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.

1. Veterinary Pathology of
Alimentary System

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

3. Diseases of Teeth and
Dental Tissue

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)

11. Superficial stomatitis
►Catarrhal
 Thrush – yeast hyphae
►Vesicular stomatitis – bullae
 Viruses, pempigus vulgaris, bullous pemphigoid
►Erossive and Ulcerative
 Feline ulcerative stomatitis – feline leukemias
 Eosinophilic ulcer of cats (lick granuloma)
 uremia
Irritant chemicals, plants, thermal, viral diseases, bacteria

12. Deep stomatitides
► Fusobacterium
necrophorum – calf
diphtheria
► Noma
pseudomembranous or
gangrenous -
spirochaetes
► Actinobacillus lignieresii –
pyogranulomatous
► Oral dermatophilosis in
cats – D. congolensis

13. Parasitic Diseases of the Oral Cavity
►Trichinella spiralis
►Oestrus ovis larvae
►Larvae of Gastriphilus in horses
►G. nasalis - gums

14. Diseases of Tonsils
►Tonsilitis
►--Pyogenic
►--Ulcerative

15. Neoplastic diseases
►Papillomatosis
►Epulides – developmental,
inflammatory, and
hyperplastic, as well as
neoplastic
►Squamous cell carcinoma
►Melanoma
►fibrosarcoma

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

18. esophagus
►Diagnosis depends on:
►Inadequate growth rate, cachexia, ptyalism,
dysphagia, regurgitation issues, vomition,
and aspiration pneumonia – in ruminants
tympany

19. Anomalies, Epithelial Metaplasia, and
Similar Lesions
►Congenital duplication – rare in animals
►Segmental aplsia
►Esophagorespiratory fistulae
►Hyper keratosis in vit. A def., chlorinated
nephthalene irritation

20. Esophagitis
►Erosive and ulcerative
 Rinderpest, mucosal disease,
malignant catarrhal fever,
infectious bovine
rhinotracheitis, herpes viral
infection, calcivirus
 Caustic chemicals, ionizing
radiation, hot ingesta
►reflux esophagitis – Hiatus
hernia

21. Esophagial Obstruction, Stenosis,
and Perforation
►Choke, impaction – larynx, base of the
heart, diaphargm

22. Dysphgia
 Oral-phase= oral lesions
 Pharyngeal phase= inflammation
 Cricoesophageal incoordination (achalasia) –
neurological issue

23.  Megaesophagus or esophagial ectasia
►Atony of esophageal musculature
►Segmental or diffuse dysfunction of body of
esophagus
►Idiopathic in dogs, glycogen storage disease,
myasthenia gravis, administration of
cholinesterase inhibitors, hypoadrenocortism,
canine giant axonal neuropathy, immune
mediated poly myositis, canine distemper,
systemic lupus erythematosus, lead
poisoning, trauma, and Chagas’ disease
►In other animals rare – congenital, hiatus
hernia, vagus nerve damage

24. Parasitic diseases of esophagus
►Sarcosporidiosis
►Gasterophillus larvae
►Hypoderma lineatum
►Gongylonema pulchrum
►Spirocerca lupi
Gongylonema pulchrum

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

26. ►Postmortem change
 Detachment of MM within few hrs
 Persistent firm attachment is not normal

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

33. Gastritis
►Arsenic, thallium, formalin, bromopol,
asprin, phosphatic fertilizers, plant poisons,
microorganisms, stress
►Catarrhal – necrotic ulcerative
►Chronic gastritis – trauma, parasitism,
viruses – Helicobactor pylori

34. intestines
► Congenital enzyme deficiencies
► Segmental anomalies – stenosis, atrasia – atresia
ani, A. coli
► Intestinal obstruction – stenosis, intraluminal mass
(enteroliths, phytobezoars, trichobezoars, tumors
etc.), pressure from outside, function obstruction,
strangulation of hernia, intussusception, volvulus,
torsion, parasites, impaction by sand etc.
► Functional obstruction

35. ►Displacement of Intestines
►Intestinal ischemia and infarction

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

38. Necrotic Entritis
Fibrinous Entritis

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