Edited to add: For an update on how we are doing with the metal allergies Koira has, check out my more recent post about it. It includes some products that we are using and love, such as collars without exposed metal, which can be hard to find otherwise. http://mylifewithflyballdogs.blogspot.com/2015/03/dealing-with-metal-allergies-in-dogs.html
First off, I am in no way an expert. I am not a vet, dermatologist, or anything else like that. What I am is the owner of a dog with an allergy to metal. If you suspect your dog has an allergy to metal or anything else, you should bring it up with your vet.
Long time readers will recall that Koira has some metal allergies that cause issues with collars, other dog equipment, vet appointments, and other sorts of fun stuff. Most likely this allergy is not to metal in general but to nickel. Nickel is the most common source of metal allergy in humans, though it is more common in women than in men. Exposure to nickel, such as by having your ears pierced, can increase your chances of becoming allergic to nickel (which is possibly why this allergy is more common in women). Once you have the allergy, you are likely affected for life, though you may go through periods of increased sensitivity, most often due to exposure.
Most of the information I have found while doing research is about nickel allergies in humans. However, there is no reason to believe that dogs have any lower rates than humans. It is possible that many dogs with this allergy go un-diagnosed because their fur prevents contact with nickel, prevents their owners from seeing the rash that occurs, or because they simply aren't taken to a vet.
I am 100% positive that Koira has an allergy to metal. I am relatively positive that this allergy is specifically to nickel, though this is a theory based on my research into human metal allergies, so may be erroneous.
When Koira was younger, she developed a really nasty rash on her neck and chest. The rash was red and very obvious due to both her fur in the area being both very thin and white. Thickening of the skin and oozing blisters came and went, occasionally getting a bit better, and sometimes getting very bad indeed. At one of the bad turns, someone even asked me if I fought my dog (as in organized dog fighting) because her neck looked so ravaged. In addition to the sores and rash on her neck, Koira's ears were affected. The tips of her ears were literally falling off in chunks. The fur and dead chunks of skin would come off in my hands when I pet her or investigated the funky looking areas on her ears. Though the ears improved and regressed as much as the rest of the rash, they were bad enough at times that I seriously thought about having her ears cropped.
As you can imagine, I tried a lot of things to help her. I put her onto an allergy formula food (Natural Balance). No improvement. I started home cooking meals for her so I could carefully control every ingredient added. No improvement. I bought her a leather collar, thinking it might be irritation from the nylon collar she was wearing. No improvement. I even took to putting a bandanna on Koira instead of a collar, but since I dangled her tags from that, there was still very little improvement. During this time, Koira also got a staph infection on her neck, chest, and belly. The theory of my vet at the time was that she had cut herself on grass and developed a staph infection from those cuts. Koira also had bad dandruff, especially on her neck and shoulders, but pretty much all down her back.
Finally, one day, completely out of the blue, a friend of mine suggested that Koira might be allergic to metal. It was like a light bulb going off. I pulled off Koira's collar and tags. I purchased plastic and ceramic bowls to replace the metal food and water bowls. I coated the hook snaps on my leashes with clear nail polish. And Koira's horrible running sores and rashes went away. Her ears (which I can only assume were coming into contact with her tags when she shook her head) improved immediately. Within days, my beautiful girl had clear skin, with nothing but a few healing scabs left over.
Since that time, I have made Koira's collars myself using heavy duty nylon hardware instead of metal. I do not put tags on her. For a while, I did try using fabric bags to hold her tags, but I never found one that kept them secure and prevented them from touching her completely. Since she is micro chipped (she did have a serious neck and face swelling in reaction to being micro chipped, but has not had any continued problems with the chip after the first couple of weeks), I have decided that her well being and comfort is more important than her wearing her tags.
When we have to go to the vet for shots or other procedures that might involve contact with metal, I make sure to dose Koira with Benadryl before we go and again later in the day. It mostly prevents site reactions. (And, yes, stainless steel DOES contain nickel.) I honestly do not know what I would do if Koira were to require something like pins to hold together a broken bone. I just hope we never have to find out.
I am bringing up all of this because I have been looking longingly at some leather collars. I really wish I could get Koira and Pallo nice matching supple leather collars to wear. But leather collars come with metal hardware. Brass does not always contain nickel. But, since I don't know how to find out if the hardware being used contains nickel or not, and I don't know for sure that it is only nickel that Koira is allergic to, I don't know what to do. Do I buy a couple of really nice dog collars, test the hardware with this nickel testing kit and then just not use them if the test is positive? It would certainly be a lot of money to spend on the collars and the test kit only to find out I can't use them.
I will admit that in the past few weeks Koira has been occasionally wearing a new collar that has a stainless steel D ring on it. The collar is an LED light up collar that she only wears out to the park and so far I have not seen any reactions. I am not, however, so foolish as to hope she is "over" this allergy- that doesn't happen. I am sure that if she were to be exposed to more metal, the full reaction would come back relatively quickly. And I don't really want to risk that.
In any case, I didn't really write this post just because I want a nice collar for my dog. I wrote it more because, while doing all of the reading and research about metal allergies this evening in an attempt to find some kind of hardware that might be safe for my dog to wear, I came across almost no mention of metal allergies in dogs. And those that I did see were mostly passing mention of it in a forum thread.
So, if anyone has a dog they think or know has a metal allergy and wants to ask any questions or share any knowledge, I would love to hear from you. If you stumble on this blog post by searching the web for what could be causing the oozing rashes your dog has, I hope this can give you something to try out to help your dog.