Lesson 84 - Herd approach to farm animal respiratory cases

What are the common clinical signs associated with farm animal respiratory diseases?

1. Cough

2. Sneezing

3. Nasal discharge

4. Stertor

5. Strider

6. Change in respiratory rate

7. Change in breath sounds or volume

What are the LESS common clinical signs associated with farm animal respiratory diseases?

1. Cyanosis

2. Exercise intolerance

3. Orthopnea

4. Abducted forelimbs

5. Change in airflow

What are the components of the a physical exam of the respiratory system?

1. Respiratory rate/rhythm/effort

2. Lung field auscultation

3. Tracheal auscultation

4. Thoracic and Sinus Percussion

5. Nasal airflow

What part of the airway is affected with expiratory wheezing?

lower airway

What part of the airway is affected with inspiratory wheezing?

upper airway

What are the diagnostic procedures for the upper airway?

1. Nasal swab

2. Nasopharyngeal swab

3. Rhinoscopy

4. Radiology

5. CT/MRI

What are the diagnostic procedures for the lower airway?

1. Transtracheal wash

2. Bronchoalvealar lavage

3. Ultrasound/Radiology

4. Endoscopy

5. CT/MRI

What are the causes of nasal cavity diseases in farm animals?

1. Granulomas

2. Foreign body

3. Trauma Fighting

4. Parasitic like nasal bots in small ruminants

5. Neoplasias like adenocarcinomas

6. Bacteria like Actinomycosis, Bordatella bronchiseptica

What can chronic allergic rhinitis lead to?

granulomas

What are the infectious causes of allergic rhinitis in cattle?

1. IBR, Adenoviruses, RSV

2. Erosive ulcers: MCF, BVD-MD

3. Actinobacillus

What are the infectious causes of allergic rhinitis in sheep and goats?

1. BTV

2. Oestrus ovis

3. allergic

4. Pseudomonas

What are the infectious causes of allergic rhinitis in pigs?

1. Atrophic rhinitis

2. Swine flu

What are the clinical signs of rhinitis?

1. Generalized inflammation of the nasal mucosa/cavity

2. Sneezing

3. Wheezing

4. Stertor

5. Nasal discharge

6. Unilateral or bilateral airway obstruction

What are the presentations of atrophic rhinitis?

nonprogressive and progressive

What is the cause of nonprogressive atrophic rhinitis?

bordetella bronchiseptica alone

What is the cause of progressive atrophic rhinitis?

toxigenic Pasteurella multocida type D

What are the environmental risk factors for atrophic rhinitis?

poor ventilation, crowding, mixing pigs

What pigs are most affected by atrophic rhinitis?

young growing pigs from 3-9 weeks old

What pigs are often carriers of atrophic rhinitis?

sows and boars

How is atrophic rhinitis transmitted?

direct, often from sow to litter

What are the clinical signs of atrophic rhinitis?

1. Epiphora

2. Sneezing

3. Coughing

4. Serous, mucopurulent nasal discharge

5. Intermittent epistaxis (progressive AR)

6. Deviation or bulging of the snout (progressive AR)

7. Production losses = reduced growth

How is atrophic rhinitis diagnosed?

1. Gross lesions on necropsy

2. Serology for B. bronchiseptica

3. Culture organism from nasal swabs or PCR

How is atrophic rhinitis treated?

antimicrobials like Tylosin, TMS, and Tilmicosin decrease severity of clinical signs but not a cure

How is atrophic rhinitis prevented?

1. Depopulate & restock with atrophic rhinitis-free pigs

2. Improve housing/ventilation/overcrowding

3. Judicious use of antimicrobials in at-risk piglet litters

4. Vaccination of sows/gilts to prevent disease in piglets

What are the nasal tumors in cattle?

1. osteosarcoma

2. squamous cell carcinoma

3. neuroblastoma

4. ethmoid adenocarcinoma

What are the nasal tumors in sheep?

adenocarcinoma

What is significant about adenocarcinomas in sheep?

contagious

What is oestrus ovis?

nasal bots

Where do the nasal bots live?

nasal passages and sometimes the frontal and nasal sinuses

What are the clinical signs of oestrus ovis?

1. Nose pressing

2. Head-shaking, and stomping

3. Sneezing

4. Mucopurulent discharge

5. Nasal obstruction

6. Stertor

7. Decreased production

8. Cribiform plate penetration (uncommon) = fatal

9. Goats often asymptomatic

How is oestrus ovis diagnosed?

presumptive based on clinical signs and visualization of the larvae

How is oestrus ovis treated?

parenteral avermectins have the best efficacy if needed

How is oestrus ovis prevented?

fly management/control

How are micotic nasal diseases treated?

surgery, sodium iodide

How are allergic nasal diseases treated?

reduce exposure, antihistamines, steroids

What farm animal species most commonly gets sinusitis?

cattle

What can cause cornual sinusitis?

post-dehorning

What can cause maxillary sinusitis?

tooth rot

What can cause frontal sinusitis?

extension of cornual sinusitis

What are the differentials for sinusitis?

fractures, tumors, actinobacillus, actinomycosis, LSA, retrobulbar abscess

What are the clinical signs of sinusitis?

1. Nonspecific: anorexia, fever

2. Nasal discharge +/- odor

3. Swelling

4. Changes in air flow

5. Boney changes

6. Stridor

7. Head tilt

8. Dull percussion

9. Exophthalmos

10. Maybe neurologic signs

How is sinusitis treated?

1. Establish drainage

2. Flushing

3. Systemic antimicrobials

4. NSAIDs

5. Fly control

6. Feed on the ground

7. Bandaging to keep clean in some cases

How can drainage be established?

1. Dehorn if still present

2. Trephination

What are the clinical signs of pharyngeal, laryngeal, or tracheal disorders?

1. Inspiratory dyspnea

2. Noisy breathing like honk, stridor, stertor, roar

3. Coughing

4. Head, neck extension

5. Painful to palpation

6. Difficulty swallowing and drooling

7. Anorexia

8. Regurgitation

9. Bloat

10. Fever

11. Swellings •

12. Halitosis (classical for necrotic laryngitis, smells like "Footrot")

What are some common etiologies of pharyngeal, laryngeal, or tracheal disorders?

1. Trauma

2. Abscesses

3. Necrotic laryngitis aka calf diphtheria

What are the causes of pharyngeal trauma and abscesses?

1. Iatrogenic from balling guns, dose syringes, stomach tubes, etc.

2. Mechanical from course feed or foreign objects

3. Infectious from mixed secondary bacterial infections or retropharyngeal LN abscess

What are the clinical signs of pharyngeal trauma and abscesses?

1. Swellings

2. Halitosis

3. Choke, difficulty swallowing and drooling

4. Pyrexia

How are pharyngeal trauma and abscesses diagnosed?

1. oral exam

2. potential FNA

3. potential radiographs or endoscopy

4. ultrasound

How are pharyngeal trauma and abscesses treated?

1. Establish airway if needed

2. Drain the abscess

3. Lavaging and wound management

4. Systemic antibiotics as needed

5. Rumen fistula for feeding if needed

What causes necrotic laryngitis or "calf diphtheria"?

1. secondary fusobacterium necrophorum infection

2. infection of laryngeal mucosa (acute) and/or cartilage (chronic)

3. mucosal injury

What is the pathophysiology of necrotic laryngitis or "calf diphtheria"?

upper respiratory tract injury causes reflex coughing, edema, mucosal damage, and ulcers leading to invasion by fusobacterium necrophorum and subsequent aspiration pneumonia, chronic poor doer or death by asphyxiation/toxemia

What are the early clinical signs of necrotic laryngitis or "calf diphtheria"?

fever, moist painful cough, looks/sounds like upper respiratory disease

What are the late clinical signs of necrotic laryngitis or "calf diphtheria"?

1. Halitosis

2. Honking

3. Severe inspiratory dyspnea

4. Dead calf

What is the treatment for necrotic laryngitis or "calf diphtheria"?

1. Antibiotics like oxytetracycline or PPG or florfenicol

2. 1 dose of steroids in severe cases

3. Tracheostomy in severe cases

4. NSAIDS

5. Nursing/supportive care

6. Surgery

How is necrotic laryngitis or "calf diphtheria" prevented?

1. Prompt intervention if respiratory disease signs

2. Weather changes

3. Vaccinations

4. Reduce stress

What is the general/nonspecific treatment for pharyngeal, laryngeal, or tracheal disorders?

1. Fix primary problem

2. +/- Systemic antibiotics

3. NSAIDs/steroids as indicated

4. Rumen support (fistula, etc.)

5. Tracheostomy

6. Surgery

A group of sheep presents with chronic nasal discharge and sneezing. On investigation, no infectious agents are identified, but granulomatous lesions are noted in the nasal cavity. Which of the following is the most likely underlying cause?

Allergic reaction to environmental plants or fungi

A group of 6-week-old pigs develops sneezing, mucopurulent nasal discharge, and progressive deviation of the snout. Which of the following is most consistent with the progressive form of this disease?

Toxigenic Pasteurella multocida type D

A flock of sheep shows head shaking, sneezing, nasal discharge, and decreased production during the summer months. What is the most likely cause?

Larval infestation of nasal passages by Oestrus ovis

Which of the following is an uncommon but fatal complication of Oestrus ovis infestation?

Cribriform plate penetration

A cow presents with unilateral facial swelling, nasal discharge, and dull percussion over the sinus. The condition developed after dehorning. What is the most likely type of sinusitis?

Cornual sinusitis

A cow develops dysphagia, drooling, swelling in the throat region, and fever after being treated with a balling gun. What is the most likely cause?

Iatrogenic pharyngeal trauma leading to abscess formation

A feedlot calf presents with fever, painful cough, inspiratory dyspnea, and a foul odor described as similar to "footrot." What is the most likely diagnosis?

Necrotic laryngitis (calf diphtheria)

Which of the following events most directly precedes infection with Fusobacterium necrophorum in necrotic laryngitis?

Mucosal injury of the upper respiratory tract

A 5-week-old group of pigs in a crowded, poorly ventilated nursery facility presents with sneezing, coughing, and serous to mucopurulent nasal discharge. Several pigs also have epiphora and intermittent epistaxis. Over the next few weeks, some animals develop deviation and asymmetrical bulging of the snout, along with reduced weight gain compared to unaffected littermates.

The herd veterinarian notes that the sow herd appears clinically normal but has not undergone recent vaccination, and piglets remain housed in mixed-age groups. Diagnostic testing confirms a bacterial etiology associated with toxin production.

Which of the following statements best describes this condition?

It is the progressive form of atrophic rhinitis caused by toxigenic Pasteurella multocida

A group of adult sheep on a farm is evaluated for chronic upper respiratory disease characterized by progressive nasal discharge and decreased productivity. Several animals show no response to antimicrobial therapy. Postmortem examination of one affected animal reveals a large proliferative mass within the nasal cavity. Histopathology confirms a neoplastic process, and herd investigation suggests a contagious etiology.

Which of the following is the most likely diagnosis and underlying cause?

Adenocarcinoma associated with a contagious retrovirus