What is Collar Allergy?

With all of the different styles, materials, and varieties of cat collars, your cat may be allergic to one of the materials or several, which can be a difficult thing to determine. However, just getting rid of the collar may not be good enough to ease your cat’s itching and pain. If your cat has had a reaction that you are able to see, the allergens have already had the time to release histamines into the body, which causes the symptoms.

It may take several weeks for the side effects to go away if you just take off the collar and do not treat the problem. It is best to take your cat to see a veterinarian and get her treated with an antihistamine or corticosteroid injection because this can help reduce the itching and inflammation right away. The veterinarian may also be able to suggest a collar that is safe enough to put on your cat.

A collar allergy is likely an reaction to one of the materials used in making the collar such as nylon, plastic, leather, fabric, elastic, and vinyl. If it is a flea collar causing the reaction, your cat could be allergic to the medication in the flea repellent or the material it is made of. Since there are so many types of collars, it may be difficult to determine what material your cat is actually allergic to, but the results are usually similar, but with one difference: the location.

For example, if your cat is allergic to the material it is made of, the symptoms may be localized to the neck area, but if it is a drug reaction it can affect the whole body and can be very dangerous for your pet. The most common signs include scratching and redness around the collar area. There is always a chance for anaphylactic shock with any allergy, which is a deadly reaction to an allergen. It can cause your cat’s throat to swell until she is suffocated, so it is important that you see a veterinary professional if you suspect that your cat has a collar allergy.

Symptoms of Collar Allergy in Cats

Because all cats have different immune systems and collars are so varied, the symptoms can vary quite a bit as well. However, the most common are:

Regular Collars

  • Red irritated rash anywhere on the body but mostly on the neck
  • Chewing on and pulling out hair  
  • Long red lesions (granulomas)
  • Crusty sores and papules
  • Hair loss in the collar area

Flea Collars

  • Scratching all over the body
  • Extremely red rash or blisters on neck under collar
  • Chewing at feet (sometimes mutilating)
  • Vomiting and diarrhea
  • Swelling of the face
  • Sore, red ears


There are many styles of cat collars made from all kinds of materials such as:

  • Safety collars that break away if the collar gets caught on something; these may be made of any kind of material
  • Elastic collars are similar to a large hair scrunchie and are usually made from some kind of fabric
  • Buckle collars are usually made of fabric, leather, nylon, or even plastic
  • Flea collars are usually made from plastic resins that are mixed with insecticide

Causes of Collar Allergy in Cats

The cause of collar allergy could be a number of different materials, which may include:

  • Vinyl
  • Plastic
  • Leather
  • Fabric
  • Elastic

Diagnosis of Collar Allergy in Cats

Diagnosing any kind of allergy can be challenging and time consuming. But, with a collar allergy, the veterinarian is usually able to tell where the main exposure area is so it is a bit easier. If may help if you bring the collar to show the veterinarian, especially if it is a flea collar that seems to be causing the problem. A comprehensive physical exam has to be done first, taking special notice of the skin. Your cat’s vital signs will be recorded and the overall health of your cat is also noted at this time. Blood, skin, urine, and stool samples will all be taken for analysis. To be thorough, your veterinarian may want to get some x-rays as well to rule out other problems.

Treatment of Collar Allergy in Cats

The treatment will include medication, and supportive care such as fluid therapy and oxygen may also be provided.


Some of the antihistamines your veterinarian may use are chlorpheniramine, clemastine fumarate, hydroxyzine, or diphenhydramine. Another drug that has shown to be effective is cyclosporine. Steroids such as triamcinolone, methylprednisolone flumethasone, dexamethasone, or betamethasone are also excellent for severe cases.  

Supportive Care

Intravenous (IV) fluid may be offered to prevent dehydration in your cat and oxygen is also available if needed.

Recovery of Collar Allergy in Cats

Your cat should be back to normal within a few days, although the rash may take a few weeks to heal if it was severe. Some cats have scars from self-mutilation, but that is rare.

Collar Allergy Questions and Advice from Veterinary Professionals

4 Years
Moderate condition
0 found helpful
Moderate condition

Has Symptoms

Swollen eyes

My cat had a very bad reaction to a flea collar and her neck broke out in a horrible rash and is completely raw in some areas. What can I do to make her more comfortable while she is healing. And if I bathe her what's the best way to do it without completely holding her down and hurting her.

Dr. Callum Turner, DVM
1170 Recommendations
First step is to remove the flea collar (many people don’t remove it), secondly if Frankie is sensitive it baths and the process would be difficult if you cannot hold her scruff it may be best to find some chlorhexidine wipes to clean the area clean as much as possible. A bath with just warm water no shampoo would be ideal but I understand if you cannot do this; cats are not famous for taking a dip. Regards Dr Callum Turner DVM

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3 or 4 yrs
Moderate condition
0 found helpful
Moderate condition

Has Symptoms


I have a stray that I have taken in. She is a tailess cat and I already love her deeply. We have tried natural remedies and also a flea collar but she still has fleas. What should we use? Also we removed her collar and all around her neck is an awful rash and the hair is gone. We want to clean the wound but don't know if a bath is a good idea? What can we use to put on the rash. I only have disability and cannot afford a large vet bill.

Dr. Callum Turner, DVM
1170 Recommendations
Bathe the area around the rash with plain old water, if the skin isn’t damaged used a sensitive shampoo. As for flea treatments, get an effective spot-on medication for cats like Frontline (fipronil) to get rid of the fleas; another spray may be needed to clear the environment of fleas too. Natural flea control is effective (depending on the product) for repelling fleas but I haven’t seen a product effective at removing fleas from an animal. Regards Dr Callum Turner DVM

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1 Year
Fair condition
0 found helpful
Fair condition

Hi we found fleas on our three cats 2 weeks ago. We killed if the fleas within 3 days by giving them a bath every night containing baking soda and salt. We noticed they had fleas again when we let on of older cats go outside. Peter who is the one I'm asking advice on, we gave him a bath an we found black dots all over his body. I assumed it was the necklace b cause it didn't look like eggs. It's been 2 days and it hasn't gone away what should we do?

Dr. Callum Turner, DVM
1170 Recommendations
If the black dots are within the coat, it is most likely flea dirt or may be from the collar it is black and he was scratching at it a lot. If the black dots are on the skin and do not come off, then this is something different altogether. It would be best to give him another bath and to rigorously bathe him to remove any dirt or debris; if the dots are physically on the skin, visit your Veterinarian as there may be something else going on and should get your Veterinarian’s attention. Regards Dr Callum Turner DVM

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