Why Is My Dog Not Responding to Treatment for His Red Skin?
"My male German Shorthaired Pointer is red all over. Red ears, red eyelids, and red private parts, including anus and tummy. Behr is 19 months old and weighs 59.6 lbs. He previously weighed 64 lbs when he came out of training but has lost weight.
This is his first year to really hunt, and we started hunting dove on September 1, 2024. His skin started turning red 6 to 8 months ago. Initially, I thought it was a heat rash from him getting into water troughs to cool off, as his belly and rear end were noticeably red. This redness has never gone away.
On October 14, I noticed Behr was sluggish and not feeling well. On the 15th, I took him to the vet. He was red all over, and his prescapular lymph nodes were swollen up. Behr did not have a fever but felt hot to the touch. The vet placed Behr on prednisone 20 mg, 1.5 tabs twice a day for 7 days, then it will be one twice a day, then one a day, for 21 days total. He is currently on day four.
Temperature is 101˚F, so no fever. His skin isn't bumpy at all, just red, VERY RED, and feels warm. He doesn't itch or scratch, and he eats and drinks normally. This has been going on for 6+ months. His chest lymph nodes are swollen.
Two vets have looked at him and are stumped as to what is causing this. It has flared up twice to where he has no energy. All labs were negative, and the lymph nodes were tested for cancer. He is currently on steroid, antibiotic, and fungal medication for three weeks. He was previously on this for a week about a month ago." - Russel
Related: How Can I Treat My Dog's Contact Skin Allergies?
Why Is My Dog's Skin Red All Over, and Why Isn’t It Getting Better?
I can certainly understand them being stumped by this, as it is very unusual. There are many causes of red skin similar to what I see in his photos, but most of them cause a dog to itch a lot and respond to that dose of prednisone. None of his symptoms are typical of any of the diseases.
Behr may have one of the following problems:
Lupoid Dermatosis
This is very unlikely but has to be considered since he is a German Shorthaired Pointer. He is older than expected, and since it has been going on for so long, he would most likely be having other, more serious symptoms.
Cutaneous Vasculitis
This is most likely what he is being treated for. It is an inflammatory disease, but it usually responds to the medications he has been prescribed. It is usually painful, and there are not lymph node changes, so it does not fit perfectly, but it is possible that there are several things going on (like a tick-borne infection).
If the symptoms are from an allergy to his food and he is being re-exposed on a daily basis, they may respond to treatment somewhat but are just going to come back.
Sterile Neutrophilic Dermatoses
This is a rare disease that does cause red skin on the belly and, in some cases, has also presented with swollen lymph nodes. There are usually crusts, and dogs have a fever and loss of appetite, so this may not be what is wrong with him. He would need a biopsy to find this out.
Canine Acute Eosinophilic Dermatitis With Edema (CAEDE)
This is a hypersensitivity reaction that can cause the red skin you described, without a fever, but there are also usually GI signs, like diarrhea and vomiting. About two thirds of the dogs do not itch and scratch more than normally. It is often secondary to food allergies, but there has been one case reported where the dog had CAEDE secondary to his T-cell lymphoma.
Only about 2% of dogs diagnosed with lymphoma are Behr's age, but it certainly cannot be ruled out since you mentioned the swollen lymph nodes.
How to Find Out Which of These Is Causing the Red Skin
Unfortunately, I do not think you can diagnose this without a biopsy. If this were a simple case of cutaneous vasculitis, he would have responded to the medications at those doses. Before starting treatment for one of the neutrophil dermatoses, veterinary dermatologists recommend that the skin be biopsied and the diagnosis confirmed.
If CAEDE is the problem, the standard treatment is to give an immunosuppressive dose of prednisone. Since his current weight is about 27 kilograms, the dose of prednisone he would need is over 60 milligrams, so he would need 3 pills a day.
There are more likely to be side effects if you give a dose of prednisone that high, so I do think it is important that you confirm the diagnosis with a biopsy first. Prednisone side effects can be very serious, like thin skin, any injuries leading to infections that are difficult to treat, urinary infections, ear infections, and sometimes even aggression.
If you do not have a veterinary dermatologist available, you can treat and see how he responds to therapy, but I would not recommend it, as there are the side effects to consider.
After this has been diagnosed by biopsy and treated with a higher dose of prednisone and oral diphenhydramine (Benadryl is usually used, but your veterinarian may choose to use cetirizine), it usually looks a lot better by about 5 days and should be cleared up within 10 days to 4 weeks. The medications are usually continued through 4 weeks so that it will totally resolve.
What Else May Have Caused His Red Skin?
There are a lot of possibilities for what caused this. A study showed that about 50% of dogs with CAEDE were treated for diarrhea with a drug called metronidazole, so if he was on any medications prior to this, you should not use that med again. It is also possible that he had a giardia infection that he picked up when out hunting, and this is an atypical type of allergic reaction.
If it is a tick-borne infection, he will need to be treated for that, and if it is a food allergy, he will need to be on a novel protein elimination diet until you find out what he is allergic to.
Will the Red Skin Come Back?
If he was on drugs and you are able to never give him that drug again, this will probably not come back. If it was caused by an allergic-type reaction (like food), you will need to figure out what he is responding to. Once that allergen is eliminated from the diet, he will be fine.
I would definitely do a tick panel to see if the swollen lymph nodes are related to a tick-borne illness.
Sources
Gains MJ, Morency A, Sauvé F, Blais MC, Bongrand Y. Canine sterile neutrophilic dermatitis (resembling Sweet's syndrome) in a Dachshund. Can Vet J. 2010 Dec;51(12):1397-9. PMID: 21358936; PMCID: PMC2978996. https://pmc.ncbi.nlm.nih.gov/articles/PMC2978996/
Strzok EC, Torres SMF, Moore MEG, Armstrong AR, Koch SN. Pathology in Practice. J Am Vet Med Assoc. 2022 May 15;259(S2):1-4. doi: 10.2460/javma.21.01.0046. PMID: 35560122; PMCID: PMC9940758. https://pmc.ncbi.nlm.nih.gov/articles/PMC9940758/
Canonne D, Dubost-Brama A, Segard M, Piette F, Delaporte E. Wells' syndrome associated with recurrent giardiasis. Br J Dermatol. 2000 Aug;143(2):425-7. doi: 10.1046/j.1365-2133.2000.03675.x. PMID: 10951158. https://pubmed.ncbi.nlm.nih.gov/10951158/
