Alimentary System - Oral Cavity Flashcards
What are the predominant type of disease of the alimentary system in dogs/cats, ruminants/pigs, and horses?
DOGS/CATS = neoplasia
RUMINANTS/PIGS = infectious diseases poorly controlled by vaccination
HORSES = intestinal displacements - colic
What is the normal morphology of the GI mucosa? What are considered a window into the health of the alimentary system?
smooth and shiny
- feces
- regurgitation
- vomit
What are the 4 main portals of entry of pathogenic agents into the alimentary system?
- ingestion**
- coughed up by lungs and swallowed (Rhodococcus equi pyogranulomatous lesions)
- systemic hematogenous route
- migration through the body (parasites)
What are 9 defence mechanisms in the alimentary system?
- saliva (lubrication, interferes with andhereance, immunoglobulins)
- resident flora and fauna (competes with pathogenic agents)
- gastric pH
- secreted immunoglobulins
- vomiting
- intestinal proteolytic enzymes
- phagocytes and other effector cells in mucosa/submucosa
- high epithelial turnover
- increased peristalsis resulting in diarrhea
What are other names for cleft palate and cleft lip? In what animals are they most common?
CLEFT PALATE = palatoschisis
CLEFT LIP = “hare lip”, cheiloschisis
calves
What are 3 common causes of cleft palate and cleft lip?
- genetic disorder
- toxins - Veratum californicum, lupines, poison hemlock
- maternal exposure to drugs during pregnancy - griseofulvin antifungal in queens and mares; steroids in primates
What is characteristic of palatoschisis? How do these animals typically die?
central defect in the midline fusion of the palatine shelves resulting in communication between oral and nasal cavities
aspiration pneumonia - unable to create negative pressure and cannot suckle correctly
Cheiloschisis, calf:
harelip, cleft lip
can be in combination with palatoschisis
What is this?
cheiloschisis - harelip, cleft lip
What are malocclusions? What do they typically result in?
failure of the upper and lower incisors to interdigitate properly
difficulties in the prehension and mastication of food - inappetance, lose weight
What is this?
brachygnathia - short lower jaw
What is this?
prognathia - protrusion of lower jaw
Oral cavity anatomy:
What is dental attrition?
loss of tooth structure caused by mastication - can be normal due to age and wear and tear or based on diet
What does the degree of dental attrition typically rely on? What is dental attrition commonly caused by in domestic animals? Herbivores?
the tooth, animal species, and type of food
DOMESTIC ANIMALS = age-associated wear and tear
HERBIVORES = abnormal wearing (step mouth)
What is the most common cause of periodontal disease?
resident bacterial films and acid/enzymes they produce lead to enamel, gingival, and periodontal ligament damage
What is dental plaque? Dental calculus?
(tartar) - clusters of bacteria attached to teeth
mineralized dental tartar/plaque
Healthy tooth vs. periodontal disease:
bacteria within gingival crevice can lead to subgingival periodontal disease at the root level
Primary diseases of the tongue is rare. What is a common exception?
actinobacillosis from Actinobacillus lignieresii causes chronic stomatitis and “wooden tongue” primarily in catttle and occasionally in swine and sheep
What are common signs of wooden tongue?
- trouble masticating
- inappetance —> lose weight
- salivation
- inflammed tongue hangin out of mouth
How can wooden tongue (Actinobacillosis) be differentiated from lumpy jaw (Actinomycosis)?
actinobacillosis rarely involves bone, typically presents as areas of focal ulceration and chronic pyelogranulomatous glossitis/stomatitis
actinobacillosis = soft tissue
What is the characteristic histological presentation of wooden tongue (actinobacillosis)?
large clusters of Gram-negative rods (A. lignieresii) in a pyelogranuloma surrounded by radiating clubs of amorphous eosinophilic material (immune complexes)
- Splendore-Hoeppli phenomenon
What is thrush? What causes it?
mycotic infection involving the stratified squamous epithelium of the oral cavity and upper GI tract (including the forestomach of ruminants)
Candidiasis - Candida spp. (albicans)
In what 2 animals is thrush (Candidiasis) most commonly seen?
- those treated with antibiotics for long periods of time
- those with underlying debilitating diseases
What are the 3 most common systemic diseases that lingual lesions are manifestations of?
- renal disease (uremic glossitis) - ventral and at margins*
- BVD
- FMD
What are the 5 common etiologies of stomatitis?
- infectious agents
- trauma
- chemical injury
- autoimmune
- idiopathic
What are the 4 most common causes of lymphoplasmacytic gingivitis and stomatitis in cats?
- FeLV
- FIV
- feline calicivirus
- immune-mediated response to the bacteria within dental plaques/tartar
What are the 4 clinical signs of feline chronic gingivo-stomatitis (FCGS)? What are 3 possible etiologies?
- oral pain
- dysphagia
- ptyalism - overproduction of saliva
- weight loss
- immune-mediated response to dental plaue
- FCV
- FIV
What animals most commonly present with chronic ulcerative (lymphoplasmacytic) paradental stomatitis?
older dogs - due to the presence of dental plaque
What is a vesicle? What are they called when they form large lesions?
raised lesion up to 1 cm filled with clear (serous) fluid located within the epithelium or between the epithelium and lamina propria
bulla
What needs to be ruled out if vesicles are observed in dogs/cats and food/large animals?
DOGS/CATS - immune-mediated diseases, like bullous pemphigoid and pemphigus vulgaris, and calicivirus (cats)
FOOD/LARGE ANIMALS - major viral diseases that are usually not fatal but result in huge economic loss
What are the 5 steps to the pathogenesis of viral vesicular stomatitides?
- viral-induced epithelial damage
- intracellular edema in keratinocytes causing ballooning degeneration
- vesicle formation
- bulla formation
- rupture leads to erosion and ulceration
Viral vesicular stomatitis, histology:
keratinocytes filled with fluid and undergoing ballooning degeneration
Vesicular stomatitis, cat:
calicivirus infection - typically upper respiratory infection in kittens, but can lead to glossitis with severe infection
What are the 4 most common causes of viral stomatitis in farm animals? What animals are susceptible?
- foot and mouth disease (Picornavirus) - ruminants, pigs (cloven-hoofed animals), NO HORSES
- vesicular stomatitis (Rhabdovirus) - ruminants, pigs, horses
- vesicular exanthema (Calicivirus) - pigs
- swine vesicular disease (Enterovirus) - pigs
**all are reportable disease that must be reported to state and federal authorities
What is foot and mouth disease? What are 3 clinical signs?
exotic (foreign) animal disease that is highly contagious with high morbidity and low mortality involving vesicular formation and eruption on the tongue and coronary bands of cloven-hooved animals (NO HORSES)
- drooling saliva (ptyalism)
- lameness
- inappetance
What are the 5 steps to the pathogenesis of foot and mouth disease?
- virus ingestion/inhalation
- infection of pharynx
- viremia
- oral mucosa and epidermal infection
- lesions develop in areas sunjected to mechanical injury
Foot and mouth disease:
- focal ulceration
- partially ruptured vesicle
- ulcer
Foot and mouth disease, mouth and hoof:
What other system is foot and mouth disease also known to affect? What is the characteristic presentation?
a malignant form of the disease lacks vesiculation and occurs in young animals (calves, pigs) and is characterized by myocardial infarction
tiger heart - multiple stripes represent areas of inflammation and necrosis
How does foot and mouth disease typically affect the hooves? Why?
causing sloughing around the interdigital space and coronary bands
this area is more susceptible to mechanical injury
What causes vesicular exanthema? How does it develop? What kind of animals are affected?
Calicivirus
vesicle —> rupture —-> ulceration and possible secondary infection
pigs only
What are the 2 most common causes of erosive-ulcerative stomatitides?
- BVD
- MCF
How does the presentation of animals with BVD and MCF compare?
BVD - multifocal erosion (only partial thickness loss of epithelium)
MCF - multifocal ulceration caused by vasculitis (more severe)
What is the most common etiology of bovine papular stomatitis? How does it present? What is it closely related to?
Parapoxvirus
proliferative multifocal coin-shaped papules and ulcers with central areas of necrosis and ulceration
pseudocowpoxvius, which causes milker’s nodules on hands
What is contagious ecthyma? How does it present?
contagious viral pustulare dermatitis, or Orf/sore mouth common in young sheep and goats 3-6 months in age caused by parapoxvirus
proliferative lesions around the lips and coronary bands give rise to pustules (neutrophils) and eventually crust (fibrion) over
What is this? Morphological diagnosis?
contagious ecthyma (Orf, sore mouth)
- loss of condition, affected animals neither suckle nor graze
proliferative pustular cheilitis with superficial crusting
Where do lesions of contagious ecthyma typically develop? Is it zoonotic?
sites of trauma - corners of mouth, mammary glands, coronary bands
Is contagious ecthyma zoonotic? What tends to happen with animals with this condition in tropical and wet climates?
YES
secondary infection from Dermatophilus congolensis
What is the most common cause of necrotizing stomatitis? What does this cause?
Fusobacterium necrophorum - Gram negative anaerobe that secretes toxins that cause caseous necrosis
- swelling of the maxilla
- fever
- inappetance
- bad breath
What is oral necrobacillosis caused by Fusobacterium necrophorum called?
calf diphtheria - ulcerative and necrotizing inflammation of the buccal, pharyngeal, and laryngeal mucosa
How does feline eosinophilic granuloma complex present? What 2 things are included in this complex? What causes this?
nodular, ulcerative swelling of the lips (firm)
- eosinophilic granuloma
- labial and rodent ulcers
immunosuppression (corticosteroids)
Eosinophilic ulcer, cat, palate:
Feline eosinophilic granulomas:
How do feline eosinophilic granuloma complexes look histologically?
accumulation of eosinophils + lymphocytes and macrophages
(histopathology to rule out squamous cell carcinoma)
What is gingival hyperplasia? In what dogs are they most common?
non-neoplastic proliferative lesion of overgrowth of gum tissue around the teeth making them seem buried
brachycephalic breeds - about 30% of Boxers older than 5 years old will develop this
What are epulis? What kinds tend to be benign? Locally aggressive?
tumors of the periodontal ligament stroma from dental mesenchyme (controversal if they are considered neoplasms)
fibromatous and ossifying epuli - not infiltrative, good prognosis
acanthomatous ameloblastoma - often recur after excision and a piece of the mandible must be taken out to treat
Oral epuli, histology:
What is canine oral papillomatosis? What dogs are most affected? How do they typically progress?
Papovavirus-induced papiliform or cauliflower-like lesions (warts) in the lips and oral mucosa
puppies younger than 1 year old (transmissible)
regress spontaneously and immunity is long-lasting
What is this?
canine oral papillomatosis
How do oral papillomas look histologically?
verrucous lesion composed of thick keratinized stratified squamous epithelium covering a pedunculate connective tissue core with intracytoplasmic inclusion bodies
In what animals are oral melanomas most common? What kind of neoplasia are they?
smaller breed, orally pigmented dogs
~90% are malignant
Oral melanoma, histology:
melanin = brown inctracytoplasmic pigment
Amelanotic melanoma, dog
lacks pigment, need serial sections
- loss of alveolar bone —> lost teeth
Oral melanoma, dog:
Where do oral melanomas typically metastasize?
lungs —> pulmonary melanoma, poor prognosis
circles = amelanotic
Where does squamous cell carcinomas arise? How do they typically act?
stratified squamous epithelium (tongue)
highly invasive and locally aggressive with slow systemic metastasis
Fibrosarcoma, QH gelding:
marked emaciation with maintained appetite = cancer cachexia
- maxilla swelling
Palate and maxillar fibrosarcoma, QH gelding:
