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Abstract

Objective—To determine whether kinematic changes induced by heel pressure in horses differ from those induced by toe pressure.

Animals—10 adult Quarter Horses.

Procedure—A shoe that applied pressure on the cuneus ungulae (frog) or on the toe was used. Kinematic analyses were performed before and after 2 levels of frog pressure and after 1 level of toe pressure. Values for stride displacement and time and joint angles were determined from horses trotting on a treadmill.

Results—The first level of frog pressure caused decreases in metacarpophalangeal (fetlock) joint extension during stance and increases in head vertical movement and asymmetry. The second level of frog pressure caused these changes but also caused decreases in stride duration and carpal joint extension during stance as well as increases in relative stance duration. Toe pressure caused changes in these same variables but also caused maximum extension of the fetlock joint to occur before midstance, maximum hoof height to be closer to midswing, and forelimb protraction to increase.

Conclusion and Clinical Relevance—Decreased fetlock joint extension during stance and increased head vertical movement and asymmetry are sensitive indicators of forelimb lameness. Decreased stride duration, increased relative stance duration, and decreased carpal joint extension during stance are general but insensitive indicators of forelimb lameness. Increased forelimb protraction, hoof flight pattern with maximum hoof height near midswing, and maximum fetlock joint extension in cranial stance may be specific indicators of lameness in the toe region. Observation of forelimb movement may enable clinicians to differentiate lameness of the heel from lameness of the toe. (Am J Vet Res 2000;61:612-619)

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To develop a partial budget analysis of direct costs associated with bovine respiratory disease (BRD) in preweaned calves on US beef cow–calf operations and identify factors that strongly influence those costs.

DESIGN Risk analysis model.

ANIMALS US preweaned beef calf inventory from 2011 through 2015.

PROCEDURES A stochastic simulation model was developed by use of a computer spreadsheet and add-in software. Input data were obtained from the USDA, peer-reviewed literature, and a survey of beef cow–calf producers. A simulation consisting of 10,000 iterations was used to account for either uncertainty or variability in model inputs. The median (90% confidence interval) was reported for each output variable. Global and local sensitivity analyses were performed to identify the most influential factors and quantitatively evaluate the effects of inputs on the estimated costs.

RESULTS From 2011 through 2015, BRD in preweaned calves cost the US beef cow–calf industry approximately $165 million annually, of which costs associated with the death, treatment, and decreased weaning weight of BRD-affected calves were approximately $126, $25, and $15 million, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE Although BRD in preweaned calves may have a fairly small effect on the total gross income for the US beef cow–calf industry as a whole, it can have a substantial adverse effect on the net profit of BRD-affected herds. The model developed provided important information regarding the cost of BRD in preweaned calves on US beef cow–calf operations and identified factors that had an import effect on those costs.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To identify hind limb and pelvic kinematic variables that change in trotting horses after induced lameness of the distal intertarsal and tarsometatarsal joints and after subsequent intra-articular administration of anesthetic.

Animals—8 clinically normal adult horses.

Procedure—Kinematic measurements were made before and after transient endotoxin-induced lameness of the distal intertarsal and tarsometatarsal joints and after intra-articular administration of anesthetic. Fourteen displacement and joint angle (metatarsophalangeal [fetlock] and tarsal joints) measurements were made on the right hind limb, sacrum, and the right and left tubera coxae. Kinematic measurements were compared by general linear models, using a repeated measures ANOVA. Post hoc multiple comparisons between treatments were evaluated with a Fisher least squared difference test at α = 0.05.

Results—After lameness induction, fetlock and tarsal joint extension during stance decreased, fetlock joint flexion and hoof height during swing increased, limb protraction decreased, and vertical excursion of the tubera coxae became more asymmetric. After intra-articular administration of anesthetic, limb protraction returned to the degree seen before lameness, and vertical excursion of the tubera coxae became more symmetric.

Conclusions and Clinical Relevance—Increased length of hind limb protraction and symmetry of tubera coxae vertical excursion are sensitive indicators of improvement in tarsal joint lameness. When evaluating changes in tarsal joint lameness, evaluating the horse from the side (to assess limb protraction) is as important as evaluating from the rear (to assess pelvic symmetry). (Am J Vet Res 2000;61:1031–1036)

Full access
in American Journal of Veterinary Research

Abstract

Case Description—A 6-month-old male Bactrian camel was examined because of a 3-week history of lameness of the left hind limb.

Clinical Findings—Lameness was initially detected in the left hind limb but resolved and was detected in the right hind limb during treatment. Lameness increased during periods of rapid growth. Radiography revealed multiple small opacities of the medullary cavity of several long bones throughout treatment. Core bone biopsies of lesions in the tibiae revealed lamellar bone with areas of loose connective tissue, osteoblasts in the medullary cavity, and periosteal new bone formation, all which were consistent with panosteitis.

Treatment and Outcome—Palliative treatment was attempted with epidural and transdermal administration of analgesics. Flunixin meglumine was administered PO, which coincided with an abrupt increase in serum creatinine concentration. Performance of multiple diagnostic bone biopsies led to remission of clinical signs of pain.

Clinical Relevance—Panosteitis should be a differential diagnosis for shifting limb lameness in young camels. Bone biopsies can be useful for diagnosis of panosteitis and possible relief of pain associated with the disease. Bactrian camels may be susceptible to the renal toxicity of flunixin meglumine, especially when dehydrated.

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To estimate costs associated with prevention and treatment of bovine respiratory disease (BRD) in preweaned calves on US beef cow–calf operations.

DESIGN Cross-sectional survey.

SAMPLE 43 beef cow–calf producers whose operations had a history of BRD in preweaned calves.

PROCEDURES Mail and electronic surveys were developed and administered to producers in Nebraska, North Dakota, and South Dakota to obtain information regarding costs of BRD prevention and treatment. Descriptive statistics were generated. Mixed linear regression models were used to assess factors associated with the costs of vaccines, medicine, and labor and percentage time spent on prevention and treatment of BRD in cows, replacement heifers, and preweaned calves.

RESULTS 7 mail and 36 electronic surveys were completed. Median annual costs for BRD vaccines were $2.25, $4.00, and $6.25/animal, and median annual labor costs for vaccination were $4.58, $3.00, and $5.00/animal for cows, heifers, and preweaned calves, respectively. Median annual costs for medicine and labor to treat preweaned calves for BRD were $11.00 and $15.00/ affected calf, respectively. Adjusted mean annual BRD vaccine cost for preweaned calves ($7.67/animal) was significantly greater than that for cows ($3.18/animal) and heifers ($4.48/animal).

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that labor costs associated with BRD vaccination and treatment were similar to or exceeded the cost of vaccines and medicine, and most of those labor costs were associated with gathering and sorting cattle. Therefore, costs associated with labor as well as medicine and vaccines should be considered during the development of BRD prevention and treatment plans.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To develop a robust molecular genetic test for α-l-fucosidosis in English Springer Spaniels and to screen dogs from the United Kingdom and United States for the mutant allele.

Animals

35 English-bred English Springer Spaniels, 60 American-bred English Springer Spaniels, and 1 affected dog and its parents from a family of English Springer Spaniels in Colorado.

Procedure

Polymerase chain reaction analysis was used to amplify the mutated region in the gene encoding α-l-fucosidase. High guanine-cytosine (GC) content of the region required use of an amplification buffer with high pH. Mutant and normal alleles were separated by polyacrylamide gel electrophoresis. Molecular genetic test results were compared with enzyme data.

Results

A 262-bp PCR product was amplified from normal dogs and compared with a 248-bp product from affected dogs. Carriers had 1 copy of each allele, distinguishable by the 14-bp size difference. Two carriers among the English-bred dogs were identified by use of enzyme and genomic DNA analyses. The molecular defect in dogs from Colorado was proven to be the same as that in British and Australian dogs. None of the other 60 American-bred dogs carried the mutant allele.

Conclusions and Clinical Relevance

A PCR method that can be used to identify dogs affected with or carriers of the autosomal recessive disease fucosidosis was established. Amplification was achieved within a GC-rich region, using a method that may be useful in overcoming amplification problems in GC-rich areas within other genes. Using this test, fucosidosis can be controlled and ultimately eradicated from the English Springer Spaniel population. (Am J Vet Res 1999;60:726-729)

Free access
in American Journal of Veterinary Research

Objective

To determine whether results of the Ortolani method of hip joint palpation in dogs were related to distraction index (DI), Norberg angle, or radiographic hip score.

Design

Cross-sectional study.

Animals

459 clinically normal dogs.

Procedure

Dogs were sedated for radiography and palpation of the hip joints. Results of hip joint palpation were classified as negative, mild positive, moderate positive, or severe positive. Distraction indices were measured for all dogs. Norberg angles were measured for 380 dogs for which ventrodorsal hip-extended radiographic projections were available. Hip scores assigned by the Orthopedic Foundation for Animals (OFA) were available for 95 dogs.

Results

Age, weight, and sex were not significantly associated with results of hip joint palpation. There was moderate correlation between results of hip joint palpation and DI (r = 0.636), low-moderate correlation between results of hip joint palpation and OFA hip scores (rs = 0.437), and weak negative correlation (r = -0.236) between results of hip joint palpation and Norberg angle. For joints without degenerative joint disease (DJD), there was a significant linear relationship between results of hip palpation and DI; however, for joints with DJD, there was not. Results of hip joint palpation were 5.3-fold as likely to be negative for dogs with DJD as for dogs without.

Clinical Implications

Results of hip joint palpation were at best moderately correlated with radiographic measures of hip joint laxity. Therefore, hip joint palpation should be combined with hip-extended and stress radiography when assessing hip joint quality. (J Am Vet Med Assoc 1999;214:497–501).

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To determine the effect of local anesthesia of the palmar digital nerves on forelimb kinematics in Quarter Horses with and without navicular disease.

Animals

12 adult Quarter Horses; 5 clinically normal (sound) and 7 with navicular disease.

Procedure

Kinematic measurements were made on adult horses trotting on a treadmill, before and after palmar digital nerve block (PDNB). Twenty-three displacement, joint angle, and temporal gait measurements of the right forelimb and head were made for 5 strides in each horse. Initial (before local anesthesia) right forelimb measurements were obtained after a left forelimb PDNB. Kinematic measurements were compared before and after PDNB of the right forelimb by multiple ANOVA with an α = 0.05, adjusted for posthoc comparisons by Bonferroni correction.

Results

In sound horses, the only significant change in kinematic measurements after PDNB nerve block was in the maximum extension of the metacarpophalangeal joint at mid-stance, which was decreased by an angle of 2°. In horses with navicular disease, mean maximum extension of the metacarpophalangeal joint during stance phase and maximum flexion of the carpal joint during swing phase were significantly increased after PDNB. Also, total stance phase, cranial stance phase, and breakover durations were significantly shorter. In horses with navicular disease, differences between minimum head heights during stance phase of each forelimb and total vertical head excursion during a complete stride were significantly smaller after PDNB.

Conclusion

Several kinematic measurements of gait can be used to determine improvement of lameness in horses with navicular disease after PDNB block while trotting on a treadmill. (Am J Vet Res 1997; 58:218–223)

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether treatment with selamectin would reduce clinical signs of flea allergy dermatitis (FAD) in dogs and cats housed in flea-infested environments.

Design—Randomized controlled trial.

Animals—22 dogs and 17 cats confirmed to have FAD.

Procedure—Animals were housed in carpeted pens capable of supporting the flea life cycle and infested with 100 fleas (Ctenocephalides felis) on days –13 and –2 and on alternate weeks with 10 to 20 fleas. On day 0, 11 dogs and 8 cats were treated with selamectin (6 mg/kg [2.7 mg/lb]). Dogs were retreated on day 30; cats were retreated on days 30 and 60. All animals were examined periodically for clinical signs of FAD. Flea counts were conducted at weekly intervals.

Results—Throughout the study, geometric mean flea counts exceeded 100 for control animals and were ≤ 11 for selamectin-treated animals. Selamectin-treated cats had significant improvements in the severity of miliary lesions and scaling or crusting on days 42 and 84, compared with conditions on day –8, and in severity of excoriation on day 42. In contrast, control cats did not have any significant improvements in any of the clinical signs of FAD. Selamectin-treated dogs had significant improvements in all clinical signs on days 28 and 61, but in control dogs, severity of clinical signs of FAD was not significantly different from baseline severity at any time.

Conclusions and Clinical Relevance—Results suggest that topical administration of selamectin, even without the use of supplementary environmental control measures and with minimal therapeutic intervention, can reduce the severity of clinical signs of FAD in dogs and cats. (J Am Vet Med Assoc 2003;223:639–644)

Full access
in Journal of the American Veterinary Medical Association

Summary

A syndrome characterized by anemia, erythrocyte dyscrasia, low body weight, and hypothyroidism was observed in 8 llamas (Lama glama). At initial examination (1 to 23 months of age; median, 7.5 months), llamas (3 males, 5 females) were markedly underweight (29 to 55 kg; median, 36 kg) and anemic (pcv, 12.9 to 25.5% [median, 19%]). Five of the llamas became progressively more anemic over time; in 2 of them, pcv decreased to < 10%. Erythrocyte changes included severe poikilocytosis, anisocytosis, asymmetric distribution of hemoglobin within the cytoplasm, and cytoplasmic extensions from one or both poles. Six llamas had moderate to severe valgus deformities of the carpus. All llamas had low baseline serum thyroxine concentration and diminished response to thyrotropin administration. Baseline and post-thyrotropin triiodothyronine concentrations did not have consistent patterns. Five llamas were hypophosphatemic and 7 had low serum iron concentration (iron concentration was not determined in 1 llama). Orally administered iron supplementation did not induce clinical improvement. Because 3 of the affected llamas were full sisters, a genetic basis for the problem has to be considered. It was not possible to evaluate the familial relationship of the other 5 affected llamas. Although the underlying cause of the problem was not established, the prognosis for affected llamas is guarded to poor.

Free access
in Journal of the American Veterinary Medical Association