Clinical aspects of feline immunodeficiency and feline leukemia virus infection

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are retroviruses with a global impact on the health of domestic cats. The two viruses differ in their potential to cause disease. FIV can cause an acquired immunodeficiency syndrome that increases the risk of developing opportunistic infections, neurological diseases, and tumors. In most naturally infected cats, however, FIV itself does not cause severe clinical signs, and FIV-infected cats may live many years without any health problems. FeLV is more pathogenic, and was long considered to be responsible for more clinical syndromes than any other agent in cats. FeLV can cause tumors (mainly lymphoma), bone marrow suppression syndromes (mainly anemia) and lead to secondary infectious diseases caused by suppressive effects of the virus on bone marrow and the immune system. Today, FeLV is less important as a deadly infectious agent as in the last 20 years prevalence has been decreasing in most countries.     

Utility of measuring plasma N-terminal pro-brain natriuretic peptide in detecting hypertrophic cardiomyopathy and differentiating grades of severity in cats

Background: Cats with hypertrophic cardiomyopathy (HCM) often have no clinical signs or subtle signs. Measurement of N‐terminal pro‐brain natriuretic peptide (NT‐proBNP) has been demonstrated in people to be highly specific for heart disease and also correlates with severity of HCM. NT‐proBNP may also be valuable in detecting and grading HCM in cats, but results to date have been equivocal. Objectives: The aims of this study were to evaluate NT‐proBNP as a screening test for diagnosis of HCM in cats and determine an appropriate cut‐off value and to determine if NT‐proBNP concentrations correlated with severity of HCM in cats. Methods: Plasma NT‐proBNP concentrations were measured in 201 cats using an ELISA designed for use in cats. Cats were classified using echocardiography as clinically healthy controls (n=99) or cats with equivocal (n=9), mild (n=15), moderate (n=17), or severe (n=61) HCM. Results: NT‐proBNP concentrations (median; 25th–75th interquartile percentiles) in mildly (216.1; 87.6–392.5 pmol/L), moderately (282.7; 131.9–466.6 pmol/L), and severely (839.5; 655.3–1046.4 pmol/L) affected cats were significantly higher than those in healthy controls (18.9; 3.4–62.4 pmol/L). Concentrations in severely affected cats were significantly higher than in cats from other HCM groups. There was no significant difference between mild and moderate HCM. Cut‐off values >49 pmol/L had a sensitivity of 97.8% and specificity of 66.7%; >100 pmol/L had a sensitivity of 92.4% and specificity of 93.9%; and >150 pmol/L had a sensitivity of 88% and a specificity of 100%. Conclusions: NT‐proBNP with a cut‐off value of >100 pmol/L was useful in detecting even mild HCM. Cats with increased NT‐proBNP concentrations should be examined by echocardiography.     

Conventional and functional magnetic resonance imaging features of late subacute cortical laminar necrosis in a dog

Cerebral cortical laminar necrosis (CLN) is a consequence of severe hypoxic, ischemic, or hypoglycemic events. In humans, these cortical lesions show characteristic linear T1‐weighted (T1W) hyperintensity in the late subacute stage. Limited information reporting magnetic resonance imaging (MRI) findings in dogs affected by CLN is available. A 3‐year‐old Belgian Shepherd dog was referred 8 days after sudden onset of blindness after general anesthesia. Neurological examination showed central blindness and mild ataxia. Three‐Tesla MRI examination of the brain revealed bilateral asymmetrical areas of T2‐weighted hyperintensity within the occipital, parietal, temporal, and frontal cortex, involving gray and white matter. Furthermore, linear T1W‐hyperintense lesions were found in the cerebral cortex of the same areas and showed heterogeneous contrast enhancement. Perfusion‐weighted images revealed hyperperfusion in the affected regions. Lesions were compatible with subacute CLN with corresponding edema suspected to be secondary to anesthesia‐related brain hypoxia. Three‐Tesla MRI enabled identification of the laminar pattern of the cortical lesions.     

Avian influenza A H5N1 infections in cats

Although cats had been considered resistant to disease from influenza virus infection, domestic cats and large felids are now known to be naturally und experimentally susceptible to infection with highly pathogenic avian influenza virus H5N1 (HPAIV H5N1). The virus causes systemic infection, lung and liver being the mainly affected organs. Infected cats show fever, depression, dyspnoea, and neurological signs, but subclinical infections have also occurred. Mostly, cats have been infected by direct contact with affected birds, especially by eating raw poultry; transmission from cat to cat may also occur. Little is known about the role of cats in the epidemiology of the virus. So far, no reassortment between avian and mammalian influenza viruses has occurred in cats, but experts fear that cats might give the virus an opportunity to adapt to mammals. This publication gives a review on avian influenza in cats with a focus on practical aspects for veterinarians.     

Characterization of chromium-containing wastes and soils affected by the production of chromium tanning agents

Purpose

Wastes of unknown composition derived from the production of trivalent chromium (Cr(III)) salts used as tanning agents are deposited in the area of Kanpur, India. The questions of whether these samples are chromite ore processing residue (COPR) and whether Cr occurs in its toxic hexavalent form (Cr(VI)) arise.

Materials and methods

Twenty-one samples from two disposal sites and surrounding soils were analyzed, specifically examining their elemental and mineralogical composition. Additionally, aqueous eluates with different liquid-to-solid ratios were performed and analyzed for Cr(VI).

Results and discussion

The samples were classified in accordance to the sum of silicon and aluminum and the sum of calcium and Cr contents: uncontaminated, moderately contaminated, and highly contaminated material. Highly contaminated material exhibited extremely alkaline pH values up to 12.5 and total Cr contents ranging from 65.7 to 110 g/kg, whereas uncontaminated material had comparatively moderate pH values and Cr contents <1 g/kg. In total, seven crystalline phases commonly found in COPR were identified in the contaminated samples, of which five phases (brownmillerite, hydrocalumite, hydrogarnet, magnesiochromite, and periclase) are known to be able to accommodate Cr whereas hydrogarnet and hydrocalumite are the main host phases for Cr(VI). Batch tests showed that dissolution controlled the Cr(VI) concentrations in the eluates.

Conclusions

Six samples were clearly identified as highly Cr-contaminated COPR. Leaching of Cr(VI) and resulting contamination of soils and water bodies is a key environmental risk arising from these COPR sites especially during the monsoon season. This situation is of particular concern as the local population use the highly Cr(VI)-contaminated water not only for the needs of livestock and irrigation but also as drinking water due to the absence of alternative water resources.     

THREE TESLA MAGNETIC RESONANCE IMAGING FINDINGS IN 12 CASES OF CANINE CENTRAL EUROPEAN TICK‐BORNE MENINGOENCEPHALOMYELITIS

Central European tick‐borne encephalomyelitis can be challenging to diagnose in dogs because the virus may not be detected in blood and cerebrospinal fluid (CSF) after the first viremic stage of the disease. The purpose of this retrospective case series study was to describe 3 Tesla magnetic resonance imaging (3T MRI) findings in a sample of dogs with a confirmed diagnosis of tick‐borne encephalomyelitis. Dogs were included if they had neurological signs consistent with tick‐borne encephalomyelitis, history of a stay in endemic areas for tick‐borne encephalomyelitis virus, 3T MRI of the brain and/or spinal cord, cerebrospinal fluid changes compatible with viral infection and positive antibody titers in cerebrospinal fluid or pathologic confirmation of tick‐borne encephalomyelitis. Twelve dogs met inclusion criteria. Ten out of 12 patients had 3T MRI lesions at the time of presentation. One patient had persistent lesions in follow‐up MRI. The 3T MRI findings included bilateral and symmetrical gray matter distributed lesions involving the thalamus, hippocampus, brain stem, basal nuclei, and ventral horn on the spinal cord. All lesions were hyperintense in T2‐weighted sequences compared to white matter, iso‐ to hypointense in T1‐weighted, nonenhancing, and had minimal or no mass effect or perilesional edema. Six patients survived while the remaining six dogs were euthanized. Necropsy revealed neuronophagia and gliosis of the gray matter of the affected regions seen in 3T MRI, in addition to the cerebellum. Findings from the current study indicated that tick‐borne encephalomyelitis should be included in the differential diagnosis list for dogs with the above described 3T MRI characteristics.     

Cognitive enrichment in farm animals--the impact of social rank and social environment on learning behaviour of dwarf goats

The influence of social rank and social environment on visual discrimination learning of small groups of Nigerian dwarf goats (Capra hircus, n = 79) was studied using a computer-controlled learning device integrated in the animals' home pen.The experiment was divided into three sections (LE1, LE1 u, LE2; each 14d). In LE1 the goats learned a discrimination task in a socially stable environment. In LE1u animals were mixed and relocated to another pen and given the same task as in LE1. In LE2 the animals were mixed and relocated again and given a new discrimination task.We used drinking water as a primary reinforcer.The rank category of the goats were analysed as alpha, omega or middle ranking for each section of the experiment.The rank category had an influence on daily learning success (percentage of successful trials per day) only in LE1 u. Daily learning success decreased after mixing and relocation of the animals in LE1 u and LE2 compared to LE1.That resulted in an undersupply of drinking water on the first day of both these tasks.We discuss social stress induced by agonistic interactions after mixing as a reason for that decline. The absolute learning performance (trials to reach the learning criterion) of the omega animals was lower in LE2 compared to the other rank categories. Furthermore, their absolute learning performance was lower in LE2 compared to LE1. For future application of similar automated learning devices in animal husbandry, we recommend against the combination of management routines like mixing and relocation with changes in the learning task because of the negative effects on learning performance, particularly of the omega animals.