Tracheal Collapse In Dogs
Tracheal collapse is a progressive dynamic respiratory condition where the cartilaginous rings of the trachea weaken and no longer hold their shape causing the windpipe to cave in and flatten during respiration.
When this occurs a dog will often struggle to breathe and have a dry, harsh cough. This condition can be life-threatening.
In this article, we advise how you can tell if your dog has tracheal collapse, what you need to be aware of and current treatments that are available.
Causes Of Collapsing Trachea In Dogs
The trachea, or windpipe, is part of the respiratory system that connects the larynx to the lungs carrying oxygen-rich air to and from the lungs.
During the process of breathing, negative pressure is generated in the windpipe.
In normal dogs, the trachea is held open along its full length by healthy semi-rigid rings of cartilage that create a circle.
However, in those dogs suffering from tracheal collapse, these tracheal cartilages become weak and flat when exposed to this negative pressure.
While the exact cause of this respiratory condition is unknown, the weakness of these cartilaginous rings is often thought to be implicated by genetics, nutrition and allergies.
The incidence of tracheal collapse can be increased by the presence of:
- Chronic respiratory disease – chronic bronchitis, secondary infection
- Cushing’s disease
- Exposure to cigarette smoke, aerosols and/or candles/incense
- Congestive heart failure
Signs Of Tracheal Collapse In Dogs
Cases of collapsing trachea are more prominent in middle-aged small toy breed dogs such as Yorkshire Terriers, Shih Tzu, Lhasa apsos, Pomeranians, Chihuahuas, and Maltese Terriers.
That is not to say that other breeds will not suffer from this, and we often see the condition in English and French Bulldogs.
The most classical symptom of tracheal collapse is a chronic, harsh, dry cough that can is often described as a ‘goose honk’ cough.
It is often paroxysmal in nature (meaning that the dog cannot control it) and will often worsen when excited or stressed.
Other common clinical signs associated with a collapsing trachea include:
- exercise intolerance,
- coughing when exercising, stressed or with excitement
- coughing when pressure is applied to the neck (such as when pulling on a lead)
- gagging while eating or drinking
- respiratory distress,
- cyanotic (turning blue)
- dyspnea followed by collapse
In chronic cases, the dog may struggle to maintain weight and sleep due to the fact they are always struggling to breathe and are incredibly anxious.
How Is A Collapsing Trachea Diagnosed?
A thorough history, combined with knowledge of breed and age and listening to the cough can give a lot of hints as to whether a dog is suffering from tracheal collapse.
On physical examination, there may be abnormalities with lung and tracheal sounds and often a cough can be elicited with a light touch of the neck region.
The standard way to diagnose tracheal collapse is by assessing a radiographic image of the cervicothoracic area.
Lateral radiographs show clearly where the flattening occurs and the degree of tracheal collapse.
If diseased tracheal rings are in the cervical region (neck), flattening will occur on inspiration.
If the problem occurs in the chest (thorax) (intrathoracic) then flattening will occur on expiration.
Because tracheal flattening is a dynamic condition, in some circumstances, we may not see it on a standard radiograph.
In these situations, your vet may recommend referral for fluoroscopy to assess ‘real-time’ movement of the tracheal rings.
Thoracic radiographs will also allow for the assessment of the lungs and heart and whether there are any conflicting diseases.
The degree of tracheal collapse can be graded in severity from I to IV, with IV being the most severe.
Dogs with grade 1 may not show any clinical signs, however as the grading increases so do the number of symptoms.
Grade I – tracheal membrane is slightly pendulous, cartilage maintains normal C shape, lumen reduced approximately 25%
Grade II – tracheal membrane widened and pendulous, cartilage is partially flattened, lumen reduced approximately 50%
Grade III – tracheal membrane is almost in contact with the dorsal trachea, cartilage is nearly flat, and the lumen is reduced by approximately 75%
Grade IV – tracheal membrane is lying on dorsal cartilage, cartilage is flattened and may invert, and the lumen is essentially non-existent.
It’s also important to assess the larynx under light anaesthesia for conditions such as laryngeal collapse and laryngeal paralysis.
In some circumstances, tracheoscopy or bronchoscopy may be recommended.
This procedure requires a general anaesthetic and involves your vet inserting a fibre optic camera down the dog’s airway.
The vet will be able to directly assess the airway for signs of inflammation and take samples for bacteriology and cytology.
It’s not uncommon for these dogs to also have signs of bacterial infection – either pneumonia or tracheitis.
Treatment Of Tracheal Collapse In Dogs
Treatment of a collapsing trachea can be a contentious issue between those advising purely a conservative medical approach to management vs those who recommend surgical intervention.
For most dogs, management is started by medical treatment focussing on symptomatic therapy to reduce cough and minimise contributing factors such as weight reduction, controlling respiratory effort and symptoms of heart disease.
Common medications used include:
- cough suppressants
It’s important to note that individual dogs will respond differently to medications and one regime doesn’t always suit all.
When medical management is no longer suitable, or there is severe tracheal collapse, intra-luminal tracheal stent surgery may be an option to prolong lifespan.
It needs to be noted that this is not a cure and some dogs are not good candidates for this surgery such as those:
- where <50% of the tracheal lumen has collapsed
- with concurrent severe illness
- where there is concurrent bronchial collapse
- that have a severe ongoing respiratory infection
Tracheal stent surgery involves placing a woven mesh, self-expanding tube made from flexible Nitonil (Nickel-Titanium alloy) into the lumen of the trachea while under light anaesthesia through the mouth under fluoroscopic guidance.
While this procedure is life-saving and has great results (90% show marked improvement), it must be noted that many patients do start to develop severe complications 2-3 years after the stent has been placed, therefore the procedure is recommended as late as possible in the animal’s life.
Sadly, there is no cure for tracheal collapse, however dogs can be managed very well.
What Is The prognosis For My Dog?
There is no cure or known prevention for canine tracheal collapse. Instead, we need to manage it.
That said, the earlier the condition is diagnosed and medical treatment is instigated the better the long term prognosis is.
About 70% of dogs who receive medical management will show signs of improvement.
However, there is some evidence that shows that older dogs and those with laryngeal or bronchial disease do have more complications.
For those dogs that undergo surgery for a stent, it’s important to minimise coughing for a good outcome.
If you need help for your dog, our vets are available 24/7.
Frequently Asked Questions About Tracheal Collapse
What Home Remedies Can Help My Dog?
While most of the medications used to assist your dog will be prescription only, some relief may be achieved by over the counter cough suppressants and anti-histamines.
It’s important to check with a vet for the correct dosage and make sure that these medications do not contain the highly poisonous sugar substitute xylitol.
In addition to these treatments, you can help manage your dog’s symptoms by:
- Using a harness in place of a collar to avoid putting pressure on your dog’s windpipe
- Making sure your dog’s environment is well ventilated
- Regularly changing or cleaning air filters
- Avoiding smoking, using aerosols, candles or incense around your pet
- Using a humidifier when the air is dry and/or in the winter when heaters are used
- Maintaining a healthy body weight as obesity will increase respiratory effort and reduce their lifespan
Are there other conditions that can be similar to collapsing trachea?
For this reason, it’s important to have your dog undergo a thorough physical exam while awake and while under anaesthesia.
Are certain breeds more often affected?
Smaller breed dogs and toy breeds are the most commonly affected by tracheal collapse.
Breeds of dogs such as the English Bulldog, French Bulldog and Pug are frequently affected and these dogs will often also suffer from a hypoplastic trachea where the diameter of the trachea is incredibly small.
At what age does tracheal collapse usually occur?
The average age of dogs developing tracheal collapse is 7 years.