By Dial A Vet Veterinary Team
Last updated: 3 November 2026
"Lupus" covers two quite different conditions in dogs. Discoid lupus is mostly a skin problem on the nose, and is usually manageable. Systemic lupus is a rare but serious autoimmune disease that can affect the joints, blood, kidneys and other organs. Both happen when the immune system turns on the body's own tissues. Because the signs overlap with many other diseases, a careful diagnosis matters before any treatment starts.
Key takeaways
- Discoid lupus erythematosus (DLE) mainly affects the nose, causing loss of pigment, scaling, crusting and ulcers.
- Veterinary Partner notes DLE does not progress to systemic lupus.
- Systemic lupus erythematosus (SLE) can affect skin, joints, blood, kidneys, heart, lungs and the nervous system.
- Sunlight makes discoid lupus worse, which matters in sunny Australian conditions.
- Diagnosis usually needs a skin biopsy (DLE) or a combination of blood tests and other tests (SLE).
- Treatment calms the overactive immune system and is guided by your vet.
When is it urgent?
See your vet the same day, or go to your nearest emergency vet clinic, if your dog:
- has a nose sore that is bleeding heavily
- has very pale gums, weakness or collapse
- has unexplained bruising or bleeding
- has a seizure
- is not eating, is very lethargic or has a persistent fever
- suddenly refuses to walk because of joint pain
VCA Animal Hospitals notes that the nose has a rich blood supply, so DLE lesions near a major vessel can bleed heavily. It also lists anaemia, bleeding disorders and nervous system problems among the signs of SLE. Our guides to nosebleeds in dogs and pale gums in dogs explain more.
Discoid lupus (DLE)
What it is. VCA describes DLE as the most common type of skin lupus in dogs. The immune system attacks a layer of skin cells, which causes the surface to break down.
Who gets it. Veterinary Partner notes a genetic tendency in collie breeds, which is why DLE is sometimes called "collie nose". VCA adds that DLE is more common in sunny climates and that UV light appears to make it worse.
Signs. According to VCA and Veterinary Partner:
- a black nose turning bluish-grey or pink
- the nose losing its normal bumpy, cobblestone texture and becoming smooth
- scaling, cracking and crusting
- erosions and ulcers
- in some dogs, lesions around the eyes, lips or ear flaps
Diagnosis. Several conditions look similar, including ringworm, skin infection on the nose, pemphigus and nasal lymphoma. Veterinary Partner and VCA both explain that diagnosis needs a skin biopsy, usually under sedation or anaesthetic because the nose is sensitive. Veterinary Partner notes a bacterial nose infection can look just like DLE, even under the microscope, so your vet may need to rule this out first.
Treatment. Veterinary Partner describes several options, from creams and ointments applied to the nose to medicines given by mouth that calm the immune system. Your vet will choose based on severity. Avoiding strong sunlight is an important part of care. Veterinary Partner warns that many human sunscreens contain ingredients that are toxic to dogs, and anything on the nose will be licked off, so ask your vet before using any sun protection product.
Systemic lupus (SLE)
What it is. The Merck Veterinary Manual describes SLE as a rare autoimmune disease in which dogs make antibodies against their own tissues. These antibody complexes lodge in tissues and trigger inflammation, so several organs are usually affected.
Who gets it. VCA lists predisposed breeds including the Afghan Hound, Beagle, Collie, German Shepherd, Irish Setter, Nova Scotia Duck Tolling Retriever, Old English Sheepdog, Poodle and Shetland Sheepdog. The average age of onset is about 5 years, though it has been reported in dogs as young as 6 months.
Signs. Merck notes signs often come and go and can mimic many other diseases. Signs listed by Merck and VCA include:
- fever that comes and goes and does not respond to antibiotics
- lameness that shifts from leg to leg, or swollen, painful joints
- a stiff gait or sore muscles
- skin changes such as redness, crusting, ulcers or hair loss (VCA notes about 46% of affected dogs have skin lesions, often on the face, ears and paws)
- mouth ulcers
- tiredness and poor appetite
- signs of anaemia, such as pale gums and weakness
- kidney problems
- enlarged lymph nodes
If your dog has shifting lameness, our guide to lameness in dogs covers other causes your vet will consider.
Diagnosis. VCA explains there is no single test for SLE. Vets look for a combination of findings, using blood tests, skin biopsies and an antinuclear antibody (ANA) test. Merck notes a blood test for specific antibodies is the usual way to diagnose it.
Treatment and outlook. VCA explains that treatment suppresses the overactive immune system, and the plan depends on which organs are involved. For example, joint inflammation needs rest, sun-sensitive skin needs sun protection, and kidney involvement may call for a prescription diet. VCA describes the outlook as guarded. Some dogs do well on long-term treatment with frequent monitoring, while others are hard to control. Immune-suppressing treatment has its own risks, so regular checks matter.
Living with a dog with lupus
- Keep your dog out of strong sunlight, especially if they have DLE.
- Give medicines exactly as directed, and do not stop them without your vet's advice.
- Watch the nose, skin, gums and joints, and take photos to track changes.
- Keep up with all recheck visits and blood tests.
- VCA advises that dogs with SLE should not be bred.
FAQ
Is lupus in dogs contagious?
No. Lupus is an immune system disease, not an infection.
Can discoid lupus turn into systemic lupus?
Veterinary Partner states that DLE does not progress to SLE.
Can I use my own sunscreen on my dog's nose?
Not without vet advice. Veterinary Partner warns that many human sunscreens contain ingredients that are toxic to dogs.
Talk with a vet
If your dog's nose is losing colour or crusting, or they have vague signs like shifting lameness and fever, Dial A Vet's real vets and vet nurses can help you work out next steps on a video consult. Heavy bleeding, collapse or seizures need your local vet or nearest emergency vet clinic. Dial A Vet consults cover dogs and cats. Book a video consult with Dial A Vet.
References
- VCA Animal Hospitals. Discoid (Cutaneous) Lupus Erythematosus.
- VCA Animal Hospitals. Systemic Lupus Erythematosus (SLE) in Dogs.
- Veterinary Partner (VIN). Discoid Lupus Erythematosus (DLE) in Dogs.
- Merck Veterinary Manual. Disorders Involving Immune Complexes (Type III Reactions) in Dogs.
Disclaimer: Educational only. This page does not replace an examination or advice from your own veterinarian. If you are worried about your pet right now, contact your local vet or nearest emergency animal hospital.