Diaphragmatic Paralysis Due to Phrenic Nerve Degeneration in a Llama

Abstract

A 7-month-old 60-kg male llama was presented to the Tufts University School of Veterinary Medicine with a 5-day history of increasing respiratory difficulty and slight dragging of his hind toes. The cria had no history of previous illness, and all other animals in the herd were healthy.On presentation, the llama appeared alert and responsive despite a markedly increased respiratory effort with pronounced costal expansion and paradoxical inward movement of the abdominal musculature during inspiration. Harsh bronchovesicular lung sounds were heard bilaterally, but auscultation of the upper airways was normal and nasal airflow was bilaterally symmetric. The cria further displayed a mild tachypnea (32 breaths/min; normal: 10-30 breaths/min) 1 but a normal, regular heart rate (62 beats/min; normal: 60-90 beats/min), 1 femoral pulse, and rectal temperature (100.2ЊF; normal: 99.5-102ЊF).1 Neurologic evaluation revealed a mild hind-end weakness and circumduction of the outer pelvic limb when turning. Bilateral scuffing of the hind toes was observed at a walk, and inappropriate posture and foot placement were evident while stepping over obstacles. The llama's anal tone and cutaneous and deep pain sensations were normal, and cranial nerve deficits were not evident. The subsequent musculoskeletal examination revealed no significant abnormalities.A CBC revealed a mildly increased white blood cell (WBC) count (24.1 ϫ 10 3 WBC/L; normal: 8-23.8 ϫ 10 3 WBC/L) 2 with an absolute neutrophilia (19.3 ϫ 10 3 neutrophils/L; normal: 2.5-13.4 ϫ 10 3 neutrophils/L) 2 and normal fibrinogen concentration (300 mg/dL; normal: 100-400 mg/dL).2 The chemistry profile was considered normal except for a mild hyperglycemia (233 mg/dL; normal: 76-176 mg/dL).2 Chest radiographs, however, revealed a diffuse interstitial lung pattern within the caudal lung field, which appeared excessive for the animal's age.Objective assessment of respiratory function was obtained through the concurrent application of respiratory inductive plethysmography (RIP) and pneumotachography. Respiratory inductive plethysmography has been described previously and has been validated for use in humans, 3,4 horses, 5-7 and sheep. Medicine, 200 Westboro Road, North Grafton, MA 01536; e-mail: daniela. bedenice@tufts.edu. Submitted November 16, 2001; Revised January 10, 2002; Accepted April 15, 2002. Copyright around the thorax and abdomen. When each band stretches and contracts because of normal respiratory movements, the sinusoidal pattern of the wire is deformed and alters the generated magnetic field. These alterations can be measured as voltage changes, which are proportional to the change in circumference and volume of the thorax and abdomen. 7 The voltage signal was amplified and digitized for processing using recording and analysis software. a Nasal flow (V n ) was measured through the use of a heated pneumotachograph.b The cria was fitted with a solid plastic facemask that was sealed approximately 5 cm behind the external nares with a latex shroud. The nose piece w...

Evaluation of Diaphragmatic Motion in Normal and Diaphragmatic Paralyzed Dogs Using M‐mode Ultrasonography

“…D iaphragmatic paralysis has been reported in a variety of animal species including llamas, alpacas, ponies, dogs, and cats . Proposed mechanisms include pneumonia, trauma, neuropathy (degeneration of the phrenic nerves that innervate the diaphragm muscles), myopathy or idiopathic causes .…”

“…The paralysis may be unilateral or bilateral, and may be temporary or permanent. Unilateral diaphragmatic paralysis can be asymptomatic; however, bilateral paralysis produces severe clinical signs such as abdominal breathing or cyanosis with apnea …”

Thoracic Imaging and Respiratory Surgery

“…The terms "rachitic rosary" or "beading of the ribs" refers to the prominent bony knobs that develop at the costochondral joints of rachitic patients. 27 The disease may be unilateral or bilateral, depending on both the left-and right-sided phrenic nerves being involved. When viewing the thoracic radiographs of young patients, the evaluator should inspect the skeletal system, as evidence of rickets may be identified early in subclinical patients who present for other reasons.…”

Diaphragmatic dysfunction in dogs with cervical spinal disorders before and after surgery using fluoroscopy, motion‐mode ultrasound and radiography was not different than a group of control dogs

“…Respiratory distress secondary to diaphragmatic dysfunction has been reported in many species including alpacas, cats, dogs, llamas, humans, and ponies . Diaphragmatic dysfunction is suspected to be a cause of respiratory complications in dogs with cervical spinal disorders .…”