What is Revolution Allergy?
Revolution (which contains the active ingredient Selamectin) is a topical medication that is used for flea and heartworm prevention. While the product has been tested and is safe, some cats may experience a reaction to it where their immune system will overreact to an element of the medication, leading to allergy symptoms. While symptoms in cases of a reaction are usually mild, it is important to seek medical attention should you notice a reaction after administering the medication in order to ensure the best outcome for your cat.
When a cat is experiencing an allergic reaction to Revolution, it is the result of their immune system overreacting to an element of the medication upon it having contact with their skin or being ingested.
Symptoms of Revolution Allergy in Cats
Symptoms of an allergy to Revolution are similar to those of other allergies. These include:
- Watery eyes
- Runny nose
- Inflammation of the skin
- Scratching, biting and/or licking his skin
- Hair loss
- Skin rashes
- Hives
- Respiratory issues
- Lethargy
It is worth mentioning that if a cat manages to lick any spot-on, drooling will usually occur. We see this often when the spot-on was applied too far down the back or when a litter of kittens was treated and are grooming each other. This is a short-lived reaction to the foul taste and not usually a sign of an allergy. Give your kitty something to eat and drink and monitor them closely.
Types
Medications to prevent fleas and heartworms in your cat are typically available in topical and ingestible forms. The topical medications will be applied to the back of your cat’s neck on his skin, where it cannot be licked off. Should your cat experience an allergy, it can present itself right away or within a few hours or days. The topical form of the medication will be administered to your cat once a month to prevent flea and heartworm infestation. Other products that protect your cat against fleas and heartworms include:
- Advantage multi
- Advantage/Advantage II
- Frontline Plus
- Comfortis
Causes of Revolution Allergy in Cats
The active drug in Revolution is selamectin. Revolution has been tested in studies using ten times the recommended amount without negative reactions occurring, however, an allergy or negative reaction, while rare, is possible. An allergy to Revolution occurs when the mast cells of your cat’s immune system mount an aggressive response to one of the components of the medication. The mast cells release histamine which will lead to inflammation in the tissues it comes in contact with as they attempt to fight what they see as an intruder. The histamine that is released leads to the allergy symptoms your cat experiences.
Diagnosis of Revolution Allergy in Cats
Should you notice concerning symptoms in your cat after applying Revolution, you will want to take him to your veterinarian. After conducting a full physical examination, your veterinarian will ask you for information in regards to the symptoms you have noticed, when you first saw them and any changes you have observed. The skin symptoms your cat is experiencing may lead to your veterinarian analysing the affected skin so that he can view cells under a microscope to see if there are any parasites, yeast or bacteria present. Once those are ruled out, your veterinarian will consider other possible causes of your cat’s symptoms.
A complete blood count and chemistry panel may be run; should a specific white blood cell level (eosinophils) be high it will point to an allergy being present in your cat. The results of the blood work will help eliminate other causes of the symptoms your cat is experiencing. Should your cat be experiencing respiratory problems, a radiograph may be taken so that your veterinarian can view his lungs and rule out illnesses like pneumonia or bronchitis.
Your veterinarian will likely ask you for information about the diet of your cat as well as any supplements and medications that he takes. Be sure to mention when you administered Revolution to your cat as this may help your veterinarian pinpoint the cause of his symptoms.
Treatment of Revolution Allergy in Cats
Your cat’s treatment will depend on the symptoms he is experiencing. Should your cat be experiencing breathing difficulties, these will be addressed immediately with oxygen therapy as appropriate. An antihistamine will likely be administered to decrease the inflammation your cat is experiencing. Unfortunately, antihistamines are not effective in all cats, so this may or may not impact your cat’s condition. The antihistamine may help with any respiratory system swelling as well as skin inflammation. Should your cat be experiencing skin symptoms, shampoos and topical ointments containing hydrocortisone may be recommended to give him immediate relief.
Corticosteroids (either injected or administered orally) are often very helpful though they can have a range of side effects when used over a long period of time. Should your veterinarian recommend corticosteroids, he will usually plan to monitor your cat’s blood chemistry levels to catch any potential issues as a result of the medication. If your cat develops a secondary bacterial infection due to their excessive licking and scratching, an antibiotic will be prescribed.
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Recovery of Revolution Allergy in Cats
You will want to work closely with your veterinarian to ensure the best outcome for your cat. Should your cat react to Revolution, you will want to avoid giving it to him in the future. Fortunately, there are other options for flea and heartworm prevention for your cat and you can choose one of those for his protection. Your veterinarian may recommend follow-up appointments so that he can see how your cat is doing and make any necessary changes to his treatment plan.
Revolution Allergy Questions and Advice from Veterinary Professionals
American Shorthair
One Year
29 found this helpful
29 found this helpful
My pet has the following symptoms:
None Yet
I mistakenly applied revolution plus on my cat's back of the head rather than between the shoulder blades. Should I be worried?
Sept. 27, 2020
Answered by Dr. Michele K. DVM
29 Recommendations
Thank you for your question.
That should not be a problem. The goal is to find a spot that they cannot turn around and lick.
Oct. 13, 2020
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short haired
Apollo
14 Weeks
48 found this helpful
48 found this helpful
My pet has the following symptoms:
Loss Of Fur
Bloody
Scabbing
My 3.5 month old kitten was given Revolution and he has developed a patch missing fur. It doesn't seem to be getting better. I come home after a few hours and it's bloody and scabby. I'm just not sure if that's from the cat itself or his body reacting poorly to it.
Sept. 5, 2018
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Maine Coon
Colby, Apricot, Thimble
4 Years
4 found this helpful
4 found this helpful
My pet has the following symptoms:
Eye Dilation
I’ve been giving my 3 cats Revolution monthly (actually every five weeks) for three years now. This time I noticed all 3 cats had their eyes dilated with no change when passing from light to dark areas. Does this normally happen with Revolution and I just never noticed it? Two cats are Maine Coons and one is a rescue who has traces of Persian characteristics (not the face part).
Aug. 19, 2018
Answered by Dr. Michele K. DVM
4 Recommendations
That is not a normal response to Revolution, but it is odd that it happened to all 3 cats. Is there a possibility that they got into something else? If the signs that you see don't resolve, it would be a good idea to have them examined by a veterinarian to make sure that they are okay.
Aug. 19, 2018
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Maine Coon
Azul
10 Months
10 found this helpful
10 found this helpful
My pet has the following symptoms:
Tremors
Rapid Breathing
My 10 month old Maine coon has been breathing fast and having intermittent tremors for a couple of months now. He has checked out normal through a cardiologist (echo and bubble study and chest x-ray). It just occurred to me what if it is the Revolution. He has no other exposure to plants or chemicals. Is it possible for the Revolution to continue to cause symptoms throughout the month and not just immediately after application?
July 29, 2018
10 Recommendations
Both tachypnea (rapid respiratory rate) and muscle tremors are known side effects of Revolution (selamectin) poisoning, these symptoms may occur for a period of time but are generally self limiting and resolve within a few days; I don’t know of month long presentations of these side effects in my experience. You could call the manufacturer (see second link) for information on this. Regards Dr Callum Turner DVM
www.zoetisus.com/_locale-assets/mcm-portal-assets/products/pdf/revolution-prescribing-information.pdf
www.zoetisus.com/contact-us.aspx
July 30, 2018
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dsh
Melvin
7 Weeks
17 found this helpful
17 found this helpful
My pet has the following symptoms:
Diarrhea
7 week old kitten given application of revolution by vet to treat fleas and worms-had diarrhea start 2 days after that! Is that normal? He is eating fine and drinking fine.. but the diarrhea is so bad he shakes from the pain when he goes! :(
July 29, 2018
17 Recommendations
Diarrhoea is a known side effect of Revolution (selamectin) and is normally self limiting, resolving itself after a few days (see quote below from prescribing information); keep an eye on Melvin and visit your Veterinarian if there is no improvement. Regards Dr Callum Turner DVM
“Following treatment with Revolution, transient localized alopecia with or without inflammation at or near the site of application was observed in approximately 1% of 691 treated cats. Other signs observed rarely (≤0.5% of 1743 treated cats and dogs) included vomiting, loose stool or diarrhea with or without blood, anorexia, lethargy, salivation, tachypnea, and muscle tremors.”
www.zoetisus.com/_locale-assets/mcm-portal-assets/products/pdf/revolution-prescribing-information.pdf
July 30, 2018
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Russian Blue mix
Milkyboi
2 Years
0 found this helpful
0 found this helpful
My pet has the following symptoms:
Lethargy
Itching
Ear Discharge
Sores
Eye Infection
Fur Loss
Teary Eyes
We had been using Revolution on my 2 year old cat all of his life until he lost a patch of fur and developed an open sore on the base of his neck two days after applying Revolution to that exact area. He developed intensely itchy skin which prescribed topical creams only seemed to aggravate.
The vet agreed due to the timing and area of the hair loss and wound that this seemed to mean my cat had developed a rare allergic reaction to the Revolution. They took the serial number of the package I used to report it.
After the topical cream did not work, the vet suggested to me that because Revolution remains in the body we could wait it out and the allergic reaction should eventually improve as the body processes it naturally. However, I asked to have my cat put on oral steroids because I read that this would help him from being itchy and scratching himself open. He was instantly much less itchy and less lethargic after we started the course of steroids and the lack of scratching allowed his hair to grow back.
After finishing the course of steroids my cat developed a new patch of hair loss on his neck and also now has an ear infection that did not completely resolve after almost two weeks of antibiotic ear drops.
We are going to try a course of Hydrolyzed Protein prescription diet just to make sure and rule out the possibility of this being food related and not just the Revolution. It would make life so much easier if all of this could be fixed with a change in diet.
Long before the first incidence of hair loss and itching my cat did shed and groom excessively compared to my other cat, vomit frequently, and had eye infections. I now wonder if these were early signs that he was allergic to the Revolution we were using on him.
Any
Any
3 Years
0 found this helpful
0 found this helpful
My pet has the following symptoms:
Muscle Tremors, Ataxia, Seizure
I was researching flea treatments for my cat and found this page. I'd just like to share some information on Revolution **PLUS**.
An active ingredient in the **PLUS** version is Sarolaner. If your pet has neurological symptoms (eg. ataxia, seizure) could it is possibly be an adverse effect of the treatment (rather than an allergy)? Please see your vet. See https://www.fda.gov/animal-veterinary/cvm-updates/animal-drug-safety-communication-fda-alerts-pet-owners-and-veterinarians-about-potential-neurologic
