Dogs cough in one of three basic ways: purposeful, warning, or nuisance.
#1: A purposeful cough is productive; either coughing up a foreign body, or coughing out bacteria and pus from pneumonia.
- ALLOW ME A MOMENT TO RELIEVE MANY CLIENTS WORST (unfounded) FEAR: In 13 years of practice, I’ve never once, EVER, and I mean EVER, had a dog present for actually choking on something or having something stuck in the throat causing a cough. Consider this: remember that last time you were drinking a glass of something and “breathed some down the wrong pipe”? Remember how painful that was, how you couldn’t STOP coughing, how distressed you were? If your dog actually, truly has a foreign object stuck somewhere, it’s like that, incessant painful coughing, or incessant, painful pawing at the face with oral foreign bodies. If you’re reading this blog instead of rushing to the emergency clinic, your dog is probably not choking on anything.
Now, back to those three basic kinds of cough…
#2: A warning cough signals severe systemic illness, like fluid buildup in the chest, lung cancer, or severe allergies. This kind of cough warrants further investigation.
#3: A nuisance cough is one that doesn’t serve a useful function, and is caused by unnecessary stimulation of the cough reflex, ie: by a “tickle in the throat”. Nuisance coughs can be caused by structural abnormalities of the windpipe like collapsing trachea, tracheal or bronchial pressure from the outside due to enlargement of the heart, uncomplicated bronchitis like “kennel cough”, chronic inflammatory bronchitis with no bacterial involvement, and mild respiratory allergies.
- If a nuisance cough is caused by bronchitis, like those numerous bacterial and viral cases of “kennel cough”, your dog will probably be standing there smiling and wagging her tail while she’s honking up piles of white foamy yuck.
- If a nuisance cough is caused by heart enlargement, though, the vet will be able to hear a murmur, and you might have noticed other symptoms like exercise intolerance, weight loss. Clearly, a complete physical examination is necessary in every case of cough.
What tests might your veterinarian recommend to diagnose a cough? What are the pros and cons of each?
After the above-mentioned complete veterinary physical exam, it’s your veterinarians job to decide if a cough is serving a purpose and should be encouraged, is acting as a warning sign of a more serious disease, or is just a nuisance and should be suppressed.
- HOW IT’S DONE: Requires pet to alternately lie perfectly still on their side, and then lie perfectly still on their back. As you might imagine, sedation may be necessary.
- WHAT IT CAN DO: Look for evidence of fluid, evaluate the overall size and shape of the heart, visualize the major airways, check for lung tumors.
- WHAT IT CAN NOT DO: See inside the heart, see inside tumors, define what kind of fluid is in the chest.
Chest ultrasound / cardiac ultrasound / “echocardiography”
- HOW IT’S DONE: With or without sedation, requires your pet to lie perfectly still on their side, on a raised, padded table.
- WHAT IT CAN DO: Can visualize the inside of the heart. May be able to look inside any large tumors, and help direct the vet’s biopsy needle. If significant fluid is built up in the chest, can look for tumors or foreign bodies that may have caused the fluid.
- WHAT IT CAN NOT DO: Because ultrasound waves bounce off air, ultrasound cannot be used to evaluate the lungs or the large airways in most cases.
Transtracheal Wash / Tracheal Fluid analysis:
- HOW IT’S DONE: Either by sticking a tube-attached needle through the front of the windpipe (under sedation), or by feeding a sterile tube down a tracheal anesthesia gas tube (under general anesthesia).
- WHAT IT CAN DO: Obtain samples to send to the lab, to determine if expelled lung fluid contains pus, cancer cells, inflammatory cells, bacteria, etc.
- WHAT IT CAN NOT DO: Diagnose many causes of bronchitis, most of which are viral. Not helpful in cases of heart disease.
- HOW IT’S DONE: Under general anesthesia, feeding a camera down the large airways
- WHAT IT CAN DO: Find and often retrieve foreign bodies, take pictures of lumps, biopsy lumps, aid in tracheal fluid analysis
- WHAT IT CAN NOT DO: Remove all foreign bodies (some of which get really, really stuck), remove all tumors (most of which grow through the tissue). Not helpful in cases of heart disease, or most lung tumors (few of which penetrate the large airways).
Chest tap / Chest fluid analysis:
- HOW IT’S DONE: Inserting a needle through the chest wall, with a syringe attached, and sucking out some of the fluid
- WHAT IT CAN DO: Therapeutic: can remove any large built-up quantities of chest fluid. Diagnostic: Fluid analysis can often tell the difference between fluid that collects because of infection, vs. heart disease, vs. cancer.
- WHAT IT CAN NOT DO: Often, fluid from heart disease patients looks awfully similar to that from tumor patients. Not helpful if there’s no fluid to analyze, or of the problem is within the large airways.
There you have it!
The answer to the (leading, admittedly self-promotional!) title of this blog? Every time your dog is coughing, take her to the vet. If she has absolutely zero symptoms besides the cough, she’s standing there wagging at you and looks the same weight she always has, and the cough started 10 days after boarding or grooming, your vet may prescribe antibiotics and send you on your way. If she’s been losing weight, or the cough has been more than 2-3 days, or sounds fluid-y, or is associated with lethargy, loss of appetite, heart murmur, or any other systemic symptom, your vet will probably more aggressively recommend one or more of the above advanced diagnostic tests.
Thanks so much for reading, and for considering Leo’s Pet Care at 317-721-7387 as your family veterinary clinic!