Her purr motor isnt running so smoothly...

Question
When Chloe is mildly happy and the purring is so soft it's not audible, there's not a problem.
However...
When Chloe is very happy and begins purring intensely, she always has physical difficulty with it.
She begins deep breathing (no rasping or anything unusual accompanying it), swallowing often and I can hear rattling throat congestion. After a minute or so of this, she'll get annoyed and stop purring. :(
I've been cat guardian for dozens of cats in My life and have never even heard of something like this.

She is an angelic 5 year old siamese-persian mix who's kept indoors. Healthy weight, eating, and behavior.
She has had the purring problem as long as I can recall.

Any ideas about what this could be?
Chloe seems bummed when it happens.

Answer
Hi Amanda,

The most common reason I see for cats having difficulty and irritation with purring is inflammation of the airways. Purring is achieved through vibration of the vocal folds in the larynx. But these can become inflamed due to a number of causes.

Infection (laryngitis and bronchitis) is probably the most common. But these infections typically either resolve or worsen within a couple of weeks. That's not to say a chronic infection isn't possible, but if Chloe has suffered from the problem for her whole life, it might be more likely that another issue is to blame. Asthma can be responsible for airway inflammation, as well, and this can remain chronic if not treated. Some less common explanations include tumors and polyps.

Sometimes, difficulty breathing is attributable to heart problems, and because purring requires more effort than breathing at rest does, it is common for cats with some form of heart disease to cough or "choke" when they purr heavily.

You should have Chloe examined by a vet. Explain the noises that she's making and explain that you don't feel comfortable assuming it's nothing to worry about. Hopefully, they will be able to rule out heart problems and get her on some antibiotics or anti-inflammatories (for asthma), if warranted.

Good luck!
Jessica