pathology

• Epidermis is the most superficial layer

  layer from which nails,claws,hoods,and horn develop

  made up of stratified squamous epithelium

  made up of four layers
• Prognathia


  Abnormal lengthening of the mandible
• Brachygnathia


  Shortness of the maxilla(superior) or mandible (inferior)
• Agnathia


  Absence of lower jaw
• Epitheliogenesis imperfecta


  Defect in skin epithelium that also affects the lining of the oral cavity, particularly the tongue
• Cause of stomatitis:

  1.Foreign bodies

  2.Renal failure

  3.Immune Mediated

  4.Malocclusion

  5.Eosinophilic granuloma

  6.Bacterial causes

  7.Fungal infections

  8.Viral Infections
• Malocclusions


  Deviations from normal teeth occlusions,accompany abnormalities of the jawbones such as bradygnathia malformed mandibles, and perfect cheek teeth
• Stomatitis may be diffuse or localized:

  • Superficial stomatitis is limited to the mucosa
  • Deep-seated stomatitis is in the connective tissue and may be a sequel to superficial inflammations
• Causes of stomatitis:

  1. Foreign bodies

  2. Renal failure
• Stomatitis is common in dogs and cats
• Chronic disease can lead to ulceration of the gums, particularly on the lateral and ventral surface of the tongue
• Common lesion in stomatitis:

  • Brownish, cyanotic appearance of the mucosa
  • Fetid or foul-smelling breath (halitosis)
• Other changes in stomatitis:

  • Mineralization of soft tissues, especially the parietal pleura, left atrium of the heart, and stomach
• Immune-mediated causes of stomatitis:

  • Pemphigus vulgaris and bullous pemphigoid present as bullae and erosion at the mucocutaneous junctions of the oral mucosa and tongue
  • Require differentiation from chemical, traumatic, and infectious injury
• Malocclusion and eosinophilic granuloma (rodent ulcers) are also associated with stomatitis
• Bacterial causes of stomatitis:

  a. Actinobacillosis:

  • Deep pyogranulomatous infection of the soft tissue
  • In cattle, caused by Actinobacillus lignieresi, often involving the tongue (Wooden tongue)
  • Lesions contain club colonies with gram-negative coccobacilli

  b. Actinomycosis:

  • Similar morphological lesion to actinobacillosis in cattle
  • Caused by Actinomyces bovis with club colonies containing gram-positive filamentous organisms
  • Lesions usually in maxillary and mandibular bones (Lumpy Jaw) rather than in soft tissue

  c. Oral Necrobacillosis caused by Fusobacterium necrophorum:
• • Most common is calf diphtheria, an acute necrotizing ulcerative inflammation of the buccal and pharyngeal mucosa with a necrotic covering diphtheritic membrane
  • May have an initiating lesion such as trauma, popular stomatitis, or herpes virus infection (IBR - Infectious Bovine Rhinotracheitis)
  • Lesion may be widespread

  d. Noma:

  • Rapidly spreading pseudomembranous or gangrenous stomatitis
  • No specific cause but tissue invasion by normal flora (fusiform and spirochaetes)
  • Predisposing factors include trauma or debilitation
• Fungal infections associated with stomatitis:

  a. Dermatophilus congolensis:

  • Causes granulomatous lesions of the tongue and tonsillar crypts in cats
  • May need to be differentiated from squamous cell carcinoma

  b. Candida albicans (Thrush):

  • Occurs mainly in young pigs and involves the entire alimentary tract
  • Lesions are pale, smooth, or wrinkled plaques covering the mucosa, also occurs in calves and foals
• Viral infections associated with stomatitis:

  • Common lesions include vesicular, erosive, or proliferative

  a. Vesicular stomatitis:

  • Vesicles and fluid-filled bullae on the oral mucosa, a virus-induced disease of large animals

  b. Ovine Ecthyma:

  • Sore mouth or orf, a pox virus infection in sheep and goats

  c. Bovine Popular Stomatitis:

  • Slightly raised papules that persist for weeks, occurs in the hard palate, lips, muzzle, and tongue

  d. FMD and Rinderpest have been eradicated in the country