| Condition |
Description |
Symptoms |
Diagnosis |
Treatment |
| Acanthosis
nigricans |
Inherited form seen in
Dachshunds; secondary form caused by friction, hormonal
abnormalities, or hypersensitivities |
Darkening of the skin; in
secondary form see scratching and hair loss |
History, physical exam; in
secondary form, testing to determine underlying cause |
Primary: no treatment;
secondary: treat underlying disease; in some cases,
steroids and Vitamin E supplementation |
|
Acral
lick dermatitis (neurodermatitis) |
Self-licking in dogs results in self-trauma; possible
causes include anxiety, boredom, stress (e.g., new member
in household); licking can develop into an obsessive
behavior |
Red, hairless, well-circumscribed, sometimes raised
lesion usually on the leg; if chronic, will drain |
Exclude other causes; history important |
Relieve underlying cause e.g., anxiety; restrict
licking, e.g., elizabethan
collar; behavior modifying medication may be
necessary |
| Adrenal sex hormone
responsive dermatosis |
More common in Pomeranians,
Chows, Keeshonden, and Samoyeds |
Hair loss starts on neck,
tail, back of thighs, and progresses to trunk; dog appears
to have a 'puppy coat'; skin darkens |
Biopsy; eliminate other
causes |
Mitotane is optional |
|
Allergic
and irritant contact dermatitis |
An allergic reaction following exposure to antibiotics
applied to the skin; metals such as nickel; materials such
as rubber, wool, and plastic; and chemicals such as dyes
and carpet deodorizers; or inflammation caused by
irritating substances such as poison ivy. Generally
requires multiple exposures. |
Red skin and small bumps or blisters on the areas of
skin that are sparsely haired and directly exposed to the
offending substance, itching; hair loss in chronic
conditions |
Patch test, exclusion trials |
Restrict exposure to the allergen or contact irritant
in the dog's environment; steroids, antihistamines |
Alopecia areata
(also Flank Alopecia) |
Thought to be an autoimmune
disorder |
Patches of hair loss
especially on head, neck, and body; no itching |
Microscopic examination of
hairs; biopsy |
Usually recover
spontaneously |
|
Atopy
(allergic inhalant dermatitis) |
Allergic reaction to something the dog inhales such as
pollen, house dust mites, and mold |
Licking of feet, inflamed ears, itching, redness, and
hair loss; sometimes development of infection or hot spots |
Intradermal
or serologic (blood) testing for allergies |
Reduce exposure to allergen (what the dog is allergic
to); steroids, fatty
acid supplements, biotin,
antihistamines, shampoos, immunotherapy |
|
Bacterial infection (pyoderma)
See Folliculitis |
Often occurs as a result of another condition such as a
parasitic, allergic, or hormonal condition |
|
|
|
| Black
hair follicular dysplasia/alopecia/dystrophy |
Rare hereditary disease in
dogs with hair of multiple colors; more common in Bearded
Collies, Basset Hounds, Salukis, Beagles, Dachshunds, and
Pointers |
Loss of dark or black hair
only; symptoms appear between 3 and 6 weeks of age;
sometimes scaling |
Clinical signs, biopsy |
Shampoos for scaling if
necessary |
| Callus |
Results from chronic
pressure, especially in large breed dogs |
Thickened, hairless raised
areas over bony pressure points such as elbows; may become
secondarily infected |
History, clinical signs |
Provide softer bedding and
padding around affected area |
| Castration responsive
dermatosis |
More common in young
unneutered dogs, and in Chows, Samoyeds, Keeshonden,
Alaskan Malamutes, Miniature Poodles, and Pomeranians |
Symmetrical hair loss in
genital area and neck; hair loss may progress onto trunk;
skin may appear darker; severe scaling; hair color may
fade; coat is similar to a 'puppy coat' |
Physical exam and history;
eliminate other causes; blood tests for hormone
levels |
Castration |
| Chemotherapy |
Loss of hair due to chemotherapy
is a concern for dog owners |
Dogs with continuously
growing hair, e.g., Poodles and Maltese, often lose some
hair; dogs may lose whiskers |
History |
None, hair will regrow after
chemotherapy discontinued; may regrow in a different color
or texture |
|
Cheyletiella
(rabbit fur mite) mange |
Infection with the Cheyletiella mite |
Itching, scaliness;
some hair loss, if severe |
Skin scraping and microscopic examination - the mite is
often very difficult to find |
Pyrethrin,
Permethrin
(Do NOT use permethrin on cats.) |
| Color
dilution/mutant alopecia |
Hereditary condition
affecting dogs with blue (diluted black) or fawn coat
colors; more common in Dobermans, Dachshunds, Great Danes,
Yorkshire Terriers, Whippets, and Greyhounds |
Hair in the blue- and fawn-colored
areas starts to thin at around 6 months of age; secondary
folliculitis often develops |
Breed; history; and coat
color |
None; avoid excessive
grooming or harsh shampoos; protect skin to prevent
secondary bacterial infections |
| Congenital hypotrichosis |
Congenital lack of hair |
Puppies born with little or
no hair; any hair they are born with is lost by 4 months
of age |
Physical exam; biopsy |
None |
| Cushing's
disease (hyperadrenocorticism) |
Caused by an increase in
corticosteroids in the body - either due to increased
production by the body or as a side effect of high doses
or prolonged therapy with corticosteroids |
Hair loss, thinning of skin,
hyperpigmentation,
easy bruising, seborrhea, comedones (black heads), may see
calcinosis cutis; lethargy, increased thirst and
urination, potbellied appearance |
Adrenal gland function
tests, urinalysis, chemistry panel, CBC |
If due to glandular tumors,
selegiline, o,p-DDD (Mitotane), or surgical removal of
tumor; if due to high steroid doses, withdraw use of
steroids slowly |
| Cyclic (cicatrical)
alopecia; seasonal flank alopecia |
Growth cycle of hair stops
at certain times of the year |
Symmetrical hair loss with
definite borders; usually on back and flanks; skin may
become darker |
History, clinical signs,
biopsy |
None |
|
Demodectic
mange
(red mange, puppy mange) |
Infection with the Demodex mite - occurs when
the immune system is deficient |
Hair loss, scaliness,
redness, pustules,
ulcers,
sometimes itching, darkening of the skin |
Skin scraping and microscopic examination |
NO Steroids!
Amitraz (Mitaban) dips |
| Dermatomyositis |
Some breeds predisposed;
cause unknown; aggravated by trauma and UV light |
Redness, scaling, crusting,
hair loss, and scarring on face, ears, and tail; atrophy
of muscles involved in chewing |
Skin biopsy |
Minimize trauma and exposure
to UV light; Vitamin E, fatty acids, short term use of
prednisone, oxpentoxifylline; some severe cases do not
respond to treatment, and euthanasia may be considered |
| Diabetes mellitus |
Abnormal immunity makes
diabetic dogs susceptible to infection and other skin
conditions |
Thin skin; some hair loss;
seborrhea; recurrent bacterial infections; unregulated
dogs also have many other signs of disease; may develop
epidermal metabolic necrosis
or xanthoma |
Blood testing |
Dietary changes; insulin |
| Drug or injection reaction |
Rare skin reaction to a drug
which is inhaled, given orally, or applied topically;
more common with penicillins, sulfonamides, and
cephalosporins; usually occurs within 2 weeks of giving
the drug |
Can vary widely and may
include itching, hair loss, redness, swelling, papules,
crusts,
ulcers,
and draining wounds |
History of being treated
with a drug, symptoms, biopsy |
Discontinue offending drug;
treat symptomatically |
| Epidermal metabolic necrosis
(necrolytic migratory erythema, hepatocutaneous disease) |
Uncommon skin disease in
older dogs; skin lesions develop in dogs with certain
diseases including liver disease, diabetes mellitus, and
some pancreatic tumors |
Reddened, often ulcerated
areas with hair loss and crusts;
foot pads may be thickened |
Biopsy; look for underlying
disease |
Treat underlying disease;
supportive therapy; poor prognosis |
| Erythema multiforme |
Hypersensitivity reaction to
infections or drugs; may also be caused by cancer
or other diseases |
Hair loss, 'bull's-eye'
lesions, and vesicles
often around mouth, ears, groin, and axilla;
in some instances, ulcers
develop; depression, fever |
History, clinical signs,
rule out other diseases causing similar signs; skin biopsy |
Treat or remove underlying
cause |
| Estrogen responsive
dermatosis (ovarian imbalance type II) |
More common in young spayed
dogs, and in Dachshunds and Boxers |
Hair loss starting at the
genital area and flanks and moving forward; hair color may
fade; coat is similar to a 'puppy coat' |
Physical exam and history;
eliminate other causes; response to therapy |
Estrogen replacement
therapy; caution - can have severe side effects |
|
Flea
allergy dermatitis (flea bite hypersensitivity) |
Severe reaction by the animal to the saliva of the flea |
Intense itching, redness, hair loss papules,
crusts,
and scales;
sometimes development of infection or hot spots |
Presence of fleas; reaction to intradermal
testing |
Flea
control in the environment and on the dog; steroids
and antihistamines for the itching |
| Follicular
dystrophy/alopecia/dysplasia (abnormal development or
growth of hair)
See Congenital hypotrichosis, Color dilution/mutant
alopecia, Black hair folliclular dystrophy/alopecia,
Follicular dysplasia (non-color linked) |
May be congenital (certain
breeds are at increased risk) or acquired later in life
from infections, hormonal abnormalities, cancer
drugs, and some other diseases |
Hair loss, sometimes only
hair of a certain color; sometimes scaling |
Clinical signs, breed, skin
biopsy |
In congenital disease,
treatment of secondary problems such as infections or
scaling; in acquired disease treat underlying cause |
| Follicular
dystrophy/dysplasia (non-color linked) |
Patchy hair loss of unknown
cause seen in the Siberian Husky, Doberman Pinscher,
Airedale, Boxer, Staffordshire Bull Terrier, Curly Coated
Retriever, Irish Water Spaniel, and Portuguese Water Dog |
In Huskies, hair loss on the
body, reddish tinge to hair; in Dobermans, hair loss over
lumbar area; in Boxers and Terriers, hair loss over lumbar
area, skin may be hyperpigmented;
in the Retrievers and Spaniels, loss of guard hairs on
back and trunk and secondary hairs are dull and lighter in
color |
Breed, biopsy |
None |
| Folliculitis |
Infection of the hair follicles,
often with staph bacteria; symptoms usually appear on skin
with less hair, such as the abdomen |
Pustules
form in follicles and break open to form 'bull's-eye,'
'annular,' and 'target lesions,' which have crusty
centers and red or darkening on the periphery, and
'epidermal collarettes,' which appear as rings of scaly
skin; may itch; short-coated breeds may develop small
tufts of hair, which are lost; breeds with long coats may
have seborrhea |
Skin scraping; culture;
biopsy |
Antibiotics for at least 4
weeks - continue antibiotics 10 days beyond the apparent
cure; if recurs, look for underlying problem such as
allergy or hormonal imbalance |
|
Food
allergies |
Allergic reaction to something in the diet |
Licking of feet, inflamed ears, itching, redness, and
hair loss; sometimes development of infection or hot spots |
Food elimination trials |
Change in diet |
| Granulomas |
May be due to infections;
the body's reaction to foreign material such as plant
material (e.g., foxtail) and suture material; other
constant irritation; or unknown causes |
Solid firm nodules
of varying sizes; those due to foreign bodies often have
draining tracts; may develop hair loss, ulcers,
and secondary
infections |
History, clinical signs,
biopsy, surgical exploratory |
Surgical removal of the
foreign body (in the case of plant material, tracts may be
extensive and require major surgery); antibiotics if
infected; treat any other underlying cause |
| Growth hormone responsive
alopecia |
Not well understood; thought
to be caused by an enzyme deficiency or decrease of
adrenal
hormones, which allows certain other hormones to
accumulate in the body: more common in Pomeranians, Chow
Chows, Keeshonden, Samoyeds, and Poodles |
Hair loss on neck, tail, and
the back of the thighs; skin darkens; usually starts when
dog is less than two years old |
Hormonal blood testing |
Neuter animal; growth
hormone; hormonal supplementation |
|
Growth Hormone Treatment:
Growth hormone (somatotropin) is a polypeptide produced by the anterior pituitary that acts either directly on target tissues or indirectly through insulin-like growth factors (somatomedins) produced by the liver. It is necessary for hair growth and for development of elastin fibers in the skin. It is used to treat growth hormone-responsive alopecia in dogs. Either bovine, porcine, or human growth hormone (0.1 IU/kg, 3 times/wk for 4-6 wk) is effective. Hair usually regrows in 2-3 mo, and remission may last from 6 mo to 3 yr. Growth hormone is diabetogenic, and dogs can develop transient or permanent diabetes mellitus during therapy. Weekly monitoring of blood glucose before and during therapy is recommended.
|
| Hair loss during pregnancy
and nursing ('blowing her coat,' telogen
effluvium) |
Excess shedding that can
also occur in other stressful circumstances such as
illness or surgery |
Sudden and widespread hair
loss |
History, clinical signs |
Treat any underlying
condition; hair will grow back |
| Histiocytosis |
There are several kinds of
histiocytosis: malignant,
which is a cancer
that affects the skin and internal organs; systemic, which
is a rare disease which affects skin and internal organs;
and cutaneous,
which is a benign
disease affecting the skin |
All cause nodules
with hair loss; malignant and systemic also have ulcers |
Biopsy, fine
needle aspirate; |
Malignant: none effective,
may need to consider euthanasia; systemic: poor response
to chemotherapy; cutaneous: corticosteroids, relapse is
common, especially in Shar-Peis |
| Hyperestrogenism (ovarian
imbalance type I) |
Rare disease in which female
animals have excess levels of estrogen; can be caused by cancer
of the ovaries |
Symmetrical loss of hair;
hair pulls out easily; darkening of the skin; enlarged
nipples and vulva; may rarely see seborrhea and itching |
History, physical exam, rule
out other causes of hair loss, measure blood estrogen
levels |
Spay; look for metastasis
to the lungs |
| Hypothyroidism |
Decreased production of
thyroid hormone;
most common hormonal disease affecting the skin in dogs |
Hair loss, dry and brittle
hair, seborrhea; secondary bacterial and yeast infections;
lethargy, obesity, slow heart rate; changes in skin
pigmentation may occur |
Thyroid gland function
tests, chemistry panel, CBC |
Lifetime thyroid
supplementation |
| Injection site alopecia |
Hair loss at the site of an
injection of a medication or vaccine; skin may become
thickened; in cats, ulcers
may develop |
Hair loss occurs several
months after injection; area may become hyperpigmented |
History and physical
examination |
None; the condition is
permanent |
| Interstitial cell tumor |
Tumor
of the testicle; may not cause any skin changes |
If skin changes occur, see
seborrhea, loss of hair on the trunk, enlargement of the
tail gland and perianal glands; may see increased pigment
in the skin |
Biopsy |
Castration; anti-seborrheic
shampoos |
| Kerion |
Complication of ringworm
infection |
Nodule
with hair loss and multiple draining tracts; may not see
other signs of ringworm |
Culture, biopsy |
Clip area and apply topical
treatment and shampoos; may require systemic treatment
with ketoconazole or itraconazole |
| Leishmaniasis |
Caused by a parasite of
blood cells; can be transmitted to people who develop a
very severe disease |
Hair loss, scaling, ulcers
on nose and ears, sometimes nodules;
many other nonskin-related signs |
Identify the organism in
blood or biopsy; blood tests |
Because it causes severe
disease in people, and treatment of dogs is not curative,
euthanasia may be performed |
|
Lice |
Infection with several species of lice |
Variable; itching, hair loss, crusts,
rough hair coat |
Finding lice or nits on skin or hair |
Pyrethrin,
ivermectin (off-label use*), Permethrin
(Do NOT use permethrin on cats.) |
|
Malassezia |
Usually follows some other underlying disease |
Itching, redness, hair loss, greasy scales;
if chronic, develop hyperpigmentation |
Skin scraping/smear and microscopic examination,
culture |
Treat underlying disease; oral ketoconazole; miconazole
shampoos |
|
Nasal solar dermatitis
See solar dermatitis |
See solar dermatitis |
|
|
|
| Pattern alopecia (pattern
baldness) |
Three types; hair loss may
occur on the ears of Dachshunds (pinnal alopecia); neck,
thighs, and tail of American Water Spaniels and Portuguese
Water Dogs; abdomen and the back of the thighs of
Dachshunds, Chihuahuas, Whippets, and Greyhounds |
Hair loss in described areas |
Breed, history, biopsy |
None |
|
Pelodera dermatitis |
Accidental infection with larvae from a non-parasitic
worm that lives in straw and other organic material |
Affects areas of skin touching ground; intense itching,
redness, hair loss, papules,
crusts,
and
scales |
Skin scraping and microscopic examination |
Remove bedding; mild antibacterial shampoo; steroids if
necessary to control itching |
| Pituitary
dwarfism |
Hereditary condition in
which the pituitary gland does not produce the necessary hormones |
Young puppies fail to grow;
dogs retain puppy coat and condition progresses to hair
loss over much of the body; thin skin, scales,
and secondary
infections |
Special blood testing for
the presence of certain hormones |
Hormone replacement therapy |
| Post-clipping alopecia |
Hair may not grow back
immediately after it has been clipped; which animals may
be affected can not be predicted; more common in dogs with
thick undercoats e.g., Huskies and Chows |
Continued lack of growth in
hair that was clipped, e.g., for surgery |
History |
None; hair will eventually
regrow, but may take up to 24 months |
| Pressure sores (decubital
ulcers) |
Lesions occur over bony
prominences like elbows; common in larger recumbent dogs |
Start as red, hairless areas
and progress to draining ulcers;
may become infected |
Clinical signs, biopsy |
Keep area clean and prevent
contact with urine; antibiotics; apply donut bandages,
which provide padding around but not over the ulcer;
surgical treatment is sometimes necessary; prevent ulcers
by turning the dog every 2 hours |
| Pyoderma-superficial
(See Folliculitis) |
|
|
|
|
|
Ringworm |
Infection with several types of fungus |
Hair loss, scaliness,
crusty
areas, pustules,
vesicles,
some itching; can develop a draining nodule
called a 'kerion' |
Culture |
Miconazole, lime sulfur dips; oral griseofulvin
or itraconazole |
|
Sarcoptic
mange |
Infection with the Sarcoptes mite |
Intense itching and self-trauma, hair loss, papules,
crusts,
and scales |
Skin scraping and microscopic examination - the mite is
often very difficult to find |
Amitraz (Mitaban) dips (off-label use*); ivermectin
(off-label use*) |
| Schnauzer
comedo syndrome |
Uncommon; only seen in
Miniature Schnauzers |
Comedones (black heads) on
back, mild itching; may see secondary
infection, thinning of hair; small crusts may
develop |
Clinical signs, breed, skin
biopsy |
Long-term antiseborrheic
shampoos; sometimes antibiotics and retinoids |
| Sebaceous adenitis |
Sebaceous
glands are destroyed, cause unknown; certain
breeds more susceptible |
Short-haired breeds:
circular areas of hair loss with fine scale;
long-haired breeds: more widespread hair loss and scale,
hair mats easily; may see itching in all breeds |
Clinical signs, breed, skin
biopsy |
Antiseborrheic shampoos,
fatty acid supplements; in more severe cases, steroids,
retinoids |
| Seborrhea |
Can be primary (inherited)
or secondary (resulting from other disease processes such
as allergies, hypothyroidism) |
Scales; depending upon the
type, may have a dry or oily coat; odor; some scratching;
may see hair loss |
Blood tests, skin scrapings,
etc., to find underlying cause |
Treat underlying cause if
present; antiseborrheic shampoos; fatty acid supplements |
| Sertoli cell tumor |
Tumor
of the testicles in middle-aged dogs |
Male dogs take on female
sexual characteristics; hair loss, increased skin pigment,
reddened area on prepuce |
Physical exam |
Castration |
| Solar
dermatosis |
Skin reaction to sunlight,
especially unpigmented skin; most common on the noses of
Collies, Shelties, and similar breeds |
Redness, hair loss, and
scaling on nose and ears, later crusts
and ulcers |
History, breed, physical
exam, skin biopsy |
Must avoid further sun
exposure, especially 9 am - 3 pm; sunblock; steroids;
tattoo nose or apply black ink |
| Tail dock neuroma |
Nerve regrowth after tail
docking causes symptoms |
Nodule
at site of docking, itching with self-mutilation, hair
loss, and hyperpigmentation |
History and symptoms |
Surgical removal |
| Tail gland hyperplasia |
Dogs have a sebaceous
gland on the top of the tail near its base; in
this disorder, the gland enlarges; seen in unneutered dogs
and secondary to other diseases such as hypothyroidism |
Oily area, hair loss, crusts,
and hyperpigmentation
on area over gland |
Clinical signs; look for
underlying cause |
Castration may help; treat
underlying cause; surgical removal |
| Testosterone responsive
dermatosis (hypoandrogenism) |
More common in old neutered
dogs, and in Afghans |
Dull, scaly,
dry coat; seborrhea; hair loss in genital and anal areas
progressing onto trunk |
Physical exam and history;
eliminate other causes; response to therapy |
Testosterone replacement
therapy |
| Vitamin A responsive
dermatosis |
May not be due to an actual
deficiency of Vitamin A, but does respond to increased
levels of Vitamin A in the diet; more common in Cocker
Spaniels |
Seborrhea; odor; hair pulls
out easily; pads of feet thickened; thick scales
on chest and abdomen, especially around nipples |
Clinical signs, breed, skin
biopsy |
Lifetime treatment with
Vitamin A |
| Zinc responsive dermatosis |
Three types: I in Huskies
and Malamutes; II in rapidly growing puppies of large
breeds; III in English Bull Terriers |
Crusting
and scaling, redness, hair loss, sometimes oily skin,
secondary bacterial infections common |
History, breed, physical
exam, skin biopsy |
Correct any dietary
deficiency, medicated shampoos, treat secondary
infections |
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