Prevalence and incidence of serum magnesium abnormalities in hospitalized cats

Total serum magnesium concentration ([Mg2+]s) was prospectively determined for 57 cats admitted to the intensive care unit (ICU) of the Cornell University Hospital for Animals. Data were collected and analyzed to determine the following: prevalence and incidence of [Mg2+] abnormalities, medical disorders associated with altered [Mg2+]s, association of altered [Mg2+]s with other electrolyte abnormalities, length of hospitalization for cats with abnormalities of [Mg2+]s versus those with normal [Mg2+]s, and survival of cats with abnormal [Mg2+)s versus those with normal [Mg2+]s. The point prevalence of magnesium abnormalities was 26%, the period prevalence was 46%, and the cumulative incidence was 23%. Hypermagnesemia was associated with abnormalities of serum potassium (P = .04) and phosphate (P = .01) concentrations. Abnormalities of [Mg2+]s were not associated with abnormal serum concentrations of Na+, Ca2+, or Cl-. On admission. hypomagnesemia was detected in cats with gastrointestinal, endocrine, and other disorders; hypermagnesemia was detected only in cats with renal disease, obstructive uropathy, or neoplastic disease. The median hospital stay for cats that developed abnormal [Mg2+]s after admission was longer than for cats that remained normomagnesemic (5 versus 4 days, respectively; P = .03). Despite the longer hospital stay, the survival of these cats was lower than that of normomagnesemic cats (54 versus 77%; P = .05). When all cats were considered, the survival of cats with abnormal [Mg2+]s also was decreased compared with normomagnesemic cats (62 versus 81%; P = .05). We conclude that abnormalities of [Mg2+]s may affect morbidity and mortality of affected cats.     

Prevalence of selected rickettsial infections in cats in Southern Germany

Prevalence of Anaplasma, Ehrlichia, Neorickettsia, and Wolbachia DNA in blood of 479 cats collected in different veterinary clinics in Southern Germany was determined using a previously published conventional PCR using 16S-23S intergenic spacer primers (5′ CTG GGG ACT ACG GTC GCA AGA C 3′ – forward; 5′ CTC CAG TTT ATC ACT GGA AGT T 3′ – reverse). Purified amplicons were sequenced to confirm genus and species. Associations between rickettsial infections, and feline immunodeficiency virus (FIV), as well as feline leukemia virus (FeLV) status were evaluated. Rickettsial prevalence was 0.4% (2/479; CI: 0.01–1.62%). In the two infected cats, Anaplasma phagocytophilum DNA was amplified. These cats came from different environment and had outdoor access. Both were ill with many of their problems likely related to other diseases. However, one cat had neutrophilia with left shift and the other thrombocytopenia potentially caused by their A. phagocytophilum infection. There was no significant difference in the FIV and FeLV status between A. phagocytophilum-negative and -positive cats. A. phagocytophilum can cause infection in cats in Southern Germany, and appropriate tick control is recommended.     

Hematologic abnormalities and outcome of 16 cats with myelodysplastic syndromes

We investigated the hematologic abnormalities and prognoses in 16 cats with myelodysplastic syndromes (MDS). Nonregenerative anemia, thrombocytopenia, and neutropenia were observed in 15, 13, and 4, respectively, of the 16 cats with MDS. Morphologic abnormalities characteristic of MDS included megaloblastoid rubricytes (9 cats), hyposegmentation of neutrophils (7 cats), nuclear abnormality of rubricytes (10 cats) and neutrophils (13 cats), and micromegakaryocytes (10 cats). Disease in these 16 cats was subclassified into refractory anemia (RA; 8 cats), RA with excess of blasts (RAEB; 5 cats), RAEB in transformation (RAEB in T; 1 cat), and chronic myelomonocytic leukemia (CMMoL; 2 cats), according to the human French-American-British (FAB) classification. In the cats in which the clinical outcome was known, 3 of 6 cats with high blast cell count MDS, including RAEB, RAEB in T, and CMMoL, developed acute myeloid leukemia, but only 1 of 8 cats with low blast cell count MDS (RA) developed acute myeloid leukemia. Based on the Dusseldorf scoring system for the prognosis of human MDS, the survival times of the cats showing high scores (> or =3 points) were significantly shorter than those of the cats with low scores (<3 points). The FAB classification and Dusseldorf scoring system were considered to be useful for predicting the prognosis of feline MDS. Furthermore, 15 of the 16 cats with MDS in this study were infected with feline leukemia virus, indicating its possible etiologic role in the pathogenesis of feline MDS.     

Efficacy and safety of transdermal methimazole in the treatment of cats with hyperthyroidism

The objective of this study was to determine whether transdermal methimazole was as safe and effective as oral methimazole for the control of hyperthyroidism in cats. Forty-seven cats with newly diagnosed hyperthyroidism were randomized to receive either transdermal methimazole in pluronic lecithin organogel (PLO; applied to the inner pinna), or oral methimazole (2.5 mg q12h for either route). Cats were evaluated at weeks 0, 2, and 4 with a physical exam, body weight determination, CBC, biochemical panel, urinalysis, measurement of total levothyroxine (T4) concentration, indirect Doppler blood pressure determinaiton, and completion of an owner questionnaire. Data between the 2 groups and over time were compared by nonparametric methods. Forty-four cats followed the protocol (17 oral and 27 transdermal). Significantly more cats treated with oral methimazole had serum T4 concentrations within the reference range after 2 weeks (14 of 16 cats) compared to those treated by the transdermal route (14 of 25; P = .027). This difference was no longer significant by 4 weeks of treatment (9 of 11 for oral versus 14 of 21 for transdermal), possibly because of inadequate numbers evaluated by 4 weeks. Cats treated with oral methimazole had a higher incidence of gastrointestinal (GI) adverse effects (4 of 17 cats) compared to the cats treated with transdermal methimazole (1 of 27; P = .04), but no differences were found between groups in the incidence of neutropenia, hepatotoxicity, or facial excoriations. Although the overall efficacy of transdermal methimazole is not as high as that of oral methimazole at 2 weeks of treatment, it is associated with fewer GI adverse effects compared to the oral route.     

N-acetyl-beta-D-glucosaminidase index as an early biomarker for chronic kidney disease in cats with hyperthyroidism

Background: Hyperthyroid cats are at risk of developing azotemic chronic kidney disease (CKD) and diagnostic tools currently used to screen for CKD in hyperthyroid cats are either unreliable or impractical.
Hypothesis: Urine N -acetyl-β- d -glucosaminidase index (NAG_i) is a good biomarker for azotemic CKD in hyperthyroid cats.
Animals: Twenty-four newly diagnosed nonazotemic hyperthyroid cats and 10 healthy cats.
Methods: All cats were evaluated for hyperthyroidism at baseline. Hyperthyroid cats were treated with methimazole and reevaluated once euthyroid. At the end of the study, cats were divided into 3 groups: healthy cats, nonazotemic, and azotemic euthyroid cats. Baseline group characteristics were compared to predict azotemic CKD. The influence of treatment on NAG_i was evaluated.
Results: Baseline NAG_i was significantly different among groups ( P = .004). Azotemic cats had a higher median value (13.12 U/g) when compared with healthy cats (1.38 U/g). With NAG_i >2.76 U/g, negative and positive predictive values for development of azotemia were 77.7 and 50%, whereas the combination of a urine specific gravity (USG) ≤1.035 and T₄ >7.80 μg/dL enhanced predictive values to 88.9 and 83.3%, respectively. NAG_i values decreased significantly over time in treated nonazotemic cats.
Conclusions and Clinical Relevance: Baseline NAG_i did not differentiate azotemic from nonazotemic euthyroid cats. NAG_i could be used to assess renal function during medical therapy allowing the clinician to adjust methimazole dosage accordingly. The combination of USG and T₄ could optimize identification of appropriate candidates for permanent treatment of hyperthyroidism.     

Prevalence of hypertrophic cardiomyopathy in a cohort of British Shorthair cats in Denmark

Background: Familial hypertrophic cardiomyopathy (HCM) has been described previously in British Shorthair cats (BSH), but until now, no reports have been published describing the prevalence of the disease within this breed. Objectives: The aim of this study was to assess the prevalence of HCM in a large cohort of BSH and to evaluate the effect of sex, weight, and increasing age as potential risk factors for this disease. Animals: Three hundred and twenty‐nine BSH presented for routine HCM screening during a 4‐year period. Methods: Prospective cross‐sectional study in which all cats were screened for HCM by conventional echocardiography. Results: A total of 329 cats were examined, 214 females and 115 males, with a median age of 2.3 years (range, 0.8–14.1). Twenty‐eight cats (8.5%) were classified as HCM‐positive, 14 (4.3%) as equivocal, 282 (85.7%) as HCM‐negative, and 5 (2.1%) were diagnosed with other cardiac diseases. The median age for diagnosis of HCM was 2.7 years (range, 0.9–14.1). Male cats had a significantly higher occurrence of HCM (20.4%) compared with the females (2.1%) corresponding to an odds ratio of 7.89 (95 % CI, 2.54–28.08) for males versus females adjusted for age and weight (P < .001). Conclusion: The BSH in our cohort had a high prevalence of HCM, often of early onset and with a significant male sex predisposition. We strongly recommend echocardiographic screening in this breed, especially cats used for breeding.     

Prognostic factors in cats with feline panleukopenia

Background: Feline panleukopenia is a highly contagious and often lethal disease. Objective: The purpose of the study was to identify prognostic factors for survival of cats with panleukopenia. Animals: Between 1990 and 2007, 244 cats were diagnosed with panleukopenia in the Clinic of Small Animal Medicine, LMU University of Munich, Germany. Diagnosis was established by electron microscopy, polymerase chain reaction of feces or blood, antigen ELISA of feces, pathognomonic histopathological lesions at necropsy, or some combination of these procedures. Methods: Medical records of each cat were evaluated retrospectively. Results: Survival rate was 51.1%. No significant correlation was found between outcome and living conditions, age, vaccination status (unvaccinated versus one or more vaccines administered), or severity of clinical signs. However, of the vaccinated cats, none had received a vaccine later than 12 weeks of age as a kitten. Nonsurvivors had significantly lower leukocyte and thrombocyte counts at presentation compared with survivors. The relative risk of death for patients with <1,000/μL leukocytes was 1.77 times as high as in patients with a leukocyte count of 1,000–2,500/μL (P= .038), and 1.85 times as high as in patients with >2,500/μL leukocytes (P= .001). The likelihood of a fatal outcome was higher when serum albumin concentration was <30 g/L or serum potassium concentration <4 mmol/L. Conclusions and Clinical Importance: Vaccination strategies that do not include vaccination of kittens beyond 12 weeks of age may not be adequate to prevent panleukopenia. Leukopenia, thrombocytopenia, hypoalbuminemia, and hypokalemia are negative prognostic factors in cats with panleukopenia.     

Prevalence of low automated platelet counts in cats: comparison with prevalence of thrombocytopenia based on blood smear estimation

Abstract: True thrombocytopenia is uncommon in cats; however, low platelet counts frequently are found using automated cell counters. Although this discrepancy is a well known problem, the prevalence of low automated platelet counts in feline blood samples has not been documented. We retrospectively compared the prevalence of low automated platelet counts with low blood smear-estimated platelet counts in feline blood samples. Results of blood sample analysis from 359 cats during a 1-year period at the University of Glasgow Veterinary Haematology Laboratory were examined. Smear estimates of platelet number were done in those cases in which records did not indicate adequate platelet numbers. Platelet counts obtained with an impedance counter (Minos Vet, Abx Hematologie) were <200×10⁹ cells/L in 256 samples (71%) and <50×10⁹ cells/L in 43 samples (12%). However, based on estimation of platelet numbers from blood smears, only 11 samples (3.1%) had platelet counts of <200×10⁹ cells/L and 9 samples (2.5%) had counts of <50×10⁹ cells/L. Four cats with thrombocytopenia estimated by blood smear evaluation had clinical signs of a bleeding disorder. Disorders associated with thrombocytopenia included neoplasia, cytotoxic chemotherapy, and infectious diseases. There was no evidence that delay due to mailing of samples was associated with lower automated platelet counts than would have been obtained on the day of sampling. The high prevalence of apparent thrombocytopenia in automated platelet counts was attributed to a combination of platelet aggregation and the impedance method of cell differentiation by size. Vigilance and careful examination of blood smears is required to identify the few cats with true thrombocytopenia.     

Prevalence of bovine herpesvirus-4 infection in cats in Central Michigan

The gammaherpesvirus bovine herpesvirus-4 (BHV-4) has been isolated from a wide variety of animals, including lions and domestic cats. Although BHV-4 antibodies have been detected in normal cats and cats with urinary disorders, the epidemiology and pathogenic role of BHV-4 in cats is unknown. The purpose of this study was to determine the prevalence of BHV-4 antibodies and viral nucleic acid in a population of free-roaming cats. Plasma and peripheral blood leukocyte samples were collected from 52 male and 52 female free-roaming cats impounded at a regional animal control facility in Central Michigan. Plasma concentrations of BHV-4 antibodies were measured with an indirect fluorescent antibody test. Peripheral blood leukocyte DNA was isolated, and a 2-stage polymerase chain reaction with heminested primers delineating a conserved portion of the BHV-4 glycoprotein B gene homologue was used to amplify BHV-4-specific DNA sequences. BHV-4 antibodies were detected in 38 (73%) male and 23 (44%) female cats. Seropositive cats were significantly more likely to be male than female (odds ratio = 3.22; P = .007). Cell-associated viremia was detected in 17 (33%) male and 11 (21%) female cats. Of the 61 seropositive cats, 23 (38%) had a detectable viremia; only 5 (12%) seronegative cats had detectable viremia. Seropositive cats were significantly more likely to be viremic than seronegative cats (OR = 4.30: P = .009). Our results suggest that BHV-4 infection may be more widespread in certain cat populations than previously reported. Furthermore, many cats seropositive for BHV-4 antibodies have a concurrent cell-associated viremia.     

Prevalence of antibodies against feline panleukopenia virus in client-owned cats in Southern Germany

Feline panleukopenia is a frequent and commonly fatal disease of cats. Recent published studies have raised suspicions that some cats fail to develop antibodies after vaccination. The purpose of this study was to assess the prevalence of antibodies against feline panleukopenia virus (FPV) in cats in Southern Germany, and to identify factors that are associated with a lack of antibodies. In total, 350 cats presented to the Clinic of Small Animal Medicine, Ludwig-Maximilians-Universitaet were randomly included in the study. Information regarding signalment, origin, environment, lifestyle, housing conditions, health status, chronic diseases, glucocorticoid therapy, and vaccination status were collected. Antibodies were detected by haemagglutination inhibition test. Asymptomatic chi-squared tests and univariable logistic regression were used to investigate associations between a lack of antibodies and the different variables. Associations determined to be statistically significant at P < 0.1 were verified by a multivariable logistic regression analysis.Of the 350 cats, 103 (29.4%) had no antibodies against FPV. Chronic kidney disease, neoplasia, glucocorticoid therapy, and vaccination status were significantly associated with a lack of antibodies. The cats with no antibodies were likely to have inadequate immunity against panleukopenia and those with chronic diseases or receiving glucocorticoids were less likely to be protected.     

Prevalence of diseases of the spinal cord of cats

A retrospective review of records of 205 cats with histologically confirmed disease of the spinal cord was performed to identify the prevalence of disease in this nonrandomly selected population of cats. Clinical records were reviewed, and age, duration of neurologic illness, and clinical and histopathologic findings in cats with spinal cord disease were abstracted. Disease processes were classified into 7 categories and 23 groups. The most common diseases affecting the spinal cord of cats were feline infectious peritonitis (FIP), lymphosarcoma (LSA), and neoplasia of the vertebral column secondarily affecting the spinal cord. Information on age, onset and duration of clinical signs, and lesion localization at the postmortem examination in cats belonging to the 7 categories of disease were analyzed to create a practical list of differential diagnoses. Cats were also subcategorized into 3 groups based on their age at death. FIP was the most common disease of cats younger than 2 years of age. LSA and vertebral column neoplasia were the most common diseases affecting cats between 2 and 8 years of age. Vertebral column neoplasia was the most common disease affecting cats older than 8 years of age. Results of this histopathologic study showed that FIP and LSA were the most common disease processes affecting the spinal cord of cats. However, at least 21 other groups of diseases and their relative prevalence were identified.     

Prevalence of enteric zoonotic agents in cats less than 1 year old in central New York State

A prevalence study of several enteric zoonotic bacterial and parasitic infections was conducted in 263 fecal samples from cats that were between 1 and 12 months old, and that were in humane shelters (n = 149) or were presented to primary-care veterinarians (n = 114). Of these samples, 2 (0.8%) were positive for Campylobacter, 2 (0.8%) were positive for Salmonella, and 10 (3.8%) were positive for Cryptosporidium, confirming that these zoonotic agents are relatively rare in cats. Toxocara cati (33.0%) and Giardia (7.3%) were found more commonly. At least 1 zoonotic agent was detected in 105 samples (40.7%). Our results suggest that clinical signs such as diarrhea are not reliable predictors of whether a cat is actively shedding enteric organisms. Therefore, the decision to test a newly adopted cat should be based on the potential risks to the client rather than on the cat's clinical presentation. The high prevalence of T. cati confirms that comprehensive testing or treatment for ascarids is warranted in newly adopted kittens.     

Adrenal function in cats with hyperthyroidism

Adrenal function may be altered in animals with hyperthyroidism. The aim of the study was to assess adrenal function of hyperthyroid cats (n = 17) compared to healthy cats (n = 18) and cats with chronic diseases (n = 18). Adrenal function was evaluated by adrenocorticotropic hormone (ACTH) stimulation test and the urinary cortisol to creatinine ratio (UCCR) was determined. Length and width of both adrenal glands were measured via ultrasound. Hyperthyroid cats had significantly higher cortisol levels before and after stimulation with ACTH than the other groups. However, the UCCR was not elevated in hyperthyroid cats. The size of the adrenal glands of hyperthyroid cats was not significantly different from the size of those of healthy cats. The results indicate that cats with hyperthyroidism have a higher cortisol secretory capacity in a hospital setting. The normal size of the adrenal glands suggests that cortisol levels may not be increased permanently.