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What is an important feature of Sporotrichosis?
zoonotic!
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What are the 3 forms of sporotrichosis?
cutaneous, cutaneoulymphatic, disseminated (rare in dogs, common in cats)
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What body areas are most commonly affected by sporotrichosis? (3)
head, ditsal limb, tailbase
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What are clinical signs of sporotrichosis?
multiple non-painful nodules that ulcerate and drain purulent exudate
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How is sporotrichosis contracted?
soil saprophyte, infection occurs from inoculation of organism into SQ tissues by rose thorns or cat fights (ie. outdoor animals and intact cats are more prone)
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How do you diagnose sporotrichosis? (6)
- cytology- easy to see in cats, fewer organisms in dogs
- culture
- histopathology
- PCR analysis
- immunofluorescent testing
- antigen testing
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What is the treatment of sporotrichosis? (2)
Itraconazole, +/- Amphotericin B
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Canine histiocytic disorders include... (4)
cutaneous and systemic canine cutaneous reactive histiocytosis, localized and disseminated histiocytic sarcoma complex
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What is the etiology of cutaneous histiocytoma?
unknown; assumed to be immune-mediated b/c have not isolated infectious agents and they respond to immunosuppressive therapy
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What animals usually present with cutaneous histiocytosis?
3-9 years old, predisposed Collies and Shetland Sheepdogs
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What are clinical signs of cutaneous histiocytosis? (6)
multiple hairless, erythematous dermal to SQ nodules, non-pruritic, non-painful, lesions wax and wane, slowly progressive and may spontaneously resolve
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Where are lesions most commonly located with cutaneous histiocytosis? (6)
face, neck, nasal mucosa, perineum, scrotum, feet
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How do you diagnose cutaneous histiocytosis?
histopathology
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What other differentials may correlate with cutaneous histiocytoma on histopathology? (3)
sterile granuloma and pyogranuloma syndrome, multiple cutaneous histiocytomas, cutaneous lymphoma
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Describe the management of cutaneous histiocytosis. (5)
- prednisone immunosuppression (most respond to this as sole therapy)
- azathioprine, cyclosporine, leflunomide, tetracycline/niacinamide (or doxy) as maintenance to avoid recurrence
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You can use ____________ concurrently with steroids to reduce the immunosuppressive dose of corticosteroids.
tetracycline (or doxy or mino) and niacinamide
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What is sterile nodular panniculitis?
inflammation of the SQ fat- unknown origin
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Sterile nodular panniculitis (SNP) has been documented in associated with... (4)
systemic lupus erythematosus, pancreatitis and pancreatic tumors, rheumatoid arthritis, lymphoplasmacytic colitis
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What are clinical signs of SNP?
single or multiple SQ nodules which can be of normal skin color or by erythematous or blue; initially nodules are firm but they become soft/ liquefied in center; nodules may regress or form draining tract; fever, lethargy, anorexia around the formation of new nodules
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How is SNP diagnosed? (5)
- diagnosis of exclusion: rule out bacteria/fungi/myobacterium, sterile granuloma/pyogranuloma syndrome, foreign bodies, injection site reaction, insect bite, drug reaction, neoplasia
- CBC/Chem/UA: rule out/ identify concurrent systemic diseases
- cytology: suppurative to pyogranulomatous or granulomatous with fat drops or cell present and sterile
- biopsy
- culture
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How is SNP definitively diagnosed? (2)
- histopath: suppurative to pyogran/granulomatous with fat drops or cells
- culture: negative for fungi, bacterial, mycobacterium
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How is SNP managed?
- surgical excision of solitary masses may be curative
- [many lesions] immunosuppressive drugs- prednisone, monitor- if no response within, 2-8 wks add another immunosuppressive agent
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How do you taper prednisone therapy in SNP management?
if remission is achieved within first 2 weeks of prednisone therapy, decrease dose by 25% every 7 days until lowest effective dose every other day
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With management of SNP, regression of nodules may take __________ to regress.
2-8 weeks
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Describe the pathogenesis of sterile granuloma/pyogranuloma syndrome (SGPS).
idiopathic, have not identified infectious agents/ respond to immunosuppressive therapy- assumed immune-mediated
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What 2 bacterial agents are proposed to be associated with development of SGPS?
Leishmania, Mycobacterium
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What are clinical signs of SGPS?
firm, hairy or alopecic erythematous papules, nodules, or plaques; may form draining tracts and ulcers on paws
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Where are lesions commonly located with SGPS? (4)
head, distal extremities, +/- tongue, +/- prepuce
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How is SSGPS diagnosed? (4)
- rule out other causes of deep infections (bacteria, fungi, foreign bodies, cutaneous eosinophilic granulomas, cutaneous neoplasms)
- clinical appearance
- histo
- negative culture
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How is SGPS managed?
- [single nodule] surgical excision can be curative
- [many lesions] immunosuppressive drugs- prednisone, cyclosporine, etc
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Describe tapering of steroids with management of SGPS?
if remission is achieved within 2 weeks of starting prednisone therapy, decreased dose by 25% every 7 days until lowest effective dose is given every other day
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How can you manage a case of SNP or SGPS that is not responding to prednisone?
[regression of lesions should occur in 2-8 weeks] if remission has not been achieved after 4 weeks of daily prednisone, the case may require combination of prednisone with azathioprine or cyclosporine
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What characterizes a nodule?
firm (solid) elevation that is >1cm
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What are your major rule outs for a single, acute nodule in an otherwise healthy animal? (4)
FB, trauma, secondary bacterial infection, kerion (deep dermatophytosis)
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Deep fungal infections commonly affect... (5)
skin, lymph nodes, lungs, eyes, CNS
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How are cytology samples usually collected from nodules? (3)
FNA or from draining tract, maybe impression smears from ulcerated areas
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__________ does NOT rule out infectious causes for nodular diseaes; you must...
Negative cytology; do sterile biopsy for bacterial and fungal culture.
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What samples should you submit when doing a work-up for nodular disease? (3)
sterile biopsy for histopathology, aerobic ad anaerobic bacterial culture, fungal culture
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What is the most prudent way to diagnose Mycobacterium?
send out fresh frozen tissue sample for PCR if you are suspicious of mycobacteria
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For what infectious causes of nodular disease can you perform antigenic testing? (2)
blasto and crypto
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What are the most common bacterial causes of nodular disease? (3)
mycobacterium, actinomyces, nocardia
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What are the most common fungal causes of nodular disease? (6)
dermatophytosis (kerions), cryptococcosis, blastomycosis, histoplasmosis, coccidiomycosis, sporotrichosis
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Describe the features of the Actinomyces microbe. (6)
- gram + filamentous anaerobic rod
- opportunistic commensal flora of mouth and GI
- found in environment/ soil
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How is actinomycosis contracted?
trauma and contamination of penetrating wounds, migrating FBs (awns, quills) [may take months to years to develop draining tract, non-healing ulcerative nodules]
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What are clinical signs of actinomycosis? (3)
SQ swelling, draining tract, non-healing ulcerative nodules
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How is actinomycosis diagnosed?
anaerobic culture, may take 2-4weeks
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What is the treatment for actinomycosis? (2)
- surgical excision or debulking, remove FB
- Penicillin/amoxicillin at least 1 month beyond clinical resolution
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What are the characteristics of the Nocardia microbe? (6)
- gram + filamentous aerobic rod, partially acid-fast
- soil saprophyte
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Why are Actinomyces and Nocardia so difficult to tell apart, and how do we achieve this?
- both are gram + filamentous bacteria
- Nocardia is partially acid-fast and aerobic, Actinomyces is not acid fast and is anaerobic
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What are clinical signs of Nocardiosis? (4)
cellulitis, ulcerated nodules, draining tracts, lymphadenopathy
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How is nocardiosis diagnosed? (3)
FNA of nodules shows filamentous gram + bacteria, aerobic culture to differentiate from actinomyces, +/- biopsy
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Describe the treatment of Nocardiosis. (3)
- if 1 or a few lesions,surgical resection
- antibiotics based on susceptibility of isolate
- combination therapy of antibiotics at least one month past clinical cure
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What antibiotics are commonly used in combinations to treat Nocardiosis? (6)
Potentiated sulfas, Mino/Doxycycline, aminoglycosides, Imipenem, Clarithromycin, cephalosporins
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What are the 3 categories of Mycobacteria?
- obligate mycobacteria (tuberculosis and lepraemurium- affect immunocompromised)
- saprophytic mycobacteria (affect immunocompetent hosts)- panniculitis
- saprophytic bacteria that affect immunocompromised hosts (feline leprosy)
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Describe the opportunistic Mycobacteria microbe. (3)
rapidly-growing, ubiquitous, acid fast
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How is Mycobacteria usually contracted in an immunocompetent host?
penetrating wound with soil contamination, causing mycobacteria granulomas
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Mycobacterial organisms thrive in _________, such as __________.
fatty tissue; feline inguinal fat pad
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What are clinical signs of an opportunistic Mycobacterial infection? (5)
non-painful, non-pruritic, firm/ fluctuant SQ nodules that ulcerate and spread outwards
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Describe the diagnosis of opportunistic mycobacterial infections. (3)
- cytology by FNA or or from draining tract- negative staining microbes with diff quik
- culture from nodule aspirate
- deep biopsy for histopath
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Describe the management of opportunistic mycobacterial infections. (2)
- aggressive surgical resection (en bloc resection wit skin flaps)
- antibiotics based on culture, usually for 3-6 months
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What antibiotics are commonly used to treat mycobacterial infections? (6)
enrofloxacin, doxycycline, gentamicin, clofazimine, clarithromycin, trimethoprim-sulfonamide
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What is the cause of canine leproid granuloma syndrome (CLGS)?
fastidious mycobacterial species probably transmitted by biting insects
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What is the usual presentation of canine leproid granuloma syndrome?
nodular skin disease that is usually localized ot the pinnae and head
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How is canine leproid granuloma syndrome diagnosed? (2)
cytology or histological examination with special staining
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What is the treatment and prognosis for canine leproid granuloma syndrome?
usually self-limiting, if not surgical resection is curative
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Describe the Cryptococcosis microbe. (3)
ubiquitous, saprophytic, yeast-like
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Where is crptyococcosis found in the environment?
nitrogen-rich alkaline environments, ie. pigeon droppings
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How is Cryptococcosis contracted? (2)
usually by inhalation (ie. preceded by respiratory disease), sometimes primary skin innoculation
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Cryptococcosis is most commonly seen in ________ and presents as... (3)
cats; upper respiratory signs, polyp-like mass in nostrils or swelling on bridge of nose
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How is cryptococcosis diagnosed? (3)
- cytology: pyogranulomatous inflammation, large microbes with a clear halo
- biopsy
- latex agglutination test for capsule Ag
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Cryptococcosis is _________ budding; Blastomycosis is _________ budding.
narrow-base; broad-base
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Describe the management of Cryptococcosis. (3)
- Itraconazole**
- Amphotercin B (if severe)
- surgical excision if feasible
- treatment may require 2 years or more
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Where can you find Blastomycosis in the environment?
moist, acidic soil rich in organic material near bodies of fresh water; endemic in Ohio
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How is Blastomycosis usually contracted? (2)
inhalation of spores from the environment (ie. preceded by respiratory disease), primary skin inoculation can occur
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What are clinical signs of Blastomycosis? (8)
anorexia, weight loss, cough, ocular disease, lameness, firm nodules, draining tracts, plaques
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Where are skin lesions commonly located with Blastomycosis? (3)
nose claw beds, face, but can be anywhere
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How is Blastomycosis diagnosed? (3)
- cytology: big. blue, broad-based budding
- biopsy
- immunoassay Ag (urine)
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Describe the management of Blastomycosis. (2)
- Itraconazole
- glucocorticoids in animals with respiratory distress
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Where can you find Histoplasma in the environment?
nitrogen-rich organic soil; bat and bird droppings
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How is Histoplasmosis contracted? (2)
inhalation of microconidia, primary skin inoculation can occur
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How is Histoplasmosis diagnosed? (3)
- cytology: intracellular oragnisms
- histopath: round to ovoid with a thinclear zone b/w cell wall and cytoplasm, intracellular
- culture- highly pathogenic- warn lab
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What are clinical signs of histoplasmosis? (9)
cough, weight loss, diarrhea, fever, ocular lesions, papules, nodules, draining tracts, ulcers
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What is the treatment for Histoplasmosis? (4)
Itraconazole, Amphotercin B (severe cases), fluconazole, ketoconazole; usually at least 6 month treatment
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