Companion Animal Species Research Articles

All lesions great and small, part 1: Diagnostic cytology in veterinary medicine

Cytopathology is a minimally invasive, rapid, and cost-effective diagnostic modality with broad utilization in veterinary medicine. Primary care clinicians often screen common cutaneous and subcutaneous aspirates, with other samples most frequently evaluated by board certified veterinary clinical pathologists in reference laboratories. Wright-Giemsa stains are frequently utilized with the application of ancillary diagnostics such as cytochemistry, immunocytochemistry, flow cytometry, and molecular diagnostic techniques complicated by the need to develop and validate species specific reagents and protocols. The interpretation of veterinary cytology samples must be undertaken with extensive knowledge of the breadth of animal species, which includes familiarity with the frequency and biological behavior of inflammatory, infectious, and neoplastic lesions that are influenced by species, breed, and husbandry conditions. This review is the first of two parts that focus on the most common domestic companion animal species (dog, cat, and horse), taking an organ system approach to survey important lesions that may be unique to veterinary species or have interesting correlates in human medicine. The first of the two-part series covers skin and subcutaneous tissue, the musculoskeletal system, and lymphoid organs. The cytologic features and biological behavior of similar lesions are compared, and selected molecular mechanisms of disease and ancillary diagnostics are reviewed when characterized. Supporting figures illustrate a subset of lesions. While not a comprehensive catalog of veterinary cytology, the goal is to give cytopathologists working in human medicine a general impression of correlates in veterinary practice.

All lesions great and small, part 2. Diagnostic cytology in veterinary medicine

This is the second in a two‐part review of diagnostic cytopathology in veterinary medicine. As in human medicine, cytopathology is a minimally invasive, rapid, and cost‐effective diagnostic modality with broad utilization. In this second part, the diagnostic applications of cytology in respiratory, gastrointestinal, genitourinary, endocrine, ocular, and central nervous system tissues are discussed with a section describing fluid analysis in veterinary medicine. As noted in the previous manuscript, which characterized the cytology of the skin/subcutis, musculoskeletal, and lymphoid tissues, the interpretation of veterinary cytology samples must be undertaken with extensive knowledge of the breadth of animal species, including familiarity with the frequency and clinical progression of diseases, both of which can be influenced by species, breed, and husbandry conditions. Similar to part one, this review focuses on the most common domestic companion animal species (dog, cat, and horse) and highlights lesions that are either unique to veterinary species or have relevant correlates in people. The cytologic features and biological behavior of similar lesions are compared, and selected mechanisms of disease and ancillary diagnostics are reviewed when appropriate. Supporting figures illustrate a subset of lesions. While not an exhaustive archive of veterinary cytology, the goal is to give cytopathologists working in human medicine a general impression of correlates and unique entities in veterinary practice. Diagn. Cytopathol. 2014;42:544–552. © 2014 Wiley Periodicals, Inc.

The fecal virome of domesticated animals.

Next-generation sequencing is a new research tool in our hands helping us to explore still unknown fields of human and veterinary virology. Metagenomic analysis has enabled the discovery of putative novel pathogens and the identification of the etiologic agents of several diseases, solving long-standing mysteries caused by divergent viruses. This approach has been used in several studies investigating fecal samples of livestock, and companion animal species, providing information on the diversity of animal fecal virome, helping the elucidation of the etiology of diarrheal disease in animals and identifying potential zoonotic and emerging viruses.

PET and SPECT Imaging in Veterinary Medicine

Veterinarians have gained increasing access to positron emission tomography (PET and PET/CT) imaging facilities, allowing them to use this powerful molecular imaging technique for clinical and research applications. SPECT is currently being used more in Europe than in the United States and has been shown to be useful in veterinary oncology and in the evaluation of orthopedic diseases. SPECT brain perfusion and receptor imaging is used to investigate behavioral disorders in animals that have interesting similarities to human psychiatric disorders. This article provides an overview of the potential applications of PET and SPECT. The use of commercially available and investigational PET radiopharmaceuticals in the management of veterinary disease has been discussed. To date, most of the work in this field has utilized the commercially available PET tracer, (18)F-fluorodeoxyglucose for oncologic imaging. Normal biodistribution studies in several companion animal species (cats, dogs, and birds) have been published to assist in lesion detection and interpretation for veterinary radiologists and clinicians. Studies evaluating other (18)F-labeled tracers for research applications are underway at several institutions and companion animal models of human diseases are being increasingly recognized for their value in biomarker and therapy development. Although PET and SPECT technologies are in their infancy for clinical veterinary medicine, increasing access to and interest in these applications and other molecular imaging techniques has led to a greater knowledge and collective body of expertise for veterinarians worldwide. Initiation and fostering of physician-veterinarian collaborations are key components to the forward movement of this field.

Effect of surgical castration at different stages of maturity with or without analgesia on growth performance and acute-phase response

Although castration is a commonly practiced management procedure, it causes pain and stress that can temporarily reduce performance. Currently, there is no approved medication for analgesia in cattle. Meloxicam is a non-steroidal anti-inflammatory drug (NSAID) approved by the FDA for analgesic use in companion animal species. The objective of this study was to determine whether surgical castration at birth or weaning with or without concurrent analgesia by administration of meloxicam impacts growth performance or the acute-phase response (APR).

Pointing the way to improved welfare for companion animals

In May this year, the VetCompass small animal surveillance project passed a notable milestone and celebrated the half-millionth animal being added to its database. To date, 190 veterinary practices across...

Prevalence of extended-spectrum β-lactamase-producing Enterobacteriaceae in humans living in municipalities with high and low broiler density

Prevalence of, and risk factors for, carriage of extended-spectrum β-lactamase (ESBL) -producing Enterobacteriaceae were determined for 1025 Dutch adults in municipalities with either high or low broiler densities. Overall prevalence of ESBL carriage was 5.1%. The hypothesis that individuals in areas with high broiler densities are at greater risk for ESBL carriage was rejected, as the risk was lower (OR = 0.45; p 0.009) for these individuals. Owning a horse increased the risk (OR = 4.69; p < 0.0001), but horse owners often owned multiple species of companion animals. Routes of transmission from animals to humans in the community, and the role of poultry in this process, remain to be elucidated.

Leptospirosis in horses

Leptospirosis in horses has been considered a relatively uncommon infection. However, recent data suggest that the infection is widespread, with the incidence and infecting serovars varying considerably in different geographical regions. The majority of infections remain asymptomatic. Clinical signs in equine leptospirosis resemble those seen in other animal species. However, leptospirosis as a cause of acute respiratory distress is becoming more frequently recognised. A particular feature of equine leptospirosis is post infection recurrent uveitis (moon blindness or periodic ophthalmia), which appears to be mediated by autoimmune mechanisms involving cross reactivity between ocular tissues and leptospiral membrane proteins. There are no leptospiral vaccines licensed for use in horses, with no prospect for any becoming available in the foreseeable future. Accordingly, prevention of equine leptospirosis must rely on good hygiene practices, minimisation of rodent contact, and vaccination of other species of production and companion animals.

The role of phosphorus in the pathophysiology of chronic kidney disease

To review the human and veterinary literature on the role of phosphorus in the pathophysiology of chronic kidney disease (CKD) and to explore why control of plasma phosphorus concentration is an important goal in the management of patients with this disease. Human and veterinary studies, reviews, clinical reports, textbooks, and recent research findings focused on phosphate homeostasis and CKD patient management. Recent studies using rodent models and human patients with CKD have focused on trying to elucidate the role of the phosphatonins, predominantly fibroblast growth factor-23, in phosphate homeostasis and the pathophysiology of secondary renal hyperparathyroidism (SRHP). Fibroblast growth factor-23 is now considered to be a key regulator of plasma phosphorus concentration in people but has only recently been investigated in companion animal species. Cross-sectional studies of naturally occurring CKD in dogs and cats have shown hyperphosphatemia and SRHP to be highly prevalent and associated with increased morbidity and mortality in these patients. Experimental studies of surgically induced renal impairment in the dog and cat, and cases of naturally occurring CKD have emphasized the ability of renal care diets to modify plasma phosphorus and parathyroid hormone concentrations. Evidence from these studies indicates that maintaining plasma phosphorus concentrations to within the International Renal Interest Society targets for CKD patients improves survival time and reduces clinical manifestations of hyperphosphatemia and SRHP. The maintenance of plasma phosphorus concentrations in to within the International Renal Interest Society targets is recommended in management of CKD patients. The discovery of the phosphatonins has improved understanding of the mechanisms involved in phosphorus homeostasis and SRHP and may lead to improved ability to monitor and manage these patients.

Isolation of canine Anaplasma phagocytophilum strains from clinical blood samples using the Ixodes ricinus cell line IRE/CTVM20

Anaplasma phagocytophilum is an intracellular tick-borne rickettsial pathogen, which causes granulocytic anaplasmosis in various species of livestock and companion animals and also in humans. Previously A. phagocytophilum has been isolated and propagated in cell lines derived from the tick Ixodes scapularis and in the human promyelocytic cell line HL60. In this study we used the Ixodes ricinus-derived cell line IRE/CTVM20 to isolate and propagate two new canine strains of A. phagocytophilum.Blood samples were collected by veterinarians from two dogs, one from Germany and the other from Austria. Suspicion of clinical canine granulocytic anaplasmosis was raised by the treating veterinarians and after confirmation of A. phagocytophilum infection by real-time PCR, buffy coat cells were isolated and co-cultivated with IRE/CTVM20 cells maintained at 28°C in L15/L15B medium.In the tick cells, rickettsial inclusions were first recognised after 86 days of incubation. Electron microscopic examination of tick cells infected with one of the isolates revealed cytoplasmic vacuoles containing pleomorphic organisms with individual bacteria enveloped by a bilayer membrane. Sequencing of 16S rRNA genes confirmed the isolation of A. phagocytophilum and showed the highest identity to the A. phagocytophilum human HZ strain. The two A. phagocytophilum isolates were passaged several times in IRE/CTVM20 cells and transferred to the I. scapularis cell line ISE6. This confirms for the first time the successful establishment and continuous cultivation of this pathogen in I. ricinus cells as well as infectivity of these canine strains for I. scapularis cells.

Post‐transfusion survival of biotin‐labeled allogeneicRBCs in adult horses

Post-transfusion survival of allogeneic RBCs has been reported to be much shorter in horses than in other species. We hypothesized that post-transfusion survival of biotinylated allogeneic equine RBCs would be greater than the survival previously reported from studies using radioactive RBC-labeling techniques. The study objective was to determine post-transfusion survival of N-hydroxysuccinimide (NHS)-biotin-labeled allogeneic equine RBCs transfused into adult horses. Horses were adults and included 5 donors and 5 recipients. All horses were blood-typed, and donors were paired with recipients based upon blood type and crossmatch results. Donor blood was collected in a volume of 4 L into citrate phosphate dextrose adenine-1 and stored for 24 hours, labeled with NHS-biotin, and re-infused into recipients. Post-transfusion blood samples were collected at 15 minutes and at 1, 2, 3, 5, 7, 14, 21, 28, and 35 days. Biotin-labeled RBCs were detected by flow cytometry using streptavidin-phycoerythrin. Post-transfusion survival at 24 hours, lifespan, and half-life of biotinylated RBCs were determined. Mean ± SD survival of biotinylated RBCs at 24 hours post-transfusion was 95 ± 24%; the mean lifespan of transfused allogeneic RBCs was 39 days based on calculation of a linear regression survival curve, and mean post-transfusion RBC half-life was 20 days. Post-transfusion survival of 24-hour stored equine allogeneic RBCs was greater than previously reported but less than that observed for other companion animal species. Mechanisms for the relatively short post-transfusion lifespan of allogeneic equine RBCs remain unknown and warrant further study.

A genome-wide association study of osteochondritis dissecans in the Thoroughbred.

Osteochondrosis is a developmental orthopaedic disease that occurs in horses, other livestock species, companion animal species, and humans. The principal aim of this study was to identify quantitative trait loci (QTL) associated with osteochondritis dissecans (OCD) in the Thoroughbred using a genome-wide association study. A secondary objective was to test the effect of previously identified QTL in the current population. Over 300 horses, classified as cases or controls according to clinical findings, were genotyped for the Illumina Equine SNP50 BeadChip. An animal model was first implemented in order to adjust each horse's phenotypic status for average relatedness among horses and other potentially confounding factors which were present in the data. The genome-wide association test was then conducted on the residuals from the animal model. A single SNP on chromosome 3 was found to be associated with OCD at a genome-wide level of significance, as determined by permutation. According to the current sequence annotation, the SNP is located in an intergenic region of the genome. The effects of 24 SNPs, representing QTL previously identified in a sample of Hanoverian Warmblood horses, were tested directly in the animal model. When fitted alongside the significant SNP on ECA3, two of these SNPs were found to be associated with OCD. Confirmation of the putative QTL identified on ECA3 requires validation in an independent sample. The results of this study suggest that a significant challenge faced by equine researchers is the generation of sufficiently large data sets to effectively study complex diseases such as osteochondrosis.

Identification of intra- and inter-individual metabolite variation in plasma metabolite profiles of cats and dogs

The purpose of the present study was first to identify drivers of variance in plasma metabolite profiles of cats and dogs that may affect the interpretation of nutritional metabolomic studies. A total of fourteen cats and fourteen dogs housed in environmentally enriched accommodation were fed a single batch of diet to maintain body weight. Fasting blood samples were taken on days 14, 16 and 18 of the study. Gas chromatography-mass spectrometry (GC-MS), liquid chromatography (LC)-MS/MS and solid-phase extraction-LC-MS/MS analyses were used for metabolite profiling. Principal component (PC) analysis that indicated 31 and 27 % of the variance was explained in PC1 and PC2 for cats and dogs, respectively, with most individuals occupying a unique space. As the individual was a major driver of variance in the plasma metabolome, the second objective was to identify metabolites associated with the individual variation observed. The proportion of intra- and inter-individual variance was calculated for 109 cat and 101 dog metabolites with a low intra-individual variance (SD < 0.05). Of these, fifteen cat and six dog metabolites had inter-individual variance accounting for at least 90 % of the total variance. There were four metabolites common to both species (campesterol, DHA, a cholestenol and a sphingosine moiety). Many of the metabolites with >75 % inter-individual variance were common to both species and to similar areas of metabolism. In summary, the individual is an important driver of variance in the fasted plasma metabolome, and specific metabolites and areas of metabolism may be differentially regulated by individuals in two companion animal species.

Deciphering the genetic basis of animal domestication

Genomic technologies for livestock and companion animal species have revolutionized the study of animal domestication, allowing an increasingly detailed description of the genetic changes accompanying domestication and breed development. This review describes important recent results derived from the application of population and quantitative genetic approaches to the study of genetic changes in the major domesticated species. These include findings of regions of the genome that show between-breed differentiation, evidence of selective sweeps within individual genomes and signatures of demographic events. Particular attention is focused on the study of the genetics of behavioural traits and the implications for domestication. Despite the operation of severe bottlenecks, high levels of inbreeding and intensive selection during the history of domestication, most domestic animal species are genetically diverse. Possible explanations for this phenomenon are discussed. The major insights from the surveyed studies are highlighted and directions for future study are suggested.

Intravenous and Intraosseous Fluid Therapy in Critically Ill Birds of Prey

Fluid therapy is a foundation of emergency medicine, thus its importance cannot be underestimated. Avian fluid therapy shares the general principles used for mammalian species, yet it seems appropriate to emphasize certain differences and highlight a few catheter techniques that are required to perform avian emergency medicine. As with other companion animal species, 4 main routes of fluid administration exist. However, in the critically ill avian patient, the intravenous and, more importantly, intraosseous routes of fluid administration become the clinician's preferred methods of vascular access. This brief communication will familiarize the reader with the intravenous catheterization of the ulnar/basilic and right jugular veins and the intraosseous catheterization of the distal ulna in raptors. The step-by-step pictorial presentation of each technique will facilitate the learning experience and provide visual cues. Accompanying information will give the reader an understanding of possible complications, the authors' suggested techniques based on the clinical presentation and the patient size, as well as a protocol to use for appropriate hydration of the avian patient. Raptors are used as a model in this article; however, these techniques and supporting information can easily be applied to most avian species.

Perspectives on transgenic livestock in agriculture and biomedicine: an update

It has been 30 years since the first transgenic mouse was generated and 26 years since the first example of transferring the technology to livestock was published. While there was tremendous optimism in those initial years, with most convinced that genetically modified animals would play a significant role in agricultural production, that has not come to be. So at first sight one could conclude that this technology has, to a large extent, failed. On the contrary, it is believed that it has succeeded beyond our original expectations, and we are now at what is perhaps the most exciting time in the development and implementation of these technologies. The original goals, however, have drastically changed and it is now biomedical applications that are playing a central role in pushing both technical and scientific developments. The combination of advances in somatic cell nuclear transfer, the development of induced pluripotent stem cells and the completion of the sequencing of most livestock genomes ensures a bright and exciting future for this field, not only in livestock but also in companion animal species.

Naturally-occurring canine herpesvirus-1 infection of the vestibular labyrinth and ganglion of dogs

Although the involvement of herpesviruses in vestibular disease of humans has been recognised for many years, knowledge of such a link in companion animal species is restricted to cats. This study was conducted to assess the prevalence of canine herpesvirus-1 (CaHV-1) infection of the vestibular labyrinth (VL) and vestibular ganglion (VG) of dogs by PCR. 'Field' herpesvirus was detected in the VL of 17% and in the VG of 19% of 52 dogs, respectively. None of the 11 dogs with infected VG and/or VL exhibited signs of vestibular disease, whereas clinical signs in the remaining three animals were attributable to intra-cranial neoplasia. As reported for other species, the putative role of herpesvirus infection in canine vestibular disease requires further elucidation.

Seroprevalence of antibodies to Encephalitozooncuniculi and Encephalitozoonintestinalis in humans and animals

The presence of antibodies against Encephalitozoon cuniculi ( E. cuniculi) and Encephalitozoon intestinalis ( E. intestinalis) was examined in 215 samples from humans and in 488 samples from five different species of domestic and companion animals in Slovakia. The 215 human samples and samples from 90 swine, 123 non-infected cattle (cattle), 24 cattle infected with bovine leukosis virus (BLV-positive cattle), 140 sheep and 111 dogs were examined by the enzyme-linked immunosorbent assay (ELISA). Samples with serum titres 1:200 or higher were considered as positive. Specific anti- E. cuniculi antibodies were found in humans (0.9%), swine (52%), cattle (2%), sheep (9%) and dogs (15%) except for the BLV-positive cattle at the titre of 1:200. The titre of 1:400 was detected only in humans (0.5%). The presence of specific anti- E. intestinalis antibodies at the titre of 1:200 was confirmed in humans (6%), swine (51%), cattle (11%), BLV-positive cattle (13%) and dogs (6%) but not in sheep. The anti- E. intestinalis antibodies reached the 1:400 in humans (1%), swine (4%) and BLV-positive cattle (17%). The presence of specific anti- E. intestinalis antibodies at the titre of 1:600 was observed only in one swine (1%). Significant differences were observed in animals at titres 1:200 and 1:400 (chi-squared test: p < 0.0001) for both pathogens and in humans only for E. cuniculi at the titre of 1:400 (chi-squared test: p < 0.0075).

Intra‐abdominal hypertension in two adult horses

To describe the clinical and pathological findings in 2 adult horses with documented increases in intra-abdominal pressure (IAP), and to describe the direct puncture technique used to measure this pressure. Two adult horses developed increases in IAP secondary to large-volume abdominal effusion. A 9-year-old Quarter Horse cross gelding was presented for evaluation of urinary and neurologic signs. Abdominal ultrasonographic examination showed a hepatic abscess along with abdominal effusion. A 4-year-old Quarter Horse gelding was presented for evaluation of castration complications. A castration site infection extended into surrounding tissues, resulting in peritonitis, abdominal effusion, and severe cellulitis of the limbs. IAP measured in both horses was increased relative to reported equine reference values. Changes in hemodynamic parameters in both horses, notably increased central venous pressure, were consistent with those seen in other species in which intra-abdominal hypertension (IAH) and its sequellae have been documented. Extensive research and clinical literature guides management of humans with IAH and abdominal compartment syndrome. Knowledge of these conditions in companion animal and large domestic species is less well developed. Recent research has established reference values for standing, sedated and recumbent, anesthetized horses. Detailed reports of equine clinical cases of IAH have not been reported in the literature. This report provides information on the clinical, hemodynamic, and pathologic characteristics of 2 horses with measured increases in IAP, and describes the direct puncture technique used to perform these measurements.

Recognition and management of pain in cattle

ATTITUDES towards pain and its control in farm animals have lagged behind those in companion animal species. However, a considerable amount of work over the past 15 years has focused...