January 20, 2017
Another Furball? It Might Be Feline Asthma
Last Updated on Sunday, January 24, 2016 07:11 PM
Published on Tuesday, September 28, 2010 01:40 PM
Written by Andrea Tasi, VMD
作者：獸醫安德莉亞．蔡（Andrea Tsai, VMD）
Has your cat been coughing? Watch the video below and you may recognize that sound. Many people assume that the cat is trying to cough up a hairball and don't realize that their cat could have asthma. Untreated, asthma can progress and even be fatal. But, like human asthmatics, cats can be treated and the disease can be managed.
It is estimated that about 1% of cats suffer from asthma.¹ Siamese, Burmese and other Oriental breeds show a greater incidence, but any breed can have asthma.² It usually first occurs in young to middle-aged cats between the ages of two and eight.³ It is widely recognized that asthma attacks can be triggered by allergens in the environment such as pollens, dust, smoke, fumes, mold, fragrances and aerosols. Heat, cold, stress and exertion can also trigger attacks.⁴
What is Feline Asthma?
Feline asthma is a disorder of the lower airways, called bronchi and bronchioles, in which inflammation causes increased production of mucus, spasms of the airways and difficulty moving air out of the airways. It is considered to be an immune-mediated condition, which means that the inflammation is triggered by some allergic or over-active response of the cat's own immune system.⁵
What are the Symptoms of Feline Asthma?
Different cats may be affected in different ways, but the most common symptom is a wheezing or gagging cough, often called a hairball-type cough. In my professional experience however, hairballs do not cause coughing, as they are gastrointestinal and not respiratory in origin. Hairballs can cause retching, gagging and vomiting. With an asthmatic cough, most cats will stretch their necks out, get in a hunkered down posture and then cough in either a dry or moist sounding fashion. They may stick their tongues out a bit when coughing. Often it sounds and seems as if they are coughing some mucus up and then swallowing it.
Other symptoms may include decreased activity, becoming winded by normal activity, increased rate and effort of breathing and even open-mouth breathing in severely affected patients who are having trouble moving air out of their lungs.
Feline asthma in its most severe form can cause death by asphyxiation: the cat simply can't breathe.
How is Feline Asthma Diagnosed?
A cat presenting with a history of coughing, wheezing and/or respiratory difficulty will usually need the following tests to determine what is going on:⁶
- A thorough physical examination, including listening carefully to the lungs and heart.
- Chest radiographs, commonly known as x-rays. These help rule out other causes of respiratory symptoms like heart enlargement, fluid in or around the lungs, tumors or pneumonia. Many cats with feline asthma have prominent airways and hyperinflated lungs, which means too much air is trapped in the lungs. It is important to note that cats can be severely asthmatic and have normal chest radiographs.⁷
- A complete blood count: a blood test which looks at red and white blood cell numbers and helps determine if a patient is responding to inflammation or infection. Many cats with feline asthma have an increased number of eosinophils, a white blood cell type that responds to allergic and parasitic inflammation.
- A heartworm test. Heartworm disease can mimic the symptoms of feline asthma.
- A fecal test for intestinal parasites. Some intestinal parasites have life stages that migrate through the lungs and can cause inflammation and respiratory symptoms.
In general, the diagnosis of asthma is made by ruling out other causes of coughing and respiratory difficulty, as there is no one test that determines with 100% assurance that a cat has asthma or not.⁸
How is Feline Asthma Treated?
Conventional medical treatment of feline asthma is based upon two main drug types:⁹
- Corticosteroids: This class of drugs is anti-inflammatory in nature. Oral prednisone or prednisolone, and/or inhaled forms of corticosteroids are used to reduce the inflammation in the airways. Side effects of corticosteroids can include increased thirst and urination, increased appetite, weight gain, diabetes, lowered resistance to infection, and even behavioral changes.
- Bronchodilators: This class of drugs helps open up the airways. Both oral and inhaled forms of bronchodilators are used. Side effects are generally minimal with bronchodilators, but these drugs should never be used alone, as that can actually worsen the condition. Special inhalant masks are available for cats to administer these medications.
- Several other drugs, such as antihistamines and anti-leukotrienes, are also used by some veterinarians.¹⁰ Holistic veterinarians may use alternative medical therapies to treat some asthmatic cats.
If a cat is in an emergency situation in a veterinary clinic, oxygen therapy will also be used.
How Does Diet Relate to Feline Asthma?
In over two decades of feline practice, I have attended many continuing education seminars on feline asthma and rarely heard diet discussed as a potential cause or trigger for the condition.
However, I have had several clients who, on their own initiative, changed what they fed their cats and found that the symptoms of asthma were either greatly reduced or eliminated. What was the change they all made? They removed all dry food and all grain-based products from their cat's diet.
Most did this by simply switching to grain-free canned cat foods. Some used balanced commercially prepared or home-made grain-free, raw meat cat foods, either as the only food fed or in combination with some grain-free canned foods. After observing this effect, I incorporated diet changes into my case management of cats with asthma. I began to see many cases where my patients no longer needed medication — or much reduced doses — to control their asthma symptoms. It is important to note that not all cases of asthma will improve with the elimination of dry food and grains. But it is worth considering this change as a much less intrusive method of reducing or controlling symptoms. I have never observed a worsening of a cat's asthma from a gradual and nutritionally balanced diet change.
Why does this diet change help some cats? It is my opinion that the processed and fractionated grain products in many cat foods are strong triggers for allergic or overactive inflammatory responses in some cats. Remove these triggers, and these cats get better or are even cured.
本文中穀物特定部位的原文是 fractionated grain products。Fractionate這個字是分割成數個部位的意思。我覺得應該是指穀物先被分割成不同部位，取走最有經濟價值的之後，其餘比較沒有價值的就拿去做動物飼料，我想本文作者用fractionated這個字實在是太客氣了。動物飼料最初是拿來餵經濟動物的，而經濟動物大多是吃草的，mind you.
If you have an asthmatic cat on medication and are interested in this approach, you must do this in consultation with your veterinarian. Do not, under any circumstances, simply stop giving your cat his/her medications.
If your cat is on high doses of corticosteroid drugs, it is also important to remember that these drugs can be suppressive to the immune system, rendering a cat more susceptible to infection. In these cases, I would advocate using either a canned or home cooked grain-free, nutritionally balanced food, not a raw diet.
Dr. Andrea Tasi, VMD, has lived with many cats over the years. Currently, she and her husband have five wonderful cats that make up their "family:" Jimmy, Bug, Peggy Sue, Fifi and Monkey. It was Dr. Tasi's lecture on Nutrition and Raw Feeding that inspired Margaret Gates to begin feeding her cats a raw diet, found Feline Nutrition and put together the team to create the RawFedKitty Campaign. We will be forever grateful to her.
1. Angie Hibbert, BVSc, MRCVS, "Therapy for Feline Asthma," European Society of Feline Medicine Pre-BSAVA Feline Symposium, April 7, 2010.
2. Danièlle Gunn-Moore, BSc, BVM, PhD, MACVSc, MRCVS, "Chronic Coughing in Cats, Part I: Causes," University of Edinburgh, 2003.
3. CM Venema and CC Patterson, "Feline Asthma: What's New and Where Might Clinical Practice Be Heading?" Journal of Feline Medicine and Surgery 12, no. 9, September 2010, 681-692.
4. Kathryn Hopper and James Perkins, "Potential Asthma Triggers" at fritzthebrave.com. The site is an approachable and comprehensive resource for feline asthma information.
5. Danièlle Gunn-Moore, BSc, BVM, PhD, MACVSc, MRCVS, "Chronic Coughing in Cats, Part II: Diagnosis," University of Edinburgh, 2003.
6. Danièlle Gunn-Moore, "Chronic Coughing in Cats, Part II: Diagnosis."
7. KK Adamama-Moraitou, MN Patsikas and AF Koutinas, "Feline Lower Airway Disease: A Retrospective Study of 22 Naturally Occurring Cases from Greece," Journal of Feline Medicine and Surgery 6, no. 4, August 2004, 227-233.
8. Danièlle Gunn-Moore, BSc, BVM, PhD, MACVSc, MRCVS, "Chronic Coughing in Cats, Part I: Causes," University of Edinburgh, 2003.
9. Danièlle Gunn-Moore, BSc, BVM, PhD, MACVSc, MRCVS, "Chronic Coughing in Cats, Part III: Treatment," University of Edinburgh, 2003.
10. Danièlle Gunn-Moore, "Chronic Coughing in Cats, Part III: Treatment."