WHAT TO DO IF YOUR DOG HAS A SKIN PROBLEM
     If your dog begins to scratch all the time, or licks, paws, bites the skin and rubs up against things to relieve discomfort, then you are faced with an itchy skin disorder and should attempt to determine the cause.
     There is another group of skin conditions that have to do with the appearance of the coat and hair. These diseases do not cause much discomfort--at least not at first. Hair loss is the main sign. It can appear as impaired growth of new hair, or you may notice patchy loss of hair from certain parts of the body. In general, hair loss caused by hormonal influences are symmetrical, while those caused by parasites are other external causes are asymmetrical. At times you may notice that the coat is course and brittle, dull and lifeless. To determine the possible cause, see Table IIa and IIb.
     Your dog has pyroderma if you see pus and other signs of infection on or beneath the skin. Pyoderma is characterized by finding cellulitis, papules, pustules, boils and abscesses. See Table III.
     There is another class of skin diseases that is characterizee by the finding of blebs. Blebs, also called vesicles, are blisters that contain clear fluid. Large ones are called bullae. All tend to progress to skin erosions and ulcers through rubbing, biting and scratching. Look for these changes to begin on the face, nose, muzzle and ears. These are the autoimmune skin diseases.See Table IV.
     During the course of grooming, playing with or handling your dog, you may discover a lump or bump on or beneath the skin. To learn what it might be, see Table V.
     If you suspect that your dog is suffering from a skin ailment, conduct a thorough examination of the skin and coat. On short-coated dogs, run a fine toothed metal comb against the lay of the hair to expose the skin. On long-coated dogs, use a pin brush. In many cases a typical finding makes the diagnosis obvious.
     Unfortunately, this is not always the case. The diagnosis of a specific skin disease in dogs can be difficult. Early signs are not easy to detect in heavy -coated dogs. The picture is often complicated by secondary trauma to the skin caused by biting and scratching. Scabs. crusts, scales, erosions and ulcerations are all secondary skin problems usually caused by self-inflicted trauma. History becomes important in trying to decide what could have caused the problem in the first place.
     Facts such as age, sex, breed, changes in activity or diet, contact with other animals, emotional states, exposure to skin irritants and environmental influences then become important points to consider.

                                                          The diagnosis of skin disease
                                                           Table I
                                                      Itchy Skin Disorders

Scabies (Sarcoptic Mange):  The most common cause of intense itching. Small red spots like insect bites on the
      skin of the ears, elbows and hocks. Identify mites. Typical crusty ear tips.

Walking Dandruff (Cheyletiella Mange): Puppies two to twelve weeks. Dry flakes over the neck and back. Mild

Fleas:  Itching and scratching along the back, around the tail and hindquarters. Fleas and/or black and white gritty
    specks in the hair (fleas feces and eggs). Fleas very mobile.

Lice:  Found in poorly kept dogs with matted coats. Not Common. Look for lice or nits beneath mats. May have
    bald spots.

Ticks:  Large insects fasten onto the skin. Blood ticks may swell to pea-size. Cause irritation at the site of the bite.
     Can be difficult to remove intact. Often found beneath ear flaps and where hair is thin.

Damp Hay Itch (Pelodera): Severe itch caused by a worm larva. Must have contact with damp marsh hay.

Inhalation Allergy (Canine Atopy): Severe itching, face-rubbing and licking at paws (hay fever-type symptoms.)
     Often begins at the same time each year (seasonal pollens). Certain breeds more susceptible.

Flea Allergy Dermatitis: Follows flea infestation. Pimplelike rash over the head of the tail, back of rear legs and
     inner thighs. Scratching continues after fleas have been killed.

Contact Dermatitis; Itching and skin irritation at site of contact with chemical, detergent, paint, dye, etc. Usually
     affects the feet and hairless parts of the body.

Allergic Contact Dermatitis:  Requires repeated or continuos contact with allergens (i.e., flea collar). Rash may
     spread beyond area of contact.

Food Allergy Dermatitis:  Nonseasonal itching with reddened skin, papules, pustules and wheals. Found over the
     rump, abdomen and back of the legs. Skin becomes thickened and dark.

Lick Sores (Acral Pruritic Dermatitis): Mainly in large, short-coated individuals. Starts with licking at wrist or

Fly-bite Dermatitis; Painful bites at tips of erect ears and bent surfaces of floppy ears. Bites become scabbed,
     crusty-black and bleed easily.

                                                             The Diagnosis of Skin Disease
                                                               Table IIa

                                         Disorders in Which Hair Is Lost or Grows Poorly:
                                                         Hormone-Related Disorders

Thyroid Deficiency (Hypothyroidism):  Males and females. Coat is thin and scanty. Hair is brittle and cooarse and
     falls out easily. Tends to involve the body and neck. Skin is thick, sometimes darker.

Cortisone Excess (Adrenal Gland Hyperfunction):  Can be caused by prolonged medication with steroids. Males
     and females. Hair loss in symmetrical pattern, especially over the trunk and body. Skin is thin. Does not involve
      the head and neck.

Estrogen Excess (Hyperestrinism): Mainly in females. Hair has greasy feel, falls out along flanks and abdomen.
     Buildup of wax in ears. In males, consider a testicle tumor, especially with a retained testicle. Loss of hair in
     genital area. Nipples enlarge. Dry skin and brittle hair.

Estrogen Dificiency (Hypoestrinism): Mainly in spayed females. Scanty hair growth (thin coat). Skin is smooth
     and soft, like a babys skin.

                                                                The Diagnosis of Skin Disease
                                                                    Table IIb

                                    Disorders in Which Hair Is Lost or Grows Poorly:
                                                            Other Disorders

Zinc Responsive Dermatosis; Crusty, scaly skin with hair loss over the face, nose, elbows and hocks. Cracked
     feet. Caused by zinc deficiency. Artic breeds most susceptible.

Acanthosis Nigrans:  Hair loss begins in armpit folds. Black, thick, greasy, rancid-smelling skin. Mainly in

Color Mutant Alopecia (Blue Syndrome): Dry, thin, brittle hair over the body, giving a mothe-eaten look. Papules
     and pustules appear on involved skin. Has a genetic basis in blue- and fawn-colored Dobermans. Can affect
     other breeds.

Seborrhea: Dry type: similiar to dandruff. Greasy type: hair and skin is oily; yellow brown greasy scales on skin.
     Hair loss in circular patches, resembles ringworm. Rancid odor.

Ringworm (Fungus Infection): Scaly, crusty and red circular patches one-half inch to two inches in size with hair
     loss at center and red margin at periphery of ring. Affects all parts of coat. Looks healthy unless complicated
     by scabs and crusts. Some cases involve a large area with hair loss.

Demodectic Mange (two forms):
     Localized--Moth-eaten look due to hair loss around eyelids, mouth and front legs. Patchs about one inch in
     diameter.  Dogs and bitches less than one year old.
     Generalized- Progression of the above. Numerous patches enlarge and coalesce. Severe skin problem
     complicated by pyoderma. Affects dogs of all ages, primarily young purebreds.

Calluses (Elbow Sores): Gray, hairless, wrinkled pads of skin usually over elbow but can occur over any bony
     pressure point from lying on hard surfaces.

                                                  The Diagnosis of Skin Disease
                                                                Table III
                                 Painful Skin Disorders with Drainage of Pus (Pyoderma)

Puppy Dermatitis (Impetigo and Acne): Puppies under 12 months. Not painful.
     Impetigo--Pus-filled blisters or thin brown crusts on hairless skin of abdomen, then groin.
     Acne---Purplish rid bumps (pestules) on chin and lower lip.

Hair Pore Infections (Folliculitis): Dogs of all ages, Schnauzers in particular. Pimplelike bumps or blackheads
     along the back and elsewhere. In severe cases, draining sinus tracts and hair loss.

Skin Wrinkle Infection (Skin Fold Pyoderma):  Macerated inflamed skin with a foul odor in characteristic
     locations: lip fold, nose fold, vulvar fold, tail fold and between toes.

Hot Spots (Acute Moist Dermatitis): Mainly in heavy-coated dogs. Rapidly advancing painful inflamed patches of
     skin covered with a wet surface exudate of pus, from which hair is lost. Skin is irritated from many cuases.
     Disease progresses through self-maceration.

Cellulitis and Abscesses:
     Cellulitis---Painful, hot, inflamed skin. Caused by wound infections, foreign bodies, breaks in skin.
     Abscesses----Pockets of pus beneath the skin. Painful swelling that comes to a head and drains.

Puppy Strangles (Juvenile Pyoderma): Puppies under 4 months. Sudden painful swelling of lips, eyelids, ears and
     face. Draining sores, crusts and sinus tracts.

Mycetomas; Painful swellings beneath skin of legs and feet, which drains puss through sinus tracts.

                                                  The Diagnosis of Skin Disease
                                                      Table IV
                                                Autoimmune Skin Diseases

                                   (We did not include this table as these diseases are not common to Chihuahuas)

                                                   The Diagnosis of Skin Disease
                                                      Table V
                                      Lumps or Bumps on or Beneath the Skin

Papillomas and Warts; Grow out from the skin and look like warts or pieces of chewing gum stuck to the skin. Can
     occur in the mouth. Not painful.

Hematomas: Collections of blood beneath skin, especially of the ears. Caused by trauma.

Tender Knots: Grequently found at the site of a shot or vaccination. Resolve spontaneously. Often painful.

Cysts: Smooth lumps beneath skin. May grow slowly. Can discharge cheesy material. Become infected. Otherwise
     not painful.

When a Lump May Be a Cancer:
     Rapid enlargement; appears hard and fixed to surrounding tissue; any lump growing from bone; a lump that
     starts to bleed; a mole that begins to spread and/or ulcerate; unexplained open sore that does not heal, especially on feet or legs; any lump in the breast. Note: Only way to tell for sure is to biopsy the lump.