Term
| 2. List the functions of hair. |
|
Definition
- trapping insulating layers of air
- if dark in color, it can absorb light, which further assists in warming the animal |
|
|
Term
| 3. What tissue does hair originate from? (epidermis, dermis, hypodermis) |
|
Definition
|
|
Term
| 4. List the 3 phases or cycles of hair growth and what occurs during each stage |
|
Definition
Anagen phase – hair is produced – dead, keratinized cells epithelial cells push up and away from the dermal papilla and are organized into the layers that make up the hair shaft and root. As more cells are added at the base of the root, the hair lengthens
Telogen phase – when max hair length is achieved, the hair stops growing , the hair follicle shortens, and the hair is held in a resting phase. This quiescent period can last from weeks to years depending on the location, type of hair, and species involved
Catagen phase – the period of transition between the anagen and telogen phase |
|
|
Term
| 2. What are the functions of the skin? |
|
Definition
| Healthy skin provides a barrier against pressure, friction, chemicals, heat, cold, UV, radiation and micro organisms. In addition, the skin is essential for maintaining the body's fluid balance and providing thermoregulation, and communicates external stimuli to the body via touch, pressure, temperature and pain receptors. In addition, we externalise our emotional state through the skin: we blush, turn pale, our hair stands on end and we emit scents (pheromones). |
|
|
Term
|
Definition
| A protective pigment that gives skin its color |
|
|
Term
| What is the pH of the skin? |
|
Definition
| The pH of the skin is approximately 4.5. The slightly acidic pH is due to the acidic protective surface film, which provides some protection against invading micro organisms. |
|
|
Term
| 4. What is the average turnover time of normal epidermis? |
|
Definition
|
|
Term
| What are papillae in the dermal layer made of? |
|
Definition
| Papillae in the dermal layer are loose connective tissue conical extensions containing capillary blood vessels, free nerve endings and hair follicles extending into the epidermis. |
|
|
Term
| What are Meissner’s cells? |
|
Definition
| Meissner’s cells are pressure (touch) receptors found in the dermal layer of the skin |
|
|
Term
| What are the functions of arteries and arterioles in the subcutaneous layer? |
|
Definition
| Arteries in the sub q layer carry oxygenated blood from the heart to the tissue |
|
|
Term
| 7. What products does serum contain |
|
Definition
| Glucose, free fatty acids, amino acids, metabolic waste products, hormones, etc |
|
|
Term
| 8. What is plasma composed of? |
|
Definition
Blood plasma is a slightly yellowish fluid containing 90% water. Dissolved in it are many proteins (7-8%) such as albumins, which are responsible for maintaining the osmotic pressure in the blood and act as transport proteins for water-insoluble materials and globulins that play a role as antibodies (eg IgG, IgA, IgM) in humoral immunity. The plasma also contains:
• nutrients (proteins, fats, sugars)
• inorganic salts
• metabolic waste products (especially urea)
• enzymes
• hormones
Fibrinogen is a component of plasma essential for blood coagulation. It is a ß2-globulin that is normally present at a concentration of 2-4 g/l. |
|
|
Term
| 9. What is another general name for white blood cells? |
|
Definition
| Leukocytes (also known as white blood cells) are present in the blood in much smaller numbers; 4000 - 11000 /µl. Their diameter is more than twice that of the erythrocytes. White blood cells always have a nucleus and exhibit amoeboid movement. They are produced in the bone marrow and mature in the different lymphatic organs (spleen, lymph nodes, tonsils, bone marrow, thymus) into cells with a variety of functions and structural appearance. |
|
|
Term
| Which cells are the body’s specific defense against harmful organisms? |
|
Definition
| B- and T- lymphocytes are specific defense cells since they possess on their cell membrane, structures allowing them to recognize specific pathogens (antigens), which they eliminate rapidly, and selectively, after contact. |
|
|
Term
|
Definition
| Repair is the process by which lost or damaged tissue is replaced by unspecific elements of connective and supportive tissue forming a scar. |
|
|
Term
|
Definition
| cars are made up of unspecific elements of connective and supportive tissue |
|
|
Term
| What are the four phases of wound healing? |
|
Definition
- vascular response
- blood coagulation
- inflammation
- formation of new tissue
these phases overlap and are to some extent interdependent |
|
|
Term
| 11. What is the purpose of a scab? |
|
Definition
| The scab protects the wound, reducing the risk of infection and dehydration |
|
|
Term
| 13. Is an inflamed wound always infected? |
|
Definition
|
|
Term
| List the signs of inflammation. |
|
Definition
redness (rubor)
heat (calor)
swelling (tumour)
pain (dolor)
functional disturbance (functio laesa).
Redness and heat are consequences of the increased blood flow in the wound area, causing an influx of immune defense cells into the site of injury (Figure 5).
The swelling or wound edema results from collections of fluid in the soft tissue. These accumulations of fluid in the tissue exert increased pressure on the small nerves, and nerve endings, causing the wound to hurt. The pain, in turn, causes the inflamed part of the body to assume a protective posture. This and the disturbed physiological processes account for the functional disturbance of the injured organ.
The inflammatory reaction is induced independently of invasion by foreign organisms, and therefore "sterile" inflammations can also develop in closed injuries, for example bruises in which the skin remains intact. Open skin wounds are usually contaminated. Even in surgical wounds, the invasion by millions of micro-organisms cannot be prevented even under the strictest sterile conditions. In such cases infection can develop initiating both the cellular and humoral immune responses. |
|
|
Term
| 13. What are the clinical signs and symptoms of an infected wound |
|
Definition
Advancing erythema
Fever
Warmth
Edema
Pain
Purulence
Leucocytosis
The Dorland’s Illustrated Medical Dictionary definition of infection is the ‘Invasion and multiplication of microorganisms in body tissues, which may be clinically inapparent or result in local cellular injury’38. Interestingly, this definition does not specify a host response. In this respect it seems to fit with some of the definitions of colonisation, ie the presence and multiplication of bacteria with no associated host reaction3 |
|
|
Term
| 17. Will skin heal in the face of infection? |
|
Definition
| At a cellular level, it is likely that infection decreases collagen synthesis and oxygen availability115, 116. Rapidly dividing aerobic bacteria will compete with healthy cells for oxygen and nutrients, causing the death of these cells in damaged tissue. Wound infection will prolong inflammation; deplete components of the complement cascade; disrupt normal clotting mechanisms and interfere with the formation of granulation tissue45. The cellular action of bacteria and the body’s response to this may lead to outward signs of infection, such as increased local pain and redness, increased exudate production or oedema. More severe infection may lead to wound extension and further tissue breakdown. |
|
|
Term
|
Definition
| A soluble protein present in blood plasma, from which fibrin is produced by the action of the enzyme thrombin. |
|
|
Term
|
Definition
| A localized physical condition in which part of the body becomes reddened, swollen, hot, and often painful, esp. as a reaction to injury... |
|
|
Term
|
Definition
| is the perfused, fibrous connective tissue that replaces a fibrin clot in healing wounds |
|
|
Term
|
Definition
| healing by the growth of epithelium over a denuded surface. |
|
|
Term
|
Definition
| In contraction, the wound is made smaller by the action of myofibroblasts, which establish a grip on the wound edges and contract themselves using a mechanism similar to that in smooth muscle cells. When the cells' roles are close to complete, unneeded cells undergo apoptosis |
|
|
Term
|
Definition
| the medical removal of dead, damaged, or infected tissue to improve the healing potential of the remaining healthy tissue |
|
|
Term
|
Definition
| a fluid with a high content of protein and cellular debris which has escaped from blood vessels and has been deposited in tissues or on tissue surfaces, usually as a result of inflammation |
|
|
Term
|
Definition
Cytology
Indications
Any pruritic, scaly, odoriferous, or alopecic animal should be evaluated for evidence of bacterial or fungal infection. Thus,
cytology is indicated for almost all patients presented with skin disease. Skin scrapings, aspirations, impressions, ear swabs
and tape preparations are different techniques to obtain cytologic samples.
A superficial skin scraping is used in areas such as the interdigital skin where impression smears may be difficult to
obtain. It is also used when the skin is normal, slightly moist, or greasy.
An aspirated sample is useful in the evaluation of pustule content and intracutaneous or subcutaneous nodules.
An impression smear is used when moist or oily skin with oozing or discharging lesions is evaluated.
Ear swabs are used to evaluate ear canals.
Dry scaly skin maybe evaluated by tape preparations. This technique is also frequently used in the interdigital area
where impression smears may be difficult to obtain. |
|
|
Term
| Cytology Technique - Skin scraping |
|
Definition
Technique
1. Skin Scraping for Cytology
Affected skin is exposed and the surface of the skin scraped very gently and superficially with a scalpel blade in the
direction of hair growth.
The debris collected on the blade is applied to a slide and spread with the blade in a "buttering the bread" motion (Fig. 1-
18). |
|
|
Term
| Cytology Technique - aspiration of nodules |
|
Definition
2. Aspiration of Nodules
Aspiration from nodules or abscesses is undertaken with a 12-ml syringe and a 22-ga needle.
The nodule is firmly grasped and the needle is then inserted (Fig. 1-19), aspirated several times (up to the 10-ml mark if
possible), the pressure released, and the syringe with needle still attached is withdrawn. |
|
|
Term
| Cytology Technique - Impression smears |
|
Definition
3. Impression Smears
Cotton swabs are used to obtain samples from ear canals by inserting them into the canal, rotating, and withdrawing
them. They are then rolled gently onto a slide. I hold ear slides uniformly on the left side with my left hand, the cotton swab
from the left ear is rolled onto the mid-section of the slide and the cotton swab from the right ear onto the right third of the
same slide.
In patients with dry skin, a cotton swap may be moistened with saline solution and rubbed on the surface of affected skin
before it is rolled onto a slide.
In patients with moist or greasy skin, the slide can be rubbed or impressed directly onto affected skin (Fig. 1-20). |
|
|
Term
| Cytology technique - Tape Impressions |
|
Definition
4. Tape Preparation
A direct impression technique uses clear sticky tape to collect debris from the surface of the skin. Although quick, this
method does take practice to establish what is "normal."
The tape is pressed sticky side down onto the skin (Fig
Next, it is pressed (also sticky side down) onto a drop of methylene blue or the blue stain of DiffQuick on a slide (The tape serves as a cover slip: the sample can be evaluated even under oil immersion (with a small droplet of oil placed
directly on top of the tape).
This technique is especially useful for Malassezia evaluation. Other items of interest that can be identified include
inflammatory cells such as neutrophils (which may have passed through the epidermis in response to a superficial
infection), nucleated epithelial cells (which are not normal and reflect a keratinization abnormality), cocci, rods,
macrophages, short-bodied Demodex mites, Cheyletiella, and occasionally Sarcoptes mites. |
|
|
Term
| Common underlying diseases causing lesions and/or pruritis otitis externa |
|
Definition
Atopy, adverse food reaction
Ear mites
Secondary infections?! |
|
|
Term
| Common underlying diseases causing lesions and/or pruritis of the pinnae |
|
Definition
Atopy, adverse food reaction
Scabies
Vasculitis |
|
|
Term
| Common underlying diseases causing lesions and/or pruritis of the head/face |
|
Definition
Demodicosis
Atopy, adverse food reaction
Microsporum gypseum
Insect allergies |
|
|
Term
| Common underlying diseases causing lesions and/or pruritis of the paws |
|
Definition
Demodicosis
Atopy, adverse food reaction
Malassezia dermatitis
Pemphigus |
|
|
Term
| K9 - Common underlying diseases causing lesions and/or pruritis of the claws |
|
Definition
| Bacterial or fungal infection, trauma, immune -mediated skin diseases. |
|
|
Term
| K9 - Common underlying diseases causing lesions and/or pruritis of the tail base |
|
Definition
| Flea-bite hypersensitivity |
|
|
Term
| Fel - Common underlying diseases causing lesions and/or pruritis of the otitis externa |
|
Definition
Atopy, food adverse reaction, parasites, polyps.
Secondary infections common! |
|
|
Term
| Fel - Common underlying diseases causing lesions and/or pruritis of the pinnae |
|
Definition
| Notoedres cati, vasculitis, pemphigus foliaceus |
|
|
Term
| Fel - Common underlying diseases causing lesions and/or pruritis of the head/face |
|
Definition
Atopy, food adverse reaction, dermatophytosis, insect allergies, feline scabies,
pemphigus foliaceus |
|
|
Term
| Fel - Common underlying diseases causing lesions and/or pruritis of the paws |
|
Definition
Atopy, food adverse reaction, pemphigus foliaceus, trauma, plasmacytic
pododermatitis |
|
|
Term
| Fel - Common underlying diseases causing lesions and/or pruritis of the claws |
|
Definition
| Bacterial infection, trauma, immune -mediated skin diseases |
|
|
Term
| Fel - Common underlying diseases causing lesions and/or pruritis of the tail base |
|
Definition
| Flea-bite hypersensitivity |
|
|
Term
| "Best in class" tx for atopy |
|
Definition
Comments:
Environmental allergies are one of the most common chronic
allergic diseases in dogs affecting 20-30% of the population.
House dust and house dust mites are the most common
allergens.
The typical allergic dog visits their vet 8 times each year.
Atopy, food allergy, and scabies can look exactly the same.
Atopic dogs are always itchy and almost always chew their feet
(food allergic dogs and scabies dogs often do not chew their feet).
Diagnosis:
Rule out scabies and food allergy.
Allergy testing: Skin testing is slightly better than blood testing.
Treatment:
1. Treat all secondary bacterial and yeast skin and ear infections
as these will worsen the itch and complicate finding good
therapies to control the symptoms of the allergy.
2. Bathe the patient with an antimicrobial shampoo and oatmeal
conditioner every 3-7 days to wash off the pollens and disinfect
the skin.
3. Maintain good flea control to reduce the additive itch effect.
4. Combine symptomatic treatments (antihistamines, EFAs, antiitch
sprays) to help reduce the symptoms.
5. Use Atopica (cyclosporine) or allergy vaccine therapy to
control moderate to severe cases.
6. Use steroids only to put out the "Itch fires" as long-term use
produces additive adverse effects.
Watchout:
Steroids should not be used to treat the "itch" since most itchy diseases
are not steroids responsive (pyoderma, yeast, fleas, scabies, food allergy)
Steroids are the cheapest therapy but have the most side effects
(secondary infections, weight gain, muscle/joint break down, premature
aging)
If a patient needs more than 3 months of steroids, allergy vaccine or
Atopica should be tried.
Atopica, allergy vaccines, and steroids work equally as well but differ in
cost and side effects. |
|
|
Term
| "Best in class" tx for Demodicosis |
|
Definition
Comments:
Generalized demodicosis is most often associated with a genetic
abnormality in young dogs or too much steroid therapy in
adults. Dogs with generalized demodicosis should be neutered.
Older dogs should be screened for underlying metabolic
diseases.
Diagnosis: Mites on skin scrapes.
Treatment:
1. Treat the secondary bacterial pyoderma which almost always
accompanies the demodex infection (see pyoderma)
2. Bathe with a moisturizing benzoyl peroxide shampoo (Benzoyl
Plus or Pyoben).
3. Kill the mites using milbemycin daily until 2 negative skin
scrapes are achieved (usually 3-4 months total treatment time).
Watchout:
For prematurely stopping the treatment: the skin will look better long
before the mites are eliminated and stopping treatment results in the
mites returning.
Ivermectin is a more economical option but has more side effects |
|
|
Term
| "Best in class" tx for fleas |
|
Definition
Comments:
Fleas are nasty and can carry zoonotic blood born diseases!
Diagnosis:
Fleas seen: flea dirt observed.
Lumbar dermatitis in dogs is almost always flea related.
Feline dermatitis is flea allergy related 80% of the time.
Treatment:
Dogs:
Frontline applied every 3 weeks.
Capstar administered every other day if lumbar dermatitis is
observed.
Capstar administered when fleas are seen.
Sentinel used for its multi-parasite control effects.
Cats:
Revolution every 3-4 weeks.
Capstar administered every other day if any dermatitis is
observed.
Capstar administered when fleas are seen.
Watchout:
Assuming that not observing fleas means that fleas are not the cause of
the skin disease is the most common error. |
|
|
Term
| "Best in class" tx for bacterial pyoderma |
|
Definition
Bacterial folliculitis is the most common skin disease in dogs and
is ALWAYS secondary to another underlying/primary disease
(usually allergies or hormonal imbalance).
Diagnosis:
Inflammatory alopecia typically with papules and crusts. Often
on the abdomen, armpits.
Treatment:
1. Find and treat the primary/underlying skin disease. If the
allergies or hormonal imbalances are not corrected and
controlled, the infections will return over and over again.
2. Administer either Simplicef or Primor at high-end doses for 3
weeks.
3. Bathe with an antimicrobial shampoo every 3-7 days.
Watchout:
If the infection does not resolve with the treatment, perform a bacterial
culture and sensitivity to identify resistant organisms; if present, treat
with aggressive antibiotic therapy using sensitive antibiotics
(clindamycin, sulfa drugs, chloramphenicol, and fluoroquinolones |
|
|
Term
| "Best in class" tx for otitis |
|
Definition
Comments:
Otitis is ALWAYS secondary to another underlying/primary
disease (usually allergies or hormonal imbalance but also ear
tumors, polyps, foreign bodies, and conformation).
Diagnosis:
Clinical evidence of inflammation and excessive exudate.
Cytology to identify mites, bacteria, or yeast.
Treatment:
All medication demonstrates better efficacy if dispensed in a dropper
bottle allowing the owner to more quickly and accurately administer
sufficient volumes.
Ear mites: MilbeMite/Acarexx/Revolution as directed.
Yeast: Otomax (clotrimazole) 1/3-1/2 dropper every 12 hours
for 7-14 days.
Bacteria (cocci): Otomax (gentamicin) 1/3-1/2 dropper every 12
hours for 7-14 days.
Bacteria (rods): trisEDTA solution (T8 Solution) with Baytril LA
injectable (100mg/ml) added to make a 1% solution (10mg/ml
final concentration). Completely fill ear canal to treat and clean
the ear simultaneously: repeat every 12 hours for 14-30 days.
Watchout:
The most common problem is the premature discontinuation of the
treatment while the underlying/primary disease is not yet controlled
resulting in repeated relapse of the ear infection. The ear therapy should
be gradually reduced in frequency until the underlying disease has been
controlled. Many otitis patients need repeated maintenance treatments
with the above list every 3-7 days to prevent the infections from
returning.
Clinical progress must be determined with BOTH clinical impression
and cytology as the organism counts is the ultimate determinant of
resolution of the infection.
If the bacterial infection (rods) does not respond to the treatment above,
perform a culture to select a sensitive antibiotic to use in high
concentration and high volumes.
Systemic antibiotics can not achieve high enough tissue levels to kill
pseudomonas: high concentration, high volume topical therapy must be
used.
Myringotomies are rarely needed except in severe and chronic cases:
consider referral. |
|
|
Term
| "Best in class" tx for food allergy |
|
Definition
Comments:
Food allergy, pollen allergies, and scabies can look exactly alike:
dogs less than 1 year of age (or older than 5 years with NO
history of itch or skin disease) should be considered.
Diagnosis:
Clinical improvement in response to a 10 week diet change
avoiding the food allergens causing the problem (most likely
BEEF, DAIRY, Wheat, egg, chicken, soy, and corn).
Treatment:
1. Treat all of the secondary infections (pyoderma, otitis, yeast)
since these will mask any improvement during the diet change.
2. Many allergic dogs improve dramatically if beef and dairy are
eliminated by feeding diets like: Hills Sensitive Skin, Hills J/D,
Royal Canin SS21, or hydrolyzed diets.
3. A strict limited ingredient food trial using 1 novel protein
(duck, rabbit, kangaroo, fish) and 1 carbohydrate fed for 10-12
weeks is the only method to diagnose food allergy.
4. A food challenge should be performed while the patient is
infection free to confirm that the food antigens in the original
diet caused the skin disease. Most food allergic dogs react within
hours when fed a food that they are allergic too. If a food
challenge is not performed and the food allergy is not confirmed,
most owners will slowly change the diets over time resulting in a
confusion of foods and clinical symptoms.
Watchout:
During the food trial, NO chewable medications, chew toys, rawhides,
treats, etc can be fed due to possible food allergens.
Revolution applied every 2 weeks during the food trial simultaneously
eliminates scabies and fleas while providing a non-flavored heartworm
preventative.
Almost all of the food trial diets have therapeutic levels of EFAs that
will improve pollen allergies and other skin diseases. This is good but
can be confused for response associated with the limited ingredients: the
food challenge will differentiate food allergy and response to EFAs |
|
|
Term
"Best in class" tx for Endocrine
Alopecia |
|
Definition
Comments:
Hormonal imbalances (hypothyroidism in big dogs and
Cushing's in small dogs) often cause secondary bacterial and
yeast skin and ear infections.
Diagnosis:
Hypothyroidism: Free T4 by ED and TSH
Cushing's: Increased Alk Phos, ACTH stim, and LDDST
Treatment:
Thyroid supplement
Withdraw steroids if iatrogenic Cushing's
Lysodren or Trilostane if Endogenous Cushing's
Watchout:
A treatment trial with thyroid hormone often produces pharmacologic
response even though the dog is not hypothyroidism.
There is no way to treat Cushing's disease cheaply: don't try to nickel
and dime Cushing's therapy.
If the thyroid and adrenal tests are normal consider treating with
melatonin for a possible follicular dysplasia.
Sex hormone testing is nondiagnostic since breed specific normals do
not exist (save your money). |
|
|
Term
"Best in class" tx for Acral Lick
Granulomas |
|
Definition
Comments:
Acral lick granulomas are caused by the combination of 3
problems: secondary bacterial infection, habitual behavior, and
an underlying trigger (primary disease: allergies, neuropathy,
hormonal, trauma, arthritis, foreign bodies). Successfully
treatment is achieved only if ALL 3 problems are controlled.
Diagnosis:
Typical clinical presentation and history.
Biopsy to rule out deep infection and tumors.
Treatment:
1. Find and treat any triggers (primary diseases): thishas the best
hope of providing long-term control.
2. Combine treatments for pain/neuropathy, behavior, and
infections: using concurrent antibiotics for pyoderma WITH
amitriptyline WITH hydrocodone achieves control in90% of
cases within 6-8 weeks.
Watchout:
Most failures are caused by treating only 1 of the 3 problems.
Most patients will require life long therapy of some form to prevent
relapse.
Bandages, collars, and muzzles should be consider a failures! |
|
|
Term
| "Best in class" tx for Scabies |
|
Definition
Comments:
Scabies is the only curable "Itchy Dog" disease. Mites may be
hard to find so any suspicious case should be treated. Clinical
symptoms range from severe (classic) to very mild (incognito).
Diagnosis:
100% - response to treatment.
80% - positive pinnal pedal response.
25% - mites found on skin scrapes.
Treatment:
Selamectin applied every 1-2 weeks for 6 weeks.
Watchout:
All in-contact dogs should be treated since scabies is highly contagious. |
|
|
Term
| "Best in class" tx for Dermatophytosis |
|
Definition
Comments:
Ringworm can look EXACTLY like pyoderma and demodicosis
("If it looks like ringworm, it probably isn't.")
Most common on kittens and puppies.
Most common zoonotic disease.
Diagnosis:
Positive fungal culture.
Biopsy –organisms in the follicles.
Finding spores on infected hairs on a trichogram is rare.
Treatment:
1. Bathe with Malaseb or Ketochlor shampoo every 1-2 days.
2. Dip patient with lime sulfur to prevent contagion.
3. Consider terbinafine (Lamisil) orally every 24 hours until
negative cultures are obtained (typically 2-4 months)(monitor
liver if anorexia develops: less than 5% risk)
Watchout:
Reinfection though the environment is the most common cause of
relapse.
A negative Wood's lamp exam or negative trichogram do not rule out
ringworm as a diagnosis: cultures are needed.
Currently, data suggests that terbinafine is more effective than
itraconazole which is more effective than ketoconazole which is more
effective than griseofulvin which is more effective than fluconazole for
dermatophyte.
(Malaseb Rinse may prove to be effective.) |
|
|
Term
| "Best in class" tx for Yeast Dermatitis |
|
Definition
Comments:
Elephant-like skin on the ventral neck, arm pits, and stomach
with SEVERE itch are classic symptoms.
Malassezia dermatitis is always secondary to an
underlying/primary disease (allergies or hormonal imbalance)
which must be treated for long-term control of the relapsing
secondary infections.
Diagnosis:
Clinical presentation is diagnostic: Elephant-like skin on the
ventral neck, arm pits, and stomach with SEVERE itch are classic
symptoms.
Cytology: yeast observed.
Treatment:
1. 1. Find and treat the primary/underlying skin disease. If the
allergies or hormonal imbalances are not corrected and
controlled, the infections will return over and over again.
2. Bathe with Malaseb/Ketochlor shampoo every 2-7 days.
3. Ketoconazole orally every 24 hours for at least 30 days. In cats,
itraconazole with food for at least 30 days. (monitor liver if
anorexia develops: less than 5% risk)
Watchout:
Yeast organisms may be difficult to find on cytology: thus if classic
clinical symptoms are present –treat.
Fluconazole may be as effective as ketoconazole and itraconazole for
Malassezia (not for dermatophytosis).
Terbinafine may be superior to ketoconazole and itraconazole but
Lamisil is expensive making the cost:benefit ratio for Malassezia
debatable. |
|
|
Term
| 11. Generally, does a food allergy develop quickly after an animal is placed on a new food? |
|
Definition
Most food allergic dogs react within
hours when fed a food that they are allergic too |
|
|
Term
| 6. If a single skin scraping is negative, does that tell you that the animal definitely does not have a skin parasite infection? Why? |
|
Definition
50% of
scabies cases may be negative on several scrapings. One mite or egg is diagnostic. Feet and faces are hard to scrape, Old English Sheepdogs, Scottish
Terriers and especially Shar Peis may be negative on scrapings and may have to be biopsied for diagnosis.
Although not documented it is thought that these breeds have more tortuous and deep hair follicles |
|
|
Term
| Deep skin scrapings for ectoparasites |
|
Definition
Deep skin scrapings
Deep skin scrapings are performed to detect Demodex mites which live in the hair follicle (often very deep).
Because they are deep it is useful to squeeze the skin prior to the scraping in an attempt to push the mites out
from the depths of the follicles. A survey conducted by summer dermatology students realized a 50% higher mite
count when squeezed prior to scraping. A blade covered with mineral oil should be used in the direction of hair
growth until capillary bleeding is observed. Feet and faces are hard to scrape, Old English Sheepdogs, Scottish
Terriers and especially Shar Peis may be negative on scrapings and may have to be biopsied for diagnosis.
Although not documented it is thought that these breeds have more tortuous and deep hair follicles. More than 1
mite is diagnostic. When evaluating Demodex scrapings it is important to assess and to note the site of scraping,
the relative numbers of adults (both live and dead), larvae / nymphs and eggs per LPF. In subsequent visits
assessment of response to therapy relies on the comparison of such numbers, we routinely repeat scrape the
same sites monthly when monitoring our demodicosis cases. |
|
|
Term
| Shallow skin scrapings for ectoparasites |
|
Definition
Superficial skin scrapings
Superficial skin scrapings are taken from large areas, usually to detect Sarcoptes or Cheyletiella. Elbows, ear
margins and belly are commonly scraped for Sarcoptes mites, the back for Cheyletiella mites. Mineral oil or
pyrethrin ear drops should be put on the scalpel blade AND the skin to make debris stick easier and to prevent
that the mites crawl away after being scraped off. Scrapings are done in the direction of hair growth. 50% of
scabies cases may be negative on several scrapings. One mite or egg is diagnostic. It is important to scrape
over a large area and in hairy dogs this may be easier if the hair is clipped away first. Should such clipping be
necessary it is important not to remove the surface scale or crust which may be present, Sarcoptes mites are
extremely superficially located within the epidermis and may be dislodged with such cleansing. We use scissors
to remove the hair and select non-excoriated sites preferably with scale and papules as the lesions. Mineral oil is
then applied to the affected skin, gently scraped off the surface, put on a slide, a cover slip is applied and the
sample is evaluated microscopically. |
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Term
| 2. What topical medications should NOT be used in cats? |
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Definition
Pyrethroids, such as Permethrin (Insecticidal)
Refined tar, Selenium sulfide (Antiseborrheic) |
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Term
| 3. Why is contact time important for topical therapies? |
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Definition
| Adequate contact time is also necessary. Shampoos should remain on the patient for 10-15 minutes before rinsing, and patients must be prevented from licking/rubbing off topical preparations |
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