Diseases of oral cavity and mucosa, animals

1. Diseases of buccal cavity &
Mucosa
Ishtiaq ahmed

2.  Feed in mouth of cadaver is abnormal except Ruminants
 In horses indicate encephalitis, leukoencephalo- malacia,
hepatic encephalopathy.
 Feed poorly masticated
 Bones indicate pica
 Foreign body stomatitis in dog occur due to plant fibers,
burrs or quills, especially in long hair breeds
 Sharp foreign bodies induce laceration, necrotic deep
stomatitis
Foreign bodies

4.  Pharyngitis
 Glossitis
 Gingivitis
 Tonsillitis
 Superficial (only mucosa involved) or deep
(connective tissue involved)

5.  Paraquat, erosive stomatitis, dogs
 Dieffenbachia Plant
 Actinomyces, Fusobacterium, and spirochetes normal flora
 Oral mucosa resistant to infection because
 Squamous mucosa
 Antimicrobial salivary contents e.g. lysozyme
 Immunoglobulins e.g. IgA
 Rich submucosal vascular network
 Inflammatory cells
Superficial stomatitis

6.  Usually involve caudal fauces, gingivitis
 often develops in the course of debilitating diseases.
 Hyperemia, edema, lymphoid tissue proliferation
 Thrus/oral candidiasis occur in dog, foals,pigs
 Patchy pale-gray pseudomembranous material on oral
mucosa and back of tongue
 Stachybotrys alternans causes catarrhal & necrotic
stomatis
Catarrhal stomatitis

7.  Vesicles, bullae, erosion
 Virus e.g. FMD virus,
 Rinderpest, BVD, MCF produce erosive/ulcerative lesions
 Bullous immune skin diseases do have oral lesions e.g
pemphigus vulgaris (desmoglein 3, suprabasilar acantholysis,
clefts,bullae)
 Bullous pemphigoid; Subepidermal blistering/cleft; IgG, IgE
against basement membrane antigens
 Mucous membrane pemphigoid most common.
 Collagen XVII or laminin-5, and basement membrane-
 fixed immunoglobulin
Vesicular stomatitides

13.  Feline calicivirus
 Erosive and ulcerative stomatitides
 Phenylbutazone intoxication in horses may cause oral
ulcers
 Feline ulcerative stomatitis and glossitis; cause unknown
 Feline plasma cell gingivitis-pharyngitis: Raised
erythematous, proliferative lesions, plasma cell infiltration,
elevated polyclonal serum gamma-globulin level

14.  Oral eosinophilic granuloma, dog, young Siberian
Huskies.
 Ulcerated raised plaques, yellow exudate, on lateral
or ventral surface of tongue
 Microscopically foci of collagenolysis, histiocytic
granulomatous infiltration, giant cells, eosinophils.
 Feline rhinotracheitis and uremia (dirty gray
brown)also induce ulcerative stomatitis

17. Oral necr0bacill0sis
Deep stomatitides

18.  Fusobacterium necrophorum
 Necrotizing lesions in upper, lower alimentary tract &
liver as well
 Occurs as a secondary invader
 Endotoxins: leukocidins, hemolysins, and a
cytoplasmic toxin
 Coagulative necrosis

19.  Calf diphtheria: Necrotizing, ulcerative inflammation
of oral cavity, pharynx and necrotizing laryngitis
 Trauma, infectious bovine rhinotracheitis, and papular
stomatitis are predisposing factors
 Fatal in youngs, localized in adults
 Early lesions:Large, well-demarcated, yellow-gray, dry
areas of necrosis, surrounded by a zone of hyperemia.

21.  Necrotic tissue slightly raised, friable, adherent
 Histologically: Necrotic tissue surrounded by vascular
reaction, thin rim of leucocytes & encapsulating
granulation tissue
 Bacteria arranged in long filaments at leading edge of
lesion
 Aspiration penumonia (due to spread from oral foci),
septicemia, pituitary and cerebral abscessation

22.  Fusobacterium necrophorum : Another syndrome in
calves with necrotic stomatitis, enteritis, and
granulocytopenia
 Nonregenerative anemia, leukopenia, neutropenia,
hypoproteinemia, and increased fibrinogen levels
 Along with characteristic oral lesions marked
depletion of lymphoid tissues and necrotic enteritis.

23.  Rapidly spreading Pseudomembranous/gangerenous
stomatitis
 Normal flora e.g. fusobacteria and spirochetes
 Predisposing: Mucosal trauma, debility
 Small tattered ulcer of the cheek or gum, spread
rapidly
 Intensely fetid, necrotic area surrounded by acute
inflammatory cells
Noma

24.  Cattle, sheep, and pigs
 Stomatitis, glossitis, lymphadenitis, sometimes
pyogranulomas in the wall of the forestomachs
 Actinobacillus lignieresi
 Pyogranulomatous inflammatory loci centered on
club colonies containing gram-negative coccobacilli.
 Arcanobacterium pyogenes, Actinomyces bovis,
Staphylococci, Nocardia may also cause
pyogranulomas.
Actinobacillosis

25.  Typically a disease of soft tissue, spreading as a
lymphangitis, lymph nodes
 wooden tongue
 Grossly: Individual inflammatory focus appear as a
nodular, firm, pale, fibrous mass a few millimeters to 1
cm in diameter, containing in the center minute
yellow "sulfur" granules, which are the club colonies.

28.  Microscopically: Pyogranuloma, centered on a mass
of coccobacilli, surrounded by radiating eosinophilic
clubs made up of immune complexes.
 Club colonies surrounded by neutrophils,
macrophages, giant cells
 Lymphocytes, plasmacytes in surrounding fibrous
reactive stroma

29.  Dermatophilus congolensis
 Exudative dermatitis in many spp but in cat oral
granulomas
 Tongue and tonsillar crypt
 DDX: SCC
Oral dermatophitosis of cats

30.  Sarcosporidiosis
 Cysticercosis
 Trichinella spiralis
 Gongylonema spp
 Gasterophilus spp. in the horse
 Oestrus ovis in sheep
 Halicephalobus gingivalis
Parasitic diseases of the oral cavity

31.  Prominent and protrude slightly from the tonsillar
fossa in the dog and cat.
 In horses tonsillar tissues are dispersed over
pharyngeal and epiglottic mucosal surfaces
 Immune surveillance in the oropharynx
 Tonsillitis may occur include pasteurellosis in sheep
and pigs, Actinomyces and Tonsillophilus in tonsils of
swine, and necrobacillosis in all species
Diseases of the tonsils

32.  Scrapie-associated prion protein in the center of
primary and secondary lymphoid follicles
 Primary replication site for Pseudorabies (Aujeszky's
disease)
 Involution of B-dependent tonsillar lymphoid follicles
due to viral lymphocytolysis in many viral infections
e.g. feline panleukopenia, canine parvoviral enteritis,
CD, BVD, RP virus,

34.  Epulis is a generic clinical term for tumor-like masses on
the gingiva
 Pyogenic granuloma: Bright red or blue mass on the
gums of dogs
 Extremely vascular granulation tissue covered by
gingival epithelium
 Exaggerated response to local irritation and infection
Reactive and hyperplastic lesions

35.  Peripheral giant cell granuloma; Gingival masses
dogs and cats
 Red, smooth, sessile,or pedunculated
 Gingival epithelium is hyperplastic or ulcerated, extends deeply
into the underlying mass
 Fibrous hyperplasia: Generalized and diffuse, or focal, localized
to one or more teeth
 Mature fibrous tissue with low cellular density, foci of hard
tissue and epithelial nests may be present
 Plasma cells band in the gingival stroma adjacent to epithelium

37.  Benign epithelial tumors ("warts") in dogs, cats, and cattle
 Papillomaviruses
 The virus is host- and fairly site-specific
 Infection of basal epithelium of the squamous mucosa,
mitosis
 viral genome replicates in the differentiating keratinocytes
of the stratum spinosum and granulosum, viral assembly
and expression in superficial squamous layers
Oral papillomatosis

40.  Incubation period 2 months
 Multiple, proliferative cauliflower like,firm, white to
gray growths
 Microscopically: Lesions is typically verrucous,
 Thick keratinizing squamous epithelium covering
thin, branching, often pedunculated cores of
vascularized proprial papillae.
 Basophilic intranuclear viral inclusions may be found in
cells in the outer spinose layers

42.  Ameloblastoma is a slowly progressive invasive but
nonmetastatic tumor, consisting of proliferating
odontogenic epithelium in a fibrous stroma
 Amyloid-producing odontogenic tumors: characterized by
dental epithelium, with deposits of amyloid
 Acanthomatous ameloblastoma:Tumor arising from the
mucosal epithelium or epithelial rests of the
gingiva of dogs
 gray-pink papillary to sessile gingival masses,
Tumors of dental tissue

43.  Histologically: Sheets, nodules, and anastomosing
cords of polyhedral epithelium bordered by a row of
cuboidal to columnar cells with round to oval nuclei
and moderate amounts of cytoplasm

44.  Feline inductive odontogenic tumor: Osteolytic
masses in the rostral maxilla, causing tooth loss or
facial distortion
 Complex and compound odontomas
 Fibromatous epulis of periodontal ligament origin;
Peripheral odontogenic neoplasm
 Indistinguishable clinically from fibrous hyperplasia,
 Most common in dogs, stromal tumor with interwoven
bundles of cellular fibroblastic tissue.

46.  Most common oral malignancy in cats
 Occur on the ventral surface of the tongue and
gingiva
 Locally invasive, especially into bone and local soft
tissues
 Grossly: Irregular, slightly nodular, red-gray, friable
masses, often with an ulcerated surface that bleeds
easily
 In dog, occur in tonsils
Squamous cell carcinomas

48.  Most common oral tumors in dogs
 Malignant, spread to regional lymph nodes
 Arise from melanocytes in the mucosa or superficial
stroma, mainly on the gingiva and labia
 Histologically: Melanomas varies greatly, from a fairly
well differentiated heavily pigmented type, to a highly
anaplastic amelanotic type
 Anaplastic cells show junctional activity
Melanomas

50.  Round or polyhedral cells with a large nucleus and
extensive cytoplasm with well-demarcated borders
 Some have spindle shaped cells with oval nuclei
containing small nucleoli
 Most frequently there is a characteristic mixture of
epithelial-like and spindle-shaped cells, which have a
marked tendency to form nests
 DOPA-positive, vimentin 100%, melan A >90%