70 | The step-by-step guide to managing feline asthma as a veterinary nurse

PodcastRespiratoryEmergency and Critical CareNursing
Written By Laura Jones

Today, we’re talking about some of the most difficult patients we see - dyspnoeic cats.

 

Yep, there’s nothing like that dyspnoeic cat emergency - they arrive SO stressed, and it feels almost counterintuitive that staying AWAY from them is actually the thing that helps them most in those early stages.

The majority of dyspnoeic cats we see have feline asthma - a form of lower airway disease. This disease is pretty misunderstood and is far more complex than ‘just’ being asthma, so today, we’re looking at exactly what it is and how to manage these patients confidently and calmly from start to finish.

So what IS feline asthma?!

Feline asthma isn’t as simple as it sounds - think of it as the respiratory equivalent of FLUTD. ‘The dyspoeic cat’ is as simple as ‘the blocked cat’ - a common emergency but with a TON of different causes and potential factors.

Feline asthma is actually a form of lower airway disease. The terms are often used interchangably (like most things in medicine) - I’ll save you the soapbox moment and instead say this: feline lower airway disease (FLAD), feline inflammatory airway disease, feline inflammatory lower airway disease, feline asthma, they’re generally all referring to the same thing (though asthma as an umbrella term is technically incorrect - we tend to use that term as clients understand it easily).

I’m going to call it feline lower airway disease or FLAD for the rest of this episode.

Feline lower airway disease is a term used to include two main disorders: asthma and feline chronic bronchitis.

Clinically, it’s often challenging to tell these two disorders apart - we need cytology to do that. However, we tend to see more acute episodes of respiratory distress with feline asthma.

Let’s talk about asthma

In humans, asthma refers to a condition characterised by spontaneous airway constriction and remodelling. Asthmatics are often dyspnoeic (and I say this as one - asthma attacks are scary!) and we respond well to bronchodilators.

Feline asthma is similar, but unlike humans, most cats also have a chronic cough.

So, how does it happen?

These patients have a hypersensitivity (allergic) reaction within their airways, where repeated exposure to specific allergens causes the release of substances like histamine. This causes the smooth muscle within the airways to contract, causing bronchoconstriction.

The reaction also increases eosinophil levels at the site, which worsens the inflammation and can cause tissue damage, further compromising the airways and worsening the patient’s respiratory signs.

The result of all of this is a hyper-reactive airway that is very sensitive to allergens, thickening of the smooth muscle lining the airway, and an increase in airway mucous production.

Which patients do we see it in, and why?!

It can be seen in any cat, though it is more commonly seen in younger to middle-aged patients. Siamese and Oriental shorthairs are more commonly affected than other breeds.

Household and environmental allergens play an important role in this disease, triggering dyspnoeic episodes if not carefully managed. Substances such as dusty cat litter, air fresheners, cleaning chemicals, perfumes, cigarette smoke, pollen, building dust and dust mites are particularly problematic and exposure to them should be avoided (or minimised) in these patients - and we play an important role in educating and supporting clients with this.

Ok, so that’s asthma. How does chronic bronchitis differ?

Feline chronic bronchitis remains a less well-understood condition compared to asthma. These patients have chronic coughing with airway remodelling and narrowing in response to inflammation, and rather than eosinophils, neutrophils are the primary inflammatory cell involved.

Chronic bronchitis does not seem to have acute episodes triggered by environmental allergens, and it does not result in bronchoconstriction, though the inflammation, increased mucous production (in response to inflammation), and airway remodelling will decrease airway diameter over time.

Because feline airways are incredibly narrow, even tiny decreases in airway diameter can significantly impact airflow. Over time, the inflammation and remodelling will lead to permanent airway changes such as fibrosis.

But it isn’t quite as simple as one or the other.

We’re talking cats here. They’re never simple (and nor is medicine, for that matter) - many patients won’t neatly fit into the ‘asthma box’ or the ‘chronic bronchitis box.’

Patients will often present with mixed inflammation and signs somewhere between the two conditions, suggesting that, like many other feline diseases, FLAD is a spectrum, and patients will present with varying degrees of airway change.

What signs do we see in our FLAD patients?

Though it depends to some extent on the type of lower airway disease they have, most of these patients will present with a chronic history of coughing, and potentially episodes of tachypnoea.

Clients may report this as the cat ‘coughing up’ something, as the cough can sound quite hacking and have a terminal retch at the end. Often, it is mistaken for bringing up hairballs.

Occasionally, exercise intolerance will be seen. This is much more noticeable in dogs than in cats, but panting/tachypnoea after play may be noticed.

Many cats will present in acute respiratory distress, with signs such as:

  • Tachypnoea

  • Dyspnoea

  • Orthopnoea

  • Open-mouth breathing

  • Wheezing

  • +/- Cyanosis (not always; patients can be hypoxaemic without cyanosis!)

Alongside varying mentation changes, and potentially appetite changes if their tachypnoea and coughing have interfered with their ability to eat.

The step-by-step approach to managing these patients

Whether they’re presenting as an emergency in respiratory distress or they’ve been stable at home, these patients need careful management.

Even previously stable patients can easily decompensate on the way to the clinic due to the stress of the journey, and many of these patients’ signs go unnoticed at home until an acute episode occurs.

As nurses and technicians, we are highly involved in stabilising and managing these cases, both in the hospital and long term. So here’s how to approach them.

Step one: stabilisation above all else.

These patients are on a knife-edge, balancing an increased demand for oxygen with a reduced ability to get oxygen in through their constricted airways - so priority number one is to get them stable, NOT to find out what’s going on.

There’s no point rushing one of these patients into X-ray - you won’t get any meaningful information from it, and you’re far more likely to end up with a decompensated (or worse, dead) patient at the end of it. If your vet really wants to do some imaging, a point-of-care ultrasound is the only thing I’d consider (as this can be done non-invasively, without restraint, and in oxygen), but after the patient has had a bit of time to settle.

Instead of imaging, focus on a hands-off, minimal stress approach. If your patient doesn’t already have IV access and won’t tolerate placement, don’t force it - instead, give them some IM sedation (if appropriate, we’ll often use something like butorphanol under the vet’s direction) and some time in oxygen.

Careful and calm handling, telling the team when the cat is stable enough for further examination, and monitoring from a distance are how we can best advocate for these patients in an emergency.

Step two: diagnostics - but only when your patient has stabilised.

After their respiratory distress has calmed and they’re feeling more settled (or they’ve had some sedation on board), we can then think about assisting with diagnostics.

We’ll gain IV access (if not already), potentially pull an emergency blood panel from the IV when we place it, and then at an appropriate time, perform imaging.

This will likely be chest X-rays (and I’d avoid doing these conscious, since restraint is likely to significantly worsen your patient’s breathing) - though CT gives more information if it is available.

Imaging usually shows a bronchial or bronchointerstitial pattern, and if you’ve got access to CT, this can also highlight areas of lung consolidation and bronchial thickening.

After imaging, airway sampling is required. This tells us about the type of inflammatory cells present within the airway and helps us rule out other respiratory diseases (like bacterial infection and infectious diseases).

We’ll perform a bronchoalveolar lavage - either blindly or via an endoscope. This isn’t without risk in cats due to their narrow and sensitive airways, so make sure everything is ready in advance to minimise anaesthetic time, and keep a close eye on their SpO2. If they desaturate, don’t be afraid to tell the vet to stop.

Step three: treating and managing these patients in the hospital

Inpatient treatment usually involves administering steroids (usually by injection initially, then transitioning to oral/inhaled versions) +/- bronchodilators (if the patient has asthma).

Alongside this, we’re going to provide supportive treatment, including oxygen therapy where needed, fluid therapy depending on hydration status, and anxiolytics or sedatives as needed.

Once these patients have stabilised and weaned off of injectable medications, it’s time to think about long-term care.

Step four: managing these patients at home

We all know how vital veterinary nurses and technicians are in managing long-term diseases, but despite it being so important, it’s often overlooked.

FLAD patients require careful ongoing management to prevent further respiratory distress episodes and manage their clinical signs. This includes:

Weight management

Preventing or managing obesity is essential, since increased weight will increase the demand for oxygen and the pressure on the respiratory system

Trigger management

Many environmental agents can worsen signs or trigger episodes in an asthmatic cat. Clients should be advised on the careful or minimal use of cleaning products, aerosol sprays and perfumes, the type of cat litter to use (avoiding dusty ones) and potentially using things like air filters at home to trap particles that would otherwise be inhaled.

Inhaler training

Many cats require long-term steroid treatment. Since oral steroids can cause diabetes, we instead administer steroids directly to the target site in these cases - the airways.

To do this, we use a metered dose inhaler connected to a face mask and spacer chamber. We must introduce this in the right way, since most cats will require this long term, and the last thing we want to do is stress a respiratory patient out whilst treating them. We also need to ensure client compliance, and asking them to do something their cat hates twice a day isn’t going to help with that at all.

We usually begin the patient on a short course of oral steroids whilst the inhaler device is introduced. This is done gradually, beginning with getting them used to putting their face in the mask for short periods, and then building from there. International Cat Care and AeroKat have some great training resources on this, which you’ll find here.

Whilst there’s a lot to think about when managing these patients, one thing really stands out - we play an ESSENTIAL role in managing these patients successfully. Prompt triage and stabilisation, careful monitoring, ensuring minimal stress and handling and providing long-term care, support and advice are just some of the many ways we can use our nursing skills to support these patients.

Did you enjoy this episode? If so, I’d love to hear what you think. Take a screenshot and tag me on Instagram (@vetinternalmedicinenursing) so I can give you a shout-out and share it with a colleague who’d find it helpful!

Thanks for learning with me this week, and I’ll see you next time!

References and Further Reading

Laura Jones
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69 | 4 things you can do to provide better care to dogs with tracheal collapse