Utility Of Dogs Research Articles

Hunting with dogs: a synthesis of ethnohistorical data and discussion of their implications for prehistoric subsistence in New Guinea

ABSTRACTThe advent of the dog is widely recognised as a major development in the economic organisation of ancient and contemporary hunter‐gatherer and agricultural societies. Although the utility of dogs in assisting recent historical and contemporary New Guinean hunters is commonly emphasised in anthropological discourse, to date there has been no critical evaluation of their actual contributions to hunting yields and nutrition. As a result, it remains unclear what significance the advent of hunting dogs is likely to have had for prehistoric economies in New Guinea. Here we present a comprehensive synthesis and review of the evidence for the use of dogs in hunting within New Guinea, focusing on the ways in which they assist; what kinds of game they help to capture; the degree to which they improve hunting yields and efficiency; and how this affects the taxonomic makeup and average body‐size of game in human diets. We then apply the findings to a consideration of how dogs likely affected the prehistoric economies of New Guinea after their introduction in the Late Holocene. As reliance on hunting dogs tends to produce over‐representation of a few mammal species within hunting yields, we identify potential zooarchaeological signatures for the use of dogs, and discuss excavated sites at which these may be visible. Dogs have a transformative effect on the outcomes of hunting in New Guinea's environments, and their novel use likely marked a significant development in the island's economies which has previously been underestimated.

Genetic Pathways of Aging and Their Relevance in the Dog as a Natural Model of Human Aging.

Aging research has experienced a burst of scientific efforts in the last decades as the growing ratio of elderly people has begun to pose an increased burden on the healthcare and pension systems of developed countries. Although many breakthroughs have been reported in understanding the cellular mechanisms of aging, the intrinsic and extrinsic factors that contribute to senescence on higher biological levels are still barely understood. The dog, Canis familiaris, has already served as a valuable model of human physiology and disease. The possible role the dog could play in aging research is still an open question, although utilization of dogs may hold great promises as they naturally develop age-related cognitive decline, with behavioral and histological characteristics very similar to those of humans. In this regard, family dogs may possess unmatched potentials as models for investigations on the complex interactions between environmental, behavioral, and genetic factors that determine the course of aging. In this review, we summarize the known genetic pathways in aging and their relevance in dogs, putting emphasis on the yet barely described nature of certain aging pathways in canines. Reasons for highlighting the dog as a future aging and gerontology model are also discussed, ranging from its unique evolutionary path shared with humans, its social skills, and the fact that family dogs live together with their owners, and are being exposed to the same environmental effects.

Lomustine chemotherapy for the treatment of presumptive haemophagocytic histiocytic sarcoma in Flat‐coated Retrievers

The Flat-coated Retriever (FCR) is a breed at-risk for histiocytic sarcoma (HS). A haemophagocytic form of HS (HPHS) occurs in the spleen ± other sites such as bone marrow, and is a CD11d+ disease of macrophage origin. Patients with HPHS typically present with regenerative anaemia. Lomustine is a well-accepted, first-line chemotherapy for dogs with HS, but its specific utility in dogs with HPHS has not been previously reported. A cohort of 10 dogs presumptively diagnosed with HPHS via splenic ± bone marrow or liver aspiration cytology were treated with lomustine, plus supportive medications as required. Cytology of liver and bone marrow was diagnostically useful in patients where splenic cytology was less convincing. No dogs experienced significant constitutional or gastrointestinal adverse effects following lomustine administration, though most dogs displayed clinical signs associated with the underlying disease. No patients appeared to derive discernible clinical benefit from chemotherapy. Neutropenia was a common adverse effect of lomustine. Concurrent medications included corticosteroids in all cases, prior to the diagnosis of HPHS, for a provisional diagnosis of immune-mediated haemolytic anaemia. Median survival time of the treated dogs was 24 days from diagnosis (range, 4-67 days). HPHS affecting FCRs appears to have a uniformly poor outcome and is rapidly fatal. Lomustine chemotherapy was unsuccessful in significantly improving outcome in this cohort of patients. Further study of this rare and devastating disease is needed.

Association of fecal calprotectin concentrations with disease severity, response to treatment, and other biomarkers in dogs with chronic inflammatory enteropathies.

BackgroundCalprotectin is a marker of inflammation, but its clinical utility in dogs with chronic inflammatory enteropathies (CIE) is unknown.ObjectiveEvaluation of fecal calprotectin in dogs with biopsy‐confirmed CIE.Animals127 dogs.MethodsProspective case‐control study. Dogs were assigned a canine chronic enteropathy clinical activity index (CCECAI) score, and histologic lesions severity was assessed. Fecal calprotectin, fecal S100A12, and serum C‐reactive protein (CRP) were measured. Food‐ or antibiotic‐responsive cases (FRE/ARE, n = 13) were distinguished from steroid‐/immunosuppressant‐responsive or ‐refractory cases (SRE/IRE, n = 20). Clinical response to treatment in SRE/IRE dogs was classified as complete remission (CR), partial response (PR), or no response (NR).ResultsFecal calprotectin correlated with CCECAI (ρ = 0.27, P = .0065) and fecal S100A12 (ρ = 0.90, P < .0001), some inflammatory criteria, and cumulative inflammation scores, but not serum CRP (ρ = 0.16, P = .12). Dogs with SRE/IRE had higher fecal calprotectin concentrations (median: 2.0 μg/g) than FRE/ARE dogs (median: 1.4 μg/g), and within the SRE/IRE group, dogs with PR/NR had higher fecal calprotectin (median: 37.0 μg/g) than dogs with CR (median: 1.6 μg/g). However, both differences did not reach statistical significance (both P = .10). A fecal calprotectin ≥15.2 μg/g separated both groups with 80% sensitivity (95% confidence interval [95%CI]: 28%‐100%) and 75% specificity (95%CI: 43%‐95%).Conclusions and Clinical ImportanceFecal calprotectin could be a useful surrogate marker of disease severity in dogs with CIE, but larger longitudinal studies are needed to evaluate its utility in predicting the response to treatment.

Serum alpha1 -proteinase inhibitor concentrations in dogs with systemic inflammatory response syndrome or sepsis.

To determine whether the concentration of serum canine alpha1 -proteinase inhibitor (cα1 -PI) has diagnostic or prognostic utility in dogs with sepsis or noninfectious systemic inflammatory response syndrome (SIRS). Prospective, observational study from May to December 2010. University teaching hospital ICU. Sixty-nine client-owned dogs: 19 dogs with SIRS or sepsis and 50 healthy control dogs. None. Serum and plasma samples were collected from dogs with SIRS or sepsis on the day of hospital admission and once on the following 2 days, and on a single day in healthy controls. Patients were assessed using the 10-parameter Acute Patient Physiologic and Laboratory Evaluation (APPLEfull ) and 5-parameter (APPLEfast ) score. Serum cα1 -PI concentrations were measured, compared among groups of dogs, and evaluated for a correlation with the concentration of serum C-reactive protein, plasma interleukin-6, tumor necrosis factor-α, the APPLE scores, and survival to discharge. Serum cα1 -PI concentrations were significantly lower in dogs with SIRS/sepsis (P < 0.001) than in healthy controls. While day 1 serum cα1 -PI concentrations did not differ between dogs with SIRS and those with sepsis (P = 0.592), septic dogs had significantly lower serum cα1 -PI concentrations on days 2 (P = 0.017) and 3 (P = 0.036) than dogs with SIRS. Serum cα1 -PI concentrations did not differ between survivors and nonsurvivors (P = 1.000), but were inversely correlated with the APPLEfull score (ρ = -0.48; P = 0.040) and plasma interleukin-6 concentrations (ρ = -0.50; P = 0.037). These results suggest a role of cα1 -PI as a negative acute phase protein in dogs. The concentration of serum cα1 -PI at the time of hospital admission does not have utility to identify dogs with sepsis from those with noninfectious SIRS, but may be a useful surrogate marker for early stratification of illness severity.

Left Atrial Strain at Different Stages of Myxomatous Mitral Valve Disease in Dogs.

BackgroundDecreased function of the left atrium (LA) is a useful prognostic indicator in dogs with myxomatous mitral valve disease (MMVD). In humans, LA strain is a novel severity indicator of mitral regurgitation, but its clinical utility in dogs has not been confirmed.ObjectivesTo examine whether LA strain as evaluated with speckle‐tracking echocardiography is associated with MMVD stage in dogs.AnimalsFifty‐two client‐owned dogs with MMVD.MethodsCross‐sectional study. Dogs were classified as stage B1, B2, C, or D, according to the American College of Veterinary Internal Medicine consensus. Physical examination findings and echocardiographic variables were compared among the groups. To assess the comparative accuracy of echocardiographic variables in identifying dogs with the presence or history congestive heart failure (CHF), receiver operating characteristic curves and multivariate logistic analysis were used.ResultsThere were no significant differences in parameters of LA strain between B1 and B2 groups. However, LA longitudinal strain during atrial contraction (εA) (median, 19.1%; interquartile range, 15.3–24.3% in B1, 19.6%; 14.1–21.4% in B2, 6.2%; 3.18–11.2% in C/D) and during ventricular systole (εS) (32.7%; 28.9–39.2% in B1, 35.6%; 31.7–41.9% in B2, 23.6%; 16.9–26.1% in C/D) were significantly lower in stages C/D than in stages B1 and B2. In multivariate logistic regression analysis, εA and peak early diastolic mitral inflow velocity were identified as independent indicators of stage C/D.Conclusions and Clinical ImportanceεA was the best predictor of the presence or history of CHF. Further studies are needed to determine the clinical implications of these findings for treatment decisions and prognosis determination.

Canine Platelet Lysate Is Inferior to Fetal Bovine Serum for the Isolation and Propagation of Canine Adipose Tissue- and Bone Marrow-Derived Mesenchymal Stromal Cells.

BackgroundMesenchymal stromal cells (MSC) are increasingly investigated for their clinical utility in dogs. Fetal bovine serum (FBS) is a common culture supplement used for canine MSC expansion. However, FBS content is variable, its clinical use carries risk of an immune response, and its cost is increasing due to global demand. Platelet lysate (PL) has proven to be a suitable alternative to FBS for expansion of human MSC.Hypothesis and ObjectivesWe hypothesized that canine adipose tissue (AT) and bone marrow (BM) MSC could be isolated and expanded equally in PL and FBS at conventionally-used concentrations with differentiation of these MSC unaffected by choice of supplement. Our objectives were to evaluate the use of canine PL in comparison with FBS at four stages: 1) isolation, 2) proliferation, 3) spontaneous differentiation, and 4) directed differentiation.Results1) Medium with 10% PL was unable to isolate MSC. 2) MSC, initially isolated in FBS-supplemented media, followed a dose-dependent response with no significant difference between PL and FBS cultures at up to 20% (AT) or 30% (BM) enrichment. Beyond these respective peaks, proliferation fell in PL cultures only, while a continued dose-dependent proliferation response was noted in FBS cultures. 3) Further investigation indicated PL expansion culture was inducing spontaneous adipogenesis in concentrations as low as 10% and as early as 4 days in culture. 4) MSC isolated in FBS, but expanded in either FBS or PL, maintained ability to undergo directed adipogenesis and osteogenesis, but not chondrogenesis.Conclusions/SignificanceCanine PL did not support establishment of MSC colonies from AT and BM, nor expansion of MSC, which appear to undergo spontaneous adipogenesis in response to PL exposure. In vivo studies are warranted to determine if concurrent use of MSC with any platelet-derived products such as platelet-rich plasma are associated with synergistic, neutral or antagonistic effects.

Novel phenotype in beagle dogs characterized by skin response to compound 48/80 focusing on skin mast cell degranulation.

Beagle dogs have long been employed in toxicology studies and as skin disease models. Compared with other experimental animal species, they are known to be susceptible to skin responses, such as rashes, from exposure to various chemical compounds. Here, a unique dog phenotype was identified that showed no skin response to compound 48/80, a mast cell degranulating agent. Although the skin responses to intradermal injection of polyoxyethylene castor oil derivative (HCO-60, a nonionic detergent), histamine dihydrochloride, concanavalin A (IgE receptor-mediated stimuli), or calcium ionophore A23187 were comparable in wild-type (WT) dogs and these nonresponder (NR) dogs, only the response to compound 48/80 was entirely absent from NR dogs. The skin mast cell density and histamine content per mast cell were histologically comparable between WT and NR dogs. By checking for skin responses to compound 48/80, NR dogs were found to exist at the proportion of 17–20% among four animal breeders. From retrospective analysis of in-house breeding histories, the NR phenotype appears to conform to the Mendelian pattern of recessive inheritance. The standard skin response in WT dogs developed at 2–4 months of age. In conclusion, this unique phenotype, typified by insensitivity in the compound 48/80-induced degranulation pathway in mast cells, has been widely retained by recessive inheritance in beagle dogs among general experimental animal breeders. The knowledge concerning this phenotype could lead to better utilization of dogs in studies and aid in model development.

Padronização do eletrorretinograma de campo total em cães

Eletrorretinograma (ERG) é o meio diagnóstico objetivo e não-invasivo para avaliar a função retiniana e detectar precocemente, em várias espécies, lesões nas suas camadas mais externas. As indicações mais comuns para ERG em cães são: avaliação pré-cirúrgica de pacientes com catarata, caracterização de distúrbios que causam cegueira, além de servir como importante modelo para o estudo da distrofia retiniana que acomete o homem. Vários são os fatores que podem alterar o ERG tais como: eletrorretinógrafo, fonte de estimulação luminosa, tipo do eletrodo, tempo de adaptação ao escuro, tamanho pupilar, opacidade de meios e protocolo de sedação ou anestesia; além da espécie, raça e idade. Objetivou-se com este estudo padronizar o ERG para cães submetidos à sedação, seguindo o protocolo da International Society for Clinical Electrophysiology of Vision (ISCEV), utilizando Ganzfeld e eletrodos Burian Allen. Foram realizados 233 eletrorretinogramas em cães, 147 fêmeas e 86 machos, com idades entre um e 14 anos. Dos 233 cães examinados, 100 apresentavam catarata em diferentes estágios de maturação, 72 eram diabéticos e apresentavam catarata madura ou hipermadura, 26 apresentaram eletrorretinograma compatível com degeneração retiniana progressiva, três apresentaram eletrorretinograma compatível com síndrome da degeneração retiniana adquirida subitamente e 32 não apresentaram lesão retiniana capaz de atenuar as respostas do ERG, sendo considerados normais quanto à função retiniana. A sedação foi capaz de produzir boa imobilização do paciente sem rotacionar o bulbo ocular, permitindo adequada estimulação retiniana bilateralmente, com auxílio do Ganzfeld. O sistema eletrodiagnóstico Veris registrou com sucesso e simultaneamente de ambos os olhos, as cinco respostas preconizadas pela ISCEV. Como o ERG de campo total tornou-se exame fundamental na rotina oftalmológica, sua padronização é indispensável quando se objetiva comparar resultados de laboratórios distintos. A confiabilidade e reprodutibilidade deste protocolo foi demonstrada com a obtenção de registros de ótima qualidade utilizando protocolo padrão da ISCEV, eletrorretinógrafo Veris, Ganzfeld e eletrodos Burian Allen nos cães submetidos à sedação.

In vitro and in vivo evaluation of combined calcitriol and cisplatin in dogs with spontaneously occurring tumors

Calcitriol potentiates cisplatin-mediated activity in a variety of tumor models. We examine here, the effect of calcitriol and cisplatin pre-clinically and clinically in canine spontaneous tumors through in vitro studies on tumor cells and through a phase I study of calcitriol and cisplatin to identify the maximum-tolerated dosage (MTD) of this combination in dogs with cancer and to characterize the pharmacokinetic disposition of calcitriol in dogs. Canine tumor cells were investigated for calcitriol/cisplatin interactions on proliferation using an MTT assay in a median-dose effect analysis; data were used to derive a combination index (CI). Cisplatin was given at a fixed dosage of 60 mg/m2. Calcitriol was given i.v. and the dosage was escalated in cohorts of three dogs until the MTD was defined. Serum calcitriol concentrations were quantified by radioimmunoassay. In vitro, CIs < 1.0 were obtained for all combinations of calcitriol/cisplatin examined. The MTD was 3.75 microg/kg calcitriol in combination with cisplatin, and hypercalcemia was the dose-limiting toxicosis. The relationship between calcitriol dosage and either Cmax or AUC was linear. Calcitriol dosages >1.5 microg/kg achieved Cmax > or = 9.8 ng/mL and dosages >1.0 microg/kg achieved AUC > or = 45 h ng/mL. Calcitriol and cisplatin have synergistic antiproliferative effects on multiple canine tumor cells and high-dosages of i.v. calcitriol in combination with cisplatin can be safely administered to dogs. Cmax and AUC at the MTD 3.75 microg/kg calcitriol exceed concentrations associated with antitumor activity in a murine model, indicating this combination might have significant clinical utility in dogs.

Canine stem cell factor augments expression of matrix metalloproteinase-9 by CD34 cells

Canine models have proved to be predictive of clinical findings in human bone marrow (BM) transplantation; consequently, the utilization of dogs is an excellent tool for supporting therapeutic purposes. Considering the role of growth factors in homing and mobilization of hematopoietic progenitors, the aim of this work was to evaluate whether canine stem cell factor (cSCF) contributes to matrix metalloproteinase (MMP)-9 secretion by CD34 cells. The study was carried out in a cell population selected by immunomagnetic techniques using the anti-canine CD34 monoclonal antibody (MAb) 3B4 produced by us. Secretion of MMP-9 was evaluated by zymography. Analyzes of canine CD34(+) cells guaranteed that the MAb 3B4 was optimum for selecting a subset population with defined characteristics of primitive hematopoietic cells. The isolated cells were able to proliferate onto irradiated pre-established stroma, giving rise to mature neutrophils. There was also a 20-fold enrichment in the long-term culture-initiating cell content when the isolated population was added to irradiated cultures, with respect to the starting mononuclear cell population. We have provided the first evidence that canine BM CD34(+) cells constitutively express MMP-9 and the role of cSCF in up-regulating the secretion of this enzyme. The fact that cSCF augments expression of MMP-9 together with the ability of the isolated CD34(+)cells to proliferate onto irradiated pre-established stroma enables further investigations to determine whether the secretion of MMP-9 mediated by cSCF is one of the factors that enhance migration, homing and repopulation of primitive hemopoietic cells.

Who let the dogs out? Infection control did: Utility of dogs in health care settings and infection control aspects

Research has substantiated that animals improve human health, both psychologically and physiologically. Therefore, healthcare facilities have begun to implement programs, such as the "Furry Friends Foundation," that bring animals into the facility to improve the quality of life of patients. When implementing these programs, consideration must be given to potential adverse events such as phobias, allergies, and particularly the possibility of zoonotic disease transmission. Santa Clara Valley Medical Centre (SCVMC), a 600-bed county teaching hospital with specialized units (e.g., for burns, rehabilitation, and pediatric care), has implemented programs that incorporate animals into the healthcare setting. This facility allows three categories of dogs to interact with their patients: service dogs, therapy dogs, and pet visitation dogs by the "Furry Friends Foundation." A blurring of the roles of the three categories of dogs occurred when these programs were put into place at SCVMC. The American with Disabilities Act (ADA) states that service animals cannot be prohibited from any area. For example, a "no pet allowed" policy could not apply to these animals. Proof of a person's disability or proof of the service animal's health or training cannot be required. The purpose of this project was to maintain these programs by clarifying the policies regarding animals, specifically dogs, in the healthcare setting. This had to take place to provide a safe and enjoyable environment for the patients and the staff. A comprehensive table was developed to delineate the three categories of dogs and the corresponding policies. Therapy dogs and the visitation animals are more restricted than service dogs. Both therapy dogs and visitation dogs require identification and certification of health and are excluded from certain areas of the facility, including intensive care units and isolation rooms. By complying with the current policies and regulations, the risks from these programs can be minimized. Staff should be educated on the proper terminology and procedures to prevent a blurring of the categories and roles of these animals.