Subnormal concentrations of serum cobalamin (vitamin B12) in cats with gastrointestinal disease

The present study sought to determine the spectrum of diseases associated with subnormal concentrations of serum cobalamin in cats undergoing investigation of suspected gastrointestinal problems. The solid-phase boil radioassay (RA) for cobalamin employed in the present study was immunologically specific, precise, and accurate, with a sensitivity of 15 pg/mL. The RA yielded results that strongly correlated with those obtained by bioassay (Spearmann rho = .805; P < .0001), although the absolute values were lower for the RA. Forty-nine of 80 serum samples submitted during the period of January 1996-January 1998 had cobalamin concentrations below the reference range for healthy cats (range 900-2,800 pg/mL; mean +/- SD, 1,775 +/- 535 pg/mL; n = 33). Cats with subnormal cobalamin concentrations (mean +/- SD; 384 +/- 272 pg/mL, range 3-883 pg/mL) were middle-aged or older and were presented for weight loss. diarrhea, vomiting, anorexia, and thickened intestines. Definitive diagnoses in 22 cats included inflammatory bowel disease (IBD), intestinal lymphoma, cholangiohepatitis or cholangits, and pancreatic inflammation. Serum concentrations of cobalamin were particularly low in cats with intestinal lymphoma, three-fifths of whom also had subnormal serum concentrations of folate (< 9 ng/mL). The simultaneous presence of disease in the intestines, pancreas, or hepatobiliary system in many cats made it difficult to determine the cause of subnormal cobalamin concentrations. The circulating half-life of parenteral cyanocobalamin was shorter in 2 cats with IBD (5 days) than in 4 healthy cats (12.75 days). The presence of subnormal serum concentrations of cobalamin in 49 of 80 cats evaluated suggests that the measurement of serum cobalamin may be a useful indirect indicator of enteric or pancreatic disease in cats. The rapid depletion of circulating cobalamin in cats suggests that cats may be highly susceptible to cobalamin deficiency. However, the relationship of subnormal serum cobalamin concentrations to cobalamin deficiency and the effect of cobalamin deficiency on cats remain to be determined.     

Serum cobalamin concentrations in cats with gastrointestinal signs: correlation with histopathological findings and duration of clinical signs

The aims of this study were to investigate the prevalence of hypocobalaminaemia in UK cats presented for referral investigation of gastrointestinal signs and to ascertain whether the duration of clinical signs or severity of disease (based on WSAVA Gastrointestinal Standardization histopathological grading) related to cobalamin concentration. The study population comprised 39 cats, of which 11 (28.2%) had hypocobalaminaemia. Eight of these cats were diagnosed with a single cause of gastrointestinal signs: intestinal inflammation (five); alimentary lymphoma (two); and cholangitis (one). Two or more concurrent diseases were diagnosed in the three remaining cases. Alimentary lymphoma and the most severe grade of histological intestinal inflammation were associated most commonly with concurrent hypocobalaminaemia, but there was no statistically significant correlation between serum cobalamin concentrations and histopathological score or duration of clinical signs.     

Serum cobalamin concentrations in dogs with leishmaniosis before and during treatment

Hypocobalaminemia in dogs is most commonly associated with gastrointestinal disorders leading to impaired absorption and utilization of cobalamin. The objectives of this study were to compare serum cobalamin concentrations between dogs with leishmaniosis and clinically healthy dogs, and to assess possible alterations of serum cobalamin concentrations in dogs with leishmaniosis at different timepoints during treatment. Fifty-five dogs with leishmaniosis and 129 clinically healthy dogs were prospectively enrolled. Diagnosis of leishmaniosis was based on clinical presentation, positive serology and microscopic detection of Leishmania amastigotes in lymph node aspiration smears. Twenty of the dogs with leishmaniosis were treated with a combination of meglumine antimonate and allopurinol for 28 days and serum cobalamin concentrations were measured in blood samples that were collected before initiation of treatment (timepoint 0) and on days 14 and 28. In order to estimate alterations of serum cobalamin concentrations during treatment, cobalamin concentrations were measured in blood samples from 20 out of 55 dogs with leishmaniosis at all timepoints. Serum cobalamin concentrations were significantly lower in dogs with leishmaniosis before treatment (median: 362 ng/L; IQR: 277−477 ng/L) compared to clinically healthy dogs (median: 470 ng/L; IQR: 367−632 ng/L; P = 0.0035). Serum cobalamin concentrations increased significantly in dogs with leishmaniosis on day 14 of treatment compared to timepoint 0 (P = 0.02).In the present study, serum cobalamin concentrations were significantly lower in dogs with leishmaniosis compared to clinically healthy dogs. In addition, there was an increase in serum cobalamin concentrations during treatment. The clinical significance of hypocobalaminemia in dogs with leishmaniosis remains to be determined.     

Prevalence of Cryptosporidium, Giardia and Isospora species infections in pet cats with clinical signs of gastrointestinal disease

This study reports the prevalence of Cryptosporidium, Giardia and Isospora species in cats showing signs of gastrointestinal disease. Records from a United Kingdom commercial diagnostic laboratory between December 2003 and December 2005 were reviewed. Of 1355 cats, Cryptosporidium species oocysts were found in 13 cats (1%), Giardia species trophozoites in 74 (6%), and Isospora felis oocysts in 46 (3%). In a second group of 48 cats, prevalence of Giardia species was 15% using an immunoassay for detection of antigen compared to 4% detected with microscopy. Prevalence of Giardia (9%) and Isospora (9%) species was higher in cats less than 6 months old. Gender and breed did not affect prevalence. There was a trend for Cryptosporidium and Isospora species infections to be detected in late autumn and early winter. Regional differences in prevalence were not detected. None of these organisms show a characteristic pattern of clinical signs. This study demonstrates that enteric protozoal infection is common in domestic cats showing signs of alimentary disease.     

Review of cobalamin status and disorders of cobalamin metabolism in dogs

Disorders of cobalamin (vitamin B₁₂) metabolism are increasingly recognized in small animal medicine and have a variety of causes ranging from chronic gastrointestinal disease to hereditary defects in cobalamin metabolism. Measurement of serum cobalamin concentration, often in combination with serum folate concentration, is routinely performed as a diagnostic test in clinical practice. While the detection of hypocobalaminemia has therapeutic implications, interpretation of cobalamin status in dogs can be challenging. The aim of this review is to define hypocobalaminemia and cobalamin deficiency, normocobalaminemia, and hypercobalaminemia in dogs, describe known cobalamin deficiency states, breed predispositions in dogs, discuss the different biomarkers of importance for evaluating cobalamin status in dogs, and discuss the management of dogs with hypocobalaminemia.     

Plasma homocysteine, B vitamins, and amino acid concentrations in cats with cardiomyopathy and arterial thromboembolism

Arterial thromboembolism (ATE) is a common complication of cats with cardiomyopathy (CM), but little is known about the pathophysiology of ATE. In people, high plasma concentrations of homocysteine and low B vitamin concentrations are risk factors for peripheral vascular disease. In addition, low plasma arginine concentrations have been linked to endothelial dysfunction. The purpose of this study was to compare concentrations of homocysteine, B vitamins, and amino acids in plasma of normal cats to those of cats with CM and ATE. Plasma concentrations of homocysteine, vitamin B6, vitamin B12, folate, and amino acids were measured in 29 healthy cats, 27 cats with CM alone, and 28 cats with both CM and ATE. No differences were found between groups in homocysteine or folate. Mean vitamin B12 concentration (mean +/- standard deviation) was lower in cats with ATE (866 +/- 367 pg/mL) and cats with CM (939 +/- 389 pg/mL) compared with healthy controls (1,650 +/- 700 pg/mL; P < .001). Mean vitamin B6 concentration was lower in cats with ATE (3,247 +/- 1.215 pmol/mL) and cats with CM (3,200 +/- 906 pmol/mL) compared with healthy control animals (4,380 +/- 1,302 pmol/mL; P = .005). Plasma arginine concentrations were lower in cats with ATE (75 +/- 33 nmol/mL) compared with cats with CM (106 +/- 25 nmol/mL) and healthy control animals (96 +/- 25 nmol/ mL; P < .001). Vitamin B12 concentration was significantly correlated with left atrial size. We interpret the results of this study to suggest that vitamin B12 and arginine may play a role in CM and ATE of cats.     

Comparison of the bacterial flora of the duodenum in healthy cats and cats with signs of gastrointestinal tract disease

OBJECTIVE: To determine whether a colony environment predisposes healthy cats to high bacterial counts, including counts of obligate anaerobes, in the duodenum and whether increased numbers of bacteria could be found in the duodenum of cats with signs of chronic gastrointestinal tract disease. DESIGN: Prospective study. ANIMALS: 20 healthy control cats (10 from a colony environment and 10 pet cats) and 19 cats with a history of chronic gastrointestinal tract disease. PROCEDURE: Undiluted duodenal fluid was quantitatively and qualitatively assessed by bacteriologic culture under aerobic and anaerobic conditions. Serum concentrations of cobalamin and folate were also measured. RESULTS: Significant differences were not detected in the numbers of bacteria found in the duodenum of cats housed in a colony environment, compared with pet cats fed an identical diet prior to sampling. All healthy cats were, therefore, combined into 1 control group. Compared with healthy cats, cats with clinical signs of gastrointestinal tract disease had significantly lower counts of microaerophilic bacteria, whereas total, anaerobic, and aerobic bacterial counts were not significantly different. None of the cats with disease had total bacterial counts higher than expected from the range established in the control cats. Differences were not detected in regard to serum folate or cobalamin concentrations between diseased and healthy cats. CONCLUSIONS AND CLINICAL RELEVANCE: These findings indicated that healthy colony cats and pet cats have high numbers of bacteria in the duodenum, including high numbers of obligate anaerobes. Our findings also suggest that bacterial overgrowth in the small intestine is not a common clinical syndrome in cats with chronic nonobstructive gastrointestinal tract disease.     

Effects of weight loss in obese cats on biochemical analytes related to inflammation and glucose homeostasis

The aim of the current study was to measure circulating metabolic and inflammation-related biochemical analytes in obese cats before and after weight loss. Thirty-seven overweight neutered cats were studied, median body weight 6.85 kg (range, 4.70 to 10.30 kg), representing a range of ages and both sexes. An individualized weight-loss program was devised for each cat and monitored until completion. Body fat mass was determined by dual-energy x-ray absorptiometry, whereas plasma concentrations of acute-phase proteins (APPs; eg, haptoglobin and serum amyloid A), hormones (eg, insulin, IGF-1, and adiponectin), and enzymes (eg, butyrylcholinesterase and paraoxonase type 1 [PON-1]) associated with inflammation and metabolic compounds (eg, glucose) were also measured. No significant changes were found in APPs after weight loss (P > 0.3), but significant increases in plasma adiponectin (P = 0.021) and IGF-1 (P = 0.036) were seen, whereas insulin (P < 0.001) and homeostasis model assessment (P = 0.005) decreased significantly. Plasma concentrations before weight loss of PON-1 (P = 0.004), adiponectin (P = 0.02), and IGF-1 (P = 0.048) were less in cats that failed to complete weight loss than cats that were successful, whereas glucose concentration was greater. Finally, multivariable linear regression analysis showed that lean tissue loss during weight management was associated with percentage weight loss (greater weight loss, greater lean tissue loss; R = 0.71, P < 0.001) and plasma adiponectin concentration before weight loss (lesser adiponectin, more lean tissue loss; R = -0.52, P = 0.023). In conclusion, various metabolic abnormalities occur in feline obesity, and these can be linked to outcomes of weight-loss programs. The changes that occur with weight loss suggest an improved metabolic status.     

Clinical and magnetic resonance imaging findings in 92 cats with clinical signs of spinal cord disease

Medical records of 92 cats presented with clinical signs of spinal cord disease, which had undergone magnetic resonance imaging (MRI), were reviewed. The cats were grouped into seven categories based upon the diagnosis suggested by results of MRI, cerebrospinal fluid analysis and other diagnostic procedures: neoplastic (n=25), inflammatory or infectious (n=13), traumatic (n=8), vascular (n=6), degenerative (n=5), anomalous (n=3) and those with an unremarkable MRI (n=32). There were two independent predictors of abnormal MRI findings: severity of clinical signs and presence of spinal pain. Abnormal MRI findings and speed of onset of disease were significantly associated with survival. For the 32 cats with unremarkable MRI findings, only nine died due to spinal disease and, therefore, the median survival time (MST) was not reached (lower 95% confidence interval (CI)=970 days). For the 60 cats with abnormal MRI findings, 37 died due to their disease and the MST was 138 days (95% CI: 7-807).     

Assessment of left atrial appendage flow velocity and its relation to spontaneous echocardiographic contrast in 89 cats with myocardial disease

The hypotheses of this prospective study were that (1) left atrial appendage (LAA) blood flow velocities can be recorded in cats with myocardial disease by transthoracic Doppler echocardiography, (2) LA enlargement, LA mechanical dysfunction, and left ventricular (LV) diastolic abnormalities are associated with decreased LAA flow velocities, and (3) low LAA flow velocities predict the appearance of spontaneous echocardiographic contrast in cats with cardiomyopathy. Transthoracic 2-dimensional, M-mode, and Doppler echocardiographic studies were performed in 89 cats with hypertrophic, restrictive, dilated, or unclassified cardiomyopathy or with hyperthyroid heart disease. Maximal LAA flow velocity (LAAmax) was decreased (P < .001) in cats with cardiomyopathy (median, 0.28 m/s; range, 0.08-1.35) compared to normal cats. Associated with decreased LAA flow velocities were increased LA size, decreased LA function, increased severity of LV diastolic dysfunction, and the presence of congestive heart failure. Multivariate logistic regression analysis detected an LAAmax <0.20 m/s as the only independent variable to predict LA spontaneous echocardiographic contrast (odds ratio, 30.1; 95% confidence interval [CI], 4.1 222.3; P < .001). Receiver operating characteristic analysis performed to predict spontaneous echocardiographic contrast indicated an area under the curve of 0.88 (95% CI, 0.80-0.95; P < .001) with sensitivities of 100 and 74% and specificities of 69 and 83% for LAAmax <0.25 and <0.20 m/s, respectively. Thus, low LAA flow velocities identified a subgroup of patients at increased risk of spontaneous echocardiographic contrast and possible thromboembolism. These findings may have important clinical implications for anticoagulation therapy and prognostication in cats with cardiomyopathy.     

Prevalence of Bartonella henselae antibodies in serum of cats with and without clinical signs of central nervous system disease

Bartonella henselae is occasionally associated with neurological dysfunction in people and some experimentally infected cats. The purpose of this study was to determine whether B henselae seroprevalence or titer magnitude varies among cats with neurological disease, cats with non-neurological diseases, and healthy cats while controlling for age and flea exposure. There was no difference in B henselae seroprevalence rates between cats with seizures and cats with other neurological diseases. Cats with non-neurological disease and healthy cats were more likely than cats with neurological disease to be seropositive. While the median B henselae antibody titer was greater in cats with seizures than in cats with other neurological disease, the median B henselae antibody titer was also greater in healthy cats than cats with seizures. The results suggest that titer magnitude cannot be used alone to document clinical disease associated with B henselae infection and that presence of B henselae antibodies in serum of cats with neurological disease does not prove the clinical signs are related to B henselae.     

Efficacy of pradofloxacin in cats with feline upper respiratory tract disease due to Chlamydophila felis or Mycoplasma infections

BACKGROUND: Upper respiratory tract disease (URTD) of cats is caused by a number of pathogens, including Chlamydophila felis and Mycoplasma spp. For effective treatment of both infections, doxycycline and enrofloxacin are recommended, but adverse effects limit their use in cats. HYPOTHESIS: That the fluoroquinolone pradofloxacin is effective against C. felis and Mycoplasma infection in cats with URTD or conjunctivitis. ANIMALS: Thirty-nine cats with signs of URTD or conjunctivitis. METHODS: Placebo-controlled, double-blind clinical trial. Cats were randomly entered into 1 of 2 treatment groups: treated PO with either 5 mg/kg pradofloxacin q24h or 5 mg/kg doxycycline q12h for 42 consecutive days. Changes in health status and clinical scores were evaluated. The presence of C. felis and Mycoplasma spp. was determined by quantitative polymerase chain reaction (PCR) and nested PCR of conjunctival swabs, respectively. RESULTS: At the beginning of the study, C. felis and Mycoplasma spp. were detected in 23 and 20 cats, respectively. Cats of both groups responded rapidly with a marked improvement in clinical signs within the 1st week. During treatment with either drug, C. felis DNA copy number declined quickly. Complete elimination of Mycoplasma spp. was achieved in both groups; however, whereas all cats receiving doxycycline eliminated C. felis, 4 cats treated with pradofloxacin remained PCR-positive. CONCLUSION AND CLINICAL IMPORTANCE: This study demonstrates that both pradofloxacin and doxycycline have good efficacy against C. felis and Mycoplasma spp., resulting in a marked improvement of clinical signs. However, C. felis DNA remained in some cats after treatment with pradofloxacin, suggesting that infection might not have been eliminated.     

Evaluation of client-specific outcome measures and activity monitoring to measure pain relief in cats with osteoarthritis

BACKGROUND: There are no validated systems for measuring pain from osteoarthritis in cats. HYPOTHESIS: Owner subjective assessments and an activity monitor (AM) can be used to detect pain in cats with osteoarthritis and to assess efficacy of treatments. ANIMALS: Thirteen cats older than 10 years old, with owner-assessed decreases in activity, painful arthritic joints, and clinically normal blood work were included and evaluated for 3 weeks. METHODS: A collar-mounted AM measured activity and a client-specific outcome measure (CSOM) questionnaire characterized the severity of impairment. Overall global quality of life was also evaluated for each treatment. In weeks 2 and 3, meloxicam (0.1 mg/kg, day 1; 0.05 mg/kg, days 2-5) or a placebo was administered in a blinded, randomized, cross-over manner to test the assessment systems. RESULTS: The cats had a median of 4 arthritic appendicular joints. Activity counts for the week when cats (complete data on activity; n=9) were administered meloxicam were significantly higher than at baseline (P = .02) but not after placebo (P = .06). Baseline activity counts were not significantly different from placebo (P = .6). The CSOM data (n=13) showed that owners considered their cats to be more active on meloxicam compared with baseline (P = .001) and placebo (P < .004), and more active on placebo than at baseline (P < .01). Global quality of life improved significantly with meloxicam (P < .042). CONCLUSIONS AND CLINICAL IMPORTANCE: Both an AM and a CSOM system can detect behavior associated with pain relief in cats that are arthritic. Objective activity data might allow subjective assessment systems to be validated for use in clinical studies.