Hello, I'm Dr Ralston, thanks for your question.
This is a hard question to answer. It's hard to know how sick your pet may or may not be without seeing it in person. Seeing the xrays are how a diagnosis of asthma is made, and response to therapy (in this case steroids) would not be a bad choice of treatment by your Veterinarian at all. But, really, severity of signs of asthma often correlate directly to those radiographs and how bad they look.
Now, what I have noticed is this. Cats that have asthma often have severe difficulty breathing overtime. They will have "attacks" where they are breathing very deeply and struggling that is true. But there are also long term changes in the lungs that cause them to receive less oxygen over time, and they struggle with this daily.
I have noticed that when starting medications that relieve this inflammation the pet is able to actually breathe easier. This allows them to relax, and even sleep more, especially at first. This is because they are relieved and actually feeling better. They sleep to make up on the loss they have had, and the strain they have encountered. I have experienced this with pets as well with medications like Rimadyl which is a non-steroidal anti-inflammatory drug used to treat pain and inflammation in dogs. Many people tell me that it makes their dogs sleepy. There is absolutely nothing in that medication that would sedate a pet or make them sleepy. But, it does relieve pain which allows them to rest comfortably.
So, I wouldn't be surprised if there are some changes in behavior over the next several days. Typically, they start to come around back to their normal selves after the first 3-4 days of treatment.
I would like to share some more detailed information with you about asthma as well. This is information I have prepared ahead of time that I share with my clients in the exam room. But I want to give this to you here as well, because I think it is very detailed and might also answer some other questions you might have.
As always, if you have questions, please feel free to follow up with me and I will help you.
Below is the information I wish to share with you :
Feline asthma is a type of bronchoconstriction, that makes it difficult to breathe deeply. It probably feels very similar to when people have asthma. People say it feels like a fish out of water, or like pressure in the chest.
The cause is not completely known. However there are several recognized possibilites:
- hypersensitivity / allergies
- environmental pollutants (smoke, air fresheners, candles, incense)
- infectious agents (bacteria, mycoplasma, viruses) that lead to chronic condition and changes
- maybe genetic in some breeds - like Siamese.
What happens is this:
Acute bronchial constriction of the air ways is initiated by the possible causes above. Think of the constriction kind of like a spasm of the trachea/airways. The muscle of the air way contracts, and forces out air. This is a cough. And the cough is usually started by foreign material in the air ways right?
Ok, but the second component is the responsive mucus. The irritation causes mucus to form in the airway, snot. So, you have constricted airways, making it harder to breathe, and they fill with mucus causing even more difficult breathing. In addition, the coughing actually makes the muscle stronger as it works out. It gets larger, and thicker, contributing to the narrowing of the airways.
The signs you see:
-and this is important, difficulty breathing OUT. You can't breathe in either, but then there is so much muscle hypertrophy (growth) and mucus that you can't push out normal air either.
You may not see signs for a while, and suddenly they are very prevalent.
Secondary complications include:
fever, pneumonia, and emphysema (big pockets of air that form in the lungs as a result of the increased pressure)
Diagnosis is usually made based on:
The physical exam, and the descriptions from the owner.
Auscultation: listening to the lungs. There will be loud wheezing sounds as the air passes through the congested airways
In advanced cases you might hear crackles as air passes through the mucus and makes clicking sounds.
But, x-rays are the best. There is classically a bronchial pattern with interstitial or pulmonary hyperinflation. That might not mean much to you. That's ok. It takes us years of training to recognize it.
This is a really good example of feline asthma on radiograph.
You can see the white "rings" in the lung spaces. These are inflamed airways. The lung should be darker, and more black as it is filled with air. The white is tissue. The airways are often not visible at all on xray, but when they are inflamed they will look like rings and tracks. Clearly visible on this x-ray.
Also, see the large black pockets that are black and towards the left of the x-ray. Those are hyperinflated lung spaces. The pet is gulping air and trying to breathe as hard as possible, hyperinflating those spaces of lung that ARE working.
I would call this a classic textbook x-ray. You don't always get this in practice.
In some cases a transtracheal wash should be done. This is when the pet is sedated, and closely monitored. A small amount of sterile saline is entered through a tube, and it mixes deep in the air ways. The pet then coughs, and the mixture of mucus and saline is collected and tested to be sure there isn't secondary infection, rare parasitic larvae, bacteria, fungus, even cancer cells that might be mimicking pneumonia.
This isn't usually needed, because the radiographs are often VERY specific and diagnosis can be made off of that alone.
Treatment for asthma:
In cases of sudden asthma, and respiratory distress in a cat, this is an emergency.
Emergency: these cats will need oxygen to help them breathe, rest, and steroids typically to reduce the inflammation as mentioned above. They will remain with oxygen until they are stable. Steroids start with injectable meds and follow up with oral steroids.
BRONCHODILATORS: Theophylline is often give IV in an emergency. This is an older medication that was used more in humans in the past, but still is valuable to us in Vet Med today.
Epinephrine and Atropine might be used in severe cases.
BUT, for LONG TERM, AT HOME STUFF, that you can manage:
Control of the cause if possible helps immensely. Eliminate dust, smoke, powders, any of the aerosolized issues as mentioned above.
Cats should become indoor cats so you can control it easier. Buy a very good vacuum with a HEPA filter, and change the filter in your air/heating
system frequently (once a month) and purchase a high quality one at that.
Fat cats have worse asthma, so a diet is never a bad idea.
Some cats will need to have steroids long term, although it is useful to use the lowest effective dose possible to avoid side effects.
Antibiotics are not usually needed long term, but are worth trying early on in case there is an infection. If culture can't be done, etc, then a choice is often made based on experience and best guess. Your Vet can do that.
Some cats do really well with an inhaler, just like people with asthma.
I'm going to give you some information on that here...
First, I'll give you these links:
Link to Feline Asthma Mostly, just more information for you to read. You can't get enough really.
Fritz the Brave Asthma Cat" target="_blank"> Good tips, hints and information.
Aerosol Chamber This is using an inhaler in cats, and is very helpful.
Flovent is used often in cats. Some will need it daily. Most really do tolerate this very well, and it can almost completely control signs over time.
Hopefully, I have given you some great information that will help you make the best decisions going forward.
Please follow up with any questions you have if I have not answered all your questions. I'm here to help!