Cat is coughing

My cat is 16 years old. She is coughing every time she has been laying down to sleep. The cough sounds wet like there is fluid in her lungs. She never coughs anything up. This happens several times a day. I took her to the vet and they could not hear any fluid in her lungs. They gave her a round of antibiotics which did nothing. Other things going on with her are she drinks an excessive amount of water every day and urinates a lot. I took her to get blood work done last October. Everything was normal except there is blood in her urine. The vet said she has early renal failure but that is common due to her age. I switched her to canned food which she loves. The cough started about 3 months ago. The vet said the only way they can really determine what is going on is if they do an ultrasound or X-ray. My cat hates the vet and gets traumatized. They would have to sedate her to do these tests. I don't want to put her through that. Any thoughts on what could be causing this cough would be helpful. My apologies on the long post.

i think you should have the x-rays done. it could be a lot of things -- asthma, congestive heart failure, etc. 

Pleural effusion, aka fluid around the lungs, and peri-cardial effusion, fluid around the heart, are the primary concerns with a geriatric kitty persistently coughing. October is too long ago for bloodwork to be helpful. No recent labs done?

A lung mass or, as detmut mentioned, CHF, are primary rule outs for causes of said effusion. She needs an Xray pronto. Interpreted by a board certified radiologist. This is available online, your vet has only to send digital imaging he captures with his Xray unit to the distance radiologist, and they'll generate a report within a couple hours.

Even for early stage renal disease, blood in the urine is abnormal. As is only adjusting to canned diet. There are other measures to discuss with your vet. What else did they recommend?

She is on a mixed diet of both wet and dry food. Just majority is canned due to the renal failure. They recommended a X-ray to see what is causing the cough. I will take her in asap to get the X-rays and request more blood work. They also said when she is sedated they can look down her ears to see if they are clear. I appreciate the feedback,

Note, do not start any corticosteroids, aka prednisone, prednisolone, dexamethasone (injection nor oral), Medrol, or injectable Depo-Medrol, until she has that Xray. If they administer steroids without knowing her cardiac health status for sure, they can induce pleural and cardiac effusion, fluid around the lungs and heart respectively.

For now, her cough may be helped by some home nebulization therapy, filling your smallest bathroom with steam, and allowing her to breathe in this steamy nebulizing goodness for 7 to 10 minutes multiple times daily.

Also, steroids are contraindicated for a renal cat, as they destroy red blood cells over time, and a renal cat already is at risk for depleted erythrepoetin which leads to decreased generation of red blood cells.

She'd benefit from quality high protein, in moderate volumes. Also, controlling her phosphorus intake can help her not feel crummy. Either by feeding low phosphorous meats, or adding phosphorus binders to her med regime, to discuss with her rDVM. Renal cats do well on supplemental nutrition, including omega 3 fatty acids in concentrated fish oil. Welactin has a good ratio of EPA and DHA, the omega 3 fatty acids that help reduce inflammation and replenish/regenerate cells. At high enough concentration, beyond skin, it helps with joint, cardiac, GI, renal, liver, endocrine and bladder health.

VetriScience Renal Essentials Feline is also a great supplement, with anti-inflammatory and antioxidant components. Prebiotic, aka fiber, in the form of psyllium husk, is also a great additive, as it binds excess protein, limiting protein from being digested and broken down into nitrogen, aka Blood Urea Nitrogen (BUN in blood chemistry labwork).

Hope her Xray yields some simple bronchial changes that are age related, no heart disease, and she just needs a little nebulization therapy to help her breathe easier. Heart disease isn't ruled out by Xray, just an enlarged heart is. An echocardiogram with a cardiologist is the only way to diagnose heart disease.

Did your vet hear a heart murmur or arrhythmia? Sometimes, only 1 out 4 vets, for example, in a practice auscult (hear) a murmur or arrhythmia. She'd benefit from a few sets of hands, eyes, and ears assessing her!