Auscultation over the larynx, trachea and thorax of healthy and sick animals. Percussion of the thorax. Examination of the cardiovascular system of healthy and dogs and cats.
Small Animal Medicine I. Practical training 2020. Part I. Auscultation and percussion
by Roland Psáder Auscultation over the larynx, trachea and thorax of healthy and sick animals
• Auscultation – Direct/immediate
– Indirect/mediate
• General rules of auscultation – the animal should stand still – a certain examination order should be followed (from the front to the back from up to down in each third of the thorax) – silent circumstances Auscultation of the respiratory tract
• Directly audible respiratory sounds/noises in the stenotic upper airways: – Nose • inflammatory fluid, blood, regurgitated food in the nasopharynx, oedema, mass (polyp, tumor), nasopharyngeal stricture, foreign body, trauma – Larynx • oedema, paralysis, collapse, elongated soft palate (brachycephal syndrome), proliferative laryngitis, tumor – Trachea • collapse, hypoplasia, foreign body, tumor Direct auscultation of stenotic upper airways
• Calm or sedated animals -> sometimes normal findings • Exercising the sick animal -> easily audible respiratory noises • Aim of direct auscultation – Detection of the stenosis – Localisation of the problem (nose/larynx/trachea) Typical directly audible respiratory noises in case of different upper airway stenotic diseases
Nose Pharynx / Larynx Trachea nasopharynx Stenosis without Fluid is Elongated Paralysis Collapse Collapse Hypoplasia fluid present soft palate (BAOS) (BAOS) (BAOS) or mass Dry stridor/ dry Wet Snoring Soft Snoring Goosehonk Snoring sniffing sound stridor/ sound „sawing” sound cough, sound wet sound resonant or or stridor sniffing vibrating sound sound like pig growl Directly audible respiratory noises in case of different upper airway stenotic diseases Auscultation with a stethoscope General rules of auscultation over the airways
• Standing position of the animal on the examination desk, assistant or owner • Certain examination order 1. Larynx 2. Trachea: cervical region, thoracic inlet 3. Thorax: from the front to the back, from up to down in each third of the thorax, both side • Silent circumstances – Environmental noises, owner complaining, colleagues, barking/growling dog, meowing/purring cat Auscultation of the dog Auscultation of the cat Respiratory sounds in different diseases
Normal Bronchial Crepitation Rattling Whistling Wheezing respiratory sound sound sound
Sound Litt12 Litt15 Litt14 Litt19 Litt18 Litt17
Occurrence Physiologic Physiologic Opening and Moving fluid Narrowed airways above larynx closing of in trachea and trachea bronchioli bronchi Accelerated airflow and cranial chest during Vibration of airways inspiration Disease - Bronchitis Chr. bronchitis Lung oedema Bronchitis Feline asthma Pulm. Tracheo- Feline asthma Pneumonia emphysema bronchitis Pulm. tumor Pulm. tumor Pulm. fibrosis Aspiration Pneumonia Above fluid level Interst. oedema pneumonia Percussion of the thorax • Procedure – Hitting with the tip of our middle finger to the distal interphalangeal joint of our other middle finger with repeated wrist bending – Tuning over the muscles
– Pushing our middle finger into the intercostal space – In a standing position/sternal recumbancy of the animal – Silent circumstances – Certain examination order – Short nails Percussion of the thorax
• Main characteristics of percussion sound – Volume/loudness • strong/sharp <–> weak/dull – Pitch/frequency • high <-> low – Tone/resonance • sonorous/resonant <->damped – Duration • short <-> long Percussion of the thorax
• Normal canine/ feline thorax – sharp (strong), high, resonant (sonorous), long sound • Muscle – weak, dull, low, short sound • Abdomen – It depends on the gas content of the GI tract Percussion of the thorax Large dogs (40kg<): sharp, low, resonant, and long percussion sound Medium sized dogs (25-40 kg): sharp, high or low, resonant, and long percussion sound Small animals: sharp, high, resonant, long Main percussion sounds
• Sonorous/resonant (fairly low, strongly resonant) • air containing organ, e.g. normal lungs
• Damped/dull (short sound of low intensity) • any organ not containing gas: liver, heart, muscle
• Tympanic (stronger, longer, higher than sonorous, higher in pitch ) • a hollow organ containing gas under pressure, e.g. gastric volvulus, gas containing intestines • pneumothorax (PTX) • pulmonary emphysema Pleural effusion
Dorsally displaced, compressed lung above the fluid level: Louder than normal or bronchial-like sounds can be heard above the fluid level
Horizontal (upper) border during percussion
No respiratory sounds can be heard under the horizontal line Horizontal dullness The Diernhofer triangle How it was made … Part II. Examination of the cardiovascular system by Gergely Kiss