Bull Terriers and zinc: zinc-responsive dermatosis vs lethal acrodermatitis
Crusty, scaly skin around the nose, eyes and paws is often blamed on zinc. In a Bull Terrier that is usually the wrong guess, and in a puppy it can be a dangerous one. Here is what the veterinary research actually says.
- Zinc-responsive dermatosis is not a Bull Terrier disease. The inherited form affects Siberian Huskies, Alaskan Malamutes and German Shorthaired Pointers; the other form affects growing puppies on a poor or over-supplemented diet.
- The zinc-related disease documented in Bull Terriers is lethal acrodermatitis (LAD), an inherited disease of puppies that zinc does not help and that is fatal.
- Do not try a home zinc trial on a crusting puppy. It delays the right diagnosis, and too much zinc is itself poisonous.
- Crusting has many causes, including infection, mites and autoimmune disease. Itch or no itch does not tell them apart.
- Diagnosis needs a vet, usually with a skin biopsy, and in a Bull Terrier puppy possibly a DNA test for LAD.
If your Bull Terrier has crusty, scaly skin around the nose, eyes, mouth or paws, you will soon find pages telling you it is zinc-responsive dermatosis and that the breed is prone to it. That is not what the veterinary literature says. Zinc-responsive dermatosis is well described in a few northern breeds and in growing puppies fed the wrong diet. The zinc-related disease that is documented in Bull Terriers is a different one, lethal acrodermatitis, and it does not respond to zinc at all. This page explains both, and why the difference matters before anyone reaches for a supplement.
What zinc-responsive dermatosis is
Zinc-responsive dermatosis (ZRD) is a skin disease that gets better when the dog is given zinc. Zinc is needed for normal skin cell renewal, and when the skin is short of it the outer layer builds up into thick, tightly stuck crusts and scale. Under the microscope a skin biopsy shows parakeratosis, a characteristic change in the outer layer of the skin that helps separate it from infection and allergy.
Typical signs are crusting and scaling around the mouth, chin, eyes and ears, and sometimes on pressure points such as the elbows and hocks. The skin can be itchy, particularly once a secondary infection has set in, so the presence or absence of itch does not identify it.
Who actually gets it
Veterinary sources describe two forms (Colombini, 1999; MSD Veterinary Manual):
- A familial form in Siberian Huskies and Alaskan Malamutes, also reported in German Shorthaired Pointers. These dogs can develop it on a complete diet, and usually need zinc for life.
- A dietary form in growing puppies fed a diet that is short of zinc or over-supplemented. Extra calcium added on top of a complete food, and diets very high in cereal or soy (whose phytates bind zinc in the gut), both reduce how much zinc is absorbed. Correcting the diet alone may cure this form.
Bull Terriers are not on either list. Any growing puppy on a badly balanced diet could in principle develop the dietary form, but there is no published evidence that the breed is predisposed to zinc-responsive dermatosis, and it is uncommon in Bull Terriers.
Lethal acrodermatitis: the Bull Terrier zinc disease
Lethal acrodermatitis (LAD) is an inherited disease of Bull Terriers and Miniature Bull Terriers. It is often discussed alongside the zinc diseases because the skin looks similar, but it behaves differently: affected puppies do not get better on oral zinc (Colombini, 1999; MSD Veterinary Manual), and it is invariably fatal. Most affected puppies die or are put to sleep before they are two (Bauer and colleagues, 2018).
- When it shows. In puppies, with the first signs in the first weeks of life.
- What it looks like. Crusting and skin lesions on the feet, lower legs, elbows, hocks and muzzle, thickened footpads and deformed nails. Affected puppies grow poorly and pick up infections easily.
- The cause. A recessive variant in the MKLN1 gene, identified in 2018 (Bauer and colleagues). A puppy has to inherit it from both parents, so two healthy carriers can produce an affected litter. It is not limited to white dogs.
- Testing. The discovery made a DNA test possible, and laboratories now offer one.
For how LAD shows in the feet and nails, see the lethal acrodermatitis section of Bull Terrier nails. For the DNA test and what to ask a breeder, see Bull Terrier health testing.
Why you should not try zinc at home
The real danger is a well-meant home "zinc trial" on a puppy with crusty skin. If the puppy has LAD, zinc will not help, and the weeks spent waiting for it to work are weeks without proper veterinary care. If the puppy has a dietary problem, the fix starts with the diet, which your vet needs to look at. Either way, a crusting puppy needs a vet promptly, not a supplement.
Zinc-responsive dermatosis and LAD compared
| Zinc-responsive dermatosis | Lethal acrodermatitis | |
|---|---|---|
| Who gets it | Huskies, Malamutes and German Shorthaired Pointers (familial form); growing puppies of any breed on a poor or over-supplemented diet | Bull Terriers and Miniature Bull Terriers |
| Age | Dietary form: growing puppies | First weeks of life |
| Where | Around the mouth, chin, eyes and ears; pressure points | Feet, lower legs, elbows, hocks and muzzle; thick footpads, deformed nails |
| Response to zinc | Improves | Does not improve |
| Outlook | Treatable with zinc and, where needed, a corrected diet | Fatal |
Plenty of other things cause crusting too: bacterial and fungal infection, mites, and autoimmune diseases such as discoid lupus erythematosus and pemphigus foliaceus. That is why the appearance alone is not enough.
How it is diagnosed
- History and examination - age, breed, diet, any supplements, and where the crusting is
- Skin biopsy - the most reliable test. It shows the characteristic changes (parakeratosis) and helps rule out infection, mites and autoimmune disease
- Blood zinc level - can be in the normal range even in a dog with zinc-responsive dermatosis, so a normal result does not rule it out
- DNA test - in a Bull Terrier puppy with these signs, your vet may suggest testing for LAD
- Response to treatment - in zinc-responsive dermatosis, improvement on zinc prescribed by your vet supports the diagnosis
If it really is zinc-responsive dermatosis
Treatment is zinc prescribed by your vet, together with correcting the diet where the diet is the cause. Your vet will choose the form (zinc sulphate, zinc gluconate and zinc methionine are the usual ones), the dose and how long to give it. Improvement takes weeks rather than days.
- Feed a complete diet and do not add calcium or bone meal on top of it; extra calcium reduces zinc absorption
- Be wary of diets very high in cereal or soy, whose phytates bind zinc in the gut
- Treat any secondary infection - crusted skin often becomes infected, and that needs treating alongside the zinc
For help choosing a food, see the best food for Bull Terriers guide.
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Frequently asked questions
Are Bull Terriers prone to zinc deficiency?
Not as far as the research shows. The inherited form of zinc-responsive dermatosis is described in Siberian Huskies, Alaskan Malamutes and German Shorthaired Pointers, and the dietary form in growing puppies of any breed on a poor or over-supplemented diet. The zinc-related disease documented in Bull Terriers is lethal acrodermatitis, which does not respond to zinc.
Can I just give my Bull Terrier a zinc supplement from the supermarket?
No. Zinc toxicity is a real risk in dogs - it causes vomiting, diarrhoea, lethargy, and in severe cases, haemolytic anaemia. If the crusting is lethal acrodermatitis, zinc will not help at all and only delays a proper diagnosis. Human zinc supplements may also contain other ingredients that are not safe for dogs. Only give zinc if your vet prescribes it.
My Bull Terrier puppy has crusty feet and face. Could it be LAD?
It is one possibility, which is why a crusting puppy needs a vet promptly rather than a home remedy. Lethal acrodermatitis shows in the first weeks of life with crusting on the feet, legs and muzzle, thick footpads, deformed nails, poor growth and repeated infections. It is inherited, does not respond to zinc and is fatal. Infections, mites and diet problems can look similar, and your vet can tell them apart with tests including a biopsy and a DNA test.
Is crusting with no itch a sign of zinc deficiency?
No. Zinc-responsive dermatosis can be itchy, especially once the skin is infected, so itch or no itch does not identify it. The dog's age, breed and diet, where the crusting is, and a skin biopsy are what separate it from other causes.
My Bull Terrier has scabs on his nose. What could it be?
Several things. Causes of crusting on the nose include bacterial or fungal infection, discoid lupus erythematosus and pemphigus foliaceus (both autoimmune), nasal hyperkeratosis and, less often, zinc-responsive dermatosis. A skin biopsy is the most reliable way to tell them apart, so ask your vet before trying any treatment at home.
Sources
- Colombini S. Canine zinc-responsive dermatosis. Veterinary Clinics of North America: Small Animal Practice, 1999;29:1373-1383. pubmed.ncbi.nlm.nih.gov
- MSD Veterinary Manual. Cutaneous manifestations of multisystemic and metabolic defects in animals. www.msdvetmanual.com
- Bauer A, Jagannathan V, Hogler S, et al. MKLN1 splicing defect in dogs with lethal acrodermatitis. PLOS Genetics, 2018. journals.plos.org
Related guides
- Bull Terrier nails - including lethal acrodermatitis, which zinc does not help.
- Bull Terrier health testing - including the DNA test for lethal acrodermatitis.
- Food label check - paste an ingredients list and see which common allergens it contains.
- English Bull Terrier rash: types, causes and treatment
- English Bull Terrier allergies guide
- Best food for Bull Terriers
- What causes skin flare-ups in Bull Terriers?
- English Bull Terrier: the complete owner's guide
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