This document summarizes diseases of the alimentary system in veterinary pathology. It describes congenital anomalies of the oral cavity, diseases of teeth and dental tissues, diseases of the buccal cavity and mucosa, and neoplastic diseases. It also discusses diseases affecting the esophagus, forestomachs, stomach, abomasum, and intestines. Common conditions mentioned include cleft palate, dental caries, stomatitis, esophagitis, bloat, gastritis, intestinal obstruction, and coccidiosis. The document provides an overview of pathological conditions that can impact the entire digestive tract in animals.
2. The Oral Cavity
► Congenital anomalies
Facial Clefts – skin only or deeper tissues as
well
►Commonest complete cleft from one angle of the
mouth to the ear of that side (harelip to eye)
Cleft palate
Brachygnathia – shortness of the mandibles
Proganthism – prolongation
Aganthia – absence of lower jaw
Epitheliogenesis imperfecta
5. Degenerative Conditions
► Pigmentation of the Teeth
Hypoplasmic enamel of chronic fluorosis – yellow to
brown
Hemorrhage
Tetracyclines
Black discoloration of ruminant cheek teeth
► Dental Attrition – loss of dental tissue by
mastication
► Odontodystrophies – nutritional, metabolic, and
toxic – enamel
6. ► Dentin 65% mineral + 35% organic matter-
odontocytes
Most of the tooth - bonelike
► Enamel 95% mineral 5% organic matter –
ameloblasts – sensitive to environmental changes
► Cementum – cementoblasts – 55% organic matter
45%
Hypercementosis – hypertrophy, hyperplasia (chronic
inflammation)
► Periodontal ligament
7. Developmental Anomalies of Teeth
►Anodontia
►Oligodontia
►Polyodontia
►Heterotopic polyodontia – extra teeth
outside dental arcade
►Dentigerous cysts
8. Infectious and Inflammatory
Diseases of Teeth and Periodontium
►Dental calculus (tartar) – pellicle +
mineralization
►Dental caries (demineralization and
enzymetic degradation of organic matrix
►Pulpitis
►Perodontal Disease – follows gingivitis
9. Diseases of the Buccal Cavity and
Mucosa
►Pigmentation – melanin, icterus
►Circulatory disturbances
►Foreign bodies
10. Inflammation of the oral cavity
►Pharyngitis
►Glossitis
►Gingivitis
►Tonsillitis
►Angina (soft palate)
16. Salivary glands
►Ptyalism – increased secretion of saliva
Mycotoxicosis (Rhizoctonia leguminicola) –
parasymthomimetic – alkaloid slaframine
Heavy metal poisoning
Organophosphate poisoning
Encephalitis and stomatitis
Must be differentiated from swallowing problem
17. ►Aptyalism
Fever, dehydration, salivary gland disease
►Foreign bodies
►Sialoliths
►Dilatation of the duct (Ranula)
►Sialoadenitis - uncommon in animals
25. The Forestomachs
► Dystrophic and hyperplastic
changes in ruminal mucosa
High propionic and butyric acid
Black club and tongue-shaped
papillae (acanthosis,
hyperkeratosis, parakeratosis,
hyperpigmentation
Vitamin A deficiency
27. Dilatation of rumen
► Primary tympany
Bloating tendency – amount and composition of saliva
►Mucins – reduce viscisity (parotid and submaxillary)
►Mucoproteins – increase viscosity
High level of soluble proteins (fraction I) released from
chloroplast – degraded by microflora – rise to the
surface tension – become insoluble – stablize froth –
optimum pH is 5.4 to 6.0 – saliva
Pectin stabilizes froth
Plant lipids destabilize froth
Feedlot bloat (roughage vs concentrates)
Cause of death increased intra-abdominal pressure
28. Lesions – blood clots poorly, subcut
hemorrhages in the neck and trunk –
marked edema and hemorrhages in the
cervical muscles and in the cervical
esophagus (bloat line) – pale mucosa
caudal to thoracic inlet
Tracheal mucosa hemorrhagic
Lungs compressed
Ischemia of abdominal viscera
29. ► Secondary tympany
Acute or chronic
Physical and functional defects in the eructation of
gases
Most common physical defects are:
►Internal or external obstruction of esophagus
►Reticular adhesions
►Abscesses, peritonitis, and tumor masses in the ab. cav.
Functional Causes
►Organophosphates= toxic
►Vagal damage due to adhesions or lymphosarcomatous
infiltrates
►Ruminal drinker calves (escape esophageal groove)
30. ► Foreign bodies in rumen
Trichobezoars, phytobezoars,
► Traumatic reticulo-pertonitis Follow fibrinous
peritonitis
Magnets
Adhesions in groove formed between reticulum,
omasum, and abomasum – vagus indigestion – bloat –
abomasum and omasum is impacted with ingesta
Pathogenesis – nerve damage due to mechanical and
functional impairment of out flow of ingesta
► Rumenitis – viral diseases, ruminal drinkers, urea
(ammonia), sulfur, plant toxicosis
31. Acidosis
►5.5 to 7.5– volatile fatty
acids – lactic acid by Str.
bovis – rumenitis
►Acidisis - death
►Fusobacterium
necrophorum
►Mycotic infection
32. Stomach and Abomasum
► Gastric dilatation – obstruction of small bowl,
engorgement with highly fermentable diet
► Gastric rupture
► Gastric displacement and volvulus – delayed
gastric emptying, aerophagia – transverse position
to longitudinal – violent movements
► Abomasal displacement and volvulus – high
producing, intensively managed cows, around the
time of parturition – displacement ventrally to the
left of the rumen
► Foreign bodies and Impaction
37. Epithelial Renewal in Health and Disease
► Villous atrophy
With an intact or hypertrophic proliferative
compartment
►A primary increase in rate of loss of epithelium
Rota and coronaviruses, coccidial infection, enteroerossive
bacteria,
►Atrophy of villi and hypertrophy of crupts - chronic
Parasites, coccidial infection, giardiasis, soyabean in calves,
wheat in dogs, John’s disease, histoplasmosis, immune
reaction
Villus atrophy associated with damage to the
proliferative compartment
►Necrotic entritis
Ionizing radiation, anticancer drugs, cytotoxic chemicals,
T-2 mycotoxins, parvoviruses, BVD, rinderpest, ischemia
Secondary invaders:
E. coli, Salmonellae, Clostridia, Compylobacteria, Yersinia, parasites
39. Pathophysiology of Enteric Diseases
►Anorrhexia, reduced growth rate, weight
loss or cachexia, hypoproteinemia, anemia
with possible hemorrhage in the gut,
dehydration, acidosis
40. PPR
►Peste-de-petits ruminants----Goat Plague—
closely resemble with rinderpest
►Goat and sheep
►Erosive stomatitis and enteritis, goat
catarrhal fever
►Stomatitis-penumoenteritis complex----
pasteurella infections
►Zebra stripes in colon and rectum
►Purulent or fibrinous bronchopneumonia