Thomas F. Fletcher

Downer cow occurrence in Minnesota dairy herds

Abstract The report contains survey data about occurrence of the downer cow syndrome in 723 dairy herds with 34 656 cow years at risk. Herds were categorized by breed, registration status, and type of housing. For the purpose of this survey, downer cows were defined as being recumbent on the sternum for > 24 h for no obvious reason. The overall incidence of downer cows in the sample was 21.4 1000 cow years at risk. The overall outcome of downer cases was that 33% recovered, 23% were slaughtered, and 44% died. Further specification of data by breed, registration, and time down before recovery, slaughter of death is noted in the text. Owners perceived that downers were high producers (48%) or average producers (46%), with only 6^ being low producers. They reported that 58% of cases occurred within one day of parturition while an additional 37% occurred during the first 100 days of lactation. The number of downers associated with dystocia was 24%, but this was 41% of the cases which went down within one day of calving. The highest incidence of downer cases was during the three coldest months (December–February) when 39% of the cases occurred. In contrast only 16% of cases occurred during the spring months (April–June). A majority of respondents (75%) had experience with hip lifting devices. Of this group 71% found them to be useful for management of downer cows.

Relative metabolite concentrations and ratios determined by use of 3-T region-specific proton magnetic resonance spectroscopy of the brain of healthy Beagles

OBJECTIVEnTo determine relative concentrations of selected major brain tissue metabolites and their ratios and lobar variations by use of 3-T proton (hydrogen 1 [(1)H]) magnetic resonance spectroscopy (MRS) of the brain of healthy dogs.nnnANIMALSn10 healthy Beagles.nnnPROCEDURESn3-T (1)H MRS at echo times of 144 and 35 milliseconds was performed on 5 transverse slices and 1 sagittal slice of representative brain lobe regions. Intravoxel parenchyma was classified as white matter, gray matter, or mixed (gray and white) and analyzed for relative concentrations (in arbitrary units) of N-acetylaspartate (NAA), choline, and creatine (ie, height at position of peak on MRS graph) as well as their ratios (NAA-to-choline, NAA-to-creatine, and choline-to-creatine ratios). Peak heights for metabolites were compared between echo times. Peak heights for metabolites and their ratios were correlated and evaluated among matter types. Yield was calculated as interpretable voxels divided by available lobar voxels.nnnRESULTSnReference ranges of the metabolite concentration ratios were determined at an echo time of 35 milliseconds (NAA-to-choline ratio, 1.055 to 2.224; NAA-to-creatine ratio, 1.103 to 2.161; choline-to-creatine ratio, 0.759 to 1.332) and 144 milliseconds (NAA-to-choline ratio, 0.687 to 1.788; NAA-to-creatine ratio, 0.984 to 2.044; choline-to-creatine ratio, 0.828 to 1.853). Metabolite concentration ratios were greater in white matter than in gray matter. Voxel yields ranged from 43% for the temporal lobe to 100% for the thalamus.nnnCONCLUSIONS AND CLINICAL RELEVANCEnMetabolite concentrations and concentration ratios determined with 3-T (1)H MRS were not identical to those in humans and were determined for clinical and research investigations of canine brain disease.

Quantitative evaluation of spinal cord lesions in canine globoid leukodystrophy.

Lesion distribution in the spinal cord was investigated by sampling an average of 26 spinal cord segments in each of ten dogs severely affected by canine globoid leukodystrophy (GLD). GLD lesions were quantified by subdividing spinal white matter into small unit areas and judging the quartile extent of lesion involvement for each unit area. Along the length of the spinal cord, lesions declined from cranial to caudal, decreasing precipitously in the midlumbar region. The lumbosacral region had the least amount of lesion, and, based on lesion per unit area, the thoracic region was most severely involved. The dorsal funiculus had the greatest concentration and the least dispersion of lesion generally among the three funiculi. White matter at the periphery of the spinal cord was involved earlier and more severely than white matter adjacent to gray matter. Amount of lesion per spinal cord could be estimated adequately by sampling one segment from each of five regions. Dogs could be divided into two groups based on rate of lesion development. Clinical signs did not correlate closely with total amount of lesion per spinal cord. Of the total amount of variability among dogs in amount of spinal pathologic involvement, 78% could be accounted for by a mathematical model expressing spinal cord pathologic involvement as a quadratic function of age at onset and duration of the clinical syndrome.

Risk factors for calcium carbonate urolithiasis in goats

OBJECTIVEnTo identify demographic or signalment factors associated with calcium carbonate urolith formation in goats.nnnDESIGNnRetrospective case series and case-control study.nnnANIMALSn354 goats with calcium carbonate uroliths (case animals) and 16,366 goats without urinary tract disease (control animals).nnnPROCEDURESnMedical records of the Minnesota Urolith Center were reviewed to identify case goats for which samples were submitted between January 1, 1984, and December 31, 2012. Control goats evaluated at US veterinary teaching hospitals in the same time period were identified by searching Veterinary Medical Database records. Age, breed, sex, reproductive status, geographic location, season, and anatomic location of collected uroliths were analyzed to identify risk or protective factors associated with calcium carbonate urolithiasis.nnnRESULTSnNigerian dwarf goats had higher odds of developing calcium carbonate uroliths than did Pygmy goats (reference group). Several breeds had lower odds of this finding, compared with Pygmy goats; odds were lowest for mixed, Anglo-Nubian, and Toggenburg breeds. Breeds of African origin (Pygmy, Nigerian Dwarf, and Boer) comprised 146 of 275 (53%) case goats with data available. Goats of African descent had a higher risk of developing calcium carbonate uroliths than did goats of non-African descent (reference group). Males and neutered goats had higher odds of calcium carbonate urolithiasis, compared with females and sexually intact goats, respectively. Age category, geographic location, and season were associated with detection of calcium carbonate uroliths.nnnCONCLUSIONS AND CLINICAL RELEVANCEnGoats with calcium carbonate uroliths were typically neutered males, > 1 year of age, and of African descent. This study identified factors associated with calcium carbonate urolithiasis in goats; however, these associations do not allow conclusions regarding cause-and-effect relationships.