Objective—To describe the clinical findings, treatments, and outcome in alpacas treated for scapulohumeral joint luxation (SHJL).
Design—Retrospective case series.
Procedures—Medical records of alpacas with SHJL that were treated at 2 referral hospitals were reviewed. History, signalment, physical examination results, radiographic findings, treatments, complications, and outcome were evaluated.
Results—Records for 8 male and 2 female alpacas with 16 instances of SHJL were reviewed. Three male alpacas each had 2 recurrences of SHJL in the treated limb. The proportion of male alpacas treated for SHJL was significantly greater than the proportion of female alpacas treated for SHJL. Closed reduction was used in 2 female and 3 male alpacas; SHJL reccurred in the 3 males. Stabilization by use of a lateral extracapsular tension band suture technique was performed successfully in 4 male alpacas; in another male alpaca, reluxation caused by self-inflicted trauma occurred postoperatively. In 2 male alpacas, arthrodesis was performed but residual lameness remained 1 year after surgery.
Conclusions and Clinical Relevance—SHJL should be considered as a differential diagnosis in alpacas with thoracic limb lameness. Luxation may occur more frequently in males. A closed reduction technique may be used successfully to treat acute luxations. Extracapsular stabilization by use of the lateral extracapsular tension band suture technique was successful for treatment of recurrent SHJL and SHJL that could not be reduced via closed reduction.
Objective—To determine effects of ambient temperature, relative humidity, wind speed, relative barometric pressure, and temperature-humidity index (THI) on nasal submucosal and rectal temperatures in cattle during extreme summer conditions.
Animals—20 black crossbred beef heifers (mean body weight, 217.8 kg).
Procedures—Nasal submucosal and rectal temperatures were monitored every 2 hours for 24 hours on 3 nonconsecutive days when ambient temperature was forecasted to exceed 32.2°C. Ambient temperature, relative humidity, wind speed, and relative barometric pressure were continuously monitored at a remote weather station located at the research facility. The THI was calculated and used in the livestock weather safety index (LWSI). Relationships between nasal submucosal or rectal temperature and weather variables were evaluated.
Results—Nasal submucosal and rectal temperatures were related to all weather variables monitored. A positive relationship was determined for ambient temperature and THI with both nasal submucosal and rectal temperatures. A negative relationship was evident for nasal submucosal and rectal temperature with relative humidity, wind speed, and relative barometric pressure. Nasal submucosal and rectal temperatures increased with increasing severity of LWSI category.
Conclusions and Clinical Relevance—Effects of environmental conditions on thermoregulation in calves exposed to extreme heat were detected. The positive relationship between nasal submucosal temperature and ambient temperature and THI raised concerns about the efficacy of intranasal administration of temperature-sensitive modified-live virus vaccines during periods of extreme heat. Environmental conditions must be considered when rectal temperature is used as a diagnostic tool for identifying morbid cattle.
Objective—To evaluate the effect of ambient temperature on viral replication and serum antibody titers following administration of an intranasal modified-live infectious bovine rhinotracheitis (IBR)-parainfluenza-3 (PI3) virus vaccine to beef calves housed in high– (> 32°C) and moderate– (21°C) ambient temperature environments.
Animals—28 calves (mean weight, 206.8 kg).
Procedures—Calves were randomly allocated to 4 treatment groups (housed outdoors during high ambient temperature with [HAT; n = 10] or without [HAC; 4] vaccination or housed indoors in a moderate ambient temperature with [MAT; 10] or without [MAC; 4] vaccination). Rectal and nasal mucosal temperatures were recorded every 2 hours from 8 AM to 8 PM on days 0 (vaccination) and 1. Nasal swab specimens were obtained on days 0 through 7 for virus isolation. Serum samples were collected on days 0, 7, 14, and 28 for determination of antibody titers.
Results—Mean rectal temperature did not differ among the treatment groups. Mean nasal temperature for the HAT group was significantly higher than that for the MAT group at 6, 24, 30, 32, and 38 hours after vaccination. Viable IBR virus was isolated from all vaccinated calves on days 1 through 6. Two weeks after vaccination, vaccinated calves had anti-IBR antibody titers that were significantly greater than those for unvaccinated calves. Mean anti-IBR antibody titers did not differ significantly between the HAT and MAT groups.
Conclusions and Clinical Relevance—Results indicated that, following vaccination with an intranasal modified-live IBR-PI3 virus vaccine, IBR viral replication and serum antibody titers did not differ significantly between calves housed in high– and moderate–ambient temperature environments.
Objective—To determine the effect of transportation during periods of high ambient temperature on physiologic and behavioral indices of beef heifers.
Animals—20 heifers (mean body weight, 217.8 kg).
Procedures—Ten heifers were transported 518 km when the maximum ambient temperature was ≥ 32.2°C while the other 10 heifers served as untransported controls. Blood samples were collected from transported heifers at predetermined intervals during the transportation period. For all heifers, body weights, nasal and rectal temperatures, and behavioral indices were measured at predetermined intervals for 3 days after transportation. A week later, the entire process was repeated such that each group was transported twice and served as the control twice.
Results—Transported heifers spent more time near the hay feeder on the day of transportation, had lower nasal and rectal temperatures for 24 hours after transportation, and spent more time lying down for 2 days after transportation, compared with those indices for control heifers. Eight hours after transportation, the weight of transported heifers decreased 6%, whereas that of control heifers increased 0.6%. At 48 hours after initiation of transportation, weight, rectal temperature, and time spent at various pen locations did not differ between transported and control heifers. Cortisol concentrations were higher 4 hours after initiation of transportation, compared with those determined just prior to transportation.
Conclusions and Clinical Relevance—Results indicated transportation during periods of high ambient temperatures caused transient changes in physiologic and behavioral indices of beef heifers.
Objective—To determine elution characteristics of bone morphogenetic protein (BMP)-2 from a polycaprolactone coating applied to orthopedic implants and determine effects of this coating on osseointegration.
Procedures—An in vitro study was conducted to determine BMP-2 elution from polycaprolactone-coated implants. An in vivo study was conducted to determine the effects on osseointegration when the polycaprolactone with BMP-2 coating was applied to bone screws. Osseointegration was assessed via radiography, measurement of peak removal torque and bone mineral density, and histomorphometric analysis. Physiologic response was assessed by measuring serum bone-specific alkaline phosphatase activity and uptake of bone markers.
Results—Mean ± SD elution on day 1 of the in vitro study was 263 ± 152 pg/d, which then maintained a plateau at 59.8 ± 29.1 pg/d. Mean peak removal torque for screws coated with polycalprolactone and BMP-2 (0.91 ± 0.65 dN·m) and screws coated with polycaprolactone alone (0.97 ± 1.30 dN·m) did not differ significantly from that for the control screws (2.34 ± 1.62 dN·m). Mean bone mineral densities were 0.535 ± 0.060 g/cm2, 0.596 ± 0.093 g/cm2, and 0.524 ± 0.142 g/cm2 for the polycaprolactone–BMP-2–coated, polycaprolactone-coated, and control screws, respectively, and did not differ significantly among groups. Histologically, bone was in closer apposition to the implant with the control screws than with either of the coated screws.
Conclusions and Clinical Relevance—BMP-2 within the polycaprolactone coating did not stimulate osteogenesis. The polycaprolactone coating appeared to cause a barrier effect that prevented formation of new bone. A longer period or use of another carrier polymer may result in increased osseointegration.
Objective—To describe clinical findings, treatments, and outcome in camelids treated for osseous sequestration.
Design—Retrospective case series.
Animals—27 alpacas and 9 llamas with osseous sequestration.
Procedures—Medical records of 2 veterinary teaching hospitals were reviewed to identify camelids evaluated because of osseous sequestration between January 1, 1999, and December 31, 2010. Data on history, signalment, physical examination and medical imaging findings, treatment, and complications were collected.
Results—Records of 36 camelids were included, of which there were 22 sexually intact males, 11 females, and 2 castrated males with a median age of 7. 5 months, 3.9 months, and 8.5 years, respectively (age and sex were not available for 1 camelid). The most common clinical signs were lameness, swelling over the affected bone, and associated draining sinus. Sequestra were associated with trauma in 7 (19%) camelids. Camelids with sequestra not associated with trauma (n = 29 [81%]) were significantly younger than those with sequestra attributed to trauma. Thirty-four camelids underwent sequestrectomy, and all survived to hospital discharge (median duration of hospitalization, 6.5 days). Recurrence of a sequestrum occurred twice in 1 (3%) camelid. Long-term follow-up (≥ 12 months) information was available on 24 camelids, of which 20 (83%) recovered without long-term complications.
Conclusions and Clinical Relevance—Unlike in other livestock, trauma was not a primary cause of osseous sequestration in camelids. Sequestra should be considered in the differential diagnostic process in camelids with lameness, a draining sinus, or a firm swelling over a bony prominence. Sequestrectomy is a successful treatment option.
Objective—To characterize amphotericin B–induced lameness in cattle and to ascertain the analgesic effects of flunixin meglumine by use of multimodal assessment.
Animals—10 healthy Holstein steers free from musculoskeletal disease.
Procedures—Steers were randomly allocated to a treatment or negative control group. Amphotericin B was injected into the distal interphalangeal joint of the lateral claw of the left hind limb of all steers. Treatment steers received flunixin meglumine at the time of synovitis-arthritis induction and at 12 hours after induction. Control steers received no medication. Multimodal analysis included vital parameters, visual lameness score, behavioral monitoring with accelerometers, pressure mat analysis, and plasma cortisol determination before and after induction. Data were analyzed by use of linear mixed models with treatment and time designated as fixed effects, accounting for repeated measures on individual calves.
Results—Amphotericin B injection induced moderate, transient lameness. Control steers were more than twice as likely to be lame as treatment steers (mean ± SD lameness score, 92.2 ± 8.1 % vs 40.7 ± 2.5%). Treatment steers placed significantly greater force and contact area on the affected foot and greater force, impulse, and contact area on the paired claw, compared with control steers. Furthermore, treatment steers spent considerably less time in recumbency than controls.
Conclusions and Clinical Relevance—Amphotericin B successfully induced synovitis-arthritis in dairy steers that was transient in nature. Flunixin meglumine was efficacious in providing analgesia for these steers.
Objective—To determine the response of cortical bone to a multicomponent and nanostructural polymeric matrix as a drug delivery system for enhancing bone healing.
Animals—20 healthy adult crossbred goats.
Procedures—A 3.5-mm-diameter unicortical defect was created in each tibia (day 0), and goats (4 goats/group) were treated as follows: not treated (control group), grafted with the matrix, grafted with antimicrobial (tigecycline and tobramycin)–impregnated matrix, grafted with recombinant human bone morphogenetic protein type 2 (rhBMP-2)–impregnated matrix, or grafted with antimicrobial- and rhBMP-2–impregnated matrix. Elution kinetics of antimicrobials was monitored through plasma concentrations. Bone response was assessed with radiographic scoring (days 1 and 30) and dual-energy x-ray absorptiometry (days 1, 14, and 30). Goats were euthanized on day 30, and histomorphologic analysis was performed. Categorical variables were analyzed with a generalized linear model, and continuous variables were analyzed with an ANOVA.
Results—Plasma antimicrobial concentrations indicated continued release throughout the study. Radiography and dual-energy x-ray absorptiometry did not reveal significant differences among treatments on day 30. Periosteal reactions were significantly greater surrounding bone defects grafted with rhBMP-2–impregnated matrix than those not treated or grafted with matrix or with antimicrobial-impregnated matrix; periosteal reactions were similar in bone defects grafted with rhBMP-2–impregnated matrix and antimicrobial- and rhBMP-2–impregnated matrix.
Conclusions and Clinical Relevance—The matrix served as an antimicrobial delivery system and stimulated bone proliferation when rhBMP-2 was present. Antimicrobial and rhBMP-2 can be used concurrently, but the presence of antimicrobials may affect the performance of rhBMP-2.
Objective—To determine electrocardiographic parameters
in healthy llamas and alpacas.
Animals—23 llamas and 12 alpacas.
Procedure—Electrocardiography was performed in
nonsedated standing llamas and alpacas by use of multiple
simultaneous lead recording (bipolar limb, unipolar
augmented limb, and unipolar precordial leads).
Results—Common features of ECGs of llamas and
alpacas included low voltage of QRS complexes, variable
morphology of QRS complexes among camelids,
and mean depolarization vectors (mean electrical
axes) that were directed dorsocranially and to the
right. Durations of the QT interval and ST segment
were negatively correlated with heart rate.
Conclusions and Clinical Relevance—ECGs of
acceptable quality can be consistently recorded in
nonsedated standing llamas and alpacas. Features of
ECGs in llamas and alpacas are similar to those of other
ruminants. Changes in the morphology of the QRS
complexes and mean electrical axis are unlikely to be
sensitive indicators of ventricular enlargement in llamas
and alpacas. (Am J Vet Res 2004;65:1719–1723)