Veterinary Medicine Commons^™

Amyloid Fibrils: Potential Food Safety Implications, Michael Greger

Human Health Collection

The demonstration of oral Amyloid-A (AA) fibril transmissibility has raised food safety questions about the consumption of amyloidotic viscera. In a presumed prion-like mechanism, amyloid fibrils have been shown to trigger and accelerate the development of AA amyloidosis in rodent models. The finding of amyloid fibrils in edible avian and mammalian food animal tissues, combined with the inability of cooking temperatures to eliminate their amyloidogenic potential, has led to concerns that products such as pâté de foie gras may activate a reactive systemic amyloidosis in susceptible consumers. Given the ability of amyloid fibrils to cross-seed the formation of chemically heterologous …

Neuroanatomy Of The Subadult And Fetal Brain Of The Atlantic White-Sided Dolphin (Lagenorhynchus Acutus) From In Situ Magnetic Resonance Images, Eric W. Montie, Gerald E. Schneider, Darlene R. Ketten, Lori Marino, Katie E. Touhey, Mark E. Hahn

Veterinary Science and Medicine Collection

This article provides the first anatomically labeled, magnetic resonance imaging (MRI) -based atlas of the subadult and fetal Atlantic white-sided dolphin (Lagenorhynchus acutus) brain. It differs from previous MRI-based atlases of cetaceans in that it was created from images of fresh, postmortem brains in situ rather than extracted, formalin-fixed brains. The in situ images displayed the classic hallmarks of odontocete brains: fore-shortened orbital lobes and pronounced temporal width. Olfactory structures were absent and auditory regions (e.g., temporal lobes and inferior colliculi) were enlarged. In the subadult and fetal postmortem MRI scans, the hippocampus was identifiable, despite the relatively small size …

Nociception In Fish: Stimulus–Response Properties Of Receptors On The Head Of Trout Oncorhynchus Mykiss, Paul J. Ashley, Lynne U. Sneddon, Catherine R. Mccrohan

Veterinary Science and Medicine Collection

This study examined stimulus–response properties of somatosensory receptors on the head of rainbow trout, Oncorhynchus mykiss, using extracellular recording from single cells in the trigeminal ganglion. Of 121 receptors recorded from 39 fish, 17 were polymodal nociceptors, 22 were mechanothermal nociceptors, 18 were mechanochemical receptors, 33 were fast adapting mechanical receptors and 31 were slowly adapting mechanical receptors. Mechanical thresholds were higher in polymodal nociceptors than in either slowly adapting or fast adapting mechanical receptors, whereas thermal thresholds of mechanothermal nociceptors were higher than those of polymodal nociceptors. Polymodal nociceptors and mechanochemical receptors gave similar responses to topical applications of …

Ethical Issues In Geriatric Feline Medicine, Bernard E. Rollin

Veterinary Science and Medicine Collection

Most veterinarians hold a ‘pediatric’ rather than ‘garage mechanic’ view of their function. In recent years, sophisticated medical modalities have allowed veterinarians to keep animals alive, and increased value of companion animals in society has increased demand for such treatment. But whereas humans can choose to trade current suffering for extended life, animals seem to lack the cognitive apparatus required to do so. Thus, veterinarians must guard against keeping a suffering animal alive for too long. Clients may be emotionally tied to the animal and blind to its suffering. Part of the veterinarian’s role, therefore, is to lead the client …

The Veterinary Profession’S Duty Of Care In Response To Disasters And Food Animal Emergencies, Kenneth E. Nusbaum, Bernard E. Rollin, James S. Wohl

Professional Veterinary Ethics Collection

No abstract provided.

Cetacean Brains: How Aquatic Are They?, Lori Marino

Anatomy Collection

The adaptation of cetaceans to a fully aquatic lifestyle represents one of the most dramatic transformations in mammalian evolutionary history. Two of the most salient features of modern cetaceans are their fully aquatic lifestyle and their large brains. This review article will offer an overview of comparative neuroanatomical research on aquatic mammals, including analyses of odontocete cetacean, sirenian, pinniped, and fossil archaeocete brains. In particular, the question of whether a relationship exists between being fully aquatic and having a large brain is addressed. It has been hypothesized that the large, well‐developed cetacean brain is a direct product of adaptation to …

Cetaceans Have Complex Brains For Complex Cognition, Lori Marino, Richard C. Connor, R. Ewan Fordyce, Louis M. Herman, Patrick R. Hof, Louis Lefebvre, David Lusseau, Brenda Mccowan, Esther A. Nimchinsky, Adam A. Pack, Luke Rendell, Joy S. Reidenberg, Diana Reiss, Mark D. Uhen, Estel Van Der Gucht, Hal Whitehead

Anatomy Collection

We believe that the time is ripe to present an integrated view of cetacean brains, behavior, and evolution based on the wealth of accumulated and recent data on these topics. Our conclusions support the more generally accepted view that the large brain of cetaceans evolved to support complex cognitive abilities.

An Hsus Report: Human Health Implications Of U.S. Live Bird Markets In The Spread Of Avian Influenza, The Humane Society Of The United States

Impact of Animal Agriculture

After millions of years of existing as a harmless infection of aquatic birds, some strains of avian flu have developed the ability to mutate into highly pathogenic forms that may not only be deadly for birds, but potentially more dangerous for humans as well. Experts from the World Health Organization, the World Organization for Animal Health, and the Food and Agriculture Organization of the United Nations have joined leading scientists in implicating industrialized poultry production for providing fertile ground for the transformation of benign bird flu into highly pathogenic strains.

Live bird markets can be the conduit by which waterfowl …

Their Bugs Are Worse Than Their Bite: Emerging Infectious Disease And The Human-Animal Interface, Michael Greger

State of the Animals 2007

In the twenty-five years since that announcement, what we now know as AIDS has killed 20 million people (National AIDS Trust 2005). Where did the AIDS virus— and other emerging diseases, such as severe acute respiratory syndrome (SARS), Ebola, mad cow— come from?

The Human/Animal Interface: Emergence And Resurgence Of Zoonotic Infectious Diseases, Michael Greger

Transgenesis Collection

Emerging infectious diseases, most of which are considered zoonotic in origin, continue to exact a significant toll on society. The origins of major human infectious diseases are reviewed and the factors underlying disease emergence explored. Anthropogenic changes, largely in land use and agriculture, are implicated in the apparent increased frequency of emergence and reemergence of zoonoses in recent decades. Special emphasis is placed on the pathogen with likely the greatest zoonotic potential, influenzavirus A.

The Ethics Of Referral, Bernard Rollin

Professional Veterinary Ethics Collection

The rapid growth of veterinary specialty practices has created a number of vexatious ethical issues relevant to veterinary medicine. The preeminent question pertains to “the duty to refer.” Do primary care practitioners have such a moral duty? If so, when does this duty arise? Does it pertain in all cases where specialized knowledge is relevant to a disease?

This raises the fundamental question of “Veterinary Ethics” — namely, does the veterinarian ideally have primary obligation to the client/owner or the animal? (1) There are 2 possible ideal types that a veterinarian can aim for — the Garage Mechanic Model or …

Does Diving Limit Brain Size In Cetaceans?, Lori Marino, Daniel Sol, Kristen Toren, Louis Lefebvre

Veterinary Science and Medicine Collection

We test the longstanding hypothesis, known as the dive constraint hypothesis, that the oxygenation demands of diving pose a constraint on aquatic mammal brain size.Using a sample of 23 cetacean species we examine the relationship among six different measures of relative brain size, body size, and maximum diving duration. Unlike previous tests we include body size as a covariate and perform independent contrast analyses to control for phylogeny. We show that diving does not limit brain size in cetaceans and therefore provide no support for the dive constraint hypothesis. Instead, body size is the main predictor of maximum diving duration …

Ethics Of Critical Care, Bernard E. Rollin

Experimentation Collection

No abstract provided.

Differential Stress Responses In Fish From Areas Of High- And Low-Predation Pressure, Culum Brown, Carolyn Gardner, Victoria Braithwaite

Aquaculture Collection

We subjected fish from regions of high and low levels of predation pressure in four independent streams to a mild stressor and recorded their opercular beat rates. Fish from low-predation areas showed higher maximum, minimum and mean opercular beat frequencies than fish from high-predation regions. The change in opercular beat frequency (scope) was also significantly greater in fish from low- than in fish from high-predation regions. Under normal activity levels, however, low predation fish showed a reduced opercular beat frequency, which may be indicative of reduced activity levels or metabolic rate. Opercular beat frequency was negatively correlated with standard length …

Carbon Dioxide For Euthanasia: Concerns Regarding Pain And Distress, With Special Reference To Mice And Rats, Kathleen Conlee, Martin Stephens, Andrew N. Rowan, Lesley A. King

Laboratory Experiments Collection

Carbon dioxide (CO₂) is the most commonly used agent for euthanasia of laboratory rodents, used on an estimated tens of millions of laboratory rodents per year worldwide, yet there is a growing body of evidence indicating that exposure to CO₂ causes more than momentary pain and distress in these and other animals. We reviewed the available literature on the use of CO₂ for euthanasia (as well as anaesthesia) and also informally canvassed laboratory animal personnel for their opinions regarding this topic. Our review addresses key issues such as CO₂ flow rate and final concentration, presence …

Cetacean Brain Evolution: Multiplication Generates Complexity, Lori Marino

Anatomy Collection

Over the past 55-60 million years cetacean (dolphin, whale, and porpoise) brains have become hyperexpanded so that modern cetacean encephalization levels are second only to modern humans. At the same time, brain expansion proceeded along very different lines than in other large-brained mammals so that substantial differences between modern cetacean brains and other mammalian brains exist at every level of brain organization. Perhaps the most profound difference between cetacean and other mammalian brains is in the architecture of the neocortex. Cetaceans possess a unique underlying neocortical organizational scheme that is particularly intriguing in light of the fact that cetaceans exhibit …

Neuroanatomy Of The Killer Whale (Orcinus Orca) From Magnetic Resonance Images, Lori Marino, Chet C. Sherwood, Bradley N. Delman, Cheuk Y. Tang, Thomas P. Naidisch, Patrick R. Hof

Veterinary Science and Medicine Collection

This article presents the first series of MRI-based anatomically labeled sectioned images of the brain of the killer whale (Orcinus orca). Magnetic resonance images of the brain of an adult killer whale were acquired in the coronal and axial planes. The gross morphology of the killer whale brain is comparable in some respects to that of other odontocete brains, including the unusual spatial arrangement of midbrain structures. There are also intriguing differences. Cerebral hemispheres appear extremely convoluted and, in contrast to smaller cetacean species, the killer whale brain possesses an exceptional degree of cortical elaboration in the insular cortex, temporal …

Neuroanatomical Structure Of The Spinner Dolphin (Stenella Longirostris Orientalis) Brain From Magnetic Resonance Images, Lori Marino, Keith Sudheimer, William A. Mclellan, John I. Johnson

Veterinary Science and Medicine Collection

High-resolution magnetic resonance (MR) images of the brain of an adult spinner dolphin (Stenella longirostris orientalis) were acquired in the coronal plane at 55 antero-posterior levels. From these scans a computergenerated set of resectioned virtual images in the two remaining orthogonal planes was constructed with the use of the VoxelView and VoxelMath (Vital Images, Inc.) programs. Neuroanatomical structures were labeled in all three planes, providing the first labeled anatomical description of the spinner dolphin brain.

The Evidence For Pain In Fish: The Use Of Morphine As An Analgesic, Lynne U. Sneddon

Veterinary Science and Medicine Collection

This paper discusses the evidence for pain perception in fish and presents new data on morphine analgesia in fish. Recent anatomical and electrophysiological studies have demonstrated that fish are capable of nociception, the simple detection of a noxious, potentially painful stimulus and the reflex response to this. To prove pain perception, it must be demonstrated that an animal’s behaviour is adversely affected by a potentially painful event and this must not be a reflex response. The present study examined the acute effects of administering a noxious chemical to the lips of rainbow trout (Oncorhynchus mykiss) to assess what changes occurred …

Magnetic Resonance Images Of The Brain Of A Dwarf Sperm Whale (Kogia Simus), L. Marino, K. Sudheimer, D. A. Pabst, J. I. Johnson

Veterinary Science and Medicine Collection

Cetacean (dolphin, whale and porpoise) brains are among the least studied mammalian brains because of the difficulty of collecting and histologically preparing such relatively rare and large specimens. Among cetaceans, there exist relatively few studies of the brain of the dwarf sperm whale (Kogia simus). Magnetic resonance imaging (MRI) offers a means of observing the internal structure of the brain when traditional histological procedures are not practical. Therefore, MRI has become a critical tool in the study of the brain of cetaceans and other large species. This paper represents the first MRI-based anatomically labelled three-dimensional description of the dwarf sperm …

Do Fishes Have Nociceptors? Evidence For The Evolution Of A Vertebrate Sensory System, Lynne U. Sneddon, Victoria A. Braithwaite, Michael J. Gentle

Veterinary Science and Medicine Collection

Nociception is the detection of a noxious tissue-damaging stimulus and is sometimes accompanied by a reflex response such as withdrawal. Pain perception, as distinct from nociception, has been demonstrated in birds and mammals but has not been systematically studied in lower vertebrates. We assessed whether a fish possessed cutaneous nociceptors capable of detecting noxious stimuli and whether its behavior was sufficiently adversely affected by the administration of a noxious stimulus. Electrophysiological recordings from trigeminal nerves identified polymodal nociceptors on the head of the trout with physiological properties similar to those described in higher vertebrates. These receptors responded to mechanical pressure, …

Trigeminal Somatosensory Innervation Of The Head Of A Teleost Fish With Particular Reference To Nociception, Lynne U. Sneddon

Veterinary Science and Medicine Collection

Trigeminal somatosensory receptors have not been characterised in teleost fish and studies in elasmobranchs have failed to identify nociceptors. The present study examined the trigeminal nerve of a teleost fish, the rainbow trout (Oncorhynchus mykiss) to determine what types of somatosensory receptors were present on the head of the trout specifically searching for nociceptors. Single unit recordings were made from receptive fields on the head of the fish innervated by the trigeminal nerve. Each receptive field was tested for sensitivity to mechanical, thermal and chemical stimulation. Five different receptor types were found: fast adapting receptors responding to mechanical stimulation; slowly …

Farm Disease Crises In The United Kingdom: Lessons To Be Learned, Michael C. Appleby

State of the Animals 2003

Over the last fifteen years, a diverse succession of disease-related crises has befallen farm animal and food industries in the United Kingdom. Some have involved animal health, with little risk to humans. Some have involved human health, with animals acting as a reservoir for infection but little affected themselves. Some, however— including the most alarming— have involved both animal and human health through zoonoses, diseases transmittable from animal to human. All of these crises are linked in the public mind and in many commentaries, and indeed there are issues that many of them share. The most common of these is …

Description Of A Poorly Differentiated Carcinoma Within The Brainstem Of A White Whale (Delphinapterus Leucas) From Magnetic Resonance Images And Histological Analysis, Sam H. Ridgway, Lori Marino, T. P. Lipscomb

Veterinary Science and Medicine Collection

In this study we used magnetic resonance imaging (MRI) to investigate neuroanatomical structure in the brain of a white whale (Delphinapterus leucas) that died from a large tumor within the brainstem. This specimen was also compared with a normal white whale brain using MRI. MRI scans of the white whale specimen show how the tumor deformed surrounding brain structure. Histopathological analysis indicated a poorly differentiated carcinoma of uncertain origin. These analyses demonstrate the usefulness of supplementing histological analyses of pathology with studies of gross morphology facilitated by MRI.

Neuroanatomy Of The Common Dolphin (Delphinus Delphis) As Revealed By Magnetic Resonance Imaging (Mri), L. Marino, Keith Sudheimer, D. Ann Pabst, William A. Mclellan, David Filsoof, John I. Johnson

Veterinary Science and Medicine Collection

In this study, magnetic resonance (MR) images of the brain of an adult common dolphin (Delphinus delphis) were acquired in the coronal plane at 66 antero-posterior levels. From these scans a computer-generated set of resectioned virtual images in orthogonal planes was constructed using the programs VoxelView and VoxelMath (Vital Images, Inc., Michigan State Univ.). Sections in all three planes reveal major neuroanatomical structures. These structures in the adult common dolphin brain are compared with those from a fetal common dolphin brain from a previously published study as well as with MR images of adult brains of other odontocetes. …

Modern Elements Of Informed Consent For General Veterinary Practitioners, Martin J. Fettman, Bernard Rollin

Professional Veterinary Ethics Collection

No abstract provided.

Endogenous Gonadal Hormone Exposure And Bone Sarcoma Risk, Dawn M. Cooley, Benjamin C. Beranek, Deborah L. Schlittler, Nita W. Glickman, Lawrence T. Glickman, David J. Waters

Endocrinology Collection

Although experimental and clinical evidence suggest that endogenous sex hormones influence bone sarcoma genesis, the hypothesis has not been adequately tested in an appropriate animal model. We conducted a historical cohort study of Rottweiler dogs because they frequently undergo elective gonadectomy and spontaneously develop appendicular bone sarcomas, which mimic the biological behavior of the osteosarcomas that affect children and adolescents. Data were collected by questionnaire from owners of 683 Rottweiler dogs living in North America. To determine whether there was an association between endogenous sex hormones and risk of bone sarcoma, relative risk (RR) of incidence rates and hazard ratios …

The Use And Abuse Of Aesculapian Authority In Veterinary Medicine, Bernard Rollin

Professional Veterinary Ethics Collection

No abstract provided.

Anatomical And Electrophysiological Analysis Of The Trigeminal Nerve In A Teleost Fish, Oncorhynchus Mykiss, Lynne U. Sneddon

Veterinary Science and Medicine Collection

The trigeminal nerve in the rainbow trout, Oncorhynchus mykiss, was examined for the presence of A-delta and C fibres. Sections of the three branches of the trigeminal nerve were found to comprise a range of fibre types including Adelta and C fibres. The size range of the cell bodies of the trigeminal ganglion reflected the fibre range since they correlated with the size range of axons in the nerve branches. Electrophysiological recordings of evoked activity from the ganglion confirmed the presence of these fibre types and the proportion of these mirrored the proportion of fibre types in the anatomical analyses. …

Anatomy And Three-Dimensional Reconstructions Of The Brain Of The White Whale (Delphinapterus Leucas) From Magnetic Resonance Images, Lori Marino, Timothy L. Murphy, Amy L. Deweerd, John A. Morris, Archibald J. Fobbs, Nathalie Humbolt, Sam H. Ridgway, John I. Johnson

Veterinary Science and Medicine Collection

Magnetic resonance imaging offers a means of observing the internal structure of the brain where traditional procedures of embedding, sectioning, staining, mounting, and microscopic examination of thousands of sections are not practical. Furthermore, internal structures can be analyzed in their precise quantitative spatial interrelationships, which is difficult to accomplish after the spatial distortions often accompanying histological processing. For these reasons, magnetic resonance imaging makes specimens that were traditionally difficult to analyze, more accessible. In the present study, images of the brain of a white whale (Beluga) Delphinapterus leucas were scanned in the coronal plane at 119 antero-posterior levels. Fromthese scans, …