Lesson 99 - Lower Airway Disease in Farm Animals

What pathogens cause atrophic rhinitis?

1. Bordetella bronchiseptica

2. Pasteurella multocida

Which clinical presentation is more consistent with atrophic rhinitis?

1. sneezing, snorting, nasal discharge, epistaxis in severe cases

2. tear staining from medial canthi is characteristic

3. no coughing

4. endemic herds can have snout deviation

What diagnostic methods are used for atrophic rhinitis?

1. necropsy: turbinate atrophy and snout deviation

2. clinical signs

3. culture of nasal swabs or turbinates

4. toxigenicity testing by PCR

You are assessing some new stock to add to your swine farm. What would be the best way to make sure that they do not have atrophic rhinitis and its agents?

culture of nasal swabs or turbinates followed by toxogenicity testing by PCR if needed

What is the agent of inclusion body rhinitis?

porcine cytomegalovirus

What are the clinical signs for inclusion body rhinitis?

1. sneezing, clear to mucopurulent nasal discharge

2. young piglets 3-6 weeks of age

3. very low mortality

4. minor and transient effect on gain and does not predispose to other disease

5. occlusion and mouth-breathing

6. edema and petechial hemorrhage

How do we diagnose inclusion body rhinitis?

1. Clinical signs

2. Histopathology

3. Intranuclear inclusions in the turbinates or harderian glands

What are the signs of an acute influenza A outbreak in swine?

1. sudden onset and rapid spread

2. fever

3. serous nasal discharge

4. dyspnea, prostration, coughing

5. high morbidity

How fast do pigs recover from an acute influenza A outbreak?

7-10 days

Which subtypes of influenza A in swine are more common in the US?

H1N1 and H3N2

How is influenza A diagnosed in swine?

1. necropsy: multifocal to diffuse red, firm areas of pneumonia, cranioventral

2. secondary bacterial bronchopneumonia common

3. PCR on lung tissue or nasal swabs

4. antigen staining of lung tissue using IHC or FA

5. serology via ELISA

6. acute form usually signs and history is enough

What is an important monitoring tool for influenza A in swine?

subtyping by PCR and/or sequencing

What is the pathogen causing mycoplasmal pneumonia in swine?

Mycoplasma hyopneumoniae

What are the clinical signs of Mycoplasmal pneumonia in swine?

1. persistent, dry cough

2. slow growth

3. endemic in nearly all herds

How do we diagnose Mycoplasmal pneumonia in swine?

1. necropsy: grey-to-purple pneumonia in atelectasis in cranioventral, marked lymphoid hyperplasia around airways

2. antigen staining (FA, IHC) on affected lung

3. PCR on lung or airway swabs

4. serology for monitoring herds

What is the agent for Pneumonic pasteurellosis in swine?

Pasteurella multocida

What are the clinical signs of Pneumonia pasteurellosis in swine?

coughing, dyspnea, fever, prostration

How do we diagnose Pneumonic pasteurellosis in swine?

1. necropsy: fibrinous bronchopneumonia cranioventrally, pleuritis, adhesions, abscesses

2. agent can be isolated readily from lung lesions

What agent causes Pleuropneumonia in swine?

Actinobacillus pleuropneumoniae

What are the signs of an acute pleuropneumonia in swine?

1. high fever, prostration, dyspnea, mouth-breathing

2. dead pigs with blood-tinged foam from nose

3. chronic cough and unthrifty appearance after recovering

What are the signs of an endemic pleuropneumonia infection in swine?

1. poor grower-finisher performance

2. sporadic acute outbreaks

3. pleuritis

How do we diagnose pleuropneumonia in swine?

1. necropsy: necrohemorrhagic pneumonia with fibrinous pleuritis in diaphragmatic lobes

2. chronic cases have pleural adhesions and necrotic foci in lungs

3. culture

4. PCR

5. serotyping important for control strategies

6. serology harder because of specific serotypes

What are the clinical signs of porcine reproductive and respiratory syndrome?

1. reproductive failure in sows

2. respiratory disease in all ages

3. high preweaning mortality

4. fever, dyspnea which can persist for weeks

How is porcine reproductive and respiratory syndrome diagnosed?

1. necropsy of young: focal or diffuse interstitial pneumonia in any lobes, thoracic lymph nodes enlarged

2. secondary bacterial infection can complicate

3. PCR on tissues or serum

4. histopathology with antigen stains

5. virus easy to isolate

What agent causes pseudorabies in pigs?

suid herpesvirus 1

What are the clinical signs of pseudorabies in pigs?

1. CNS signs and death in neonates

2. respiratory disease in swine >3 weeks

3. sneezing, coughing, nasal discharge, dyspnea, occasionally seizures

4. grower-finisher pigs can be indistinguishable from influenza A

How do we diagnose pseudorabies in pigs?

1. necropsy suckling piglets: white, necrotic foci in the liver and spleen

2. necropsy postweaning pigs: rhinitis, tracheitis, tonsillitis, keratoconjunctivitis

3. nonsuppurative encephalitis, tracheitis, bronchiolitis, alveolitis

4. FA, VI, PCR tonils, spleen, brain

5. histopathology with antigen staining

6. serology critical for differentiating vaccine from wild-type virus

A finishing-stage pig presents with chronic sneezing, tear staining, and mild snout deviation. Progressive atrophic rhinitis is suspected in these animals. Which diagnostic method is most appropriate to confirm the presence of Pasteurella multocida?

nasal swab culture

3 multiple choice options

A cohort of nursery pigs show sudden fever and severe coughing with pig morbidity and low mortality. Some piglets have already recovered, but one died and a necropsy was performed. Diffuse areas of pneumonia were the most severe gross lesions that was identified. What is the best test to run on a sample of lung tissue that will be submitted for pathology to confirm the most likely etiology?

PCR

3 multiple choice options

A group of grower pigs are exhibiting clinical signs of a chronic dry cough, and the producer is concerned because their growth rate is delayed for market timelines. A diagnosis of Mycoplasma hyopneumoniae is suspected. What is the best test to confirm this diagnosis?

PCR nasal swabs

3 multiple choice options

A group of finisher pigs are demonstrating clinical signs consistent with acute dyspnea, fever, and bloody, foamy nasal discharge. A diagnosis of Actinobacillus pleuropneumoniae is suspected. What is the best diagnostic test to confirm this diagnosis?

PCR of lung lesions

3 multiple choice options

A group of sows in a commercial swine operation are demonstrating clinical signs associated with reproductive failure; in the same herd; nursery pigs are showing clinical signs consistent with fever and dyspnea. Porcine respiratory and reproductive syndrome is suspected. What is the best diagnostic test to confirm this diagnosis?

PCR on lung tissue from a deceased piglet

3 multiple choice options

A group of grower pigs are exhibiting clinical signs of a chronic dry cough and the producer is concerned because their growth rate is delayed for market timelines. A necropsy is performed on one of the pigs to assist with a diagnosis. Gross lesions of atelectasis in the cranioventral lung lobes with lymph node hyperplasia are noted on examination of the thoracic cavity. What is the most likely etiology?

Mycoplasma hyopneumoniae

3 multiple choice options

A group of 12 wk old finishing pigs on a commercial swine operation are found acutely ill early one morning, with several animals already dead and others showing severe respiratory distress. Affected pigs are febrile, lethargic, and reluctant to move, with pronounced tachypnea, open-mouth breathing, and occasional blood-tinged froth at the nostrils. Some exhibit a deep, painful cough and cyanosis of the ears and extremities. On auscultation, lung sounds are harsh with areas of absence of sounds suggestive of consolidation. A freshly decreased pig shows dark, firm, hemorrhagic lung lobes with sharply demarcated regions of necrotizing pneumonia and fibrinous pleuritis tightly adhering the lungs to the thoracic wall. What is the most likely etiology?

Actinobacillus pleuropneumoniae

3 multiple choice options

A group of late gestation sows on a farrow-to-finish swine operation begin showing clinical signs associated with decreased appetite and mild fever, followed over several days by a sudden spike in abortions, early farrowing, and weak, trembling piglets that often die shortly after birth. The farmer also notes increased stillborn and mummified fetuses in multiple litters. In the nursery, recently weaned pigs appear lethargic with dyspnea, "thumping" respiration, rough hair coats, and several exhibit secondary bacterial pneumonia. Mortality is elevated across age groups, and affected pigs show poor growth and a prolonged recovery. What is the most likely etiology?

porcine reproductive and respiratory syndrome

3 multiple choice options

What is the importance of the bovine respiratory disease complex?

1. most common disease processes that affects production besides diarrhea

2. patient morbidity and mortality

3. costs for producers

4. increasing drug resistance

5. exam questions

What pathogens are involved with the porcine respiratory disease complex?

1. porcine reproductive and respiratory syndrome virus

2. swine influenza virus

3. porcine circovirus type 2

4. mycoplasma hyopneumoniae

5. actinobacillus pleuropneumoniae

6. pasteurella multocida

7. bordetella bronchiseptica

8. glaesserella parasuis

What are two classifications of bovine respiratory disease complex?

1. enzootic pneumonia

2. shipping fever

What cows usually get enzootic pneumonia?

1. holsteins

2. housed calves

3. preweaned up to 5 months

What cows typically get shipping fever?

1. beef

2. post shipping (10-21 day post arrival)

3. 6-18 months old

What contributes to noisy respiration seen with BRDC?

1. crackles

2. wheezes

3. friction rubs

4. decreased or lack of sounds

5. increased cranio-ventral lung sounds

Which sequence best describes part of the pathogenesis of shipping fever in cattle?

Viral infection → immune suppression → bacterial colonization → fibrinous pneumonia → pleuritis

3 multiple choice options

What is the viral aspect of the BRDC?

1. bovine viral diarrhea virus

2. bovine herpes virus

3. bovine respiratory syncytial virus

4. parainfluenza 3 virus

What is the bacterial aspect of BRDC?

1. Mannheimia haemolytica

2. Mycoplasma spp.

3. Pasteurella multocida

4. Histophilus somni

What is the parasitic aspect of BRDC?

1. Dictyocaulus viviparus

2. Dictyolcaulus filaria

3. Muellerius capillaris

What systems does BVDV affect?

1. reproductive

2. respiratory

3. immune system

4. gastrointestinal

How is BVDV transmitted?

easy to transmit and all fluids are infective

What is the pathogenesis of a BVDV infection?

immunesuppression from the virus exposes to secondary bacterial infections

What is a result of BVDV being immunosuppressive?

1. secondary bacterial infections

2. leukopenia and lymphoid depletion

3. impairs viral clearance

Which of the following best describes the clinical signs associated with bovine viral diarrhea virus infection in cattle?

acute infection: fever, diarrhea, leukopenia; chronic PI animals: stunted growth, mucosal disease later

How is bovine herpesvirus-1 transmitted?

requires contact because it does not survive outside host long but has low infectious dose so its very contagious

What are the subtypes of bovine herpesvirus-1?

1. BHV 1.1 - respiratory and abortion

2. BHV 1.2 - respiratory and genital

3. BHV 1.3 - neurologic also known as BHV-5

What are the manifestations of BHV-1?

1. Infectious bovine rhinotracheitis

2. infectious pustular vulvovaginitis

3. balanoposthitis

4. conjunctivitis

5. abortion

6. encephalomyelitis

7. mastitis

What are the signs of IBR?

1. sudden onset fever (104-106)

2. anorexia

3. nasal hyperemia

4. pustules, grey necrotic membranes on nasal mucosa

5. serous nasal/ocular discharge

6. salivation, panting

7. conjunctivitis

How long does it take to recover from IBR?

10-14 days

What are some complications that can occur from IBR?

1. bacterial bronchopneumonia

2. tracheitis, bronchitis

What animals are affected by the bovine syncytial virus?

1. all ages, mostly young

2. cattle likely reservoir

3. other SR versions for caprine and ovine

How is bovine respiratory syncytial virus spread?

respritory secretions

What are the clinical signs of bovine respiratory syncytial virus?

1. only respiratory tract

2. fever 104-108

3. coughing, nasal/ocular discharge, panting

4. dyspnea, open mouth breathing, expiratory grunting

5. crackles, pulmonary and subcutaneous emphysema

6. anorexia and salivation

What do we know about parainfluenza 3 virus effects and transmission?

1. remarkably stable

2. cattle, sheep, goats

3. less severe than BRSV

4. disruption of mucociliary apparatus

5. immunosuppression

6. ubiquitous

What is the clinical presentation like for parainfluenza 3 virus?

1. incubation of 24-36 hours

2. fever

3. increase respiratory rate, coughing, nasal/ocular discharge

4. increased lung sounds cranioventral

5. recovery 4-7 days if uncomplicated

6. risk for secondary bacterial pneumonia

What is the most common bacterial isolate from BRDC?

Mannheimia haemolytica

Which of the following best explains how Mannheimia haemolytica causes pneumonia in cattle?

It is a normal inhabitant of the upper respiratory tract that proliferates and descends into the lower respiratory tract following stress or viral infection

Where do most of the bacteria involved in the BRDC normally inhabit?

upper respiratory tract

What does it mean if you have bacteria from URT causing an infection in the lungs?

pulmonary defenses are impaired, they damage tissues via toxins and mediators

Which bacteria in the BRDC is not a normal inhabitant of the URT?

Mycoplasma bovis

What is the treatment of Mycoplasma spp.?

1. longer term antiobiotic

2. Draxxin (tulathramycin)

3. Nuflor (florfenicol)

4. Zactran (gamithromycin)

5. Baytril (enrofloxacin)

What are some clinical signs of M. bovis?

1. multisystemic

2. mastitis

3. otitis

4. arthritis

5. respiratory

What is important about being careful with sample selection?

chronic cases may not have the inciting cause present anymore so acute cases might be better

What animals do you pick for samples?

1. acutely sick animals that fail to respond

2. target the secondary infections

3. target animals showing the typical signs

What samples can be taken from animals?

1. nasopharyngeal swabs

2. transtracheal wash

3. bronchoalveolar lavage

When would you want to take a nasopharyngeal swab sample?

1. upper respiratory diseases

2. if you suspect a virus or non-commensal bacteria

3. not for M. haemolytica or M. bovis

What is a pro and con for a BAL?

1. pro: less invasive and can sample small airways

2. con: contamination and harder when doing blind

What is a pro and con for TTW?

1. pro: more sterile and less contamination

2. con: more invasive

What is the best candidate for postmortem evaluation?

1. common in pigs

2. untreated animals early in disease

What is evaluated on a necropsy?

1. serum

2. lymph nodes

3. ear notch, ileum, liver, spleen, kidney

What is important about treatment bovine respiratory disease?

1. treat early

2. quarantine

3. frequent re-evaluation

Typically what lobe are you sampling with a blind BAL?

right dorsal lung lobe

When do you know if you should treat the whole herd?

>10% of group affected

How do you treat for viral pneumonia?

1. antimicrobials

2. NSAIDs

3. dose of dexamethasone if needed

What antibiotics are common for Mycoplasma?

macrolides

What are some common respiratory focused antimicrobials?

1. tulathromycin (Draxxin)

2. florfenicol (nuflor)

3. gamithromycin (zactran)

4. long acting oxytet (LA-200, Biomycin)

5. enrofloxacin (baytril)

6. tilmicosin (micotil)

7. cephalosporin (excede)

What are the main aspects of supportive care for BRD?

1. rest in a dry, comfortable, ventilated, protected place

2. fresh palatable feeds and don't force concentrates for rumen health

3. rehydration wither oral or IV

What are the prevention strategies for BRDC?

1. management

2. reduce stress

3. early detection

4. vaccination

What is important about vaccination protocol for BRDC?

1. no MLV on arrival at feedlot

2. no improvement in morbidity/mortality in young dairy calves

3. mlv abortion risk in pregnant cows

4. mucosal immunization may be better to not interfere with maternal antibodies

What are the viral agents for small ruminant lower airway disease?

1. respiratory syncytial virus

2. parainfluenza 3 virus

3. bluetongue virus

4. adenovirus

5. ovine progressive pneumonia virus

6. adenocarcinoma virus

What are the bacteria involved in small ruminant lower airway disease?

1. Mannheimia haemolytica

2. Pasteurella multocida

3. Mycoplasma

4. Corynebacterium pseudotuberculosis

What are pneumonia risk factors for small ruminants?

1. age

2. stress

3. recent shearing and cold weather

4. unshorn, no shade, hot weather

5. poorly ventilated barns

What antibiotics are not used in small ruminant lower airway disease?

1. baytril

2. micotil in goats

How do we treat lower airway disease in ruminants?

1. antibiotics

2. NSAIDs like flunixin meglumine, meloxicam

3. supportive care

4. vaccine for pasteurella and mannheimia

A group of 8-month-old feeder Angus calves develops fever, anorexia, depression, and increased respiratory effort approximately 14 days after arrival at a feedlot. Several calves have harsh lung sounds with crackles over the cranioventral lung fields. One untreated calf dies and is submitted for necropsy, which reveals fibrinous bronchopneumonia. Culture of submitted lung tissue grows Mannheimia haemolytica. What underlying risk factor most likely contributed to the development of this disease outbreak?

primary viral infection causing immunosuppression and disruption of respiratory defenses

3 multiple choice options

When should you start to consider if verminous pneumonia is a cause?

1. if can't diagnose other cause

2. diffuse pneumonia

3. small ruminants > cattle

4. fall or spring

5. neonates

6. secondary bacterial pneumonia

What is the lungworm for small ruminants?

1. Dictyocaulus filaria

2. Muellerius capillaris

3. Protostrongylus refuscens (big horn sheep)

What are the lungworms for cattle?

Dictyocaulus viviparus

What is the snail an intermediate host for?

1. Protostrongylus

2. Muellerius

What is the most common lungworm in SRs?

Muellerius capillaris

What is the life cycle like for Dictyocaulus filaria?

1. prepatent period 4 weeks

2. direct life cycle

What is involved with an acute lungworm infection?

1. history of new pasture

2. high morbidity

3. sudden onset of tachypnea, tachycardia, nasal discharge, fever, cough

4. widespread abnormal sounds

5. progression to severe dyspnea and cyanosis

6. death in 2-14 days

What is involved with a subacute lungworm infection?

1. 3-4 week course

2. paroxysmal coughing

3. loud crackles, widespread

4. secondary bacterial infection

5. weight loss

What is the most common presentation for lungworms in SR?

subacute