1. Respiratory System

2. Respiratory System
Includes a series of tubes and sacs that function together with the cardiovascular system to provide the body with the exchanges of carbon dioxide and oxygen required for cellular metabolism and life
Oxygen is essential for cellular metabolism
Cells use oxygen and produce carbon dioxide

3. Respiratory System Nose/Nasal Cavity & Mouth/Oral Cavity
Air is warmed and filtered
Pharynx (throat), Larynx (voice box) & Trachea (wind pipe)
Carry air to lungs, communication/ vocalization

4. Respiratory System Bronchi Bronchioles Lungs/Alveoli
trachea splits into two bronchi, one leads to the left lung and the other to the right
Bronchioles
once within the lungs the bronchi continue to divide into these smaller tubes
Lungs/Alveoli
the bronchioles end in small sacs called alveoli. This is where the gas exchange takes place

5. Gas Exchange
the passing of oxygen from the alveoli into the blood and the excess carbon dioxide within the blood flow passing back into the alveoli to be breathed out
each alveoli is surrounded by capillaries

6. Gas Exchange
Oxygen passes through the alveoli walls to the capillaries
The red blood cells take up the oxygen (hemoglobin) and carry it throughout the body (organs and muscles)
Simultaneously, carbon dioxide (waste product) is collected from organs and muscles
Blood carries the carbon dioxide to the lungs where it passes into the alveoli to be breathed out
What would happen if the body did not get rid of carbon dioxide?

7. Breathing Breathing IN = Inspiration Breathing OUT = Expiration
Main Breathing Muscles:
Intercostal
positioned between the ribs
Diaphragm
sheet of muscle; under ribs and lungs

8. Breathing Inspiration
The volume of the thoracic cavity (chest) increases to draw air into the lungs
intercostal muscles and the diaphragm contract
rib cage moves up and out and diaphragm flattens
increases the space
decreases lung air pressure causing air to rush in from outside

9. Breathing
Expiration
At the end of a breath, the intercostal muscles and diaphragm relax
thoracic cavity volume decreases
lung pressure increases
Air forced out

10. Lung Capacity Tidal volume Inspiratory capacity
amount of air breathed in or out with each breath
Inspiratory capacity
maximum amount that can be breathed in (after a normal breath out)
Expiratory reserve volume
additional amount you can breathe out after breathing out normally

11. Lung Capacity Vital capacity Residual volume
maximum amount of air one can possibly breathe in or out in one breath
Residual volume
amount of air left in the lungs after one has breathed out as much as possible

12. 9Lung Volumes (ml) for Normal Young Adult
Humans
9Lung Volumes (ml) for Normal Young Adult
Male
Female
Tidal Volume
500
Inspiratory Reserve Volume
3100
1900
Expiratory Reserve Volume
1200
800
Total Lung Capacity
6000
4200
Functional Residual Capacity (FRC)
2400
1800
Inspiratory Capacity
3600
Vital Capacity
4800
3200

13. Diseases/Disorders Collapsed Trachea
trachea supported by tough rings of cartilage
trachea loses its rigidity and collapse while the dog is breathing (idiopathic)
mostly seen in toy breeds
obese dogs more prone to it

14. Diseases/Disorders Clinical Signs Treatment/Management
Difficulty breathing, especially during exercise
Coughing (attempt to clear airway)
Blue gums and tongue (severe cases)
Treatment/Management
Limited exercise
Harness instead of collar
Diet (if obese)
Cough suppressant (Torbutrol)
Surgery (rare)

15. Diseases/Disorders Laryngeal Paralysis
disorder in which the nerves that control the muscles and cartilage that open and close the larynx (voicebox) do not function properly, causing voice changes and difficulty with eating or breathing
normally, the laryngeal cartilages (arytenoid cartilages) are pulled open during breathing, but with laryngeal paralysis, these cartilages do not open and close properly, making it difficult for the animal to take in air normally

16. Diseases/Disorders Etiology Idiopathic (common) Hereditary (rare)
older, large breed dogs (Labs, Goldens, Saint Bernards, and Siberian Huskies)
over time, the nerves and muscles that control the laryngeal cartilages lose function
Hereditary (rare)
Dalmatian, Bouvier des Flandres, Siberian Husky and English Bulldog
signs of breathing difficulty usually be seen by 2-6 months of age
Injury
Trauma, such as a bite wound

17. Diseases/Disorders Clinical Signs Diagnosis
voice change (bark sounds hoarse)
noisey breathing
gag or choke during eating
Severe: animal cannot take in sufficient air (potentially fatal)
Diagnosis
Under light anesthesia the larynx is examined

18. Diseases/Disorders Treatment
Surgery (“arytenoid lateralization” or “laryngeal tie-back”)
involves putting one or more permanent sutures to hold the arytenoid cartilage open
usually successful

19. Diseases/Disorders Feline Viral Respiratory Diseases highly contagious
spread rapidly
few adult cats die of upper respiratory disease
death rate among young kittens ~ 50%

20. Diseases/Disorders Etiology Clinical Signs
80-90% caused by the herpesvirus group and the calicivirus group
Clinical Signs
Sneezing
Conjunctivitis
Fever (pyrexia)
Eye and nasal discharge
Decrease in appetite (anorexia)
Low energy
Depending on virus: stomatitis and ulceration in oral cavity

21. Diseases/Disorders Diagnosis Treatment Clinical signs Throat cultures
Blood tests
Treatment
Isolate affected cat
Disinfect any fomites
Antibiotics (treat secondary bacterial infections)
Immune supplements (vitamins, amino acids, etc.)