Derm and Repro Flashcards
1
Q
What cells are located in the epidermis
A
-Keratinocytes- 4 layers of squamous epithelium (Stratum corneum, granulosum, spinosum, and basale)
-Melanocytes
-Langerhans cells (dendritic cells)
2
Q
What is the most abundant cells in the epidermis
A
the keratinocytes, organized into distinct vertical zones of stages of differentiation. Important in understanding physiologic and pathological changes
3
Q
What is the most superficial layer of the epidermis
A
stratum corneum
4
Q
what cell type are the keratinocytes of the epidermis
A
squamous epithelium
5
Q
What is the most bottom layer of the epidermis?
A
Stratum basale- 1 layer thick and functions in keratinocyte proliferation and anchoring epidermis to the dermis (hemidesmosomes)
6
Q
Hemidesmosomes
A
how the stratum basale layer attaches to the basement membrane
7
Q
What is the second to last layer of the epidermis
A
Stratum spinosum- 1-2 layers of haired skin (>20 in non-haired skin) does cell to cell mediated attachment through desmosomes (intracellular) and tonofilaments (intracellular filaments that anchor desmosomes to the cell membrane)
8
Q
Tonofilaments
A
intracellular filaments that anchor desmosomes to the cell membrane
9
Q
Stratum granulosum
A
the layer under the stratum corneum that is 1-2 layers when present. Squamous cells with distinct basophilic cytoplasmic granules
have lamellar granullars that contrain phospholipids that are extruded into the intercellular space and also keratohyalin granules that contain fibrous proteins (filaggrin) that provide strong cross-linking of cells
10
Q
Lamellar granules
A
granules of the stratum granulosum that contain phospholipids that are extruded into the intercellular space
11
Q
Keratohyalin granules
A
granules of the stratum granulosum that ocntain fibrous proteins (filaggrin) that provide strong cross-linking of cells
12
Q
Stratum corneum
A
the outermost layer of the epidermis. Thin squamous, anuclear cells. not truly dead
form a resistant protective layer/barrier (anchored by intercellular hydrophobic phospholipid “mortar”
13
Q
Acanthosis
A
hyperplasia of the stratum spinosum
14
Q
Hyperkeratosis
A
hyperplasia of the stratum corneum
15
Q
Generally, the rate of skin cell production equals the
A
rate of desquamation
16
Q
Melanocytes
A
in the stratum basale and produces melanin pigment that injects into the keratinocytes around it.
melanin pigment is for photoprotection
17
Q
Langerhans cells
A
dendritic cells located in the stratum basale and spinosum that function to trap and process antigen (immune surveillance)
18
Q
Macule
A
a flat, distinct, discolored area of skin that is less than 1cm
19
Q
Patch
A
a macular lesion (flat, distinct, discolored) that is greater than 1cm in diameter
20
Q
Papule
A
a solid, elevated, firm, circumscribed lesion that is less than 1cm in diameter. that is caused by the infiltration of inflammatory cells.
associated with hair shaft (folliculitis) or not
21
Q
What is the most common cause of papular dermatitis
A
bacterial pyoderma
22
Q
Plaque
A
a primary skin lesion where that is an elevated firm lesion with a flat top >1cm in diameter
ex: feline eosinophilic plaque
23
Q
Pustule
A
an elevated accumulation of purulent material within epidermis
ex: bacterial pyoderma
24
Q
Vesicle
A
a blister- elevated fluid filled cavity within or below epidermis, <1cm in diameter
25
Bulla
a vesicle that is >1cm in diameter. typically caused by burns, viral infection, and autoimmune disease
26
Cyst
epithelial lined cavity filled with fluid or semisolid material. Located in the dermis or subcutis
ex: folliclar or apocrine cyst
27
Wheal
hive, urtica- raised, solid region of edema, often with irregular borders
Ex: insect bite, type 1 hypersensitivity reactive
28
Nodule
a raised, firm round lesion >1cm in diameter
ex: neoplasia, bacterial or fungal infection, sterile granulomas
29
Epidermal collarette
a flat to minimally raised scale arranged in circular rim
ex: superficial bacterial pyoderma, fungal infections
30
Dermis cellular contents
fibroblast, macrophages, T cells, mast cells
31
Dermis acellular components
for structural support
fibers- collagen, elastin, reticulin
ground substance (fluid) composed of H20, salt, proteoglycans, and glycoproteins
32
Sebaceous glands
within the dermis, adjacent to follicles with duct that opens into the infundibulum
Basal cells differentiate into sebum producing cells which die, releasing sebum into duct
responsible to hormones (androgens increase activity, estrogens and glucocorticoids lead to atrophy and involution)
33
Sebum
composed of triglycerides, waxy esters, and contributed to surface oil emulsion on epidermis (moisture and pliancy)
34
What effect do androgens have on sebaceous glands of the dermis?
increase their activity
35
What effect do estrogens and glucocorticoids have on sebaceous glands of the dermis?
Atrophy and involution
36
What is the function of dermis apocrine glands
thermoregulation (sweat) and surface emulsion, antimicrobial components-interferon, transferring, NaCl, complement
37
Eccrine glands (dermis)
on the paw pads of dog/cat, frog of ungulates, carpus, and snout of pigs
actively secrete product directly onto skin surface
38
hair follicle stages of growth cycle
1) Anagen phase - growth
2) Catagen phase - transition
3) Telogen phase - resting (end stage)- controlled via hormones, daylight, temperature, nutrition, growth factors
39
Hypodermis/subcutis/panniculus
the deep layer of fibroadipose tissue
thickness varies based on location, species, and nutritional state
function- insulation, protection, and energy storage
40
Comedone
a secondary skin lesion where dilated hair follicle is filled with keratin or sebum
ex: chin acne, many endocrine diseases, demodex
41
Callus
a secondary skin lesion where there is a thick, hard, hairless plaque often located over pressure points (elbow)
42
Crus (scab)
a secondary skin lesion where dried exudate in the stratum corneum composed of serum, blood, keratin, and degenerate neutrophils
43
Scale
a secondary skin lesion where loose fragments of keratin on the skin surface (hyperkeratosis) ex: cornification abnormalities, sebaceous adentitis, seborrhea, low humidity
44
Erosion
a secondary skin lesion where partial loss of epidermis
ex: secondary to ruptured vesicle
45
Ulceration
a secondary skin lesion where full thickness loss of epidermis with exposure of the dermis
ex: vasculitis
46
Excoriation
a secondary skin lesion where there is a linear loss of epidermis
ex: scratch or abrasion
47
fissure
a secondary skin lesion where there is a vertical crack in epidermis to the dermis
48
Lichenificiation
a secondary skin lesion where there is rough thickened epidermis. Results from chronic scratching/irritation
ex: non-specific chronic dermatitis
49
How might an infectious agent enter the skin
through epidermal surface, opening of hair follicles or gland ducts, migration along nerves, hematogenous
50
Pyoderma
pus in the skin where follucular opening is a common portal of entry
superficial and deep bacterial infections
Gross lesions: papules, pustules, epidermal collarettes/epidermitis/folliculitis
51
Bacterial pyogranulomatous dermatitis
traumatic implantation of saprophytic organisms
Slowly progressive nodular lesion with/without a draining tract.
-Mycobacterial infections
-Botryomycosis (Staph, Strp, Pseudomonas)
-Filamentous bacteria (Nocardia, Actinomyces)
52
What is a major cause of superficial and deep bacterial pyoderma in the dog
staphylococcus pseudointermedius
53
What is a major cause of superficial and deep bacterial pyoderma in the horse
staphylococcus aureus of pseudointermedius
54
What is a major cause of superficial and deep bacterial pyoderma in the pig
staphylococcus hyicus (exidative epidermitis)
55
What is a major cause of superficial and deep bacterial pyoderma in the sheep, horse, and cattle
Dermatophilis congolensis (Rainrot)
56
Pyoderma predisposing causes
Allergies, endocrine disease, immune deficiency, matted hair coat, parasitic infection, irritants
57
Perifolliculitis
inflammation around the hair follicles
58
Folliculitis
inflammation within the hair follicles
mural - within the follicular wall
luminal- within the follicular lumen
59
Furunculosis
rupture of the hair follicle resulting in the release of contents into the dermis and secondary foreign body reaction to keratin
other causes: fungus (dermatophytosis) and mites (demodex)
60
Systemic bacterial infections in skin lesions
bacteremia leading to embolization to skin, bacterial toxins, direct infection of endothelial cells, type III hypersensitivity reaction (immune complexes desposit in vessel walls leading to complement and vasculitis)
61
Pig differentials for vasculitis
Erysipelothrix rhisiopathiae, salmonella septicemia, procine circovirus 2, others
62
Vasculitis clinical signs
erythematous plaques or macules dermal edema, hemorrhage bullae, necrosis, well-demarcated ulcerations
Chronicity- regions of alopecia due to atrophy or prior necrosis of hair follicles
Commonly lon paws, pinnae, lips, tails
commonly unrelated to infectious agents- type II drug reaction and type I
63
Poxvirus infections
caused by many different poxviruses (mostly affect large animals) can cause localized or systemic disease
Epitheliotropic, caused by viral infection of epithelium, vascular injury, induction of epidermal hyperplasia
Microscopic lesions: keratinocyte vacuolization (intracellular edema) -> rupture leading to vesicle, marked epithelial hyperplasia, intracytoplasmic inclusions
64
how do pox virus cutaneous lesions develop?
Macule -> papule -> vesicle -> umbilicated lesion with raised peripheral rim -> Crust
65
Contagious pustular dermatitis
ORF- a parapoxvirus of sheep and goats that is zoonotic. lesion distribution typically around lips, muzzle, +/- around the eyes
66
Dermatophytosis
Common in animals (and humans-zoonotic)
Microsporum canis- lives in dogs and cats, rarely soil
Microsporum gypseum- soil inhabitant- most common in dogs in some regions)
can be localized, multifocal, or generalized
generally confined to the keratin layer if skin and hair
Lesions- patches of alopecia with scaling; papules due to folliculitis/perifolliculities/furuncolosis
67
Dermatophytosis pathogenesis
Micro-abrasions of stratum corneum help facilitate invasion, produce proteolytic enzymes, penetrate and invade hair shafts, hair damaged, leading to alopecia
68
Malassezia pachydermatis
a normal inhabitant of the skin and ear canal. Disease seen with correct microclimate (overgrowth) or secondary to other skin conditions like allergies
Erythema, thickening, hyperpigmentation
Diagnosis: cytology, commonly lost during tissue processing for histopatholgy
69
What are some time mites that cause ectoparasitic infection of the skin?
Demodex and sarcoptes
70
Demodectic mange
normal commensal inhalant of skin disease- disease associated with overgrowth (stress, corticosteroids, poor nutrition, immuno-incompetence)
Localized or generalized
Localized-one region of body (face most common) with 1-5 areas of alopecia, erythema, scaling
Lesions: folliculitis, perifolliculitis. furinculosis
Diagnosis: deep skin scrapings (mites are in hair follicles), pluck hairs
71
Sarcoptic mange
burrows into the stratum corneum causing intense pruritus due to hypersensitivity reaction
results in hyperkeratosis and acanthosis due to self trauma
diagnose with superficial skin scraping
72
What parasite cause eosinophilic/granulomatous reaction
hookworms
73
Stephanofilaria stilesi
a nematode of the skin, commonly seen in cattle, ventral midline
alopecia and lichanification
74
Type I hypersensitivity reaction
antigen binds to IgE, complexes bind to mast cells, degranulate, release of histamine and other mediators
can lead to hypersensitivity dermatoses
75
Type IV hypersensitivity reaction
Cell (T lymphocyte) mediated/delayed hypersensitivity. can lead to hypersensitivity dermatoses
76
What are some sources of hypersensitivity dermatoses
-insect bites (including flea allergy), atopic environmental allergy, food sensitivity dermatitis
77
What histological findings do you see with hypersensitivity dermatoses
eosinophilic and mastocytic perivascular dermatitis with dermal edema.
may see some changes associated with self-trauma due to severe pruritus
may see some changes associated with secondary bacterial or malassezia infections
78
Atopic dermatitis
a common, genetically predisposed allergic skin disease to environmental allergens (hust, mite proteins, plant proteins, mold spores,etc.)
can be seasonal or non-seasonal
Pruritic- skin lesions, generally secondary to self-trauma
erythema, wheal, alopecia, excoriation, salivary staining
chronicity- lichenification and hyperpigmentation
distribution- face,paw, caudal carpi, distal extremities, ear and ventrum
79
Flea allergy
pruritus of mostly caudal half of animal
Primary skiun lesion- crusted papules, somewhat bulaterally symmetric pattern
80
Food allergy
non-seasonal pruritis with self trauma
primary lesions (generally not present) erythema, erythematous papules and wheals
Mostly see secondary lesions (same as atopy)
81
Feline eosinophilic nodular disease
the feline eosinophilic granuloma complex (underlying allergic reaction) that is:
1) Plaque- raised erythematous plaques- ventral abdomen, perineum, and medial thigh
2) Granuloma- papular, nodular or linear lesion skin- skin, mucocutaneous junctions, pawpads, oral cavity
3) indolent ulcer (rodent ulcer)- ulcerated lesion on the upper lip (unilateral of bilateral)
82
Equine eosinphilic nodular disease
cause is unknown but suspected to be hypersensitiviity. Single or multiple cutaneous papules or nodules (withers, neck, back, other sites) - eosinophilic granulomas
83
Pemphigus complex
immune mediated, autoimmune disordrs that are associated with pustules and vesicles
antibodies target keratinocytes desmosomes resulting in loss of cell-cell adhesions/ loss of acantholytic cells)
84
Pemphigus foliaceous
the most common autoimmune condition of horses and cats
2nd most in dogs
Pustules and vesicles that rupture easily
secondary lesions- erosions, crusts, scales
can progress to generalized disease
85
Pemphigus vulgaris
more severe than Pemphigus foliaceous, rare.
Pustules and vesicles that rupture and result in erosions, crusts, and scales
typically at oral mucosa or combination of oral mucosa, mucocutaneous junctions and skin
occur deep in the epidermis (above the basal cell layer)
86
Bullous dermatoses
a heterogeneous group of diseases characterized by blistering/ulceration of skin and mucous membrane epithelium following minor mechanical trauma
caused by abnormalities at the level of the dermal and epidermal junction
87
Bullous pemphigoid
a blistering disease that is caused by abnormalities in the dermal/epidermal junction through disruption in hemidesomoses
88
Epidermolysis bullosa
a blistering disease that is caused by abnormalities in the dermal/epidermal junction through the basement membrane anchoring fibrils
89
Cutaneous lupus erythematosus/ discoid lupus erythematosus (DLE) and Systemic Lupus erythematosus (SLE)
a disorder of basal cell injury where antibodies are directed against self-antigens, type III sensitivity with antigen-antibody complex deposition on the basement membrane
this leads to bullae, vesicles, and ulcers
lesions are exacerbated by UV light
Histological lesions is interface dermal/epidermal junction dermatitis with damage to the basal cells. Pigmentary incontinence is secondary to basal cell damage
90
Discoid Lupus Erythematous (DLE)
a common canine autoimmune skin disease that typically affects younger dogs 2-5 years of age
slow progression
lesions usually restricted to the face, nasal planum depigmentation, erythema, scaling, loss of cobblestone appeaance, dorsal muzzle, lips, perioral, and ears
often confused with mucocutaneous pyoderma
91
Systemic lupus erythematosus (SLE)
a rare multi-systemic potentially fatal autoimmune disease of dogs and cats resulting in inflammation and tissue damage in the skin, heart, lungs, kidneys, joints, nervous system, or blood
Present as polyarthritis, fever, anemia, thrombocytopenia, glomerulonephritis
Blood test needed for diagnosis- positive for anti-nuclear antibodies (ANA)
Collies, Shetland, and GSD +/- are predisposed to both DLE and SLE
92
Erythema multiforme/ toxic epidermal necrolysis
a disorder of keratinocyte injury, thought to be host specific T-cell mediated hypersensitivity (type IV) with immune cells directed against keratinocyte-associated antigens leading to single keratinocyte necrosis with surrounding lymphocytes
often induced by drugs: chemicals infectious agents and neoplasia
EM is minor and major based on severity and involvement of mucous membrane
TEN is more severe and life threatening condition that resembles thermal or chemical burns
93
Uveodermatologic syndrome
an acquired depigmentation disorder common in arctic breeds, thought to be immune mediated rxn to epidermal melanocytes
bilateral panuveitis and bilateral cutaneous depigmentation
94
Sebaceous adenitis
a disorder of sebaceous glands in dogs (rare in cats) that is suspected to be immune mediated destruction of sebaceous glands leading to alopecia, scaling, and dry/brittle hairs
Histologically see a granulomatous to pyogranulomatous inflammation and epidermal and follicular hyperkeratosis
Chronic disorder leads to a complete lack of sebaceous glands
95
What are the different mechanisms in which alopecia can occur
1) Follicular dysplasia (abnormal formation)
2) Follicular atrophy (genetic, ischemic, trauma, inflammation
3) Abnormal growth/hair cycle arrest - endocrine, nutritional, metabolic
96
Color dilution alopecia
See in color dilate animals of many breeds of dogs and cattle. develop alopecia within the first few months to years of life
97
Black hair follicle dysplasia
alopecia associated follicular dysplasia where bi and tricolor black and white dogs and cattle have alopecia of only black haired region of coat.
Due to clumping of melanin in the pigment in the hair bulb
98
Congenital Alopecia/Hypotrichosis
Usually a spontaneous genetic mutation resulting in complete or partial hairlessness, hair that is present is typically abnormal
hereditary lack of hair follicles
99
Alopecia areata
an autoimmune condition targeting hair bulb leading to non-scarring alopecia. characterized by inflammation in or around the follicle bulb
100
How do you differentiate endocrine alopecia?
there is non-pruritic, bilaterally symmetric alopecia and the remaining hair coat is dull, dry, easily epilated. fails to regrow after clipping
Hair follicles-catagen or telogen phase with lack of hair shafts
101
What will you see microscopically in animals with endocrine alopecia
the hair follicles are catagen or telogen phase with lack of hair shafts
102
Hypothyroidism associated alopecia
idiopathic thyroid atrophy or lymphocytic thyroiditis resulting in alopecia because thyroid hormone is necessary for the anagen stage
myxedema is rare
103
Hyperadrenocorticism associated alopecia
mostly seen in dogs, but also can be in cats
Can be primary, secondary, or iatrogenic
characterized by calcinosis cutis (dogs) - dystrophic mineralization usually with iatrogenic cushings disease, cats have fragile skin
104
Hyperestrogenism associated alopecia
alopecia seen in female dogs with ovarian cysyst, ovarian neoplasia, estrogen administration, enlarged vulva and abnormal estrus cycle or male dogs with functional sertoli cell tumor, gynecomastia, enlarged prostate due to squamous metaplasia of ducts
105
Hyposomatotropism assoicated alopecia
alopecia seen in pituitary dwarfism- failure to grow and retention of puppy hair cut
106
Cyclical flank alopecia
alopecia seen in dogs but cause is unknown. thought to be due to changes in photoperioid- melatonin released from pineal gland
107
Alopecia X
alopecia that has an unknown cause - dog breeds with plush hair coat, alopecia sparing head, normal thyroid and glucocorticoid levels
108
Dermatomyositis
idiopathic vasculitis of skin and muscle
ischemia and atrophy of hair follicles and muscle
leading to vesicular dermatitis -> crusty ulcerated alopecic regions with hypo or hyperpigmentation
healed lesions have muld alopecia and pigment changes
seen in muscles of mastication atophy
109
Albinism
a disorder of pigmentation where melanocytes are present but they are defective in the function/synthesis of melanin
110
Piebaldism
a disorder of pigmentation where there is a genetic absence/failure of migration of melanocytes to regions
111
Vitiligo
a disorder of pigmentation where there is a destruction of melanocytes
112
Pathogenesis of hypopigmentation
1) destruction of epidermal-melanocyte units (autoimmine, post-inflammatory disease, trauma, neoplasia)
2) Reduced melanin synthesis ~ tyrosinase, Cu deficiency "Steely Wool"
113
Lentigo
non-neoplastic proliferation of melanocytes seen in dogs and cats leaded to pigmentated macules on mucocutaneous junctions
114
Hyperpigmentation
a disorder of pigmentation that is acquired through chronic inflammation/irritation, UV exposure leading to increased proliferation of melanocytes and increased melanin synthesis
115
Congenital icthyosis
an autosomal recessive scaling defect where there are scales due to defects in stratum corneum formation.
suspectible to secondary infections
Histologically see orthokeratotic hyperkeratosis
116
What effects on the skin do Vitamin A and zinc deficiencies have?
scaling disorders as they are used for keratinization and maturation of the epidermis. Deficiencies lead to hyperkeratosis and ancanthosis, disordered maturation
leading to compromised barrier function leading to 2nd bacterial infections
117
Seborrhea
can be either sicca (dry scale) or oleosa (oily sale) but is the excessive scaling disorder (disordrr of keratinization)
primary or secondary
118
Skin fragility syndrome
a defect in collagen production, quality, or packaging where skin is fragile, easily torn, and commonly hyperextensible/loose leading to frequent skin lacterations with minimal hemorrhage when handling. healing scales are pale and wrinkled/tissue paper like.
can be genetic or acquired (cats-hyperadrenocorticism, diabetes mellitus, hepatic disease)
119
collagen dysplasia
stretchiness of the skin
Dog- congenital
Feline- hyperadrenocorticism
Horse- hereditary equine regional dermal astheia (HERDA), autosomal recessive in quarter horses, hyperextensible, loose fragile skin with poor wound healing
120
Cutaneous mucinosis
caused by excess deposition or accumulation of mucin in dermis related to excess production of polysaccharide hyaluronan by fibroblast
primary: Normal in sharpei
secondary: myxedema associated with hypothyroidism or focal- inflammation or neoplasia
121
Solar (Actinic) injury
caused by UV light damage, typically lightly or non-pigmented, sparsely haired region
initial exposure: sunburn
Long exposure: solar elastosis, actinic keratosis that can progress to squamous cell carcinoma in situ or hemagioma/hemangiosarcoma
122
Solar elastosis
degenerative changes in the dermis due to long-term sun exposure
123
Actinic keratosis
pre-neoplastic changes of the epidermis due to long term sun exposure that can progress to squamous cell carcinoma or hemangioma/ hemangiosarcoma
124
Type 1 (primary photosensitization)
ingestion of preformed photodynamic substances such as St John's wort, buckwheat, spring parsley, phenothiazine drug
125
Type 2 photosensitization
abnormal porphyrin metabolism
126
Type 3 photosensitization
impaired liver function leading to the inability to excrete phylloerythrin (formed from the breakdown of chlorphyll in the GI tract)
127
Photosensitization
long wavelength UV light is absorbed by photodynamic chemicals in the skin leading to the release of energt and production of reactive oxygen species leading to mast cell activation and production of inflammatory mediators and subsequent cellular damage
Regions with non-pigmented skin/hair have erythema and edema leading to blisters, necrosis and sloughing of skin
coagulative necrosis of epidermis and hair follicles
128
First degree burns
burn damage to only the epidermis
129
Second degree burns
burn damage to epidermis and part of dermis
130
Third degree burns
Damage to the epidermis and entire dermis (including adnexal structures)
131
Fourth degree burns
Similar to 3rd degree burns where there is damage to the entire epidermis and dermis but it extends into or beyond the subcutaneous fascia
132
How does chemical injury to the skin differ from allergic contact dermatitis?
It does not require prior sensitization to develop while allergies does (Type IV hypersensitivity)
133
Acral lick dermatitis/ lick granuloma
physical injury to the skin, psychogenic dermatitis due to persistent licking/chewing
usually a single lesion that is hairless +/- ulcerated
134
Superficial necrolytic dermatitis
a ski ncondition where metabolic hepatic dysfunction leads to catabolism of amino acids and hypoaminoacidemia and subsequent epidermal protein depletion.
rarely seen with glucagon producing pancreatic tumors
135
Sterile granuloma/pyogranuloma syndrome
a skin condition mostly seen in dogs where single or multiple firm, erythematous papules or nodules form
need to rule out infectious agents first through negative cultures and respoonse to immunomodulatory therapy
136
Paraneoplastic syndrome impacting the skin
pancreatic or bile duct carcinoma and thymoma associated exfoliative dermatitis
137
Benign tumors
tumors that dont metastasize, dont invade adjacent tissues, well-circumscribed or encapsulated
grow by expansion
composed of well differentiated cells
complete excision curative
138
Malignant tumors
tumors that have the potential for metastasis, are invasive, lack of normal differentiation/anaplasia, usually no capsule
139
Epithelial tumors of skin
Benign: Papilloma and basal cell tumor
Malignant: Squamous cell carcinoma in situ, Squamous cell carcinoma, basal cell carcinoma
140
Squamous papilloma
a benign epithelial tumor that is mostly papillomavirus induced (dogs, cattle, horses, cats)
wart-like exophytic masses that can spontaneously regress
has features of malignancy but is not invaded beyond the basement membrane
can progress to invasive SCC
141
Squamous cell carcinoma
may be solar induced (preceded by actinic keratosis) or some can progress from papillomas
142
Hamartoma
a tumor that is derived from adnexa
mass of disorganized but mature specialized cells or tissue indigenous to the particular site
143
calcinosis circumscripta
focal area of dystrophic calcification forming a tumor like nodule. over tje [ressure points pr at sites of previous trauma
144
Perianal (hepatoid) gland adenoma
benign tumors that are common in intact male dogs. Androgen responsive and usually respond to castration
Cytology reveals clusters of epithelial cells resembling hepatocytes
145
apocrine gland adenocarcinoma (anal gland)
a malignant neoplasm with frequent region metastasis (iliac/sub lumbar lymph nodes)
Some produce PTH related peptide that results in hypercalcemia (humoral hypercalcemia of malignancy)
146
Benign mesenchymal tumors of the skin
fibroma, lipoma, myxoma, neuroma, hemangioma
147
148
What causes equine and feline sarcoids and do they metastasize?
Bovine papillomavirus, no but the do commonly recur
149
Mast cell tumor
the most common cutaneous tumor of dogs and second most common in cats
often red-raised or noduar alopecic mass
can resemble areas of inflammation due to mast cell degranulation and the release of inflammatory mediators
Boxers and boston terriers predisposed breeds
surgical excision with wide margins is recommended
diagnose via using cytology and determining monomorphic population of mast cells and variable numbers of eosinophils
150
Canine cutaneous histiocytoma
common skin tumor of young dogs. often raised alopecic button like tumors. spontaenous resolution is usual
cytology is usually monomorphic population of histiocytes
151
melanocytic tumors
common in dogs and horses where the location of the tumor is important
-haired skin usually benign (melanocytoma)
-mucocutaenous junctions and digits are commonly malignant (melanoma)
Prognosis is based on histiologic appearance (mitotic rate)
all equine tumors are potentially malignant
152
How does feminization of the tract occur?
XX chromosome -> no Sry gene -> no TDF/Testosterone/ AMH. ovaries develop from undifferentiated gonad. fallopian tubes, uterus, cervix develop from mullerian duct ( paramesonephric)
153
How does masculinization of the tract occur?
XY chromosome -> Sry gene -> sex determining region Y on the chromosome leads to testis determining factor (causes bipotential cells of primordial gonad to develop Sertoli cells) Sertoli cells produce AMH which prevents feminization and degrades paramesonephric ducts
Leydig cells produce testosterone and cause development of male tubular and external genitalia
154
Aneuploidy
a rare sex chromosome disorder in domestic species (XXY/XXX= Kelinefelter-like syndrome) seen in Toroishell or calico male cats
or X_ Turner like syndrome
155
Chimera
multiple genotypes in one organism from the merging of two zygotes with different genetics leading to male, female, or intersex.
156
Freemartinism
a sex chromosome disorder in cattle seen in pregnancies of male/female twins where there are anastomoses of blood supply leading to a microchimera
AMH and testosterone suppressed feminization leading to an incomplete/partial development of reproductive structures and absent communication between vagina and uterus
Male is unaffected
157
What is seen in the female twin of freemartinism
depends on the hormonal influence from the male twin. Typically have remnant seminal vesicles, lack a cervix and some degree of ovotestes
92% of the female calves will be infertile
Normal vagina is 13-15cm while a free martin vaginal length is 5-6cm.
158
XX chromosome disorders
ambiguous phenotype with XX genotype, caused by gene expression abnormalities, excess endogenous and exogenous steroids leading to inutero adrenal cortical hyperplasia or steroid producing tumor (fetal or maternal), or idiopathic
Mild: ovarian cyst
Moderate: ovotestes: hormonal disrrangement, freemartinism
Severe: Complete Sex Reversal: SRY like gene on X chromosome- mice, pigs, dogs
159
XY chromosome disorders
XY genotype with aspects of female phenotype. Divided into XY SRY+ and XY SRY-
SRY+: sry gene is present can have relatively nx testicle formation and can have mutation effecting gonadal formation
SRY- SRY gene is not present on Y chromosome and can lead to poorly fpr,ed testicle to full ovary development
160
XY chromosome disorders SRY+
Androgen insensiticity due to loss of receptors (testes present and produce testosterone and anti-mullerian hormone, external genitalia develops with female differentiation
varuable expression of SRT- found in horses can lead to undifferentiated gonads to ovotestes
Cryporchidism
161
Swyer syndrome
an XY SRY- disorder where there is a male karyotupe with complete female phenotype due to deletion of SRY gene from the Y chromosome
162
Hermaphroditism
can fit under any category of sexual disorders but based primarily on gonad development.
163
male pseudohermaphrodite
testicle with female phenotype
164
female pseudohermaphrodite
ovary with male phenotype
165
true hermaphrodite
both gonads present - ovotestis
166
Cystic ovarian disease (follicular cysts)
ovulation fails to occur (no LH surge) but the follicle continues to grow.
167
Luteinized cysts
an anovulatory follicle with theca cells that have undergone luteinization. Forms a thickwalled cells composed of luteal cells and fibrous capsule
168
Sex cord tumors
can be granulosa-theca cell or just thecoma origin.typically unilateral with smooth surface
commonly benign
Produce high levels of T, inhibin, E2, P4, and AMH leading to behavioral changes (masculinization), persistent estrus or anestrus
although benign, can rupture and cause hemoabdoment
associated with pyometra and cystic endometrial hyperplasia
169
Adenocarcinoma
arise from subsurface epithelial structure
grossly can resemble GTCT
170
Avian ovarian carcinomatosis
common in backyard flocks, often difficult to differentiate between ovarian, oviductal, and pancreatic carcinoma
171
Dysgerminoma
neoplasm of the primordial follicles, rare but can be malignant. synonymous with male seminoma
172
Teratoma
a rare benign gonadal tumor that exist rarely in extragonadal sites. Contain components of all 3 germinal layers (endoderm, mesoderm, and ectoderm)
173
oophoritis
inflammation of the ovary
rare in primary inflammation
secondary to asecending infection to pyometra or systemic infection
174
uterine torsion
180 degree rotation of the uterus causing circulatory disruption and is prone to rupture
175
Prolapse
protrusion of the uterus following partition. occurs in cows, ewes, and sow
176
cystic endometrial hyperplasia
a common endometrial disease of the ewe, bitch, and queen
Caused by persistent CL, pregestational compound admin, granulosa cell tumors, follicular cysts, bacteria, or estrogenic plants
Associated with pyometra
estrogen leads to increased progesterone receptors. Increased progesterone during diestrus leads to cystic and hyperplastic endometrial response
177
Hydrometra
accumulation of mucous (mucometra) or serous fliud that is secondary to prolonged progesterone/ CEM/ or obstruction
178
Pyometra
a form of endometritis that commonly present during diestrus and associated with CEH.
Commonly caused by Ecoli
open cervix -> vaginal discharge
closed cervix -> marked uterine distension and potential rupture
179
taylor equigenitalis
the bacterial cause of contagious equine metritis, a highly contagious venereal disease that causes transient infertility
dx: culture or PCR
180
Endometrial adenocarcinoma
common in rabbits, also seen in cattle
due to prolonged estrogen stimulation
neoplasia of the endometrium
181
Leiomyoma/ Leiomyosarcoma
tumor of the uterine smooth muscle
common in female goats and dogs
typically benign
can occur in cervix and vagina as well
common in GSH, paraneoplastic syndrome of polycystic renal adenocarcinoma and inherited autosomal Birt Hogg Dube gene
dx: biopsy
182
Birt Hogg Dube Gene
a gene that when mutated leads to nodular dermal fibrosis and uterine leiomyomas
183
Bovine uterine lymphoma
associated with BLV (bovine leukosis virus) causing lymphosarcoma manifestation in the uterus
184
Pathological vulvar edema
mostly seen in pig and dog
typically caused by mycotoxins (zearalenone) typically found in young gilts, can lead to vaginal prolapse
185
Equine coital exanthema cause
equine herpesvirus 3
186
infectious bovine pustular vulvovaginitis cause
bovine herpes virus 1
187
canine clitoral adenocarcinoma
neoplasia of the apocrine glands within the clitoris
closely resemble anal sac adenocarcinomas (hypercalcemia, often metastasize to regional nodes)
188
Transmissible venereal tumor
contagious round cell neoplasm that is derived from genetically altered histiocytes
presents at the male, female, nose, oral cavity, skin, etc.
cytology: pleomorphic round cells with punctate cytoplasmic vacuoles
189
mastitis
typically caused by bacterial infections (ascending)
-Staphylococcal- gangrene mastitis
-Coliform (E.Coli) - not contagious
-Streptococcal (agalactiae, dysgalactiae)- permanent
, fibrosis
-Mycoplasma bovis- sudden agalactia, rapid spread of infection
190
Causes of viral mastitis
Maedi-visna virus (ovine progressive pneumonia) affects both mammae, predominantly histiocytic and lymphocytic interstitial inflammation
Caprine arthritis- encephalitis virus- hard bag
191
Cryptorchidism
most common disorder of sexual development in males
more often unilateral than bilateral
will remain small even after puberty
leads to increased risk of testicular neoplasms
Sertolo?Seminoma> Leydig
192
Testicular Hypoplasia
defect in spermatogenesis prior to or at the time of puberty
secondary to other diseases or as a primary disease
193
Testicular Degeneration
defect in spermatogenesis after puberty
numerous causes can be unilateral or bilateral
acute: soft and flabby
chronicL small and firm
194
orchitis
inflammation of the testicles
commonly caused by Brucella and Tuberculous
195
epididymitis
inflammation of the epididymis
way more common that orchitis
commonly caused by bacteria. almost all ascending except for Brucella
196
Sperm granuloma
inflammatory response to germ cells escaping immune priviledged seminiferous tubules/ epidymitis
197
Leydig cell tumor
common in dog, bulls, and cats
yellowish in color, well demarcated
firm to semi-firm
often cystic +/- hemorrhagic
most do not produce testosterone
almost always benign
198
Sertoli cell tumor
common in dogs, firm and fibrous
does not bugle on cut section
pale tan to white
1/3 cause gynecomastia (through estrogen and inhibin release)
199
Gynecomastia
production of estrogens and inhibins in sertoli cell tumors lead to this condition
200
Sertoli cell tumor pathogenesis
estrogens lead to alopecia, gynecomastia, prostatic hyperplasia (+/- squamous metaplasia)
inhibins lead to decreased testosterone and atrophy to contralateral testicle
201
Seminoma
most common testicular neoplasm in the horse and common in the dog
soft, pale tan to pinl +/- hemorrhage
bugles on cut surface
Rare reports of metastasis
202
varicocele
an enlargement of the veins within the loose bag of skin that holds the testicles
203
Canine prostatic hyperplasia
caused by a hormonal imbalance leading to squamous metaplasia of the prostate gland
vary from cystic to solid
Can be seen with dogs with Sertoli cell via estrogen stimulation
causes tenesmus and sometimes stranguria
204
Prostatitis
benign prostatic hyperplasia can predispose animals to this condition
often caused by infectious agents ascending from the urinary tract (E coli, Proteus vulgaris, streptoccim and staphylococci
vary from abscess formation to diffuse inflammation
Brucella can commonly be isolated
204
Canine prostatic carcinoma
the only prostatic neoplasm of importance in domestic animal
not hormonally induced- castration is not protective
typically in dogs over 10
prognosis is poor (80% presenting patients already have mets)
Difficult to differentiate from urothelial carcinomas (which are far more common)
204
Penile trauma
rupture of the erectile tissue, typically due to incorrect deviation during breeding
can be life threatening
can fracture os penis
205
Persistent frenulum
band of tissue between the ventral raphe or the penis and prepuce
most important in boar and bull
minor anatomic abnormality- can impede breeding
occurs between the penis and prepuce or from glans penis to base of penis
205
Penile Priapism
prolonged erection lasting more than 4 hours
will become traumatized, dry, and undergo necrosis
205
Penile Paraphimosis
inability to retract the penis
most common in the stallion
usually secondary due to trauma, infection of neoplasms
206
Balanitis
inflammation of the glans penis
207
Posthitis
inflammation of the prepuce
208
Balanoposthitis
inflammation of both the prepuce and glans penis
most common in castrated animals
209
Herpesviral balanoposthitis
Inflammation of both the prepuce and glans penis
Caused by:
Equine herpesvirus 3 (stallions)
Bovine herpesvirus 1
Canine herpesvirus 1
short clinical course, ulcerative to resolution
necrosis
210
Enzootic Posthitis/balanoposthitis
Sheath rot, pizzle rot
caused by corynebacterium renale
disease of the ram
caused by increased protein diet leading to increased urinary urea which is hydrolyzed by urea and ammonia production causing local irritation and injury via ammonia
211
Habronemiasis
"Summer sores" caused by parastic larvae being depositied via flies resulting in granulmatous lesions
Appear like squamous cell carcinoma
common around the face, eyes, and penis
212
Fibropapillomas
caused bovine papilloma virus , occur in young animals, leading to penile neoplasia and multiple warty masses with ulcerations
issues with warty masses with ulcerations
213
Penile squamous cell carcinoma
penile neoplasia, common in geldings and stallions
associated with equine papillomavirus 2
more commonly on nonpigmented skin
dx: habronema, equine sarcoid, exuberant granulation tissue
214
early embryonic death
occurs several days after conception leading to fetal resorption
caused by genetic defects, maternal stress, endocrine deficits, and infectious diseases
215
Abortion
expulsion of the fetus prior to the time of expected viability leading to a fetus with autlysis, fetus with no autolysis, mummification, and maceration
216
Mummification
fetus is retained and dehydrates, bacteria must be absent
common in multiparous species
217
Maceration
liquefied fetus due to bacterial infection
fetal emphysema (Clostridium species)
218
Stillbirth
fetus is delivered at or near term and is potentially viable
219
How do you investigate abortions?
-Maternal serum
-Uterine samples
-Placenta
-Fetus
220
Using maternal serum for abortion investigation
Ideally collected before breeding, pregnancy diagnosis, and at abortion of the aborting dam and its herd mates
collect acute and convalescent samples 2-3 weeks apart- may show declining titers
221
Using uterine samples for abortion investigation
taking uterine tissue when the placenta is not available, submit for histopathology, bacteriology, virology, PCR
222
Using placenta samples for abortion investigation
collect fresh whole or partial placenta
collected directly from the dam (unrealistic), lesions may only be present in the placenta as regional distribution is common
223
Using the fetus for abortion investigation
perfom a complete necropsy, maximize sample collection, external examination, crown to rump length for approximate fetal age
Collect lung, liver, thymus, spleen, GI contents and more
Histopath, bacteriology, virology, molecular assays, toxicology
224
What does it mean if you detect multiple microorganisms upon abortion investigation
consistent with sample contamination or postmortem overgrowth
225
What does it mean if you see lesions suggesting a specific etiology but ancillary tests are consistent?
there is likely improper handling of samples or destruction of microorganism due to autolysis
226
What does it mean if there are no lesions, no pathogens in a single case or abortion
sporadic abortion is likely on an unknown cause (genetic or metabolic)
227
What are the bacterial causes of abortion?
Brucella
Chlamydia
Leptospira
Listeria monoctogenes
Campylobacter spp
Coxiella burnetti
228
Brucella spp
Gram negative, facultative intracellular bacilli that causes late term abortions in cattle, goats, pigs, and dogs
B. abortus in bison and elk from Great Yellowstone area
Zoonotic (except B.ovis)
placenta is often retained
Placenta and fetal lesions, placenta is often retained
cotyledonary and intercotyledonary necrosis in goats and bison
229
What lesions are seen with Brucellosis abortions
-Cotyledonary and intercotyledonary necrosis
-Microscopic lesions: Intracellular trophoblast bacteria and fetal bronchopneumonia
230
Leptospira spp
a gram negative spirochete that can cause late term abortions in cattle, horses, and pigs
Zoonotic, survives for months in the moist environment
also see hepatic degeneration
231
Chlamydia spp
a gram negative, obligate intracellular bacteria that causes abortion, stillbirths, and weak offsprings in cattle, sheep, and goats.
early infection leads to late term abortion while late infection leads to abortion in the next pregnancy
Zoonotic
see necrotizing placentitis
232
What placental lesions will you see in a sheep with chlamydiosis abortion?
necrotizing placentitis
233
Listeria monocytogenes
a gram positive, intracellular bacilli that causes late term anoirtions in cattle, sheep, and goats
Zoonotic
causes encephalitis in adult animals
lesion: multifocal necrotizing hepatitis
234
Coxiella burnetii
gram negative, intracellular bacteria that causes late term abortion and weak offspring
More common in goats but also occurs in sheep
Zoonotic, causing Q fever
causes intercotyledonary necrosis and placentitis
235
Campylobacter spp.
gram negative rods that can cause abortion at any stage of pregnancy in sheep and cattle
zoonotic
lesions: cotyledonary necrosis and necrotizing hepatitis
236
What agent causes target lesions on the liver
Camplyobacter- necrotizing hepatitis
237
Porcine Reproductive and Respiratory Syndrome (PRRS)
an arterivirus (RNA) that causes late term abortion (mummification), stillbirths, and weak piglets in swine, often no lesions or variable growth lesions
238
Porcine Circovirus-2
an ubiquitous DNA virus that causes late term abortion (mummification), stillbirths, and weak piglets, varying C-R lengeths in swine
Early to mid-gestation infection causes myocarditis and cardiomegaly
Late gestations infection= antigen detectable in lymphoid tissues
239
Porcine Parvovirus
an ubiquitous DNA virus that causes late term abortions (mummification), stillbirths, and weak piglets in swine
Infection:
<30days= embryonic death
30-70 days = mummification
>70 days = no lesions
240
Bovine viral diarrhea virus (BVDV)
a pestivirus with CP and NCP biotypes that causes abortion in cattle via cerebellar hypoplasia, hydranencephaly, brachygnathia, and pulmonary hypoplasia
infection
50-100 days: fetal death, abortion, mummification
100-150 days: term calf with malformation
2-4 months: PI calf (if fetus survives)
>4months: transient infection
241
Bovine herpes virus-1
a viral cause of abortions leading to abortion stores in naive cattle during the second half of gestation
Fetus and placenta are often autolyzed but microscopic lesions are often presented
viral inclusion boddies in adrenal gland and liver
242
Equine herpesvirus-1 (EHV-1)
a viral cause of mid to late gestation abortions in horses. occur in solated events and outbreaks
fetus and placenta are fresh, no placental lesions but hydrothorax, axcires, and multifocal hepatic necrosis, fibrin plug in trachea lumen, and bronchiolar epithelium with synytial cells and intranuclear inclusions are seen
243
Equine viral arteritis
an arterivirus that causes late term abortions and outbreaks in horses, placenta and fetus are fresh and have no lesions
244
Canine herpesvirus-1
a virus that causes abortion and neonatal death in dogs
puppies up to three weeks are at higher risk of infection and death
see renal hemorrhages in puppies
245
What are the causative agents of mycotic abortions?
aspergillus fumigatus and zygomycetes
246
Mycotic abortion
spradic abortions caused by aspergillus fumigatus and zygomycetes in cattle and mares.
Mares- ascending infection
Cattle- hematogenous spread
leads to Severe necrotizing placentitis (cupping)
Fetal lesions- hyperkeratosis, no internal lesions
microscopically see fungi and hyperkeratosis
247
What are the causative agents of protozoal abortions?
Neospora caninum, toxoplasma gondii, tritrichomonas foetus
248
Neospora caninum
a protozoal causative agent of midterm abortion, stillbirths, and weak calves, oocytst seen in canine feces
Cattle>sheep and goats
Lesions- necrotizing myocarditis on bovine fetus
Suppurative myositis, necrotizing encephalitis
249
Toxoplasma gondii
a protozoal causative agent of abortion (any stage of gestation) leading to mummified/reabsorbed fetus early in infection or born live in late gestation
environment contaminated with cat feces
sheep and goats (naive)
cotyledonary necrosis placentitis
250
Tritrichomonas foetus
a protozoal agent that causes abortion in the first half of pregnancy in cattle.
Pyometra is consistent finding in cows/heifers
Recurrent nature
No specific gross or histological lesions, presence of organisms in fetal fluid
Cotyledonary hemorrhages in the placenta
251
