Chapter 46 Diseases of the Respiratory System SNAKES Pneumonias Pneumonia is a common presenting sign in the sick reptile patient. Although pneumonia is primarily a disease of the respiratory system, its cause may be multifactorial. A number of infectious agents can cause pneumonia, and if linked to poor husbandry, an inadequate diet, and poor sanitation, a serious and often life-threatening disease may result. The respiratory system of the reptile is unlike that of the mammal. The glottis of snakes is situated rostrally in the oral cavity, allowing for respiration while eating large meals. Most snakes have only one functional lung, the left one being absent. Reptiles, unlike mammals, can function using anaerobic metabolism, which allows them to compensate for increasing respiratory disease until it is well advanced. Respiration is usually controlled, not by blood carbon dioxide levels and pH, but by the temperature and the partial pressure of oxygen (PO2) in the tissues. As the temperature increases so does the oxygen demand, which the patient meets by increasing tidal volume, not respiratory rate. Environments rich in oxygen (oxygen cages) can, therefore, suppress ventilation in the sick patient. Together, the poor ability of the reptile lung to move inflammatory exudates out of the lung, the suppressed tidal volumes resulting from pulmonary infiltrates and exudates, and the ability of the reptile to shift to anaerobic metabolism can make early diagnosis of disease quite difficult. CLINICAL SIGNS • Dyspnea (open-mouth breathing) • Extension of the neck to facilitate breathing • Increased respiratory rate • +/− Nasal discharge • Abnormal respiratory sounds • Cyanotic mucous membranes • Depression, lethargy • Reluctance to feed DIAGNOSIS • Physical examination and history • Radiographs • Transtracheal wash (catheter inserted via the glottis) • Culture and sensitivity; wet mount for parasites • Complete blood cell count (CBC) and serum chemistries TREATMENT • Will depend on the diagnostic laboratory results • Antibiotic therapy Usually begin with a combination therapy of aminoglycoside/β-lactam antibiotic while waiting for culture results Nebulization using antibiotics: 10 to 30 minutes three to four times daily • Increase environmental temperatures to top of the preferred optimal temperature zone (POTZ) • Maintain hydration (1%–2% body weight subcutaneously daily) • Force-feed if not too stressful • It is often difficult to know when to stop treating the patient. Antibiotics should be used for a minimum of 3 weeks or until the hemogram and patient appear to be improving (eating, breathing better, etc.) IGUANAS The respiratory system of the lizard is different from that of mammals. The position of the glottis is variable in lizards, being more rostral in carnivorous lizards and at the base of the tongue in others. The tracheal rings are incomplete, and the trachea bifurcates near the base of the heart. Lizard lungs are equal in size, and gas exchange occurs in the cranial portions. The caudal portions function similar to the air sacs of birds, being poorly vascularized and not used for respiratory functions. Both inspiration and expiration are active processes in the lizard, and no diaphragm exists to facilitate respiration. As in snakes, lizards have the ability to function with anaerobic metabolism and may be able to conceal disease until it is advanced. Pneumonias Pneumonias are common in reptiles. They may be the result of bacterial, viral, fungal, or parasitic infections. CLINICAL SIGNS • Dyspnea; open-mouthed breathing • +/− Nasal discharge • Increased respiratory sounds on auscultation • Anorexia • +/− Cyanotic mucous membranes • Depression • Lethargy DIAGNOSIS • CBC and serum chemistries • Radiography (lateral view is most important) • Transtracheal wash (actually done by passing a catheter through the glottis and injecting sterile saline into the lung, then retrieving the fluid for culture and sensitivity) • Culture and sensitivity testing of tracheal wash Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Hematologic and Immunologic Diseases Hematologic and Immunologic Diseases Diseases of the Cardiovascular System Diseases of the Musculoskeletal System Stay updated, free articles. Join our Telegram channel Join Tags: Common Diseases of Companion Animals Aug 31, 2016 | Posted by admin in GENERAL | Comments Off on Diseases of the Respiratory System Full access? Get Clinical Tree
Chapter 46 Diseases of the Respiratory System SNAKES Pneumonias Pneumonia is a common presenting sign in the sick reptile patient. Although pneumonia is primarily a disease of the respiratory system, its cause may be multifactorial. A number of infectious agents can cause pneumonia, and if linked to poor husbandry, an inadequate diet, and poor sanitation, a serious and often life-threatening disease may result. The respiratory system of the reptile is unlike that of the mammal. The glottis of snakes is situated rostrally in the oral cavity, allowing for respiration while eating large meals. Most snakes have only one functional lung, the left one being absent. Reptiles, unlike mammals, can function using anaerobic metabolism, which allows them to compensate for increasing respiratory disease until it is well advanced. Respiration is usually controlled, not by blood carbon dioxide levels and pH, but by the temperature and the partial pressure of oxygen (PO2) in the tissues. As the temperature increases so does the oxygen demand, which the patient meets by increasing tidal volume, not respiratory rate. Environments rich in oxygen (oxygen cages) can, therefore, suppress ventilation in the sick patient. Together, the poor ability of the reptile lung to move inflammatory exudates out of the lung, the suppressed tidal volumes resulting from pulmonary infiltrates and exudates, and the ability of the reptile to shift to anaerobic metabolism can make early diagnosis of disease quite difficult. CLINICAL SIGNS • Dyspnea (open-mouth breathing) • Extension of the neck to facilitate breathing • Increased respiratory rate • +/− Nasal discharge • Abnormal respiratory sounds • Cyanotic mucous membranes • Depression, lethargy • Reluctance to feed DIAGNOSIS • Physical examination and history • Radiographs • Transtracheal wash (catheter inserted via the glottis) • Culture and sensitivity; wet mount for parasites • Complete blood cell count (CBC) and serum chemistries TREATMENT • Will depend on the diagnostic laboratory results • Antibiotic therapy Usually begin with a combination therapy of aminoglycoside/β-lactam antibiotic while waiting for culture results Nebulization using antibiotics: 10 to 30 minutes three to four times daily • Increase environmental temperatures to top of the preferred optimal temperature zone (POTZ) • Maintain hydration (1%–2% body weight subcutaneously daily) • Force-feed if not too stressful • It is often difficult to know when to stop treating the patient. Antibiotics should be used for a minimum of 3 weeks or until the hemogram and patient appear to be improving (eating, breathing better, etc.) IGUANAS The respiratory system of the lizard is different from that of mammals. The position of the glottis is variable in lizards, being more rostral in carnivorous lizards and at the base of the tongue in others. The tracheal rings are incomplete, and the trachea bifurcates near the base of the heart. Lizard lungs are equal in size, and gas exchange occurs in the cranial portions. The caudal portions function similar to the air sacs of birds, being poorly vascularized and not used for respiratory functions. Both inspiration and expiration are active processes in the lizard, and no diaphragm exists to facilitate respiration. As in snakes, lizards have the ability to function with anaerobic metabolism and may be able to conceal disease until it is advanced. Pneumonias Pneumonias are common in reptiles. They may be the result of bacterial, viral, fungal, or parasitic infections. CLINICAL SIGNS • Dyspnea; open-mouthed breathing • +/− Nasal discharge • Increased respiratory sounds on auscultation • Anorexia • +/− Cyanotic mucous membranes • Depression • Lethargy DIAGNOSIS • CBC and serum chemistries • Radiography (lateral view is most important) • Transtracheal wash (actually done by passing a catheter through the glottis and injecting sterile saline into the lung, then retrieving the fluid for culture and sensitivity) • Culture and sensitivity testing of tracheal wash Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Hematologic and Immunologic Diseases Hematologic and Immunologic Diseases Diseases of the Cardiovascular System Diseases of the Musculoskeletal System Stay updated, free articles. Join our Telegram channel Join Tags: Common Diseases of Companion Animals Aug 31, 2016 | Posted by admin in GENERAL | Comments Off on Diseases of the Respiratory System Full access? Get Clinical Tree
