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in Journal of the American Veterinary Medical Association

Abstract

Case Description—A 2-year-old alpaca was evaluated because of acute onset of cervical scoliosis.

Clinical Findings—Physical examination revealed severe scoliosis of the caudal portion of the cervical vertebral column with a C-shaped curvature to the right side. No gait deficits were observed. Cervical radiography confirmed severe curvature of C4 to C6 but did not reveal any bony changes. Cerebrospinal fluid had high total protein concentration and extremely high nucleated cell count with a high proportion of eosinophils, suggesting parasitic infection.

Treatment and Outcome—The alpaca was treated for suspected parelaphostrongylosis with ivermectin, fenbendazole, flunixin, vitamin E, thiamine, physical therapy, and a custom-made neck brace. The alpaca's condition continued to deteriorate, and it developed tetraparesis and ataxia and was euthanized after approximately 1 month. Microscopic evaluation of the cervical spinal cord revealed marked vacuolar changes in the left medial portion of the ventral funiculus, mild lymphoplasmacytic infiltration, and multifocal granulomas. The lesions were continuous from C1 to C7 and were compatible with parasite migration.

Clinical Relevance—To the authors' knowledge, this is the first report of acquired scoliosis in an alpaca, which appears to represent an unusual manifestation of parelaphostrongylosis that was reported in horses.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To develop a method of measuring 3-dimensional kinematics of the temporomandibular joint (TMJ) in horses chewing sweet feed.

Animals—4 mature horses that had good dental health.

Procedure—Markers attached to the skin over the skull and mandible were tracked by an optical tracking system. Movements of the mandible relative to the skull were described in terms of 3 rotations and 3 translations. A virtual marker was created on the midline between the rami of the mandibles at the level of the rostral end of the facial crest to facilitate observation of mandibular movements.

Results—During the opening stroke, the virtual midline mandibular marker moved ventrally, laterally toward the chewing side, and slightly caudally. During the closing stroke, the marker moved dorsally, medially, and slightly rostrally. During the power stroke, the mandible slid medially and dorsally as the mandibular cheek teeth moved across the occlusal surface of the maxillary cheek teeth. The 4 horses had similar chewing patterns, but the amplitudes varied among horses.

Conclusions and Clinical Relevance—The TMJ allows considerable mobility of the mandible relative to the skull during chewing. The method presented in this report can be used to compare the range of motion of the TMJ among horses with TMJ disease or dental irregularities or within an individual horse before and after dental procedures.

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in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the accuracy of sow culling classifications reported by lay personnel on commercial swine farms.

Design—Retrospective cohort study.

Animals—A convenience sample of 923 sows from 8 conventional, farrow-to-wean farms that followed standard operating procedures.

Procedures—Sows were examined at slaughter, and lesions were recorded. Individual production records were reviewed to determine the farm-reported reason for culling the sows, and criteria were developed to assess the accuracy of recorded culling classifications.

Results—For 209 of the 923 (23%) sows, the farm-reported culling classification was judged to be inaccurate. The culling code was considered to be inaccurate for 62 of 322 (19%) sows reportedly culled because of old age, 48 of 172 (28%) sows reportedly culled because of failure to conceive, 31 of 90 (34%) sows reportedly culled because of poor body condition, and 23 of 73 (32%) sows reportedly culled because of poor farrowing productivity.

Conclusions and Clinical Relevance—Results suggested that for commercial swine farms, farm-reported culling code classifications were frequently inaccurate. This degree of inaccuracy may cause severe limitations for studies that rely on farm-reported assessments of clinical conditions.

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in Journal of the American Veterinary Medical Association

SUMMARY

The effects of whole-body potassium depletion induced by food deprivation on plasma, erythrocyte, and middle gluteal muscle K concentrations was quantified in 16 healthy, adult horses before, during, and at the end of a 7-day period of food deprivation during which water and sodium chloride were available ad libitum. Potassium concentrations were determined by atomic absorption spectroscopy.

Plasma K concentration remained constant (3.49 ± 0.09 mM K/L of plasma; mean ± sem) throughout the study. Erythrocyte potassium concentration decreased from 93.10 ± 1.94 mM K/L of erythrocytes on day 0 to 88.63 ± 2.39 mM K/L of erythrocytes on day 2 (decrease of 4.8%; P < 0.05) and thereafter did not change. The K concentration of the middle gluteal muscle decreased from 91.06 ± 2.96 μM K/g of muscle (wet weight) to 79.61 ± 2.09 μM K/g of muscle (decrease of 12.6%; P < 0.05) on day 4 and decreased further on day 7 to 73.62 ± 1.85 μM K/g of muscle (decrease of 19.2%; P < 0.05). There was no correlation between the plasma and erythrocyte K concentrations (r = −0.066), the erythrocyte and middle gluteal muscle K concentrations (r = 0.167), or the plasma and middle gluteal muscle potassium concentrations (r = −0.018). The water content of the middle gluteal muscle remained constant (73.23 ± 0.36%) throughout the study.

Erythrocyte membrane potential did not change (−99.26 ± 0.87 mV) during the study, whereas the magnitude of the membrane potential of the middle gluteal muscle decreased from −105.84 ± 1.67 mV on day 0 to −100.93 ± 2.10 mV on day 7 (P < 0.05).

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in American Journal of Veterinary Research

Abstract

OBJECTIVE To evaluate the effect of MgSO4, alone and in combination with propofol, on the minimum alveolar concentration preventing motor movement (MACNM) in sevoflurane-anesthetized dogs.

ANIMALS 6 healthy purpose-bred adult male Beagles (least squares mean ± SEM body weight, 12.0 ± 1.1 kg).

PROCEDURES Dogs were anesthetized 3 times at weekly intervals. The MACNM was measured 45 minutes after induction of anesthesia (baseline; MACNM-B) and was determined each time by use of a noxious electrical stimulus. Treatments were administered as a loading dose and constant rate infusion (CRI) as follows: treatment 1, MgSO4 loading dose of 45 mg/kg and CRI of 15 mg/kg/h; treatment 2, propofol loading dose of 4 mg/kg and CRI of 9 mg/kg/h; and treatment 3, MgSO4 and propofol combination (same doses used previously for each drug). A mixed-model ANOVA and Tukey-Kramer tests were used to determine effects of each treatment on the percentage decrease from MACNM-B. Data were reported as least squares mean ± SEM values.

RESULTS Decrease from MACNM-B was 3.4 ± 3.1%, 48.3 ± 3.1%, and 50.3 ± 3.1%, for treatments 1, 2, and 3, respectively. The decrease for treatments 2 and 3 was significantly different from that for treatment 1; however, no significant difference existed between results for treatments 2 and 3.

CONCLUSIONS AND CLINICAL RELEVANCE MgSO4 did not affect MACNM, nor did it potentiate the effects of propofol on MACNM. Administration of MgSO4 in this study appeared to provide no clinical advantage as an anesthetic adjuvant.

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in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association

Summary

Serum lipoprotein concentrations, routine serum biochemical values, and morphologic changes of the liver were evaluated in cats undergoing weight loss. Food was witheld from 6 obese and 6 control cats for 3 days (days 0 to 2), followed by feeding 50% of previous food intake for 26 days (days 3 to 28). Percutaneous liver biopsy specimens were obtained from all cats on days 0, 7, 14, and 28. Blood samples for serum biochemical analysis and lipoprotein profiles were obtained on days 0, 3, 7, 14, and 28. All cats lost weight throughout the study, and none developed signs of clinical illness, including those of idiopathic hepatic lipidosis syndrome. Serum total cholesterol concentrations decreased initially in all cats, but rapidly returned to normal after day 3 in obese cats, suggesting altered cholesterol metabolism during dietary restriction. Low-density lipoprotein concentrations decreased throughout the study in control cats, but were unchanged in obese cats. Examination of liver biopsy specimens from each cat revealed minimal lipid accumulation in all specimens, although some specimens contained hydropic degeneration.

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in American Journal of Veterinary Research