C14 pt 2 Flashcards
Malignant oral tumours
- common or rare in LA? aggressive?
Malignant oral tumours are rare in large animals and usually not very aggressive when they do occur
Clinical signs of oral tumours
- Clinical signs of oral tumours are similar regardless of tumour type
o Ptyalism, pain, halitosis, dysphagia, anorexia, loose teeth, bleeding, etc
Malignant oral tumours
- speed of progression, prognosis
- Malignant tumours progress rapidly with a poor prognosis unless resected early
oral Mast cell tumours
- are they worse if affecting mucosa or dermal
- Mast cell tumours affecting mucosa are more malignant than dermal ones
oral Melanoma
- how common in dogs?
- how commmon in other species
- what have most done by Dx
- how aggressive
- pigmentation?
- progression?
o Most common oral tumour in dogs (40 % of oral tumours), rare in other species
o Malignant and highly aggressive, most have metastasized by diagnosis
o Variable pigmentation, many at least partly amelanotic
o Necrosis, ulceration, rapid growth, bone invasion
oral melanoma in dogs
- what % metastasize
- prognosis
- how to Dx
- breed disposition, age
o 70% metastasize to regional lymph nodes, often also metastasize to lung
o Median survival WITH TREATMENT 3 months (NOT LIKE CUTANEOUS)
o Often need immunohistochemistry to diagnose
o Small, dark coloured breeds predisposed, usually elderly (11-12 years)
- Squamous cell carcinoma (SCC)
- most common oral tumour in what species
- 2nd most common in what species?
- resembles what
- metastatic?
- prognosis?
- appearance
o Most common oral tumour in cats
o 2nd in dogs, especially tonsils (increased metastatic risk)
o Resembles gingivitis in early stage but usually advanced by presentation
o Locally invasive, metastasis possible but uncommon
o Poor prognosis due to invasiveness, especially with large masses
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Irregular, nodular, red-grey, friable, often ulcerated and bleed easily
oral Fibrosarcoma
- how common in cats? dogs?
- dog signalment
- histo, growth
- recurrence
- metastatic?
- appearance
o Second most common oral tumour in cats (much less common than SCC)
o Third most common in dogs, 15-25 % of oral tumours
o More common in younger dogs, larger breeds predisposed
o Bland histology but aggressive growth, invasion (“hi-lo”)
o Commonly recur following removal
o 20-35 % metastasize to lymph nodes, 10-20% in lung at diagnosis
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Fleshy grey mass, fixed to underlying bone, may ulcerate
dental tumors
- common?
- malignant?
- removal?
- Most dental tumours are rare, all are non-malignant
o Tend to destroy teeth and bone and can be difficult to remove
Fibromatous epulis of periodontal ligament origin
- dogs or cats?
- signalment
- what is epulis?
- appearance
- attachment
- prognosis
Fibromatous epulis of periodontal ligament origin: dogs > cats, brachycephalics
o Epulis: generic term for tumour-like masses on the gingiva
o Gross appearance identical to gingival hyperplasia
o Firm, grey-pink, project from between or near teeth, lobulated surface
o Attached to the periosteum, may physically displace teeth but no invasion
o Good prognosis with removal, so distinction from hyperplasia not relevant
esophageal diverticula
- etiology
- true vs pseudo
Diverticula: usually acquired, incidental or can impact with feed and rupture
o True diverticulum: all layers of wall involved
o Pseudodiverticulum: mucosa evaginates through defect in muscle layer
Vitamin A deficiency and anorexia (lack of abrasion) can lead to what in esophagus?
hyperkeratosis
bloat line in esophagus is a sign of:
increased abdominal pressure
‘Red = head’
esophageal ulceration _____ with viral diseases
common
Liquefactive necrosis due to ____; coagulative necrosis due to ____
alkalis
acids
Reflux esophagitis
- what is it?
- species?
- sequelae
- predisposing condition
Reflux esophagitis: loss of sphincter integrity, mostly non-ruminants
o Squamous epithelium is not acid-resistant
o Chronic acid exposure leads to columnar and/or mucous
metaplasia (like stomach)
o Hiatal hernia can predispose (usually intussusception of
stomach into esophagus or esophagus into itself)
Esophagus: Obstruction
- intrinsic vs extrinsic
- what is ‘choke’
- locations
- 2 populations?
- sequelae
- Intrinsic (within lumen) or extrinsic (space-occupying)
- Choke: feed impaction, areas of narrowing or change in direction predisposed
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1. Over the pharynx
2. Thoracic inlet
3. Heart base
4. Diaphragm
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Oral to obstruction: dilation
o May be food-filled, ulcerated
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Can cause pressure necrosis
o May lead to perforation or diverticula
o If impaction is removed, can lead to scarring and stricture
Esophagus: Obstruction
- result of perforation
- If esophagus perforates, severe cellulitis results
o Can track along fascia into the pleural space
Esophagus: Obstruction
- Extrinsic usually due to what in carnivores?
Extrinsic usually due to vascular ring anomalies in carnivores
o Persistent right aortic arch
Megaesophagus
- cause
- result
- Due to muscular dysfunction, leads to food impaction and regurgitation
Congenital idiopathic megaesophagus
- what species?
- progression over time?
- vs adult onset?
o In dogs, can improve with age
o Also seen in cats, foals, calves (acquired more common)
- Adult-onset idiopathic megaesophagus can also occur in dogs
- Possible sequelae?
Ruminant forestomachs
- after death, how fast does epithelium slough
- if remains attached, suspect what?
- Epithelium sloughs within hours of death
o If it remains attached, there may be adhesions (rumenitis) – suspect acidosis
rumen contents PM
- appearance for vagus indigestion
- toxins?
- pH after death?
- Always examine rumen contents – hydration, froth, odour (ammonia, acidosis), pH
o Contents are abundant and watery in vagus indigestion
o Look for toxic plant material in suspected toxicity
o pH can increase after death (interpret with caution, normal 5.5-7.5 depending on diet)
Rumen papilla development is dependent on what?
- and how?
- Rumen papilla development is dependent on diet
o High concentrates: blunted, hyperkeratotic, clumped papillae
o High forages: longer papillae
foreign bodies in ruminants
- what species?
- what are common in young animals, with what diet? consequences?
Foreign bodies very common in cows, rare in other ruminants
o Important if cause toxicity (ex. lead) or traumatic reticuloperitonitis
o Trichobezoars common in young animals, especially on low fibre diets, usually incidental
Rumenitis: Carbohydrate overload
- species?
- tolerance?
- animals commonly affected?
- acute death due to what?
- lesions and consequences?
- PM clues?
- Primarily a disease of cattle, possible but rare in small ruminants
o In all ruminants, tolerance of high CHO levels is possible if introduction is gradual
o Especially common in feedlot cattle due to introduction to high CHO diet
<><><><> - Acute deaths are usually due to lactic acidosis rather than rumenitis
<><><><> - In survivors, lesions act as a portal for pathogen entry
o Can also develop laminitis, encephalopathy
<><><><> - Gross lesions are nonspecific – history is key!
o Low postmortem rumen pH is confirmatory but high
does not rule it out (recall: pH can rise after death)
Rumenitis: Carbohydrate overload
- pH & motility relationship
- pathogenesis
pH 7.5:
- Increased VFAs
- Decreasing pH
- Altered flora
pH 5:
- Gram –ves die
- Streptococci increase
- Lactic acid produced
pH 4.5:
- Streptococci die
- Lactobacillus spp increase
pH 4:
- fatal
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as pH decreases:
- Decreasing motility
- Increasing osmotic pressure
- Fluid drawn from blood to lumen - dehydration
Rumenitis: Carbohydrate overload
- PM Dx?
- what happens as acidic rumen contents move into intestines?
- what is needed for recovery?
- Rumen epithelium may be hard to peel off, but histology is more reliable
- As liquid, acidotic rumen contents move into the intestines, it causes diarrhea
- Recovery requires normal flora to be re-established
Rumenitis: Sequelae
> Fusobacterium necrophorum
- where found normally?
- issues with rumenitis?
- what does it cause?
- appearance of lesions?
o Normal part of rumen flora, invades damages epithelium (especially ventral sac)
o Causes necrosis and sloughing of papillae (ulcers)
o Healing by contraction and epithelial migration (papillae may not regrow)
o Can seed to liver via portal vein and form abscesses
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- Stellate scars of old ulcers
- liver abscess
Rumenitis: Sequelae
> Mycotic invasion
- severity?
- when to consider?
- progression?
- appearance?
o More severe than Fusobacterium spp., often fatal
o If inflammation extends to serosa, consider fungal infection
o Produce submucosal venous thrombi and infarction, can also seed to liver
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- Circular, transmural red-black lesions with pale centre
- Often serosal fibrin (peritonitis)
Bloat
- most common form?
> cause?
- effect?
- pathogenesis
- PM evidence? timing?
- progression
- Acute/primary bloat: most common form
o High concentrate or legume diets
o Decreased saliva production (low forage diet)
o Microbiota disruptions
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Normally little foam is produced and it is unstable (breaks apart)
In bloat, foamy contents can’t be eructated May disappear if PM delayed 10-12 hours
<><><><> - Cardiorespiratory collapse due to increased abdominal pressure
- Found dead in sawhorse stance, congested head and neck
- Bloat line in esophagus
Chronic/secondary bloat
- cause?
- common signalment?
Chronic/secondary bloat: free gas retention due to defect in eructation
o Esophageal obstruction, vagus indigestion, etc (rule out postmortem bloat)
o Often has periods of acute exacerbation
o Bucket-fed calves with ruminal drinking – milk ferments in rumen, produces gas (also
causes lesions of acidosis)
Traumatic reticuloperitonitis
- cause
- progression
- late stages
- PM, what may be gone?
- can lead to…
- Perforation of the reticulum by a long, thin, sharp foreign body
- Followed by acute local peritonitis, potentially fibrinopurulent pericarditis if it penetrates the diaphragm and pericardium
(Sudden death if heart or large vessels involved)
<><><><> - Later stages: adhesions, often can find a tract with suppurative material
- Foreign body may be absent by the time of diagnosis
- Can lead to vagal indigestion
o Not fully understood, believed to be functional or structural problem with
forestomach outflow
o May not be associated with lesions of the vagus nerve itself
Ruminant forestomachs: Neoplasia
- common?
- possible sequelae
- Rare, can interfere with eructation and cause bloat
Ruminant forestomachs: Neoplasia
> papillomas
- agent
- sometimes affects what else
- severity
- progression
Papillomas: bovine papillomavirus-4
o Sometimes also affects esophagus
o Usually mild in healthy animals, masses are mostly small
o Regress in ~12 months due to cell-mediated immunity
o Can progress to SCC in immunosuppressed animals or bracken fern exposure
Ruminant forestomachs: Neoplasia
> Fibropapillomas
- agent
- anatomic location
- SCC association
Fibropapillomas: bovine papillomavirus-2
o Esophagus, esophageal groove and rumen in cattle
o Not associated with squamous cell carcinoma
- Lymphoma can affect the _____ in cows
forestomachs
