Lecture 22 and 23 Flashcards
Normal pig lung
Normal rats lung
What do the black dots represnet
Inhaled particles trapped in mucous
What are the 3 types of lining in the alvioli
- Type I aveolar
- Type II aveolar
- Macrophages
Why is the respiratory system vulnerable to injury
- Constant exposure to - microes, particles, fibres, toxicgases a vapours in the air
- Large surface area in the alveoli
- Large volume of air passing continuously into the lungs
- Lungs are also susceptible to haematogenous microbes,toxins and emboli
5.
What is the conducting defense mechanism of the lungs
- Sneezing, coughing
- Mucociliary clearance, mucous
- Antibodies
What is the transitional system of the lungs
- Clara cells (detoxify foregin substances)
- Antioxidants, antibodies
What is the exchange system of the lungs
- Alveolar macrophages
- Intravascular monocytes
- Antibodies, surfactant, antioxidants
When is the defensce mechanism of the lungs altered
- Injured epithelium
- Enhances bacterial attachment
- Impaired mucociliary clearance
- Reduction in antibacterial secretory products
- Dysfunction of alveolar macrophages and lymphocytes
- Immunosupressive effects of some virsues
What viruses predispose to bacterial pneumonia
- Influenzia
- Bovine herpesvirus 1, parainfluenza-3, bovine syncytial virus
- Canine distemper
- Bacterial infections may result from normal flora of the respiratory tract
Blue: large macropahage that has ingested bacteria
Red: small cluster of neutrophils
R. Equui
What are the effects of gases on the respiratory system
- Render respiratory tract susceptible to secondary bacterial infections - impaired defense mechanisms
- Hydrogen sulphide and ammonia in housed animals: overcrowding of animals increases the problem
- Pollutants in cities
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What is epistaxis
Blood flow from the nose - either from the nasal cavity or lungs
What is haemoptysis
Coughing up blood in septum or saliva - commonly from lung lesions
What is ethmoidal haematomas
Important in horses
- Chronic, progressive, often unilateral nasal bleeding
- Appears as soft, tumour-like, dark mass arising from the mucosa of the ethmoidal conchae
What is hyposmia
Reduction of olfactory function secondary to chronic injurt to olfactory epithelium
What is anosmia
Loss of olfactory function
Ethmoidal haematoma - horses
What is serous Rhinitis
Clear fluid
What is catrrhal rhinitis
Thick mucus with some leukocytes and cellular debris
Progressto mucopurulent with neutrophils present
What is mucopurulent rhinitis
- Heavy neutrophil content plus mucous and cellular debris
- More severe damage to mucosa, necrosis
- Indicates secondary bacterial infections
Suppurative Rhinitis: calf
What is fibrinous rhinitis
- Inflammation with increased vascular permeability
- Large amount of fibrinogen coagulates into fibrirn
- Yelow, tan or grey rubbery mat on the mucosa
- May form a pseudomemrane that is difficult to remove and has underlying necrotic tissue
Fibrinous rhinitis: calf
What is granulomatous rhinitis
- Chronic allergic inflammation
- Fungal infections
- Foreign bodies
- Granulomatous masses may obstruct nasal cavity
- May lead to destruction of the turbunates or erosion into sinuses
Granulomatous rhinitis: cow with fungal infection on nasal septum
What is sinusiis
- Can occur with rhinitis
- Can develop from penetrating wounds or tooth infection into maxillary sinus
- Poor drainage of sinuses tend to cause
- Accumulation of mucus
- Accumulaion of pus
- May extend into adjacent bone
Fungal sinusitis: dog
Fungal sinusitis: dog
What is equine viral rhinopneumonitis and what does it cause
- Equine herpies virus
- Mild respiratory disease in foals and young adults
What is equine influenza
- Highly contagious, self-limitying
- Upper respiratory infection
- Hige morbidity and low mortality
What bacteria causes strangles
Streptococcus equi spp equi
What does strangles cause
- Suppurative rhinitis
- Copious amounts of mucopurulent nasal discharge
- Hyperaemia of nasal mucosa
- Mandibular and retropharyngeal
- Inflammation of lymphnodes
- May spread to lungs and other organs ‘bastard strangles’
What causes glanders
Burkholderia mallei
What is seen with glanders
- Nasal mucosa
- Pyogranulomatous nodules
- Lungs
- Nodules resembling millent seeds
- Cutaneous lesions
- Suppuratie lymphangitis
What is infectious bovine rhinotracheitis
- Bovine herpesvirus 1
- Significant in intensive feedlot systems
- Synergism of IBR with Mannheimia haemolytica producing pneumonia
What is the respiratory form of IBR
- Severe hyperaemia anf focal necrosis of nasal, pharyngeal, larygneal and tracheal mucosa
- Secondary bacterial infection leading to fibrinonecrotic layers
- Post mortem diagnosis confirme by virus isolation or identification of the virus by immunocytochemistry or PCR
IBR calf: fibrinous laryngitis and racheitis
What is atrophic rhinitis
Inflammation and atrophy of the nasal conchae
Atrophic Rhinitis: pigs
- Nasal septum is distorted
- Conchae are smaller and asymmetrical
- Dorsal and venral meatuses appear enlarged or entrie conchae may be missing
What is inclusion body Rhinitis
- Disease of young pigs
- Mild rhinitis
- Necrotising, non-suppurative rhinitis
Inclusion body rhinitis
What is feline viral rhinotracheitis
- Herpes virus
- Common
- Predisposes to secondary bacterial pneumonia
What is feline calicivirus
- Different strains
- Mild to severe rhinitis
- Mucopurulent conjunctivitis
- Ulcerative gingivitis and stomatis
- Secondary bacterial infection
What is felie clamydiosis
- Chlamydophila felis
- Conjunctivitis and serous to mucopurulent rhinitis
What are avian respiratory diseases
- Infectious coryza - avibacterium paragallinarum
- Pasturellosis - pasteurella multocida
- Mycoplasmosis - mycoplasma spp.
Infectious Coryza - caused by avibacterium paragallinarum
Fowl cholera
Mycoplasmosis: turkey
Explain nasal neoplasia
- Can arise from any of the tissues
- Most nasal neoplasms are malignant
- Become secondarily infected with bacterai
- Chilical signs may overlap thoses of infectious rhinitis
- Mucopurulent discharge, periodic haemorrhage, sneezing, blockage of nasolacrimal ducts
Squamous cell carcinoma: horse
Nasal adenocarcinoma: sheep
What are abnormalities of the pharynx, guttural pouches, larynx and trachea
- Brachycephalic airway syndrome
- Tracheal collapse and stenosis
What are degenerative disorders of the pharynx, guttural pouches, larynx and trachea
Laryngeal hemiplegia
What are inflammation of the guteral pouch in horses
Diverticula of the eustachian tubes
What is brachycephalic airway syndrome
- Stenotic external nostrils
- Extensive lengthof soft palate
- Eversion of laryngeal saccules
How is tracheal collapse and sternosis caused
- Aquired or congenital
- In toy breeds or brachycephalic breeds of dogs
- May extend to whole length of trachea
- Abnormal cartilaginous glycoproteins and loss of elasticity of tracheal rings causes the collapse
- Have a localised abnormality with stenosis
What is laryngeal hemiplegia
- Roaring
- Common
- Atrophy of dorsal and lateral circoartyenoid muscles
- Recurrent laryngeal nerve degeneration
- Idiopathic
- Inflammation or compression of nerve
What causes inflammation of the gutteral pouch (Empyemia)
Infected with a variety of pathogens including fungi esp in stabled horses
Empyema is also a sequela to stranles
Can extend to the carotid artery and cause fatal bleeding, also nerve damage leading to dysphagia
What usually causes pharyngitis and laryngitis
- Most cases are due yo trauma or are component of a respiratory tract infection
- Pharyngeal proliferation
- Necrotic laryngitis
- Opportunistic infection with Fusovacterium becrophorus
- Yellow-grey, thick crusted, fibrinecrotic exudate surrounded by a zone of hyperaemia
- Can progress to deep ulceration
- Opportunistic infection with Fusovacterium becrophorus
Necrotic laryngitis: calf
Fusobacterium necrophorum
Trichomoniasos in a bird of prey
Trichomonas gallinae
Why do birds need vit A and what does deficiency cause
- Normal cell function
- Mucous gland cells undergo squarmous metaplasia
- Glands become enlarged with keratin and become infected
- Conjuntivitis, pharyngitis and tracheitis
- Can occur in back yard poultry with no greed feed and fed only grain
- Rainforest birds fed grain
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Vit A deficiency
Squamous metaplasia in pharyngeal mucous glands
What is petechial haemorrahages
- Seen in coagulopathies, inflammation and septicaemia
- In pigs, can be seen in classical swine fever and salmonellosis
- Severe dyspnoea and asphyxia before death can cause congestion, ecchymotic and perrechial haemorrhages
What is infectious laryngotracheitis
- Higly infectious disease affecting birds of all ages
- Rapid onset of respiratoy distress with gasping, respiratory gurgling and rattling
- Vaccine avaliable
Infectious laryngotracheitis
