choice here.