Why Does My Dog Hack All The Time?

Heartworms will cause a dog to hack because their lungs are collapsing. You need to get her checked.

First of all you should differentiate between choking and hacking cough and hiccups because all these have similar symptoms. Chocking sound in dogs can be heard if something is stuck up in throat.  Neck constrictions due to collars and ropes are other possible cause of chocking. Symptoms of chocking are gagging, drooling, difficulties in swallowing, regurgitation etc.

Spasm in diaphragm is responsible for hiccups in dogs. Infrequent hiccup in dogs is not a sign of illness. It can be due to rapid eating  or minor gastrointestinal problems. Persistent and prolong hiccups can be due to serious illness and requires vet visit immediately.

Irritation in the airway, lungs and throat can cause cough in dogs. There are many reasons of cough in dogs. Respiratory tract infections, Infections in mouth and tooth, are common causes. Other factors and conditions like allergy, internal parasites, distemper, heartworms and heart diseases, etc can also cough in dogs.
Cough that can persists for 1-3 weeks or more is kennel cough in dogs. Both bacteria and virus can cause this type of cough that is contagious also.  Its signs are sneezing and soft dry cough. Different causes cough require different treatment approach.Your local vet can help in this regard, so, take your dog to vet.

I'm not a vet. But Ive had some different experiences.  1 reason..some dogs do this weird reverse sneezing thing.. Its got to do with their trachea especially in small dogs.. Its nothing to worry about but looks scary.  Another possibility is to check the dog for heartworms that makes them hack or possibly a cold.. Or something stuck in the throat.. Once had a dog get a piece of rawhide chew stuck.
Good luck..

May be that your dog has allergies or something is irritating his throat. Make sure he has a good fresh water supply at all times

Reverse sneezing is not a problem with the trachea and can affect dogs of all sizes.  Reverse sneezing is related to irritation of the nasal passage. 
A hacking cough is often secondary to kennel cough or another type of upper respiratory infection.  Cough can be secondary to heartworm disease--this is more likely if you are in an endemic area.
The best thing to do is have your dog examine by a veterinarian.

Take her to a vet. It might be heartworms which can be fatal.