Oral cavity
Oral cavity
Inflammation of the oral cavity:
May be :
(A)diffuse inflammation in oral cavity -----> stomatitis
(B)localized predominantly in certain regions to produce :
If the pharynx is involved ------> pharyngitis
If the tongue is involved ------>glossitis
If the gum is involved ------->gingivitis
If the tonsils are involved------>tonsillitis
If the soft palate is involved---->angina
Stomatitis
Causes:
1-physical:
a)Trauma by awns , thons , wood or glas pieces , irregular sharp teeth or sharp edged feeding utensils .
b)Hot drenches or eating frozen foods.
c)Electric burns ( in puppies and kittens through chewing electric wires )
2-chemical:
causitic alkaline or corrosive acids.
3-hypovitaminosis A or niacin deficiency .
4-micro-organisms :
-Bacteria ---- as Actinomyces bovis , Actinomyces lignieresi , spherophorus , necrophorus , pseudomonas aeruginosa , corynbacterim byogenes , streptococci and staphelococci.
-Fungi --- as monilia albicans.
-Viruses --- as virus causing foot and mouth disease , cattle plague , vesicular stomatitis , vesicular exanthema , virus diarrhea mucosal disease , sheep pox and blue tongue .
Stomatitis can be divided into :
1-Superficial stomatitis :
lesions imited to the mucosa of the oral cavity and include :
1)catarrhal stomatitis
2)vesicular stomatits
3)erosive and ulcerative stomatitis
2-Deep stomatitis :
processes seated in the connective tissue of the mouth and include :
1)purulant stomatitis
2)gangrenous stomatitis
3)necrotic stomatitis
1-Superficial stomatitis
1-cattarhal stomatitis :
Definition : common non specific lesion usually usually involves the oral mucosa .
Gross apperance :
- The mucosa is hypermic and oedematous .
-The mucosal surface undergoes rapid degeneration and desquamination and becomes dull gray in color .
-There is excessive mucous production by the palatine gland .
-Edem and hyperplasia of the lemphoid tissues of the soft palate and tonsils .
2-vesicular stomatitis :
Definition : stomatitis is characterized by the formation of vesicles occurs in most species of domestic animals .
Causes :
1-viral infections such as foot and mouth disease.
2-irritant chemicals in feed or bedding .
-the vesicules develop as accumulations of serous fluid within the epithelium or between epithelium and lamina propria .
-these may coalesce to form bullae and the elevated epithelium is easily rubbed off during chewing to leave raw eroded patches with bits of epithelium adherent.
3-erosive and ulcerative stomatitis :
Definition :stomatitis is characterized by local epithelial defects of the oral mucosa and naso-labium and is usually associated with acute diffuse stomatitis and pharyngitis .
Causes :
viral infections , rinderpest , bovine viral diarrhea and malignant catarrhal fever .
erosions :
- circumscribed areas of loss epithelium which leave the stratum germinativum and basement membrane more or less intact .
-they are usually associated with acute inflammation in the underlying propria .
-the erosions vary in size and shape .
-they heal cleanly and quickly, but if secondarily infected or complicated , may develop into ulcer.
ulcer :
-in contrast to erosions , ulcers are deeper defects that extend into the substantia propria .
-vary greatly in size and shape.
-the edges tend to be elevated and ragged , it heals by scar formation .
2-Deep stomatitis
1-purulant stomatitis:
causes:
-entry of the pyogenic bacteria into the connective tissue of the submucosa and muscle through lesions of the oral mucosa result in the development of purulant inflammation or cellulites in the lips , tongue , cheek , soft palate and pharynx.
NB abscess may form and may fistulate through mucosa and the skin .
2-gangrenous stomatitis :
causes:
-entry putrefactive micro-organisms into lesions of deep stomatitis , especially purulant stomatitis.
gross lesions :
-intensely fetid , grayish green , dirty necrotic masses containing gas bubbles and surrounded by zone of acute inflammation.
-the necrotic tissue may slough to leave deep ulcer.
Noma
-it is rapid pseudo-membranous or gangrenous stomatitis .
-it is not caused by specific pathogen but is associated with tissue invasion by the normal oral flora .
-mucosal trauma and debility are probable predisposing factors.
- the disease occasionally observed in horse and dog .
3-necrotic stomatitis :
causes:
-thermal or chemical agents .
-fusibacterium necrophrum and other anaerobes.
examples :
1-calf diphtheria
-it is a form of necrobacillary stomatitis characterized by acute necrotizing ulcerative inflammations of the buccal and pharyngeal mucosa.
-fusibacterium necrophorum is the primary cause of calf diphtheria .
-the organism is usually a secondary invade following previous mucoal damage, once established in a suitable focus , it proliferates and produce variety of exotoxin and endotoxins leads to coagulative necrosis.
2-actinobacillosis
-it is is a deep stomatitis caused in cattle by actinobacillus ligneresi.
-it enters through initially traumatized mucosa , when introduced into the mucosa , it causes pyogranulomatous inflammatory foci else where in the soft tissue of the mouth.
Sequlae of the stomatitis
1-starvation as prehension and mastication are prevented.
2-spread infection to other parts such as esophagus ,lung and stomach.
Tonsils
The most common affections of the tonsils :
1-foriegn bodies
such as small particles of food grains or small stones may cause inflammation and pressure atrophy.
2-enlargment of tonsils
may be due to :
1-hyperplasia.
2-tumors.
3-inflammatory swelling.
3-tonsillar plugs
are whitish ,pus like deposits in the crypts consisting of desquamated epithelium , bacteria , necrotic debris and neutrophils. they develop as results into inflamattory process.
4-tonsillar calculi
are formed arround forien bodies in the crypts from inspissated secretions , desquamated epithelium , leucocytes and calcium salts.
5-tonsillitis
inflammation of the tonsils may occur independently(primary) or associating many infectious diseases (strangles of horse , distemper , viral hepatitis and interstitial nephritis of dog .
tonsilitis may be
a) superficial tonsilitis :
which may be acute catarrhal or purulant catarrhal
b)deep tonsilitis :
this may be ulcerative ,phelegmonous with formation of follicular abscess or gangrenous (canine distemper )
Salivary glands
The salivary glands of animals (parotid , mandibular , sub lingual ) are rarly affected because of thrie well protected situations and the antibacterial properties of saliva they may participate in infectious inflammatory processes arising in their vicinity.
the most common affections of salivary:
1-ptyalism
abnormal accumulation of saliva in the mouth .
causes:
a) heavy metal poisoning.
b)poisoning with organophosphates.
c)encephalitis.
d)stomatitis .
2-Aptyalism
reduced or ceased secretion of saliva .
causes :
1-fever
2-dehydration
3-salivary gland disease
3-foreign bodies
-occasionally present in the ducts , usually the parotid duct , but sometimes submaxillary.
-they are usually plant awns or fiber .
-they invariably cause some degree of inflammations and possibly
dilatation and obstruction of the duct .
4-salivary calculi (sialolith)
-they usually formed in a duct or in the gland itself .
-may cause obstruction and inflammation .
-they are more common in horses than other species .
-calculi are composed largely of calcium carbonate , and are white , hard and laminated .they are usually single and cylindrical and they may be quite large .
-they are thought to originate from microliths , which are formed routinely and undergo regular turnover .
-secretory inactivity can cause microliths to accumulate more material, leading to calculi that may be obstructive .
-most of them lodge at the orifice and cause some degree of salivary retention , glandular atrophy ,and predisposition to infection and further inflammation .
5-dilation of the duct
-occur due to stagnation of flow , and this in turn results from obstruction due to congenital atresia or by foreign bodies , calculi and inflammatory strictures .
-the dilated duct appear as flactuating cords , sometimes with local diverticula.
6-ranula
-cystic distention of the duct in the floor of the mouth .
-rupture of a duct or a gland to epithelial surface result in permanent fistula .
-the content may be serous or thick tenacious mucous .
7-salivary mucocele or sialocele
- accumulation of secretion os salivary gland in single or multiloculated cavities in the soft tissue of the mouth or the neck .
-these cystic formations not have epithelial lining .
-sialocele can occur in any breed of dogs , where they become large enough to require surgery .
-there may be history of an accident ranula like swelling in the mouth .
-many sialocele are probably the result of trauma to duct .
8-sialodenitis
-it is inflammation of salivary gland .
-uncommon in animals , but it is after sialocele and malignant neoplasms , the most frequently diagnosed lesion involving salivary gland of dog and cats .
-the submandibular gland is usually affected .
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