Term
| If you are considering hypothyroidism and cushings disease in your patient which differential should you pursue first? |
|
Definition
| Always pursue Cushings first because elevated serum cortisol will cause T4 and T3 to be falsely low |
|
|
Term
| What two secondary dermatologic problems are commonly seen in patients with Cushings disease? |
|
Definition
| superficial pyoderma (erythematous papules, pustules and yellow brown crusts) Seborrhea sicca (scales along dorsum and/or trunk) |
|
|
Term
| What is the pathophysiology of a decubital ulcer (ie. pressure sore)? |
|
Definition
| pressure compresses blood vessels in the skin resulting in ischemia and tissue necrosis |
|
|
Term
| What clinical signs are commonly appreciated in cases of Cushings disease? |
|
Definition
(5 Ps) pot belly, PU/PD, panting, polyphagia, poor wound healing AND
hypothricosis to non-inflammatory alopecia, thin skin, muscle atrophy, exercise intolerance, hyperpigmentation, commedons, calcinosis cutis |
|
|
Term
| What hematologic abnormalities are associated with Cushings disease? |
|
Definition
| steroid leukogram (lymphopenia +/- mature neutrophilia, monocytosis, eosinopenia) |
|
|
Term
| What biochemical abnormalities are associated with Cushings disease? |
|
Definition
elevated ALP (occurs in >80% of cases secondary to glucocorticoid induction)
+/- elevated ALT (massive glycogen deposits within hepatocytes induce swelling that damages the integrity of the cell membrane allowing the enzyme to escape into circulation)
+/- mild hyperglycemia, hypercholesterolemia, hypertriglyceridemia |
|
|
Term
| What urinalysis findings are consistent with Cushings disease? |
|
Definition
urine SG < 1.020 (high cortisol interferes with ADH function and/or secretion resulting in diabetes insipidus with compensatory PD
+/- mild protinuria (pre-glomerular, secondary to systemic hypertension)
+/- glucosuria (5% of dogs with Cushings will develop diabetes mellitus, these patients are also at increased risk of developing secondary UTI <- WBC/RBC/bacteria on urine sediment) |
|
|
Term
| What test is used to definitively rule out Cushings disease? |
|
Definition
urine cortisol:creatinine ratio
this test has 100% negative predictive value, as such is great for ruling out the disease in patients presenting without classical clinical signs or lab abnormalities. If cortisol:creatinine ratio is positive additional diagnostic tests are necessary to confirm a diagnosis of Cushings disease. |
|
|
Term
| On an ACTH stimulation test (inject synthetic corticotrophin and compare plasma cortisol values pre and 1 hour post IM injection) what result would be expected in a normal healthy dog? In a dog with spontaneous cushings? In a dog with iatrogenic cushings? |
|
Definition
normal: post injection cortisol levels should be mildly increased
Spontaneous cushings: post injection levels will be markedly increased (because the adrenal glands are hyperplastic/functional tumor)
iatrogenic Cushings: minimal to no increase in post injection values (administration of high levels of exogenous corticosteroids results in atrophy of the adrenal glands) |
|
|
Term
| Which diagnostic test can distinguish between spontaneous and iatrogenic cushings disease? |
|
Definition
ACTH stimulation
spontaneous --> markedly increased post values
iatrogenic --> minimal to no increase in post values |
|
|
Term
| What diagnostic test is most sensitive to diagnose all potential cases of cushings disease? |
|
Definition
low dose dexamethasone test
(identified 90-95% of cases. No suppression in serum cortisol at 8 hours post injection of low dose dex is consistent with a diagnosis of Cushings disease) |
|
|
Term
| What historical findings are consistent with sarcoptic mange? |
|
Definition
| intense non-seasonal pruritis that doesn't respond to highest dose of steroids, good response to ivermectin treatment trial +/- other dogs or people in the household affected |
|
|
Term
| What are the lesions and distribution classically associated with sarcoptic mange? |
|
Definition
erythematous papules +/- thick yellow gray crusts
distribution is usually limited to the edge of the pinnae, elbows, hocks, ventral chest and abdomen; although lesions can become generalized |
|
|
Term
| Where do sarcoptic mites live on the host? |
|
Definition
females burrow in the superficial layers of the epidermis, males live on the surface of the skin.
The entire life cycle is completed on a single host animal |
|
|
Term
| How do you diagnose sarcoptic mange? |
|
Definition
| mites are hard to find on skin scrapings (multiple scrapings should still be done) so appropriate response to therapy (kerolytic shampoo + ivermectin) in association with suggestive clinical signs is considered diagnostic |
|
|
Term
| Although sarcoptic mange is contagious and zoonotic, what are three potential reasons that dogs or people living with an affected animal might not have any clinical signs of infection? |
|
Definition
long incubation period
transmission is primarily via direct contact (if animals are isolated they may never be exposed)
some people and animals will never develop clinical signs despite being in contact with affected individuals |
|
|
Term
| How do you treat sarcoptic mange? |
|
Definition
kerolytic shampoo + systemic (Ivermectin injection is most effective, can also use Milbemycin oxime PO) or topical (revolution or advantage multi) parasiticides
*** remember, treat all dogs in contact with affected individual, clean the environment (premises flea spray) and discard bedding |
|
|
Term
| Should you clean the environment in a case of sarcoptic mange? |
|
Definition
YES!!! Mites, larvae, and eggs can survive off host for up to six days (esp if low temp + high humidity)
clean environment with premises flea spray or pyrethrins and remove contaminated bedding |
|
|
Term
| If you diagnose sarcoptic mange and there is a cat in the household should it receive treatment? |
|
Definition
Only if showing clinical signs.
Cats are rarely infected with sarcoptic mange
**** vs. dogs, treat all dogs in contact with infected animals regardless of clinical signs |
|
|
Term
| What are some differentials for an older, intact male dogs presenting with lethargy, exercise intolerance, non-pruritic alopecia and comedons? |
|
Definition
HYPOTHYROIDISM
less likely include hyperadrenocorticism (no PU/PD, muscle atrophy, pot belly or thin skin)
sex hormone imbalance (intact animal)
Follicular dysplasia (more common in younger animals) |
|
|
Term
| What secondary dermatologic problems are often seen in conjunction with hypothyroidism in dogs? |
|
Definition
| endocrine disorders alter skin structure predisposing animals to develop seborhea sicca (presents as scales), superficial pyoderma (crusts, epidermal colleretes, pruritus) and these animals (with non-inflammatory alopecia) should be scraped to r/o adult onset demodicosis |
|
|
Term
| What laboratory abnormalities can be seen in cases of hypothyroidism? |
|
Definition
mild non-regenerative anemia (ie. anemia of chronic disease)
sometimes see hypercholesterolemia but most chem abnormalities are non-specific to hypothyroidism |
|
|
Term
| How do you diagnose hypothyroidism? |
|
Definition
gold standard is TSH stimulation test; however, human recombinant TSH is extremely expensive so this test has fallen out of use.
In a patient with clinical signs consistent with hypothyroidism, low total T4 or fT4 + high TSH (measured from a single blood sample) a diagnosis of hypothyroidism can be made. For borderline cases a treatment trial can be used to support the diagnosis, recheck hormone levels in 2-3 months although energy level should improve within 7-10 days of therapy. Alopecia may take up to 12 weeks to respond to hormone replacement therapy.
In dogs that appear clinically normal/healthy, and are not taking any drugs that interfere with thyroid hormone synthesis, normal basal T4 levels can be used to r/o hypothyroidism. |
|
|
Term
| How do you diagnose follicular dysplasia? |
|
Definition
|
|
Term
| What is the most common endocrine disorder in dogs? |
|
Definition
|
|
Term
| What is the treatment for hypothyroidism? |
|
Definition
hormone replacement therapy with synthetic T4- sodium levothyroxine (always use name brand)
re-check hormone levels 6-12 weeks after starting therapy by taking a blood sample 4-6 hours after the morning pill was given (well controlled patients should have T4 levels at or slightly above upper limit of the reference interval) |
|
|
Term
| What are the client education points for a newly diagnosed case of hypothyroidism? |
|
Definition
endocrine diseases require careful monitoring to ensure adequate hormone therapy (q 6 months in the first year of tx, and then yearly if the patient is clinically stable)
Hypothyroidism can be managed but not cured so treatment must be lifelong. |
|
|
Term
| How can the low dose dexamethasone test differentiate between cases of pituitary and adrenal dependent Cushings (only in 40% of cases)? |
|
Definition
| first confirm cushings disease by a lack of cortisol suppression in the 8 hour post sample (normal dogs will have suppressed values) then look at the 4 hour post sample: If the dog has pituitary dependent Cushings the 4 hour post sample will be suppressed, if the Cushings is due to an adrenal tumor cortisol levels will never be suppressed (ie. no suppression at both 4 and 8 hours post low dose dex injection) |
|
|
Term
| What test is most useful for differentiating cases of pituitary vs. adrenal dependent Cushings? |
|
Definition
High dose dexamethasone can differentiate about 75% of cases
vs. low dose dex can only differentiate 40% of cases |
|
|
Term
| What is the value of performing a high dose dex suppression test? |
|
Definition
it's the most sensitive test for differentiating adrenal vs. pituitary dependent cushings (75% of cases)
BUT it cannot be used to make an initial diagnosis of Cushings because the high dose of dexamethasone will suppress cortisol levels in normal dogs as well as those with pituitary dependent disease. |
|
|
Term
| How does the high dose dexamethasone test differentiate between cases of pituitary dependent and adrenal dependent cushings? |
|
Definition
If a dog has a pituitary tumor high dose dex will suppress cortisol levels in the post injection blood sample.
If a dog has an adrenal tumor it will continue to secrete cortisol independent of the high dose dex and consequently the post injection blood sample will not be suppressed.
*** remember, high dose dex is better at localizing the disease than low dose dex, but cannot be used to make an initial diagnosis of Cushings because normal dogs will also suppress following high dose dex |
|
|
Term
| How does the high dose dexamethasone test differentiate between cases of pituitary dependent and adrenal dependent cushings? |
|
Definition
If a dog has a pituitary tumor high dose dex will suppress cortisol levels in the post injection blood sample.
If a dog has an adrenal tumor it will continue to secrete cortisol independent of the high dose dex and consequently the post injection blood sample will not be suppressed.
*** remember, high dose dex is better at localizing the disease than low dose dex, but cannot be used to make an initial diagnosis of Cushings because normal dogs will also suppress following high dose dex |
|
|
Term
| Other than high and low dose dex suppression, what other test can be used to localize Cushings? |
|
Definition
endogenous ACTH
values less than 5 pg/ml support adrenal dependent or iatrogenic cushings
values over 6pg/ml support pituitary dependent cushings |
|
|
Term
| What are the current therapies available for treatment of Cushings? |
|
Definition
poor surgical candidate or pituitary dependent tumor --> medical therapy: Trilostane (enzyme inhibitor and REVERSIBLE) or Mitotane (cytotoxic and NON-REVERSIBLE, risk of developing addisons)
monitor medical therapy via ACTH stim after initiation regiment (7-10 days) and then continue rechecking ACTH stim q 3-4 months to gradually titrate dose down to lowest effective dose
Operable adrenal tumor and good surgical candidate --> surgery can provide definitive treatment |
|
|
Term
On physical examination you noticed thick honey-colored to brown crusts localized to the bridge of the nose, both pinnae, and around the eyes. Multiple papules, pustules and yellowish crusts were also present on the ventral abdomen, inguinal region and medial thighs. Scattered crusts were also observed on the trunk. The skin adjacent to the footpads was very erythematous, scaly and crusty. The footpads of all 4 feet were
hyperkeratotic.
What are your differentials? |
|
Definition
Pemphigus foliaceous (distribution of lesions, acute onset of clinical signs, variably puritic - manifest more as rubbing at the skin)
Discoid lupus (less likely because no systemic illness, typically no foot pad involvement and lesions tend to extend past the dorsum of the muzzle to affect the nasal planum) |
|
|
Term
| What is the pathophysiology of pemphigus foliaceous? |
|
Definition
| autoimmune disease in which antibodies are directed against desmosomes in the epidermis. Normal function of desmosomes are to act as dynamic junctions between cells, allowing keratinocytes to migrate upwards through the epidermis as they become increasingly keratinized. When the autoantibodies bind to the desmosomes enzymes are released that degrade them resulting in the loss of normal cellular attachements ---> acantholysis as well as pustule and vesicle formation. |
|
|
Term
| Although crusts, papules, and pustules can all be seen in isolated cases of pemphigus foliaceous what secondary problems should still be considered and ruled out in these patients? |
|
Definition
bacterial folliculitis and/or superficial pyoderma
*** do cytology, if you see large numbers of bacteria + large numbers of acanthocytes suggestive of concurrent disease. Pemphigus alone should be sterile. |
|
|
Term
| How do you diagnose pemphigus foliaceous? |
|
Definition
collect a cytology sample from an intact pustule (gently rupture by rubbing a 25g needle across the surface) or an impression smear from the bottom of a crust - should see non-degenerate neutrophils, many acantholytic keratinocytes and potentially some eosinophils. Classically you would expect NO bacteria; however, if secondary superficial poyderma is complicating the case bacteria will be evident.
definitive dx from histopathology of skin biopsy (collect 3-5 samples of intact pustules, crusts, or papules) which should reveal subcorneal pustule containing neutrophils, acanthocytes +/- eosinphils |
|
|
Term
| What is the treatment of choice for pemphigus foliaceous? |
|
Definition
50% of cases will respond to glucocorticoids alone, should recheck two weeks after starting therapy to begin gradually titrating the dose down to 1mg/kg/ADT. Monitor with CBC/CHEM/UA+culture yearly.
If glucocorticoids are not sufficiently controlling the disease, or if side effects are bad can also add azathioprine to reduce dose of steroids needed. Must obtain baseline CBC, and monitor every 2 weeks for the first 4 months of therapy because azathioprine causes bone marrow suppression. Also want monthly chemistry screenings to monitor for hepatotoxicity (uncommon, but when it does occur its BAD) |
|
|
Term
| What is an alternative to azathioprine that can be used for immunosuppression in cats? |
|
Definition
|
|
Term
| What are some important client education points for a newly diagnosed case of pemphigus foliaceous? |
|
Definition
Most dogs need to be treated with immunosuppresive therapy for life (caveat: if a manifestation of drug reaction these cases do occasionally resolve following initial therapy).
We need to monitor for drug side effects with bi-yearly to annual bloodwork and urinalysis.
It is important not to keep the patient on high doses of glucocorticoids due to the risk of iatrogenic cushings, lowering the dose may result in reappearance of some lesions but as long as the patient is comfortable this is preferable to cushings.
In cases that do not respond to steroids or azathioprine, IV immunoglobulin therapy has been successful, although this treatment is expensive. |
|
|
Term
On PE: multiple erythematous papules, a few pustules and yellowish crusts localized to the ventral abdomen, inguinal region, medial thighs and
axillary areas. Papules and crusts were also present along the trunk. The skin around the anus was very erythematous and had a few papules. The caudal aspects of both metacarpus were alopecic and erythematous. The interdigital spaces of all 4 feet were
bright-red and oily. Both ear canals were erythematous and had mild to moderate amounts of dark-brown exudate. 2 month history of severe puritus that resolves with glucocorticoid therapy.
What are your differentials? |
|
Definition
Atopic dermatitis (the itch that rashes, commonly associated with alopecic matacarpal region due to licking/chewing)
Food allergies
parasites are not likely because puritus improved with glucocorticoids. Flea allergy is not likely due to distribution of lesions (classically caudal and lumbosacral only)and papules should be present concurrently with onset of puritus. |
|
|
Term
| What secondary conditions are commonly associated with atopic dermatitis and/or food allergies? |
|
Definition
superficial pyoderma (papules, pustules, and crusts)
malassezia dermatitis (erythematous, oily interdigital spaces)
otitis externa (erythematous ear canals with dark brown exudate)
excoriations (in association with severe puritus) |
|
|
Term
| T/F skin scrapings should be the first diagnostic test performed in a case of glucocorticoid responsive pruritus with areas of alopecia. |
|
Definition
| FALSE if pruritus is due to parasitic causes glucocorticoid trial will exacerbate clinical signs |
|
|
Term
| What are the characteristics of a patient that is an ideal candidate for intradermal skin testing? |
|
Definition
Clinical signs have been present for a minimum of 1 year (allow you to determine seasonality and choose antigens for testing)
Has already undergone a food elimination trial to r/o food allergies.
Has been off of oral glucocorticoids (4 week withdrawal) and antihistamines (10-14 day withdrawal).
Owner wants to persue immunotherapy. |
|
|
Term
| T/F it is possible to start a food eliminiation trial for evaluation of potential food allergies simultaneously with antibiotic therapy for treatment of secondary superficial pyoderma |
|
Definition
TRUE
Superficial pyoderma will likely resolve before the food elimination trial is complete (takes 8-10 weeks) and then any improvement will be confirmed via CHALLENGE (feed old diet, see if clinical signs return)
*** in the case of severe puritus it is a good idea to give short course of steroids (anti-inflammatory dose) to prevent the animal from traumatizing the skin which will impede resolution of any superficial pyoderma despite appropriate antibiotic therapy |
|
|
Term
| How do you perform a skin cytology for assessment of suspected superficial pyoderma? |
|
Definition
impression smear from crusts or from rupturing intact pustules can be made. Slides should be air dried and heat fixed, then stained with Diff quick and examines under oil emmersion.
Can use tape to collect samples from interdigital spaces (stain the tape, place on a slide and examine under oil) |
|
|
Term
| What are the most common bacteria isolated from cases of superficial pyoderma and otitis externa? What are the most common fungal organisms? |
|
Definition
bacteria: Staph. pseudointermedius
fungal: Malassezia sp. |
|
|
Term
| T/F you must choose an antibiotic based on culture and sensitivity results in the case of the first presentation of a superficial pyoderma |
|
Definition
FALSE
if you are presented with a patient who has never had superficial pyoderma before and has not received any antibiotics for their condition then you can empirically treat with a broad specturm antibiotic.
If response is not as expected this is an indication to culture. |
|
|
Term
| What treatments are indicated for a patient with secondary superficial pyoderma and otitis externa and likely underlying atopy? |
|
Definition
short course of prednisone, anti-inflammatory dose
antibiotics (3-4 weeks worth to make it to the recheck apt, need to continue antibiotics 1 week past resolution of clinical signs) +/- antimicrobial shampoo
depending on ear cytology antibacterial/antifungal/cerulytic otic cleanser +/- topical antimicrobial drops
E collar to prevent excoriation |
|
|
Term
| When should you recheck a patient with secondary superficial pyoderma, otitis externa and likely underlying atopy? |
|
Definition
| recheck in 3-4 weeks to assess response to antibiotics and glucocorticoids |
|
|
Term
| What client education points are important in newly suspected cases of atopy with secondary superficial pyoderma/otitis externa? |
|
Definition
Your pet likely has an underlying skin condition that is predisposing him to develop skin and ear infections.
Environmental and food allergies in dogs require life long therapy and sometimes symptoms can be challenging to control. Relapses of secondary problems are to be expected and no one treatment is universally effective.
We are going to first rule out food allergies with a dietary elimination trial. For the next 8-10 weeks your pet must only eat the special diet and cannot have any additional treats, bones, rawhides, flavored medications, or human foods. |
|
|
Term
| What are some differentials for symmetrical non-pruritic alopecia in a cat? |
|
Definition
Demodex gatoi (surface mite, causes variable pruritus)
Food allergies
atopic dermatitis
psychogenic-anxiety neurosis
dermatophytosis (usually lesions are more sharply demarcated, distribution is generally non-symmetrical, lesions are often associated with erythema and/or scaling) |
|
|
Term
| What diagnostic tests should be performed on a cat that presents with bilaterally symmetrical non-inflammatory alopecia? |
|
Definition
Trichogram- confirm alopecia is self inflicted by visualizing broken hair shafts. Also look for fungal spores or hyphea.
Multiple skin scrapings from affected and non-affected (head and neck- ie. hard to groom) areas + fecal float to look for D. gatoi (remember, this is the surface mite and is challenging to find on scrapings). IF no mites are found do a trial (lyme sulfur dips, 3 within a period of 3 weeks)
food elimination trial to r/o food allergies
If all other diagnostics have been negative, and the clinical signs have been present for at least 1 year can do intradermal skin test or serum allergy test with the intention of trying immunotherapy. Once parasitic DDX have been ruled out can also do a glucocorticoid trial to increase our support of an allergic etiology. |
|
|
Term
| How do you treat D. gatoi? |
|
Definition
| Lyme sulfur dips q 5-7 days for a total of 6-8 treatments. Can try oral ivermectin but this is less effective for the D. gatoi than for the follicular mite. Treat all cats in the household |
|
|
Term
| What are the treatment options for atopic dermatitis? |
|
Definition
allergen specific immunotherapy (60-80% of patients will respond- can take up to one year of tx before response is appreciable)
antihistamine trial (try a new one every 10-14 days and have the client keep a log of any side effects and benefits to help determine which is most efficacious)
Essential fatty acids (must use for a min of 12 weeks)
glucocorticoids (DON'T use injectables in cats --> more likely to induce DM, side effects etc)
cyclosporine can be used (esp. in diabetic cats) but is expensive and can cause ginigival hyperplasia. |
|
|
Term
| Once all other potential diseases (d. gatoi, atopy, food allergies etc.) have been ruled out, and you diagnose a cat with psychogenic alopecia, what are some treatment strategies that can be used? |
|
Definition
behavioral modification! (limit exposure to stressful situations, do not interact with the cat when it's grooming- this can reinforce compulsive behavior, ensure 10-15 min/day of quality one-on-one interaction, provide varied enrichment with toys, cat safe plants etc.)
medical therapy may include TCAs, SSRIs, and diazepam. These drugs are generally expensive and can have significant side effects. |
|
|
Term
PE: hair coat was diffusely thin (hypotrichotic)and the skin was erythematous in most areas. The hair coat felt greasy on touching the skin. An interesting finding was the presence of multifocal areas of well circumscribed alopecia localized to the trunk and, to less extent the front and back legs. The skin
involving these areas was mildly scaly and hyperpigmented in some of the sites. On the ventral abdomen and inguinal area there were papules, pustules and crusts. The skin in
between the digits and in between the pads was very erythematous. In addition, some hemorrhagic bullae and some draining tracts exudating a serosanguineous material were
noticed in the feet. The muzzle and chin were alopecic, erythematous and had papules, nodules and the same hemorrhagic bullae and draining lesions present in the feet. Alopecia, erythema and scales were also noticed around both eyes. The mandibular and prescapular lymph nodes were mildly enlarged.
with a history of clinical signs worsening with glucorticoid trial. What are you DDX? |
|
Definition
Demodicosis (juvenile generalized)
Superficial and/or deep pyoderma
pemphigus foliaceus
hair follicle dysplasia |
|
|
Term
| Describe the procedure for peforming and interpreting a skin scraping? |
|
Definition
| squeeze skin, scrape until capillary bleeding, scrape multiple areas, examine under 10x with mineral oil |
|
|
Term
| How long should you treat a deep pyoderma (often present with draining tracts and deep hemorrhagic bullae)? |
|
Definition
| treat for two weeks past negative culture and/or cytology |
|
|
Term
| What is the treatment for follicular demodicosis? |
|
Definition
Ivermectin PO starting at a low dose and gradually increasing each week to a final dose of 600 ug/kg/day.
Continue treatment for 30 days after two consecutive negative skin scrapings (obtained at 4 to 8 week intervals)
Continue monitoring with skin scrapings over the following year before declaring a cure |
|
|
Term
| When should you recheck a case of deep pyoderma? |
|
Definition
|
|
Term
| What is the prognosis for juvenile generlized demodicosis? |
|
Definition
| good, some cases even resolve spontaneously |
|
|
Term
| What client education points are important to address regarding a newly diagnosed case of juvenile generalized demodicosis? |
|
Definition
Ivermectin is not FDA approved for tx of this disease
You dog should be spayed/neutered because this disease has a hereditary basis
Course of therapy is protracted |
|
|
Term
PE: a well demarcated area of hair loss localized to the outer
aspect of the left pinna. A thin layer of adherent white scales was covering the alopecic area. The skin was not clinically erythematous at this area. Similar lesions on the supra-scapular region and medial aspect of the right front leg. Other then mild scaling along the dorsal trunk, no other significant findings were present.
History of recent adoption from a shelter. Lesion on pinna has been slowly progressing for the last two week.
What are your DDX? |
|
Definition
dermatophytosis
Follicular demodicosis (D. cati)
Cheyletiellosis – typically diffuse scaling along the trunk and scales are not adherent |
|
|
Term
| How do you diagnose dermatophytosis? |
|
Definition
Trichogram- choose broken hairs from the periphery but within the lesion and perform superficial skin scrapings in same location. Place scales and hairs in some mineral oil on a slide and observe under 10-20x for fungal spores and/or hyphea
Fungal culture is gold standard! Collect samples as for trichogram and place in DTM media. Observe daily for colony growth and color change (should occur simultaneously in the case of dermatophytosis)
+/- Woods lamp (only 50% of M. canis strains will fluoresce, can be used to identify hairs for trichogram or culture) Do NOT use for definitive DX |
|
|
Term
| What method can be used to collect samples to screen for dermatophytosis in asymptomatic cats? |
|
Definition
| McKenzie toothbrush technique |
|
|
Term
| How do you treat dermatophytosis in a cat? |
|
Definition
SYSTEMIC THERAPY IS A MUST FOR CATS!
Itraconazole very good option for cats
but, anorexia, vomiting or diarrhea may still occur; it can increase liver enzyme activity and can be hepatotoxic but, less frequently than ketoconazole. It can be used as pulse
therapy, alternate three weeks on therapy, three weeks off – reduce cost and toxicity.
Terbinafine (30-40mg/kg per day) is another good option.
Griseofulvin should not be used in cats due to potential for bone marrow suppression, if it is the only option must monitor CBC weekly.
Topical therapy can be used as an adjunct. Lyme sulfur dips or antifungal shampoos, and enilconazole dips are all options.
Treat until two negative cultures are obtained at two week intervals |
|
|
Term
| Should you treat the environment in a case of a pet with dermatophytosis? |
|
Definition
YES, fungal elements can survive in the environment for 18 months!
Vacuum the whole house and carefully dispose of the bag. Confine cats in a room that is easy to keep clean. Clean hard surfaces with a 1:10 bleach:water solution or enilconazole |
|
|
Term
| If you diagnose a case of dermatophytosis in a cat, do you need to treat the assymptomatic dog that lives in the same household? |
|
Definition
| Dogs more rarely become asymptomatic carriers but, it is a good practice to recommend weekly lime sulfur dips for the cohabiting asymptomatic dog throughout the course of treatment |
|
|
Term
| How should you treat an asymptomatic cat that lives in a household with another cat that has been diagnosed with dermatophytosis? |
|
Definition
Cats can be asymptomatic carriers of dermatophytosis. The cat should be cultured (McKenzie technique), and separated from affected cat.
Start the cat on weekly lime sulfur dips until culture results return. If culture returns positive add systemic therapy. If negative still maintain this asymptomatic cat on lime sulfur dips and re-culture the cat at the time you will re-culture the affected one to make sure that the non-affected did not become infected. |
|
|
Term
| What are some important client education points in regards to a newly diagnosed case of dermatophytosis? |
|
Definition
this is a ZOONOTIC disease and can be contagious to other dogs and cats in the household as well.
It is very important to treat the environment but because it is challenging to completely clean it up we must treat until a minimum of one negative (ideally two) fungal cultures from ALL animals in the household are negative
Cats can be assymptomatic carriers and can act as sources of infection to other pets and humans in the household.
Important to monitor for all side effects associated with prescribed drugs |
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|
