Objective—To evaluate the features, underlying causes,
results of diagnostic testing, and treatment of
pneumothorax in dairy cattle.
Animals—30 dairy cattle.
Procedure—Medical records of all cattle with a diagnosis
of pneumonia were reviewed. For cattle with
pneumothorax, information was obtained pertaining
to signalment, anamnesis, diagnosis, treatment, and
outcome. Survival data were compared between cattle
with pneumonia with or without pneumothorax.
Results—Pneumothorax was associated with bronchopneumonia
in 18 cattle, interstitial pneumonia in 7
cattle, pharyngeal or laryngeal trauma in 3 cattle, and
neonatal respiratory distress in 2 calves. Bovine respiratory
syncytial virus was the most commonly detected
infectious agent. Eighteen of 30 (60%) cattle survived;
8 were euthanatized and 4 died. Survival rate
was 81% for cattle with pneumonia without pneumothorax
during the same time period. Pneumothorax
was a significant risk factor for failure to survive to discharge
from the hospital for cattle with underlying
Conclusions and Clinical Relevance—Pneumothorax
in dairy cattle appears to occur most commonly in
association with chronic bronchopneumonia. Cattle of
both sexes and all ages can be affected. (J Am Vet Med
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.
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.
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.
Objective—To determine whether Salmonella spp
could be isolated from the environment of free stall
dairies in Wisconsin without any history of clinical salmonellosis
and determine the serotype and antimicrobial
susceptibility of any Salmonella isolates recovered
from the environment.
Study Population—20 free stall dairies with no history
of clinical salmonellosis.
Procedures—Dairy owners completed a questionnaire
regarding management and production practices.
Multiple swab samples were obtained from
throughout the free stall facilities and submitted for
bacterial culture for Salmonella spp. Odds ratios were
calculated to compare herd-level risk factors between
dairies from which Salmonella organisms were isolated
and herds from which Salmonella organisms were
Results—Salmonella organisms were isolated from 9 of
the 20 (45%) dairies. Salmonella serotype Meleagridis
was isolated from 4 dairies, S Meleagridis and S
Kentucky were isolated from 2 dairies, S Meleagridis and
S Cyprus were isolated from 1 dairy, S Cerro was isolated
from 1 dairy, and S Corvallis was isolated from 1
dairy. All isolates were susceptible to all antimicrobial
agents tested. None of the potential risk factors analyzed
demonstrated a significant association with an
increased likelihood of isolating Salmonella spp.
Conclusions and Clinical Relevance—Environmental
Salmonella contamination was demonstrated on free
stall dairies with no history of clinical salmonellosis.
(J Am Vet Med Assoc 2004;225:574–577)
Objective—To evaluate antiviral activity and toxicity
of recombinant human interferon alfa-2a in calves persistently
infected with noncytopathic type 1 bovine
viral diarrhea virus (BVDV).
Animals—5 Holstein heifers, 4 to 12 months of age.
Procedures—Calves persistently infected with noncytopathic
type 1 BVDV were treated with recombinant
human interferon alfa-2a every other day for 12
weeks. Viral loads were measured during the treatment
period and compared with pre- and post-treatment
values. Complete physical examinations were
performed weekly, and calves were observed daily for
signs of systemic illness. Complete blood counts and
serum biochemical analyses were performed before,
during, and after the treatment period. Because
calves developed anemia during the treatment period,
bone marrow biopsy specimens were collected. Antirecombinant
human interferon alfa-2a antibody concentrations
in serum samples obtained before, during,
and after the treatment period were measured by
use of an ELISA.
Results—Recombinant human interferon alfa-2a had
no antiviral activity against noncytopathic type 1
BVDV in persistently infected calves. All calves developed
microcytic anemia during the treatment period
that persisted for up to 13 weeks after cessation of
treatment. Anti-interferon antibodies were detected
during the treatment period and persisted for at least
2 weeks after cessation of treatment.
Conclusions and Clinical Relevance—Because of
lack of in vivo antiviral activity against BVDV, recombinant
human interferon alfa-2a has little promise as a
therapeutic agent for the treatment of BVDV infection,
at least in persistently infected cattle. Furthermore,
treatment was associated with adverse immunologic
and hematologic effects. (Am J Vet Res
Objective—To evaluate cytotoxicity and antiviral
activity of recombinant human interferon alfa-2a and
recombinant human interferon alfa-B/D hybrid against
cytopathic and noncytopathic bovine viral diarrhea
virus (BVDV), infectious bovine rhinotracheitis virus
(IBRV), and vesicular stomatitis virus (VSV) in vitro.
Sample population—Primary bovine testicular cells
and Mardin Darby bovine kidney cells.
Procedures—To evaluate cytotoxicity, cells were added
to serial dilutions of each interferon. To evaluate antiviral
activity of each interferon, interferons were serially diluted
1:10, and tissue culture cells were added; virus was
then added at 3 time points. Prevention of viral infection
by interferon was defined as failure to induce cytopathologic
effect for VSV, IBRV, and cytopathic BVDV and failure
to detect virus immunohistochemically for cytopathic
and noncytopathic BVDV.
Results—No evidence of cytotoxicity in either cell
line was detected after incubation with interferon alfa-
2a or interferon alfa-B/D. However, reduced growth
rates of tissue culture cells were detected for each
interferon when undiluted interferon was tested.
Comparable and profound antiviral activities against
cytopathic and noncytopathic BVDV were evident for
each interferon. Interferon alfa-2a and interferon a-B/D
had comparable antiviral activities against VSV.
Neither interferon had antiviral activity against IBRV.
Conclusions and Clinical Relevance—The safety
and marked in vitro antiviral activity against noncytopathic
BVDV, cytopathic BVDV, and VSV suggest that
interferons alfa-2a and alfa-B/D may be useful for
treatment of natural disease after infection with these
viruses. (Am J Vet Res 2004;65:871–874)
Case Description—A 7-day-old female alpaca was examined because of an acute onset of diffuse central neurologic deficits.
Clinical Findings—Diagnostic imaging with CT and MRI identified an intracranial cyst occupying approximately one-third to one-half of the dorsal portion of the cranial cavity, markedly displacing the cerebral hemispheres bilaterally.
Treatment and Outcome—Initial surgical management via trephination and needle drainage was only transiently effective at resolving the neurologic signs. Craniotomy and drainage and removal of the cyst lining resulted in a sustained improvement in neurologic status, and the cria remained clinically normal and well grown at follow-up 5 months after surgery.
Clinical Relevance—This report represented the first description of the successful treatment of an intracranial cyst in a New World camelid.
Objective—To describe signalment; surgical findings; short-, medium-, and long-term outcome; and recurrence rate for cattle undergoing celiotomy because of jejunal hemorrhage syndrome (JHS) and to analyze risk factors associated with outcome and recurrence.
Design—Retrospective case series.
Animals—31 dairy cattle with JHS.
Procedures—Medical records were analyzed. Follow-up information was obtained from owners of cattle surviving until discharge.
Results—18 of 31 (58%) cattle undergoing celiotomy survived to initial discharge. Fifteen (48%) and 13 (42%) were alive 6 and 12 months after discharge, respectively. All 5 deaths within 12 months after discharge were attributed to JHS recurrence. Survival time was 12 to 85 months for the 13 long-term survivors. Six of 7 that died > 12 months after celiotomy did so for reasons unrelated to JHS. Recurrence rate among short-term survivors was 7 of 18; 1 of these survived long-term. A significant proportion of affected cattle were Brown Swiss, compared with proportions for other breeds. Manual massage of the bowel to break down clots was associated with a significantly higher short-term survival rate than was en-terectomy or enterotomy. Medium- and long-term survival rate was higher in cattle referred 24 to 48 hours after onset of signs. Length of obstructing blood clots was not associated with outcome. Other factors were not significantly associated with recurrence.
Conclusions and Clinical Relevance—Survival rates were higher than those in other reports. Prompt celiotomy and resolution by use of manual massage were associated with higher survival rates. In this population, JHS recurred in 7 of 18 short-term survivors.