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  • Author or Editor: Loren G. Schultz x
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Objective—To characterize serum trace mineral, sex steroid hormone, and vitamin D concentrations and identify factors associated with metacarpophalangeal and metatarsophalangeal hyperextension in llamas and alpacas.

Samples—Serum samples from 79 llamas and 15 alpacas and owner survey data for 573 llamas and 399 alpacas.

Procedures—Serum samples were stored at −20°C until analysis and were evaluated for trace mineral, vitamin D, estradiol, progesterone, and testosterone concentrations. Information regarding age of onset, number of affected animals in herd, feed and supplements given, type of housing, and management practices was obtained in an owner survey.

Results—Higher serum zinc and iron concentrations were associated with metacarpophalangeal and metatarsophalangeal hyperextension in camelids, compared with controls. In summer and fall months, vitamin D concentrations were significantly higher in affected camelids than controls. Overall prevalence was 13.3% in llamas, compared with 0.7% in alpacas. No management factors were found to be predictive of this condition. No other factors examined were associated with metacarpophalangeal and metatarsophalangeal hyperextension.

Conclusions and Clinical Relevance—Despite similar supplementation practices and environmental conditions between affected and unaffected animals, an association of high serum zinc, iron, and vitamin D concentrations in affected camelids, compared with controls, may indicate differences of intake or absorption of dietary supplements.

Full access
in American Journal of Veterinary Research


Objective—To determine whether vaccinating cows during late gestation against Mycoplasma bovis will result in adequate concentrations of M bovis–specific IgG1 in serum, colostrum, and milk.

Animals—78 dairy cows.

Procedures—Serum samples were obtained 60 and 39 days prior to expected parturition in vaccinated and control cows from a single herd. Serum and colostrum samples were also obtained at parturition. Milk samples were obtained 7 to 14 days after parturition. Samples were analyzed for anti–M bovis IgG1 concentrations.

Results—Prior to vaccination, control and vaccinated cows had similar anti–M bovis IgG1 concentrations. After initial vaccination and subsequent booster and at parturition, there was a significant difference between the 2 groups, with vaccinated cows having higher IgG concentrations. Colostrum from vaccinated cows had higher anti–M bovis IgG1 concentrations, compared with control cows; however, IgG1 concentrations in milk did not differ between the 2 groups.

Conclusions and Clinical Relevance—Vaccination of late-gestation cows resulted in increased concentrations of anti–M bovis IgG1 in colostrum. However, ingestion of colostrum by calves may not guarantee protection against M bovis infection.

Full access
in American Journal of Veterinary Research


Objective—To determine the amount of colostral IgG required for adequate passive transfer in calves administered colostrum by use of oroesophageal intubation and evaluate the impact of other factors on passive transfer of colostral immunoglobulins in calves.

Animals—120 Holstein bull calves.

Procedures—Calves were randomly assigned to specific treatment groups on the basis of volume of colostrum administered and age of calf at administration of colostrum. Colostrum was administered once by oroesophageal intubation. Equal numbers of calves received 1, 2, 3, or 4 L of colostrum, and equal numbers of calves received colostrum at 2, 6, 10, 14, 18, or 22 hours after birth. Serum samples were obtained from calves 48 hours after birth for IgG determination by radial immunodiffusion assay. Effects of factors affecting transfer of colostral immunoglobulins were determined by use of a stepwise multiple regression model and logistic regression models.

Results—A minimum of 153 g of colostral IgG was required for optimum colostral transfer of immunoglobulins when calves were fed3Lof colostrum at 2 hours after birth. Substantially larger IgG intakes were required by calves fed colostrum > 2 hours after birth.

Conclusions and Clinical Relevance—Feeding 100 g of colostral IgG by oroesophageal intubation was insufficient for adequate passive transfer of colostral immunoglobulins. At least 150 to 200 g of colostral IgG was required for adequate passive transfer of colostral immunoglobulins. Use of an oroesophageal tube for administration of 3 L of colostrum to calves within 2 hours after birth is recommended.

Full access
in American Journal of Veterinary Research


Objective—To determine the effect of time interval from birth to first colostrum feeding on colostrum intake and serum IgG concentration and the effect of varying colostral volume intake and colostral IgG concentration on the probability of failure of passive transfer (FPT) in bottle-fed calves.

Design—Randomized controlled study.

Animals—104 calves.

Procedures—Equal numbers of calves were randomly assigned to groups and fed 3 L of their dam's colostrum at 1, 2, 3, or 4 hours after birth by use of a nipple bottle. Calves were allowed to feed for 15 minutes, and intake was recorded. A second 3-L bottle feeding of colostrum was offered at 12 hours of age.

Results—17.2% of calves ingested 3 L of colostrum at the first feeding and 3 L at 12 hours of age. Calf age, up to 4 hours, had no significant effect on the calf's ability to ingest colostrum or on 48-hour serum IgG concentration. Colostral intake at 1, 2, 3, or 4 hours had no effect on intake at the second feeding. Probability of FPT in calves ingesting 3 L at both feedings was < 0.05.

Conclusions and Clinical Relevance—Allowing calves fed by nipple bottle to ingest as much colostrum as they can within 4 hours after birth and at 12 hours of age substantially reduced the probability of FPT. Bottle-fed calves that do not ingest 3 L of colostrum within the first 4 hours after birth should be targeted for oroesophageal intubation.

Full access
in Journal of the American Veterinary Medical Association


Objective—To evaluate prevalence of and risk factors for hip dysplasia (HD) and cranial cruciate ligament deficiency (CCLD) in dogs and determine change in prevalence over time.

Design—Cross-sectional study.

Animals—1,243,681 dogs for which information was reported to the Veterinary Medical Database between 1964 and 2003.

Procedures—Information on breed, sex, and age was collected, and prevalences and odds ratios were calculated.

Results—Castrated male dogs were significantly more likely than other dogs to have HD (odds ratio [OR], 1.21), and castrated male (OR, 1.68) and spayed female (OR, 2.35) dogs were significantly more likely to have CCLD. Dogs up to 4 years old were significantly more likely to have HD (OR for dogs 2 months to 1 year old, 1.22; OR for dogs > 1 to 4 years old, 1.48), whereas dogs > 4 years old were significantly more likely to have CCLD (OR for dogs > 4 to 7 years old, 1.82; OR for dogs > 7 years old, 1.48). In general, large- and giant-breed dogs were more likely than other dogs to have HD, CCLD, or both. Prevalences of HD and CCLD increased significantly over the 4 decades for which data were examined.

Conclusions and Clinical Relevance—Results suggested that sex, age, and breed were risk factors for HD, CCLD, or both in dogs and that prevalences of HD and CCLD have increased over time.

Full access
in Journal of the American Veterinary Medical Association



The objective of this study was to evaluate the prevalence of abnormal findings in gross necropsy, histopathology, and ancillary test results from neonatal beef calves submitted to a veterinary diagnostic laboratory.


This retrospective clinical case study was conducted by reviewing necropsy reports submitted between 2015 to 2020. Case inclusion criteria were animals had to be a bovine, 2 to 21 days of age, and a nondairy breed.


Gross necropsy, histopathology, and laboratory test results were recorded. Identified lesions and abnormal test results were categorized based on body systems and infectious agent type. Age and system affected were analyzed using a 1-way ANOVA and Bonferonni pairwise comparisons.


Overall, 1,060 reports were reviewed and 95 met the inclusion criteria. Median age of enrolled calves was 9 days (range, 2 to 21). A total of 252 lesions were identified with a median of 3 lesions/calf (range, 0 to 7) and 2 different body systems involved/calf (range, 0 to 5). The most common disorders were classified as digestive (42.1% [106/252]), respiratory (12.7% [32/252]), and multisystemic (11.1% [28/252]). With respect to age and system affected, calves with neurologic lesions were significantly younger (mean age, 5.1 days) than calves with digestive lesions (mean age 9.6 days).

Clinical Relevance

These data suggest a high prevalence of infectious diseases, mainly digestive, respiratory and multisystemic in origin. These findings could help guide producers and veterinarians when assessing factors contributing to neonatal beef calf loss.

Full access
in Journal of the American Veterinary Medical Association