Hi, several causes are possible.
We won't be able to tell you exactly what happened, but let's look at some possibilities:
-When she was coughing she might have choked on some secretions. If she lost a tooth last month, she may have more infection in her mouth, and she may even have choked on some teeth she lost, or secretions from an tooth abscess.
-Collapsing trachea. They can cough a lot. Those small breeds of dogs are prone to get this condition.
Here is a link to it:
-Heart condition: she might have a heart problem. They can develop this as they aged. She might have had what we called an arrhythmia (irregular heart beats) from a heart problem.
Now for the less common:
-Addison disease: in this disease, the adrenal gland does not function well, and they can get very weak.
-She may have had a transient hypoglycemic crisis (low blood sugar)
-Partial seizures. They usually have full tremors, shaking, but it may be a partial type of seizures
Best for you to see your primary care veterinarian, since we do not know what caused this episode. They will examine her and let you know if treatments and diagnostic tests are necessary
Let me know if you have more questions, or need additional information.
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