Nhờ bác sĩ thú y mà thể trạng tốt.

It means thanks to ... , ... or because of ... , ... with a positive result.

So in Nhờ bác sĩ thú y mà thể trạng tốt, the idea is:

• nhờ bác sĩ thú y = thanks to the veterinarian / thanks to the vet
• mà thể trạng tốt = the physical condition is good

This structure is very common in Vietnamese when you want to show a good outcome caused by someone or something.

In this sentence, mà does not mean but.

Here, it is part of the fixed structure nhờ ... mà ..., which connects:

• the cause: nhờ bác sĩ thú y
• the result: thể trạng tốt

So mà is acting like a linker between the two parts. In English, you often would not translate it directly. You just translate the whole pattern as thanks to ...

Bác sĩ thú y means veterinarian or vet.

Breakdown:

• bác sĩ = doctor
• thú y = veterinary / animal medicine

So literally it is something like veterinary doctor.

Thể trạng refers to someone's or an animal's physical condition, constitution, or general bodily state.

It is close to sức khỏe (health), but not exactly the same:

• sức khỏe = health in a broad sense
• thể trạng = physical condition/build/overall bodily state

So thể trạng tốt means something like:

• in good physical condition
• physically healthy
• having a good constitution

It sounds a bit more formal or clinical than everyday sức khỏe tốt.

Vietnamese often leaves out the subject when it is already known from context.

So Nhờ bác sĩ thú y mà thể trạng tốt is understood as something like:

• Nhờ bác sĩ thú y mà nó có thể trạng tốt.
• Nhờ bác sĩ thú y mà con chó có thể trạng tốt.

In English, you usually need a subject, but in Vietnamese it can be omitted if it is obvious.

Because of that, this sentence feels a bit elliptical or context-dependent on its own.

Vietnamese often does not use a verb equivalent to to be when describing a state or quality.

So:

• thể trạng tốt literally looks like physical condition good
• natural English translation: the physical condition is good

This is normal Vietnamese grammar. Adjectives can function as predicates without needing a separate to be verb.

Because là is usually not used before adjectives like tốt in this kind of sentence.

Compare:

• Anh ấy là bác sĩ. = He is a doctor.
  Here là links a subject to a noun.

But:

• Anh ấy khỏe. = He is healthy.
• Thể trạng tốt. = The physical condition is good.

With adjectives or states, Vietnamese usually does not use là.

So thể trạng là tốt would sound unnatural here.

It is understandable, but by itself it sounds a little compressed or incomplete because the subject is omitted.

A fuller and more natural version might be:

• Nhờ bác sĩ thú y mà nó có thể trạng tốt.
• Nhờ bác sĩ thú y mà con vật có thể trạng tốt.
• Nhờ được bác sĩ thú y chăm sóc nên thể trạng của nó tốt.

The original sentence can work if the context already makes the subject very clear.

No. Nhờ has more than one use.

1. nhờ = to ask someone for help

   • Tôi nhờ anh một việc. = I'm asking you a favor.

2. nhờ = thanks to / due to

   • Nhờ bác sĩ thú y mà thể trạng tốt.

In your sentence, it is the second meaning: thanks to.

So you have to understand it from the sentence pattern.

Not exactly.

• nhờ usually suggests a positive cause
  → thanks to

• vì is more neutral
  → because of

• do is also neutral to formal
  → due to / because of

• tại often sounds like assigning blame
  → because of / it's someone's fault that

So in this sentence, nhờ is the best choice because the result is good: thể trạng tốt.

Sometimes yes, but nhờ ... mà ... is a very standard and natural pattern.

For example:

• Nhờ bác sĩ thú y, thể trạng tốt hơn.
• Nhờ bác sĩ thú y nên thể trạng tốt.

But nhờ ... mà ... clearly marks the cause-result relationship and sounds very natural.

A more complete version would include the subject and sometimes có:

• Nhờ bác sĩ thú y mà nó có thể trạng tốt.
• Nhờ bác sĩ thú y mà con mèo có thể trạng tốt.

Here:

• nó / con mèo = the subject
• có thể trạng tốt = has good physical condition

This may feel easier for an English speaker because it matches English structure more closely.

Usually it suggests overall physical condition, not just a momentary feeling.

So it is more like:

• good physical state
• strong condition
• healthy constitution

If you wanted to say someone is simply feeling well right now, Vietnamese might use other expressions depending on the context, such as khỏe.

So thể trạng tốt sounds a bit broader and more clinical.