Aubrey N. Baird

Prevalence and distribution of radiographically evident lesions on repository films in the hock and stifle joints of yearling Thoroughbred horses in New Zealand.

Abstract AIM: To characterise the prevalence and distribution of radiographic changes in the hocks and stifles of Thoroughbred yearling colts and fillies in New Zealand and compare them with other populations of young horses. METHODS: Repository radiographs taken in New Zealand for the 2003–2006 Thoroughbred national yearling sales were evaluated by two individual readers. The distribution of radiographic changes was classified as left side only, right side only, or bilateral. Lesions were categorised by type, location, and sex of the yearling. Complete sets of hock and stifle radiographs of 1,505 yearlings were evaluated. RESULTS: Osteophytes or enthesophytes were seen radiographically in the distal tarsal joints of 460/1,505 (31%) horses. Osteochondrosis was seen in the tibiotarsal joint of 66/1,505 (4%) horses, and in the femoropatellar joint of 40/1,505 (3%) horses. Radiographic lucency in the distal or axial aspect of the medial femoral condyle was seen in 247/1,505 (16%) horses, and lucencies consistent with subchondral cyst-like lesions were seen in 26/1,505 (2%) horses. No significant difference was seen in the proportion of colts and fillies with radiographic changes in the hock or stifle. The prevalence of osteochondrosis and subchondral cyst-like lesions in the stifles of the yearlings examined were similar to those reported in Thoroughbred yearling sale horses in the United States of America (USA). The prevalence of changes in the distal tarsal joints was similar to those reported in Standardbred and Thoroughbred yearlings from Scandinavia and the USA. CONCLUSIONS: There was no significant difference in the prevalence of osteochondrosis in the hock and stifle, lucencies in the distal medial femoral condyle, or radiographic changes in the distal tarsal joints between colts and fillies. CLINICAL RELEVANCE: Establishment of the normal prevalence and distribution of radiographic changes in the hocks and stifles of Thoroughbred yearlings in New Zealand will allow comparison with populations of young horses in other countries. Knowledge of the normal prevalence will assist veterinarians to identify abnormally high or low prevalences on individual farms, to further investigate the pathogenesis of the lesions.

Umbilical surgery in calves.

Calves benefiting from umbilical surgery can be affected by several different conditions. However, the practitioner should be able to correct any of these conditions surgically, especially in young calves, as a field procedure. Like other aspects of veterinary practice, the individual must decide what services he/she wishes to offer clients in the field or clinic setting and which ones will be referred. The objective of this article is to equip practitioners who wish to treat umbilical masses surgically with the information they need.

Evidence-Based Use of Prokinetic Drugs for Abomasal Disorders in Cattle

Abomasal hypomotility is a prerequisite for abomasal displacement in cattle and is present immediately after surgical correction of left displaced abomasum or abomasal volvulus. Hypocalcemia, hypokalemia, and hyperinsulinemia should be corrected in cattle suspected to have abomasal hypomotility. The most effective prokinetic for calves and adult cattle suspected to have abomasal hypomotility is erythromycin.

Use of the Thomas Splint and Cast Combination, Walker Splint, and Spica Bandage with an Over the Shoulder Splint for the Treatment of Fractures of the Upper Limbs in Cattle

Many tibial and radial-ulnar fractures in cattle and small ruminants may be treated successfully with Thomas splint and cast combinations (TSCC). The Walker splint has been specifically designed for treating tibial fractures and stifle injuries in cattle.It usually fits better in rear limbs of cattle than the TSCC and thus can provide more stability. Spica bandages combined with lateral splints placed over the dorsum of the affected limb and down the contralateral shoulder may be used for partial immobilization of humeral fractures in calves and small ruminants when surgical repair is not an option.

Surgery of the Umbilicus and Related Structures.

Ruminants of all types requiring umbilical surgery can be affected by a number of different conditions. However, the practitioner should be able to correct any of these conditions surgically, especially in young animals, as a field procedure if appropriate restraint and environment are available. Like other aspects of veterinary practice, the individual must decide what services he or she wishes to offer clients in their practice and which ones will be referred. The objective of this article is to equip veterinarians who wish to treat umbilical masses surgically with the information they need.

Disseminated Rhodococcus equi in an Anglo‐Nubian goat

Disseminated Rhodococcus equi infection was diagnosed in an Anglo-Nubian goat presenting for non-weight bearing lameness of the right pelvic limb. Radiographs showed a moth-eaten osteolytic lesion in the proximal tibia suggestive of an aggressive bone lesion. Two pulmonary nodules were also present on thoracic radiographs. Initial antemortem cytology of the tibial lesion was suggestive of Rhodococcosis and the goat was sent to necropsy. Necropsy and bacterial culture confirmed the diagnosis of disseminated R. equi infection in the right tibia, lungs, and liver.

Clinical signs and outcomes of beef cattle undergoing cesarean section because of dystocia

OBJECTIVE To characterize signalment, clinical signs, reproductive history, surgical management, and outcomes of beef cattle undergoing cesarean section because of dystocia at a veterinary teaching hospital. DESIGN Retrospective case series with nested cohort study. ANIMALS 173 beef cattle admitted to a veterinary teaching hospital from 2001 through 2010 that underwent cesarean section because of dystocia. PROCEDURES Medical records were reviewed and information collected on cattle signalment; reproductive history; cause of dystocia; anesthetic protocol; surgical management; number, sex, and body weight of calves delivered (alive or dead); perioperative treatment; duration of hospitalization; and discharge status. A questionnaire regarding postoperative fertility was mailed to all owners, and owners who did not respond were contacted via telephone. RESULTS Overall mortality rate for calves was high, with 37.6% (62/165) of calves delivered dead or dying ≤ 24 hours after cesarean section. Mortality rate was higher for female versus male calves and for calves from dams with signs of labor for ≥ 3 hours versus < 3 hours before hospital admission. Overall mortality rate for dams was low, with only 10 of 161 (6.2%) dams failing to survive for ≥ 21 days after hospital discharge. Postoperative fertility rate was acceptable, with 75% (44/59) of dams that were rebred after cesarean section giving birth to ≥ 1 live calf. CONCLUSIONS AND CLINICAL RELEVANCE Cesarean section was a clinically useful method for resolving dystocia in beef cattle, providing a high dam survival rate and an acceptable postoperative fertility rate. Beef cattle producers should seek veterinary assistance whenever clinical signs of dystocia are noticed, preferably within 6 hours after onset of parturition.

Optimized computed tomography protocol for assessment of dentition in alpacas

OBJECTIVE To determine the optimal protocol for acquisition of CT images of the dentition in alpacas. ANIMALS 3 healthy adult male alpacas. PROCEDURES Each alpaca was anesthetized with an IM injection of a combination of ketamine, xylazine, and butorphanol and positioned in sternal recumbency on the CT couch with its legs folded in a natural cush position and its head positioned within the isocenter of the gantry of a 64-slice CT scanner. Images were acquired by means of 6 protocols (sequential and helical modes at slice thicknesses of 1.25, 2.5, and 5 mm). Five images (2 molar, 2 premolar, and mandibular incisor teeth) were selected from each protocol for evaluation by 3 veterinary radiologists. For each image, tooth root visibility and sharpness and image noise artifact were subjectively evaluated on a 3-point scoring system. RESULTS Slice thickness significantly affected tooth root visibility and tooth root sharpness but did not affect image noise artifact. Acquisition mode significantly affected tooth root visibility and tooth root sharpness as well as image noise artifact. Tooth root visibility and sharpness did not differ significantly between the helical and sequential images when the slice thickness was 1.25 mm. Image noise artifact was greater for helical images than sequential images but did not differ by slice thickness within either acquisition mode. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that for a 64-slice CT scanner, the optimal protocol for the acquisition of CT images of the dentition in alpacas was a sequential scan with a slice thickness of 1.25 mm.

Evaluation of three intravenous injectable anaesthesia protocols in healthy adult male alpacas

Few studies have investigated the effects of intravenous injectable anaesthesia in alpacas. The objective of this study was to evaluate three intravenous injectable anaesthesia protocols in healthy adult alpacas exposed to noxious stimulation. A prospective randomised crossover study was done using six healthy adult male alpacas. Cardiopulmonary variables including heart rate, respiratory rate, mean arterial pressure, end-tidal pCO2 and haemoglobin oxygen saturation were collected immediately after and every two minutes following induction of each of three anaesthesia protocols in six male castrated alpacas. A hoof tester was used to apply consistent pressure every two minutes after induction and the response was recorded. Time from induction to muscle contraction and leg withdrawal were recorded, as well as time from induction to extubation, sternal recumbency and standing. There was no significant difference in duration of anaesthesia or cardiopulmonary variables among the three anaesthesia protocols. Total duration of anaesthesia was approximately 20 minutes for each protocol. Hypoxaemia and mild hypercarbia were common among all protocols. Induction and recovery scores were excellent.

Comparison of omentopexy versus pyloro-omentopexy for treatment of left abomasal displacement in dairy cows: 87 cases (2001–2005)

OBJECTIVE To evaluate reproductive performance and productive longevity of dairy cows treated for left displaced abomasum (LDA) with 1 of 2 surgical techniques (omentopexy vs pyloro-omentopexy). DESIGN Retrospective case series. ANIMALS 87 Holstein cows that underwent omentopexy or pyloro-omentopexy for LDA during a 5-year period. PROCEDURES For each cow with LDA, the most recent date of calving, age at time of surgery, and surgical procedure were recorded. Dairy records of cows treated for LDA in the 5-year period were reviewed to determine their reproductive performance. Records available for up to 4 years after the last surgery (ie, when all treated cows had left the herd) were reviewed to determine cull dates and reasons for treated and untreated cows in the herd. RESULTS Of the 87 cows with LDA, 58 underwent pyloro-omentopexy and 29 underwent omentopexy. Cows in the 2 treatment groups did not significantly differ in age. Fifty-six cows completed > 1 subsequent lactation cycle after surgery. The median time that cows with LDA remained in the herd was 566 days (range, 24 to 1,838 days); the times for the 2 treatment groups did not significantly differ. For treated and untreated cows, cull rates for reproductive failure or other problems were similar. Four (14%) omentopexy-treated cows and no pyloro-omentopexy-treated cows had a reoccurrence of LDA. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that cows with LDA that underwent omentopexy or pyloro-omentopexy had similar cull rates and reasons as unaffected herd mates over their productive time in the herd. Between the 2 treatment groups, only the LDA reoccurrence rate differed.