Objective-To investigate telomere lengths in tissues of domestic shorthair (DSH) cats of various ages, evaluate the relationship between telomere length and age of cats, and investigate telomerase activity in the somatic tissues of cats. Sample Population-Tissues obtained from 2 DSH cats and blood samples obtained from 30 DSH cats. Procedure-DNA isolated from blood cells and somatic tissue samples was subjected to terminal restriction fragment (TRF) analysis to determine mean telomere repeat lengths. Protein samples were subjected to analysis by use of a telomeric repeat-amplification protocol to assess telomerase activity. Results-Mean TRF values of cats ranged from 4.7 to 26.3 kilobase pairs, and there was significant telomeric attrition with increasing age of cat. Telomerase activity was not found in a wide range of normal tissues obtained from 2 cats. Conclusions and Clinical Relevance-Analysis of these results clearly indicates that telomeres are shorter in older cats, compared with young cats; therefore, telomeres are implicated in the aging process. The analysis of telomerase activity in normal somatic tissues of cats reveals a pattern of expression similar to that found in human tissues. Impact for Human Medicine-Fundamental differences in the biological characteristics of telomeres and telomerase exist between humans and the other most widely studied species (ie, mice). The results reported here reveal similarities in telomere and telomerase biologic characteristics between DSH cats and humans. Hence, as well as developing our understanding of aging in cats, these data may be usefully extrapolated to aging in humans.

We studied the frequency and timing of abortion and the serum levels of 17β-estradiol and progesterone in Korean native cows fed pine needles during pregnancy. Fifteen pregnant cows were randomly assigned to groups of 5. The control group was fed a concentrate and rice straw, and the other 2 groups were fed, in addition, either 1.3 or 2.7 kg (dry weight) of Korean pine needles daily, starting at an average of 91 d of gestation and continuing until 245 d of gestation. The health status of the dams and the viability of the fetuses were ascertained by rectal palpation and ultrasound scanning during pregnancy. Simultaneously, blood samples were collected for analysis of serum 17β-estradiol and progesterone. Two abortions in mid-pregnancy (at 126 and 150 d of gestation) occurred in the group ingesting the higher daily amount of pine needles. Premature parturition occurred at 259 d of gestation in this group and at 241 and 252 d of gestation in the group ingesting the lower daily amount of pine needles. The serum 17β-estradiol concentration was significantly higher (P < 0.05) at 4 mo of gestation and the serum progesterone level significantly lower (P < 0.05) at 8 mo of gestation in the group ingesting more pine needles daily than in either of the other 2 groups. These results suggest that the ingestion of pine needles may play a role in abortion in Korean native cows by increasing the serum 17β-estradiol concentration and decreasing the serum progesterone concentration.

Objective-To compare aesthesiometer-determined corneal sensitivity between diabetic and nondiabetic dogs and to investigate the correlation between corneal sensitivity and duration of diabetes or status of glycemic control, as estimated by use of glycated blood protein concentrations. Animals-23 diabetic and 29 nondiabetic normoglycemic dogs. Procedure-A Cochet-Bonnet aesthesiometer was used to measure corneal touch threshold (CTT) in 5 corneal regions of each dog. At the time of ocular examination, duration of diabetes mellitus was estimated from the history, and blood was drawn for assessment of blood glycosylated hemoglobin and serum fructosamine concentrations. Results-Median CTT for central, nasal, dorsal, temporal, and ventral corneal regions in nondiabetic dogs (1.6, 2.3, 2.8, 2.8, and 5.1 g/mm2, respectively) was significantly lower than in diabetic dogs (2.8, 4.0, 5.1, 5.1, and 6.6 g/mm2, respectively). Median regional CTT in diabetic dogs was not significantly correlated with estimated duration of diabetes mellitus or blood glycated protein concentrations. No significant difference was found in regional CTT between eyes of normoglycemic dogs with unilateral cataracts. Conclusion and Clinical Relevance-Diabetic dogs have significantly reduced corneal sensitivity in all regions, compared with nondiabetic normoglycemic dogs. Regional variation in corneal sensitivity is similar in diabetic and normoglycemic dogs. Neither glycemic control nor duration of diabetes, as estimated, is significantly correlated with corneal hyposensitivity. Corneal nerve dysfunction may be associated with recurrent or nonhealing ulcers in diabetic dogs for which no other underlying cause can be found.

Objective-To determine the prevalence of biofilm formation under long-term cell culture conditions in serum samples of dairy cattle, goats, cats, and dogs, and to determine whether there is an association between nanobacteria and biofilm formation. Sample Population-Serum samples of clinically normal animals (313 dairy cattle, 48 goats, 140 dogs, and 44 cats) and animals with various medical conditions (60 dogs and 116 cats). Procedure-Serum was incubated under cell culture conditions and observed for biofilm formation by use of light microscopy, electron microscopy, and spectroscopy. A polymerase chain reaction assay was developed to identify 16S rRNA gene sequences of nanobacteria. Results-Biofilm formation developed in serum samples of 304 of 313 (97%) cattle, 44 of 48 (92%) goats, 44 of 44 (100%) cats, and 126 of 140 (90%) dogs. Prevalence of serum samples with positive results for biofilm formation was not significantly different between cats or dogs with and without medical conditions associated with pathologic extraskeletal calcification processes. Scanning electron microscopy and spectroscopy of biofilm samples revealed small coccoid particles consisting mainly of calcium and phosphate. Polymerase chain reaction assay failed to amplify sequences of nanobacteria. Conclusions and Clinical Relevance-Under longterm cell culture conditions, biofilm made up of aggregates of calcium and phosphate crystals does form in serum samples of clinically normal dairy cattle, goats, cats, and dogs. Disease, however, does not predispose to biofilm formation in serum samples of dogs and cats. Our findings did not support the existence of nanobacteria in serum samples of cattle, goats, cats, and dogs.

Nursing sickness, the largest single cause of mortality in adult female mink (Mustela vison), is an example of a metabolic disorder, which develops when the demands for lactation require extensive mobilization of body energy reserves. The condition is characterized by progressive weight loss, emaciation, and dehydration with high concentrations of glucose and insulin in the blood. Morbidity due to nursing sickness can be as high as 15% with mortality around 8%, but the incidence is known to vary from year to year. Stress has been shown to trigger the onset of the disease and old females and females with large litters are most often affected. Increasing demand for gluconeogenesis from amino acids due to heavy milk production may be a predisposing factor. Glucose metabolism is inextricably linked to that of protein and fats. In obesity (or lipodystrophy), the ability of adipose tissue to buffer the daily influx of nutrients is overwhelmed (or absent), interfering with insulin-mediated glucose disposal and leading to insulin resistance. Polyunsaturated fatty acids of the n-3 family play an important role in modulating insulin signalling and glucose uptake by peripheral tissue. The increasing demand on these fatty acids for milk fat synthesis towards late lactation may result in deficiency in the lactating female, thus impairing glucose disposal. It is suggested that the underlying cause of mink nursing sickness is the development of acquired insulin resistance with 3 contributing key elements: obesity (or lipodystrophy), n-3 fatty acid deficiency, and high protein oxidation rate. It is recommended that mink breeder females be kept in moderate body condition during fall and winter to avoid fattening or emaciation. A dietary n-3 fatty acid supplement during the lactation period may be beneficial for improved glycemic control. Lowering of dietary protein reduces (oxidative) stress and improves water balance in the nursing females and may, therefore, prevent the development and help in the management of nursing sickness. It is also surmised that other, thus far unexplained, metabolic disorders seen in male and female mink may be related to acquired insulin resistance.

The use of naturally-farrowed, artificially-reared piglets as an alternative model to study Haemophilus parasuis infections was evaluated. Two trials were performed in order to evaluate the proposed model. In trial 1, animals were vaccinated and challenged with H. parasuis. Results showed that the proposed model was effectively used to evaluate protective immunity against this organism. In trial 2, animals were challenged with different doses of H. parasuis. Results showed that the severity of clinical signs and lesions tended to increase with higher doses. The reproduction of clinical signs and lesions characteristic of H. parasuis systemic infection was successful in both trials, proving that this model is a viable alternative to specific-pathogen free and cesarean-derived, colostrum-deprived pigs.

Multiplex nested polymerase chain reactions (PCRs) were developed for the simultaneous detection and differentiation of genomic material of porcine circovirus 1 (PCV1), porcine circovirus 2 (PCV2), and porcine parvovirus (PPV) in formalin-fixed, paraffin-embedded tissues. Multiplex conventional and nested PCR and in situ hybridization were compared for their ability to detect the 3 viruses in such tissues. Xylene deparaffinization followed by proteinase K digestion yielded DNA of sufficient quality for reliable and consistent PCR analyses. The DNA from PCV1, PCV2, and PPV was detected by both multiplex nested PCR and in situ hybridization in lymph-node tissue from 12 pigs experimentally co-infected with the 3 viruses, as well as in formalin-fixed, paraffin-embedded lymph-node tissue from 30 pigs with naturally occurring postweaning multisystemic wasting syndrome; the agreement rates for the 2 methods were 100% in both groups of pigs. Thus, multiplex nested PCR could be applied successfully to formalin-fixed, paraffin-embedded tissues for simultaneous detection of these 3 porcine viruses.

Objective-To compare the minimum alveolar concentration (MAC) of isoflurane required to prevent corticocerebral activation, autonomic responses, and purposeful movements after somatic or visceral stimulation in cats anesthetized with isoflurane. Animals-17 healthy spayed female cats. Procedure-Bispectral index (BIS), autonomic parameters, and purposeful movements were monitored before and after somatic or visceral stimuli in cats anesthetized with isoflurane. End-tidal (ET) isoflurane concentration was varied to determine MAC values for cortical arousal (MACBIS), autonomic responsiveness (MACBAR), and purposeful movement (MAC). Bispectral index values greater than 60 were considered to represent corticocerebral activation. Results-Minimum alveolar concentration for purposeful movement was significantly less than MACBIS and MACBAR for both somatic and visceral stimulation. Individual MAC values for somatic stimulation were not significantly different from respective MAC values for visceral stimulation. The percentage of cats that had a BIS response greater than 60 was inversely related to the end-tidal isoflurane concentration. Conclusions and Clinical Relevance-Corticocerebral arousal and subcortical autonomic reflexes occured at isoflurane anesthetic concentrations at which reflexive or purposeful movements were absent. These results suggested that isoflurane had a preferential effect on voluntary motor output at low end-tidal isoflurane concentrations, and that sensory pathways, subcortical sympathetic output, and cortical responsiveness are less susceptible to the anesthetic effects of isoflurane. Bispectral index values obtained after somatic or visceral stimulation were sensitive for the detection of early changes in cortical excitability.

Objective-To compare measurements of blood flow in the common femoral artery obtained by duplex Doppler ultrasonography (DDU) and a reference ultrasonic transit-time flow (TTF) method and to examine the impact of Doppler spectral waveform measurement techniques on volumetric estimates. Animals-5 healthy female pigs. Procedure-Femoral arterial blood flow was measured simultaneously in anesthetized pigs by use of a TTF probe (left femoral artery) and transcutaneous DDU (right femoral artery). A range of flow states was induced pharmacologically by using xylazine, bradykinin, dobutamine, and isoflurane. Volumetric blood flow was calculated from DDU waveforms, using the product of the flow velocity integral (FVI), the cross-sectional vessel area, and heart rate. Three calculations of FVI were obtained by manually tracing the Doppler spectral envelopes at the outer envelope, the modal, and the inner envelope of the spectral dispersion pattern. Data analysis included calculation of Pearson correlation coefficients and Bland-Altman limits of agreement. Results-Blood flow measured by DDU was more closely correlated with TTF measurements when the modal or inner envelope tracing method was used ( r, 0.76 and 0.78; limits of agreement, -100 to 54.2 and -48.5 to 77.0 mL/min, respectively). Limits of agreement for the outer envelope tracing method were -238.5 to 64 mL/min. Conclusion and Clinical Relevance-Transcutaneous DDU is a reliable noninvasive technique for measuring blood flow in the femoral artery of pigs over a range of flow states. Tracing the inner envelope of the Doppler spectral dispersion pattern provided the best estimate of blood flow in this study.

Objective-To evaluate a modified digital imaging technique for quantitative assessment of the grade of osteoarthritis across the proximal articular surface of the first phalanx in horses. Sample Population-6 metacarpophalangeal (fetlock) joint specimens from 6 horses with various stages of osteoarthritis. Procedure-First phalanx specimens, together with 4 gray scale reference calibration targets, were positioned in a bath with the proximal articular cartilage surface submerged in saline (0.9% NaCl) solution. Digital images were obtained from the articular surface before and after staining with Indian ink. Computer-controlled gray level analysis of the nonstained and Indian ink-stained cartilage surfaces and gray scale reference calibration targets was performed by use of the mean pixel value (based on 255-gray scale). An increase in the mean pixel value after staining was used to calculate the cartilage degeneration index (CDI). Results-The CDI of the proximal articular cartilage surface of the first phalanx specimens ranged from 9.2 +/- 5.7 (early stage osteoarthritis) to 41.5 +/- 3.6% (late stage osteoarthritis). The effect of repeating the measurement 6 times in nonstained (including repositioning) and stained specimens (including repositioning and restaining) was not significant. Up to 10 measurements of nonstained specimens could be made without refreshing the bath solution. In stained specimens, mean gray level increased significantly after the sixth measurement. Conclusion and Clinical Relevance-The modified digital imaging technique allowed quantitative assessment of cartilage degeneration across the articular cartilage surface. The CDI is the first quantitative measure for osteoarthritis-induced cartilage degeneration over an entire joint surface in horses.