The etiology and surgical management of tracheal collapse in calves

A retrospective analysis for criteria of surgical intervention in Japanese Black calves with respiratory signs caused by perinatal rib fracture

Medical records of 16 Japanese Black calves with respiratory signs associated with perinatal rib fracture were analyzed, retrospectively, to speculate criteria of surgical intervention for the disease. For this analysis, the severity of respiratory condition was classified into three grades: Grade 1, with no wheezing, Grade 2, with wheezing after excitement but not at rest and Grade 3, with wheezing at rest. Grade 1 (n=3) received only conservative management. Seven of Grade 2 (n=8) and all of Grade 3 (n=5) had surgical management. Clinical outcome was good in all of Grade 1, and the surgical success rate was 83% in other groups. Our result suggests that surgical intervention should be considered for cases with more the severity of Grade 2.

Resolution of tracheal collapse and stenosis without surgical intervention in two Holstein calves

CASE DESCRIPTION

A 4-month-old 127.5-kg (280.5-lb) Holstein heifer calf (patient 1) and a 4-month-old 174-kg (382.8-lb) Holstein bull calf (patient 2) of high genetic value were examined because of signs of respiratory tract disease (dyspnea, wheezing, and coughing) of 2 and 3 months' duration, respectively, that did not respond to antimicrobial and anti-inflammatory treatment. Patient 1 was born with assistance owing to malpresentation and dystocia. The birth of patient 2 was unobserved.

CLINICAL FINDINGS

For both calves, results of a physical examination, CBC, serum biochemical analysis, thoracic radiography and CT, and nasotracheal endoscopy led to the diagnosis of tracheal collapse and stenosis secondary to perinatal rib fractures. Neither calf had evidence of substantial lower airway disease.

TREATMENT AND OUTCOME

Both calves were discharged from the hospital with the recommendation that they be individually housed in cool, well-ventilated stalls with no access to headlocks. The clinical signs abated, and surgical intervention was not pursued in either patient. Both patients grew as expected and achieved reproductive maturity, with patient 1 becoming an oocyte donor and patient 2 being purchased by a commercial bull stud company. Patient 1 was reevaluated at 21 months old, and patient 2 was reevaluated at 26 months old. Results of follow-up thoracic radiographic (patient 1) and nasotracheal endoscopic (both patients) examinations indicated an anatomically normal trachea with no evidence of collapse or stenosis.

CLINICAL RELEVANCE

This report was the first to describe successful resolution of tracheal collapse and stenosis secondary to perinatal rib fracture in dairy calves without surgical intervention.

Perinatal rib fractures in 18 calves delivered from Holstein dams

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We diagnosed rib fractures by palpation, computed tomography, and thoracic necropsy.

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For 163 symptomatic calves delivered from Holstein-Friesian dams on farms in Japan, 11.0% (18) showed rib fractures by palpation.

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Four of five calves that were scanned or necropsied presented with pneumonia despite not having tracheal stenosis.

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Rib fractures decreased sale prices at a livestock market and longevity.

Cranial rib fractures during dystocia and the ensuing callus formations in calves often cause tracheal stenosis. Rib fractures may affect the lung since ribs tend to fracture above the costochondral junction during delivery. Considering that calving assistance rates for dystocia are high, calves with fractured ribs may develop respiratory disease which results in economic loss. The objective of this study was to elucidate the contribution of rib fractures to economic loss through respiratory disease in calves. Of 163 sick calves delivered from Holstein-Friesian dams included in this study, a total of 18 rib fractured calves was found, giving an incidence of rib fracture in sick calves of 11.0%. There were significant differences in incidence by the rib involved, indicating the 2nd to 7th ribs tend to break. Many of the rib fractured calves showed dyspnea and pyrexia. In this study, four of five scanned or necropsied calves had pneumonia lesions despite the fact that these four calves did not have tracheal stenosis. Rib fractured calves sold at below market value with a median difference from average sale price of minus 64,861 yen. Survival analysis indicated an overall association between rib fracture and time to death. In this study, we demonstrated that rib fractures happened most frequently in the 2nd to 7th ribs, and these cases tended to cause pneumonia, which decreased sale prices and longevity. Farmers should work to reduce risks and rates of dystocia so as to lessen economic loss and poor welfare in calves due to rib fractures.

Case report: clinical and postmortem findings in four cows with rib fracture

Background

Published reports of rib fractures in adult cattle are limited to the occurrence of chronic rib swellings caused by calluses, which are unremarkable from a clinical standpoint, whereas studies identifying clinical signs of rib fractures were not found in a literature search. This report describes the clinical and postmortem findings in four cows with rib fractures.

Case presentation

The 13th rib was fractured in three cows and the 11th rib in the remaining cow; three fractures were on the right and one on the left side. Clinical and postmortem findings varied considerably, and percussion of the rib cage elicited a pain response in only one cow. One cow had generalised peritonitis because of perforation of the rumen by the fractured rib. One cow was recumbent because of pain and became a downer cow, and two other cows had bronchopneumonia, which was a sequel to osteomyelitis of the fracture site in one. In the absence of a history of trauma, the diagnosis of rib fracture based on clinical signs alone is difficult.

Conclusions

Although rib fractures undoubtedly are very painful, the four cases described in this report suggest that they are difficult to diagnose in cattle because associated clinical signs are nonspecific.

Respiratory Surgery

This article is a review of the most frequent disorders affecting the upper airway of cattle that are suitable for surgery. Information regarding the clinical signs, diagnostic methods, and the chemical restraint of cattle in respiratory distress are highlighted. Surgeries that can be performed in a field setting are thoroughly described.

Partial costectomy for tracheal collapse and stenosis associated with perinatal rib fracture in three Japanese Black calves

2.3-month-old (Case 1), one-month-old (Case 2) and 6-month-old (Case 3), Japanese Black calves presented with mild to severe wheezing. All calves had histories of dystocia at birth with breech presentation. Physical examination, thoracic radiography, endoscopy or computed tomography indicated wheezing associated with tracheal collapse and stenosis caused by perinatal rib fractures. Partial resection of the fractured first and second ribs was performed on all calves. The respiration in Cases 1 and 2 immediately improved after the surgery, while Case 3 required two weeks to improve. Cases 1 and 3 grew up healthy and were sold at auction, but Case 2 had a recurrence of wheezing at three months post-discharge and showed growth retarding. Partial costectomy may be an effective solution for control of respiration, however, further cases are required to discuss the criteria for surgical management and to obtain favorable postoperative prognosis in calves with tracheal collapse and stenosis caused by perinatal rib fractures.

Thoracic trauma in foals: post mortem findings

REASONS FOR PERFORMING STUDY

Thoracic trauma occurs in newborn foals and may cause associated clinical signs; this condition remains poorly documented.

OBJECTIVES

The purpose of this study was to describe the pathological features of thoracic trauma in newborn foals presented for necropsy examination between 1990 and 2000.

METHODS

Necropsy reports of foals with thoracic trauma from 1990-2000 were reviewed. Subject details, clinical signs, thoracic and abdominal lesions were noted and analysed statistically.

RESULTS

Sixty-seven (9%) of 760 necropsied foals had thoracic trauma. In 19 foals, fractured ribs were considered to be the cause of death (Group A). The remaining foals had fractured ribs (Group B, n = 20) or rib contusions (Group C, n = 28) that were incidental findings. Ribs 3 to 8 accounted for 86% of the traumatised bones. The most common site of injury was the costochondral junction and an area immediately above it (94%). In Group A, all but 2 foals died within the first 8 days postpartum. Haemothorax and subsequent pulmonary collapse was cited most commonly as the cause of death (53%). Diaphragmatic rupture and hernia (n = 2) also occurred.

CONCLUSIONS

The focal site, consistent location and presence of lesions during the first week post partum, all suggest that thoracic trauma in newborn foals probably occurs during parturition.

POTENTIAL RELEVANCE

The description of lesions and site of occurrence of thoracic trauma in foals will increase awareness and improve the diagnosis and treatment of this life threatening condition.

Use of intraluminal nitinol stents in the treatment of tracheal collapse in a dog

Tracheal collapse is a common problem that is typically observed in middle-aged and older small-breed dogs. It is a structural, obstructive airway disease with a dynamic component that can affect the intra- and extrathoracic portions of the trachea and mainstem bronchi. Many methods of treatment have been suggested, including medical management and provision of extraluminal and intraluminal support. All techniques used to treat intrathoracic and mainstem bronchial collapse have been associated with major complications or limitations. This report describes the implantation of intraluminal nitinol stents to successfully treat intrathoracic as well as extrathoracic tracheal collapse in a dog. The stents are composed of material that has characteristics similar to those of the trachea; nitinol stents may provide a method of supporting intrathoracic tracheal and mainstem bronchial collapse in dogs.

Surgery of the respiratory system

Diseases affecting the respiratory tract are common in cattle; however, surgery required for treatment of these diseases is infrequent. Therefore, veterinarians may be reluctant to perform these surgical procedures. Familiarity with the variety and complexity involved in various surgical procedures should reduce this anxiety. When used, surgery of the respiratory tract can offer significant benefit to the patient and profitable returns to the owner.

Tracheal collapse

Tracheal collapse in calves usually is associated with dystocia at birth, especially breech presentations. Inspiratory dyspnea typically is seen within the first several months of life and may worsen progressively. Lateral cervical radiographs are useful in defining the affected segments as well as identifying previously fractured ribs. Surgical stenting of the trachea will improve the calf's condition, but because this procedure is done on young calves, the tracheal diameter of the affected segment is permanently limited by the size of the prosthesis.

Assessment of the ruminant respiratory system

With practice, complete use of the methods of this assessment: history, detailed examination of the head and neck, cough induction, chest auscultation and percussion, and chest auscultation following forced rebreathing can be completed within 10 minutes. The examination can provide a great deal of new information regarding the respiratory system that would go undetected on a more general physical examination. In cases in which the diagnosis is still in question or requires confirmation, this will also enable the optimal use of appropriate ancillary tests, as described in the article on ancillary testing for the respiratory tract elsewhere in this issue.

Upper respiratory obstruction in foals, weanlings, and yearlings

Upper airway obstruction may result from nasal, pharyngeal, or tracheal diseases. In the young horse, a relatively severe obstruction usually is present before clinical signs are evident. This article reviews the clinical manifestations, diagnostic features, treatment, and outcome of commonly encountered conditions of the nasal passages, pharynx, larynx, and trachea in young horses.