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Which of the following are signs your cat could have a food allergy or intolerance?
a) Upset stomach
b) Dull coat
c) Itchy skin
[You’ll find the answer at the end of this article!]
Under estimated, overlooked, and under diagnosed: Pretty much sums up food allergy and food intolerance in the cat. This is a pity, because the effects are far reaching and yet once diagnosed, with the co-operation of the cat’s appetite (more of this later!) the patient can often be ‘cured’ of their symptoms.
But first, let’s break these problems down into bite-sized chunks.
One For All and All For One?
Are food allergy and food intolerance the same thing?
Actually, no, they aren’t. There are subtle differences between an allergy and intolerance.
- Results from an overactive immune system which acts inappropriately when faced with certain food types. This is a similar idea to hay fever in people, with an allergic reaction to pollen.
- Food allergy tends to develop over time, as the immune response builds with each repeated exposure. This means a food the cat was initially fine with, when fed regularly could cause an allergic reaction.
- This is the inability to digest a certain food. The classic example is the cat that develops diarrhoea when they drink milk. This is the results of a lack of lactase, the enzyme necessary to break down the milk sugar, lactose.
- Food intolerance is often present from birth, and causes ill effects the first time the cat eats that food.
The implications of this are that a cat with a bad reaction to a food the first time they eat it, is likely to have food intolerance, whereas the cat that develops symptoms despite no recent change of diet may have a food allergy.
Signs and Symptoms
There are three main reasons food-related disorders go under diagnosed. These are:
- The symptoms are very general
- There is no lab test that accurately diagnoses the problem
- Getting a cat to eat a special elimination diet can be tricky
OK, let’s chew this problem over and digest the general nature of the symptoms. These tend to affect the digestive tract and /or the skin.
- Sickness / vomiting
- Colitis (soft stools with mucus and blood)
- Poor coat (due to poor absorption of vitamins)
- Weight loss (poor absorption of nutrients)
- Itchiness, especially a non-seasonal itch
- Over grooming
- Symmetrical hair loss, most likely around the head and neck
- Miliary dermatitis (small, millet-sized scabs scattered over the skin)
- Rodent ulcers: Erosive, yellow-cream ulcers on the lips or mouth
Here we have a problem, because there are many reasons that a cat might be sick or have diarrhoea that are nothing to do with food allergy or intolerance. For example, a quick brainstorm of causes of stomach upsets goes something like this: Eating spoilt food, hairballs, worms, infection, pancreatitis, cancer…you get the picture!
Likewise, the itchy cat might have a simple common problem such as flea-saliva allergy or be hosting mites that make her itchy. She may even be stressed and licks herself as a comfort strategy, in the same way a child sucks their thumb.
So given the general natural of food allergy and intolerance, how is the problem diagnosed?
Diagnosing Food-Related Disorders
Remember we said there was no lab test that can accurately diagnose food allergy or intolerance? This poses a problem.
Given the general nature of the signs there’s nothing for it but to rule out all other problems first, and if the results are normal or negative, consider a dietary trial. Indeed, for the co-operative cat that is otherwise well, the vet may suggest an ‘elimination’ diet to run in parallel with those other tests.
Thus, the vet may run faecal tests (screening for parasites and infection), blood tests (checking organ function), bowel function tests (looking at the balance of digestive enzymes and vitamins in the gut), ultrasound (looking for signs of cancer), and possibly even bowel biopsies.
If there’s a strong suspicion early on that food is the culprit then the vet may deworm the patient, make sure they have good parasite control in place, and then suggest an elimination diet.
The Details of an Elimination Diet
If your head hurts because you keep banging it against a brick wall, the answer is not painkillers but to stop knocking your head. In the same way, food-related disorders settle down once the offending food is removed.
An elimination diet means feeding a tightly restricted diet, often consisting of a single protein and carbohydrate that the cat has never eaten before. The idea is that removal of the offending food stuff allows the symptoms to settle. In short, if the cat improves on the special diet then food intolerance or allergy is highly likely.
Sounds easy! However, there are drawbacks. Number one is the cat herself. Many cats are fussy eaters, and being offered a new food and being expected to eat it rarely goes down well. Secondly, the cat must eat that diet and absolutely nothing else, which can be tricky. Thirdly, it can take eight weeks of a strictly controlled elimination diet before improvements start to be seen.
Put like that, it doesn’t sound quite so easy, does it?
Treatment of Dietary Allergies or Intolerance
For those in the happy position that the cat chows down on the restricted diet, there is every chance of a full resolution of symptoms. The choice is then either to keep feeding that diet, or slowly reintroducing one new food every two weeks, monitoring carefully for signs of ill health. If the new food generates symptoms, it’s removed from the menu.
However, for many cats a compromise is reached. They avoid the offending foods as much as possible, but medical treatment may be necessary to suppress the worst of the signs.
These treatments include:
- Steroids: These are potent anti-inflammatory drugs which help to reduce swelling of the bowel wall that result from food allergy
- Antibiotics: Such as metronidazole, which has a dual action of killing some unwanted bowel colonizers and having an anti-inflammatory action
- Immunosuppressive medications: Such as chlorambucil, work by supressing the immune system and down-regulating the exaggerated response.
And finally, remember the question posed at the beginning of this post. . . here’s the answer.
Answer: Well done if you answered “All of them: a, b, and c” because as you know now, dietary related disorders can affect the gut, skin, and general well-being.
Tenacious Little Terrier says
Mr. N gets itchy if he eats too much chicken for more than a day in a row. He doesn’t get it enough for me to know if his coat changes too.
Food allergies are a pain! I have them as a human (and strange ones at that), but I’ve been fortunate never to have a cat with food allergies. The elimination diet would certainly be a challenge with a picky cat. It is a great point, and so important, that cat owners need to have a veterinarian diagnose the allergy and not try to diagnose it themselves. Too many illnesses look the same in cats.
Sweet Purrfections says
Luckily, Truffle and Brulee exhibit no symptoms of food allergies.
Allergies are so awful, even when they aren’t life threatening. I think it would be especially difficult to diagnose cat allergies for the reasons you mentioned. My dog Nelly seems to have both seasonal allergies and a grain intolerance. It is easy to find food for her, not so easy to hide from Mother Nature.
Food allergies in cats are really difficult to figure out. Thanks for this article — so informative and helpful!
Kitty Cat Chronicles says
Great article! Sophie has a food intolerance for grains. When we first adopted her, she would always have an upset stomach and diarrhea. We switched to a grain free food (which cats should be on anyway) and have had no trouble since!
Tonya Wilhelm says
Great article. Allergies are tough, but so worth trying to figure out the cause. Home cooking for my cat really allows me to pay close attention to each ingredient and to note changes.
The Daily Pip says
Our dog has lots of allergy and immune system issues. It’s interesting because I have heard more about dog allergies, but not so much cat allergies. Once again, I learned a lot and will save this post for future reference.
Cathy Armato says
Food allergies can be so complex in pets & difficult to diagnose or treat. Great summary and framework for detecting & treating food allergies in cats.
Golden Daily Scoop says
Food allergies, no matter who they are from are no fun. We have been very fortunate with our cat, nothing seems to bother her. Very thorough and helpful post for all cat owners!
Ruth Epstein says
I have been through itchies with Layla big time but have finally sorted it out and we are good at the moment, it is a nightmare
M. K. Clinton says
It is so difficult to find the cause of allergies. We just did a hair and saliva test on Bentley. He is allergic to bananas and he LOVES them. He is not happy with the results. LOL!
Joely Smith says
Thankfully we have not experienced this with our cats yet BUT I love having this info just in case! Thank you!
This post is so timely for me right now. I have a new cat Sally who has extreme food allergies and her symptoms are beyond what’s described here. She’s been on steriods, but can’t be forever because they can damage organs. She’s in a case study trial right now on a new prescription food that is not working. New medications are on the way. If that doesn’t work, I’m going back to the elimination diet and consulting holistic practitioners. There will be a post on dogtrotting.net (even thought it;s about a cat).
Three Chatty Cats says
Our Sophie has trouble with certain foods, so she’s on a different diet than our other cats.
Food allergies are no fun for cats or dogs. I always feel so bad when my dog Dante gets itchy but he has seasonal allergies.
My human got the answer right! Food allergies in kitties are so frustrating.
Fantastic post mew guys! We think our new brofur Fudge has a food intolerance and are currently trying different brands to find what is best fur him… thanks so much fur sharing all this great info today, it will help the P.A. lots!
Excellent post. One of my cats has a food allergy so she has to eat rabbit protein. I had another cat that used to get ear infections when she ate something she was allergic to like chicken.