Companion Animal Medicine Research Articles

Imaging and score-based quantification of ovine pulmonary adenocarcinoma using computed tomography as an additional tool in advanced clinical diagnosis

Computed tomography (CT) is well established as an up-to-date technique in lung diseases in human medicine and is being progressively used in companion animal medicine as well. So far, visualisation of lung diseases in sheep has been mainly undertaken using X-ray and sonographic techniques.In this study, we examined repeatedly lungs of three sheep from a flock naturally infected with Jaagsiekte sheep retrovirus (JSRV). The infection is known to cause progressive pulmonary adenocarcinoma (OPA). Clinical signs and detection of proviral DNA of JSRV in bronchoalveolar lavage fluid by PCR confirmed the infection of the animals. CT of the lung was carried out under general anaesthesia. Data were compared to thoracic X-rays as well as to a CT scan and X-rays of a non-infected sheep (control). In two animals post-mortem/histopathology was included. A new CT-OPA score system was generated to classify the cancer stage and to quantify cancer progression.In general, CT diagnosis of the lung seemed to be appropriate as an additional diagnostic tool in sheep. Different stages of lung tumours as well as an unattended abscess cavity can clearly be visualised. The presented score-based quantification of oncogenesis provides a scientific tool to characterise adenocarcinoma progression over time in consecutive examinations objectively. Postmortem findings and histopathology showed good correlation with CT data. The obvious advantage of the CT technique in contrast to established X-ray imaging was the early and sensitive detection as well as clear localisation of even slight lung alterations in JSRV infected sheep.

Acute phase proteins: Biomarkers of infection and inflammation in veterinary medicine

Acute phase proteins (APPs) have been used as biomarkers of inflammation, infection and trauma for decades in human medicine but have been relatively under-utilised in the context of veterinary medicine. However, significant progress has been made in the detection, measurement and application of APPs as biomarkers in both companion and farm animal medicine over recent years. In the dog, C-reactive protein, haptoglobin and serum amyloid A have been identified as significant diagnostic 'markers' of steroid-responsive meningitis-arteritis, while in cats and cattle haptoglobin and alpha(1) acid glycoprotein and haptoglobin and serum amyloid A have proved valuable biomarkers of disease, respectively. In dairy cattle, haptoglobin and a mammary-associated serum amyloid A3 isoform, produced by the inflamed mammary gland during episodes of mastitis, have great potential as biomarkers of this economically important disease. Understanding the use of APP as biomarkers of inflammatory conditions of domestic animals has expanded significantly over recent years, and, with the insights provided by ongoing research, it is likely that these compounds will be increasingly used in the future in the diagnosis and prognosis of both companion and farm animal disease.

Illness Severity Scores in Veterinary Medicine: What Can We Learn?

Illness severity scores are gaining increasing popularity in veterinary medicine. This article discusses their applications in both clinical medicine and research, reviews the caveats pertaining to their use, and discusses some of the issues that arise in appropriate construction of a score. Illness severity scores can be used to decrease bias and confounding and add important contextual information to research by providing a quantitative and objective measure of patient illness. In addition, illness severity scores can be used to benchmark performance, and establish protocols for triage and therapeutic management. Many diagnosis-specific and diagnosis-independent veterinary scores have been developed in recent years. Although score use in veterinary research is increasing, the scores available are currently underutilized, particularly in the context of observational studies. Analysis of treatment effect while controlling for illness severity by an objective measure can improve the validity of the conclusions of observational studies. In randomized trials, illness severity scores can be used to demonstrate effective randomization, which is of particular utility when group sizes are small. The quality of veterinary scoring systems can be improved by prospective multicenter validation. The prevalence of euthanasia in companion animal medicine poses a unique challenge to scores based on a mortality outcome.

The Changing Face of Veterinary Practice: A Special Focus on Rural America

Rural and food animal veterinary practice is evolving in response to changes in society, veterinary student demographics, and business opportunities available in the 21st century. The gravitation of veterinarians toward metropolitan areas has created a perception of under-serviced animal health needs in rural communities. Many rural communities are heavily reliant on agriculture; therefore, this perceived need for veterinarians influences the food animal industry as a whole. Veterinary colleges have changed in response to the increased number of students who are interested in companion animal medicine. These changes have resulted in diminished large animal content in the professional curricula, attrition of the number of faculty teaching food animal medicine, increases in the number of faculty dedicated to small animal curriculum, and an overwhelming sense that the veterinary program is centered around training in preparation for a career in companion animal practice. A multitude of factors likely contribute to the continued gravitation of veterinary students toward small animal practice. Veterinary colleges must strive to maintain a balanced, open-minded view of the profession so that students have an equal opportunity to choose a path that best suits their desires and interests.

Differential inhibition of cyclooxygenase isoenzymes in the cat by the NSAID robenacoxib

Robenacoxib is a new nonsteroidal anti-inflammatory drug (NSAID) developed for use in companion animal medicine. The objectives of this study were: to quantify the inhibitory actions of robenacoxib on cyclooxygenase (COX) isoenzymes in feline whole blood assays; to establish blood concentration-time profiles of robenacoxib after intravenous and subcutaneous dosing in the cat and; to predict the time courses of inhibition of COX isoforms by robenacoxib. COX-1 and COX-2 activities in heparinized feline whole blood samples were induced with calcium ionophore and lipopolysaccharide, respectively. Inhibition of thromboxane B2 provided a marker of both COX-1 and COX-2 activities and a nonlinear parametric mixed effects modelling approach was used to establish the pharmacodynamic parameters describing this inhibition. Mean values (and prediction intervals) of IC50 were 28.9 (16.4-51.1) microM (COX-1) and 0.058 (0.010-0.340) microM (COX-2). These parameters were used to compute several selectivity indices. Selectivity IC ratios (COX-1:COX-2) were 502.3 (IC50/IC50), 451.6 (IC95/IC95) and 17.05 (IC20/IC80). Based on a clinically recommended dosage regimen of 2 mg/kg, it was predicted that the corresponding mean robenacoxib blood concentration over the first 12 h after drug administration corresponded to 5% inhibition of COX-1 and 90% inhibition of COX-2.

Anthelmintic activity of cyclotides: In vitro studies with canine and human hookworms

Hookworm infection is a leading cause of maternal and child morbidity in countries of the tropics and subtropics, as well as being an important parasite in companion-animal medicine. The cyclotides are a novel family of cyclic cystine knot containing peptides from plants that have been shown to possess anthelmintic activity against Haemonchus contortus and Trichostrongylus colubriformis, two important gastrointestinal nematodes of sheep. In the current study we demonstrated the in vitro effects of three representative cyclotides, kalata B1, kalata B6 and cycloviolacin O14, on the viability of larval and adult life stages of the dog hookworm Ancylostoma caninum, and larvae of the human hookworm Necator americanus. The cyclotides showed significant anthelmintic activity towards both hookworm species. The different cyclotides showed similar patterns of relative activity as that seen previously with the livestock nematode species. This study demonstrates that cyclotides have promising activity in vitro against important parasites of companion animals and humans.

Intraosseous Catheterization of Exotic Animals

Abstract Vascular access is an important component of therapy of the critical patient, in particular for fluid resuscitation in cases of circulatory collapse, or during cardiopulmonary resuscitation. Intravenous access is well described in companion animal medicine, but becomes increasingly more difficult with decreasing patient size. Intraosseous catheterization provides vascular access in these patients for which intravenous catheterization is difficult or impractical. Intraosseous catheterization can be accomplished in avian, exotic mammal, and some reptile patients. Reports of serious complications are rare.

Redefining and developing exotic animal medicine

Redefining and developing exotic animal medicine

Clinical Technique: Application of Computed Tomography for Diagnosis of Dental Disease in the Rabbit, Guinea Pig, and Chinchilla

Abstract Computed tomography (CT) is a well-recognized diagnostic tool in human and traditional companion animal medicine, and is beginning to find application in exotic companion mammals as well. In particular, CT is useful for evaluation of patients with dental disease, and aids diagnosis, determination of a more accurate prognosis, and planning of treatment. Although axial slices provide the most useful information, new reconstruction software allows images to be converted to virtual 3-dimensional forms, providing yet another imaging tool for the practitioner.

Superiority of needle-free transdermal plasmid delivery for the induction of antigen-specific IFNγ T cell responses in the dog

Although successful needle-free DNA vaccination has been described on several occasions, the true benefit of this delivery technology over needle-based injections for DNA vaccination of dogs has not yet been documented. We conducted a side-by-side comparison of needle-free transdermal plasmid delivery vs. intramuscular vs. intradermal needle-based delivery of the same plasmid in dogs. Our data confirmed the importance of the route of plasmid delivery and further established the unique potential of needle-free transdermal plasmid delivery to elicit strong antigen-specific, hTyr-specific IFNgamma T in the dog. Further, this study demonstrated that properly enabled DNA vaccination has the potential to trigger very significant cell-based immune responses in dogs, establishing needle-free transdermal plasmid delivery as a critical technology for successful immunotherapy of cancer and/or chronic infectious diseases in companion animal medicine.

MICROCHIP-ASSOCIATED LEIOMYOSARCOMA IN AN EGYPTIAN FRUIT BAT (ROUSETTUS AEGYPTIACUS)

Microchips are commonly used in companion, research, and zoo animal medicine for easy, reliable, and cost-effective identification with relatively low risk of side effects. This report describes development of a metastatic leiomyosarcoma associated with a microchip in an Egyptian fruit bat (Rousettus aegyptiacus).

The need for a food supply–exclusive college of veterinary medicine

JAVMA, Vol 230, No. 3, February 1, 2007 T pressing need for more new graduates who will enter FSVM has been made abundantly clear during the past few years. Food supply veterinarians occupy a greater role than ever in the veterinary profession, and there is a critical shortage of qualified individuals. Many potential solutions have been proposed, and there is a long list of worthy strategies. However, there is a solution that has not received much attention. I believe the time has come to establish a new veterinary medical institution in the United States with the express purpose of graduating veterinarians for careers in FSVM. The current system in the United States provides all veterinary students with exposure to FSVM. In theory, each graduate has received an education that would enable him or her to pursue a career in this arena. The authors in another report echoed the common sentiment that veterinary education is not doing an adequate job of training for societal needs as it relates to FSVM and proposed a number of reasons that FSVM often has second-class status in veterinary colleges. A system is needed that prioritizes FSVM and trains students to fill the shortage. Veterinary students interested in FSVM careers need to achieve the full depth of experience to immediately seize the reins of a challenging career after graduation. The requirements of companion animal medicine represent an unnecessary burden and hindrance to the goals of those students. The generalized veterinary curriculum is inhibiting the schools from producing a sufficient number of veterinarians to occupy the essential roles in the worldwide food animal supply chain.

High-level pyrantel resistance in the hookworm Ancylostoma caninum

While anthelmintic resistance is now a widely recognized issue in the livestock industries, its existence within companion animal medicine has been rarely established conclusively. We undertook a placebo-controlled in vivo trial to measure the efficacy of pyrantel embonate against pooled isolates of the hookworm Ancylostoma caninum from Brisbane, Australia. A statistically significant fall in adult worm burden was observed among dogs in the pyrantel treatment group compared to the control dogs (178.0 ± 24.5 versus 239.7 ± 14.0; p = 0.02), equating to an efficacy of just 25.7% (95% CI, 15.0–35.1%), as based upon reduction in mean worm burden. Analysis of faecal egg count trends through the course of the study revealed that egg counts rose in both control and pyrantel-treated dogs, with a greater rise observed in the latter group (11.6 ± 8.3% versus 17.3 ± 7.6%; p = 0.04), despite the decrease in adult worm numbers in this group. Our results indicate that high-level anthelmintic resistance does occur in companion animal medicine, and highlight the need for greater vigilance and more judicious use of anthelmintics in small animal practice. They further indicate that the faecal egg count reduction test needs to be used with caution with this parasite.

The Singular History of a Canine Transmissible Tumor

In this issue of Cell, Murgia et al. (2006) confirm that the infectious agent of canine transmissible venereal tumor is the cancer cell itself and that the tumor is clonal in origin. Their findings have implications for understanding the relationship between genome instability and transmissible cancer and for conservation biology, canine genomics, and companion animal medicine.

Stakeholder position paper: Companion animal veterinarian

The total quantity of use in companion animals is generally believed to be relatively small in comparison with antimicrobial use in food animals. Use in companion animals is principally for treatment, whereas the greater proportion of use in food animals is for prophylaxis, metaphylaxis and growth promotion. Therefore, it is important to collect data on end use in companion animals so that overall estimates of use in companion animals can be generated and separated from estimates for food animals. However, data from antimicrobial use in companion animals are extremely limited and no serious attempts to collect such data have ever been made in the United States. The lack of usage data in is concomitant with the dearth of information on antimicrobial resistance in companion animals. Companion animals have been involved in the transmission to humans of, or become infected with, foodborne zoonotic bacteria such as Salmonella and Campylobacter. Companion animals are an integral part of the ecology of antimicrobial resistance through their contact with food animals and exposure to antimicrobials for disease treatment and through contact with humans and the environment. In the practice of companion animal medicine, antimicrobial use data are important for understanding the potential impact on companion animal heath posed by antimicrobial resistance transferred from food animals, humans and the environment, and the threat to humans and other companion animals posed by antimicrobial use in companion animals. Basic information on the patterns and quantities of antimicrobial use in combination with resistance surveillance data, could help companion animal veterinarians understand the potential for development, or evidence of, an antimicrobial resistance problem in their practices, the role of companion animals in the overall epidemiology of antimicrobial resistance, and for comparison with local, regional, or national data. The combination of data from either a sentinel site system of clinics or a use survey with national data from the pharmaceutical industry should provide sufficient data to credibly estimate the total volume and patterns of antimicrobial use in companion animal medicine. The time and effort for use monitoring or to complete a survey would likely become burdensome. Practice management software now utilized at most companion animal clinics could be used to generate antimicrobial use data as well as patient population data as surrogate for the true population at risk for patient encounters in a companion animal practice.

Mixed Ehrlichia canis, Hepatozoon canis, and presumptive Anaplasma phagocytophilum infection in a dog

A 5-month-old, female, mongrel dog was admitted to the Clinic of Companion Animal Medicine, Aristotle University of Thessaloniki, Greece, with depression, anorexia, fever, peripheral lymphadenopathy, splenomegaly, oculonasal discharge, nonregenerative anemia, and mild thrombocytopenia. Cytology of Giemsa-stained buffy coat, bone marrow, and lymph node aspiration smears revealed numerous morulae in mononuclear leukocytes and in neutrophils, and Hepatozoon canis gamonts in neutrophils. The dog was seropositive to Ehrlichia canis (immunofluorescence assay [IFA]) and Hepatozoon canis (ELISA) but not to Anaplasma phagocytophilum (IFA). A nested polymerase chain reaction performed on bone marrow aspirates was positive for E canis. This method was not applied for the detection of A phagocytophilum. Treatment with doxycycline and imidocarb dipropionate resulted in both clinical and parasitologic cure. This is the first reported case of a mixed infection with E canis, H canis, and presumptive A phagocytophilum. The findings emphasize the value of cytology in offering a quick and inexpensive diagnosis in mixed tick-borne infections of dogs.

Susan D Jones, Valuing animals: veterinarians and their patients in modern America, Baltimore and London, Johns Hopkins University Press, 2003, pp. xii, 213, illus., £33.50 (hardback 0-8018-7129-8).

The intertwined histories of domesticated animals, human–animal relationships and veterinary medicine represent a very interesting scholarly field; nevertheless, they have received only limited attention from historians. Veterinarians have written the majority of books on the history of veterinary medicine, however; most of them lack proper documentation and analysis in a broader cultural context. Work on the contextual history of veterinary medicine has only recently emerged. Therefore, this study by Susan Jones is very welcome. Based on a wide variety of scientific and popular sources, she has approached the history of veterinary medicine and the veterinary profession in twentieth-century America from the perspective of changing human–animal relationships, particularly the changing economic and emotional value of domesticated animals. In five thematic chapters, Jones explores a particular group of animals and its role in American society. The chapters deal with crucial junctures at which transformations in animal valuation and the development of the veterinary sciences and the veterinary profession influenced each other: the transition from horse power to motorized vehicles, public health concerns over animal food products, the rise of factory farming and the emergence of companion animal medicine. The final chapter highlights how veterinarians worked during the twentieth century to reconcile animal exploitation with morality. The book also includes a very useful introduction to sources on veterinary history and human–animal relationships. In an original and compelling way the author describes how the relationship between Americans and their domestic animals changed dramatically during the last century. Around 1900, almost half of the population lived and worked on farms in close contact with animals. A century later the population was mainly urbanized, horses changed from common working animals into popular hobby animals, while pets changed from luxury animals for the elite into members of the common family. In the same period a comprehensive infrastructure for animal food production and quality control developed. Some important related issues such as antivivisectionism, animal welfare, anthropomorphism, concern over food safety, and the development of veterinary practices in the livestock industry and specialized companion animal medicine are taken into account. Considerable attention is paid to the role of veterinarians in valuing domestic animals as well as their role in changing human–animal relationships. When working horses were replaced by motor vehicles, veterinarians intensified their activities in making the livestock industry more profitable and created the field of veterinary public health. Later veterinarians paid more attention to the growing number of pets that represented a high sentimental value for their owners, thus creating a “modern pet culture”. According to Jones, veterinarians contributed to and manipulated animal value in order to claim a place as indispensable mediators of human–animal relationships. She argues that veterinarians' contribution to the reconciliation of animal use with concerns about morality “shaped the development” of large-scale production of animals for food and commercialized pet keeping. “Veterinarians have sought to address Americans' uncertainty about the ‘proper’ human–animal relationship as the ideological driving force of their profession. They did not pretend to be philosophers, but operated as rationalists meeting social needs” (p. 3). One could question such an influential and active role for the veterinary profession within social-economic and political processes that determined the value attributed to animals and the development of animal health care. As representatives of a very practical profession, even with a certain aversion to theorizing, most veterinarians operated from an economic rather than an ideological point of view. They simply wanted to make money. One could also argue that veterinarians did not shape Americans' relation with domestic animals but just took advantage of new business opportunities that resulted from social, economic and political change. Nevertheless, Susan Jones has written a very interesting book. It suggests the necessity for an international comparison of the historical development of the veterinary profession, before we can evaluate whether indeed this profession constituted a significant directing force in twentieth-century history in general, and in human–animal relationships in particular.

Needs, Difficulties, and Possible Approaches to Providing Quality Clinical Veterinary Education with the Aim of Improving Standards of Companion Animal Medicine in Sri Lanka

Companion animal medicine has now gained prominence in Sri Lanka as a result of an increased public interest in pets; however, veterinary education has not kept pace with current developments. The main constraints faced by the veterinary education system are those common to all university education in Sri Lanka. Changes in the current system, though important, depend heavily on political will and vision, which are not forthcoming in the near future. It is therefore both necessary and important that the private sector provide the impetus to improve standards of veterinary medicine in Sri Lanka. The immediate focus should be on improving the skills of practitioners through clinically based continuing education programs. Later, more specialized and intensive programs may be initiated. Interaction and sharing of knowledge with more developed countries are critical in leading the way to improved standards of companion animal medicine in Sri Lanka.

Editorial

If you are reading this editorial, you are quickly realizing that the dawn of a new era in information dissemination is upon us. While it is “early in the morning” for the Journal of the American Animal Hospital Association, the day is already advanced in many other disciplines and for information provision in general. Recognizing that our traditional delivery model was quickly becoming nontraditional/ antiquated, the JAAHA editorial team responded proactively to the changing publishing landscape and readership habits. In conjunction with Highwire Press, we are benefiting from earlier forays into online publishing and are pleased to incorporate these evolving refinements into the online Journal that you now have at your “mousetip.” From easy accessibility, advanced archiving and search functions, to e-mail alert and desktop publishing features, information management has never held such flexibility to address the needs of each and every reader.While this represents an exciting new journey for the Journal and its readership to embark upon, I must bid adieu as my path is following a different direction. While the decision to pass the role of editor on to someone else has been a difficult one, it was a wonderful dilemma to be faced with. On the one hand was the option to continue as JAAHA editor and forge into new territory that promises to bring many more wonderful enhancements as time unfolds. On the other hand was a career opportunity with an emerging pharmaceutical company, also forging new territory in the field of companion animal medicine. While I chose the latter, I will continue to play a part in the Journal in the role of “logged-on” reader.It is with great pleasure that I provide the introduction to JAAHA’s new editor, Dr. Rhea Morgan. For most, no further introduction is necessary, as Dr. Morgan’s high-profile career as a veterinarian, lecturer, author, and editor speaks for itself and has already touched many in the veterinary profession. A diplomate of both the Colleges of Veterinary Internal Medicine and Ophthalmology, Dr. Morgan has played significant roles in both academia and private practice, including Boston’s Angel Memorial Animal Hospital, the University of Tennessee’s College of Veterinary Medicine, and Rowley Memorial Animal Hospital in Springfield, MA. The author of textbooks and many articles in peer-reviewed journals, she most recently held the position of senior editor for an online veterinary information resource network. She has also been honored by state and national veterinary medical associations for her contributions, including receiving the AAHA’s Award for Distinguished Service in 1990. It is an honor for the JAAHA editorial team to welcome her to the fold and a testament to the stature that JAAHA has attained to attract such an accomplished individual.Change is inevitable, and it is not so much the change that generates anxiety for those involved, but how that change is managed. For me, this is simply not an issue, because I take great comfort in the knowledge that I am passing the reins into hands that are far more capable than my own.I will look back on this time and the accomplishments achieved as a definite highlight in my veterinary career. I have been proud to be part of the JAAHA editorial team, a team that was never afraid to “think outside the box” and break new ground; hence living by my personal guiding philosophy, so eloquently summed up by Ralph Waldo Emerson:

Pharmacology of drugs used to treat osteoarthritis in veterinary practice.

As in humans, pain in animals may be associated with a wide range of conditions and circumstances, ranging from acute trauma to joint diseases. Joint diseases are common in companion animal medicine (horse, dog, cat) and at least 80% of cases are classified as osteoarthritis (OA). Several drug classes are available for OA therapy, including corticosteroids, non-steroidal antiinflammatory drugs (NSAIDs), agents with potential disease modifying properties and nutraceuticals. For long-term maintenance OA treatment, particularly in the horse and dog, NSAIDs are routinely and extensively used. This review outlines the pharmacokinetics (PK) and pharmacodynamics (PD) of NSAIDs in companion and farm animal species. NSAID PK and PD have been studied in models of acute inflammation, which enable use of PK-PD modeling to facilitate (a) studies of mechanism of action at the molecular level and (b) prediction of dosages for clinical use. The PK-PD approach is a powerful but underutilized tool which also facilitates inter-species comparisons.