Wildlife–livestock interactions in a western rangeland setting: Quantifying disease-relevant contacts

Disease transmission between wild ungulates and domestic livestock is an important and challenging animal health issue. The potential for disease transmission between wildlife and livestock is notoriously difficult to estimate. The first step for estimating the potential for between-species disease transmission is to quantify proximity between individuals of different species in space and time. This study estimates second-order statistics of spatio-temporal location data from radio-collared free-ranging deer, elk and cattle in northeast Oregon. Our results indicate, that when observed simultaneously, elk and cattle occur in closer proximity to each other than what would be expected based on general space use of these species. The same is true for deer and elk but not for deer and cattle. Our analysis also demonstrates that average distances between cattle and elk are largely driven by rare events of close co-mingling between the species, which extend over several hours. Behavioral causes for these co-mingling events are currently unknown. Understanding the causes for such events will be important for designing grazing practices that minimize wildlife–livestock contacts.     

Endothelial cells and angiogenesis in the horse in health and disease—A review

The cardiovascular system is the first functional organ in the embryo, and its blood vessels form a widespread conductive network within the organism. Blood vessels develop de novo, by the differentiation of endothelial progenitor cells (vasculogenesis) or by angiogenesis, which is the formation of new blood vessels from existing ones. This review presents an overview of the current knowledge on physiological and pathological angiogenesis in the horse including studies on equine endothelial cells. Principal study fields in equine angiogenesis research were identified: equine endothelial progenitor cells; equine endothelial cells and angiogenesis (heterogeneity, markers and assessment); endothelial regulatory molecules in equine angiogenesis; angiogenesis research in equine reproduction (ovary, uterus, placenta and conceptus, testis); angiogenesis research in pathological conditions (tumours, ocular pathologies, equine wound healing, musculoskeletal system and laminitis). The review also includes a table that summarizes in vitro studies on equine endothelial cells, either describing the isolation procedure or using previously isolated endothelial cells. A particular challenge of the review was that results published are fragmentary and sometimes even contradictory, raising more questions than they answer. In conclusion, angiogenesis is a major factor in several diseases frequently occurring in horses, but relatively few studies focus on angiogenesis in the horse. The challenge for the future is therefore to continue exploring new therapeutic angiogenesis strategies for horses to fill in the missing pieces of the puzzle.     

Chronic Bartonellosis in Cats: What are the potential implications?

Practical relevance: Bartonellae are small, vector-transmitted Gram-negative intracellular bacteria that are well adapted to one or more mammalian reservoir hosts. Cats are the natural reservoir for Bartonella henselae, which is a (re-)emerging bacterial pathogen. It can cause cat scratch disease in humans and, in immunocompromised people, may lead to severe systemic diseases, such as bacillary angiomatosis. Cats bacteraemic with B henselae constitute the main reservoir from which humans become infected. Most cats naturally infected with B henselae show no clinical signs themselves, but other Bartonella species for which cats are accidental hosts appear to have more pathogenicity. Global importance: Several studies have reported a prevalence of previous or current Bartonella species infection in cats of up to 36%. B henselae is common in cats worldwide, and bacteraemia can be documented by blood culture in about a quarter of healthy cats. The distribution of B henselae to various parts of the world has largely occurred through humans migrating with their pet cats. The pathogen is mainly transmitted from cat to cat by fleas, and the majority of infected cats derive from areas with high flea exposure. No significant difference in B henselae prevalence has been determined between male and female cats. In studies on both naturally and experimentally infected cats, chronic bacteraemia has mainly been found in cats under the age of 2 years, while those over 2 years of age are rarely chronically bacteraemic. Evidence base: This article reviews published studies and case reports on bartonellosis to explore the clinical significance of the infection in cats and its impact on humans. The article also discusses possible treatment options for cats and means of minimising the zoonotic potential.     

A review of developments in nutrition as it is related to fertility in cattle: 1964–9

Mice given sporidesmin in their drinking water for 10 days developed bilirubinaemia. Mice immunized with some 2-amino-5-chloro-3, 4-dimethoxy benzyl alcohol-bacteria complexes were apparently more resistant to the bilirubinaemic effect of sporidesmin than were unimmunized mice.     

Sialolithiasis in horses: A retrospective study of 25 cases (2002–2013)

This study evaluated outcomes of surgical treatment of equine sialolithiasis, highlighting cases involving the proximal parotid salivary duct. Sialoliths in the proximal parotid duct were difficult to identify radiographically and more frequently associated with draining tracts and sialadenitis compared with sialoliths in the distal parotid duct. Ultrasonography confirmed the diagnosis of sialolithiasis in all cases in which there was no radiographic evidence of a sialolith. All cases of proximal parotid duct sialolithiasis required transcutaneous removal. A longer duration of illness was observed in cases of proximal parotid duct sialolithiasis compared with cases involving the distal parotid duct, and in cases requiring transcutaneous removal compared with cases requiring transoral removal. Recurrence of sialolithiasis was documented in 24% of cases, all of which were located in the distal parotid duct. The average time to recurrence was 2.8 years.     

Scrotal tumors in dogs: A retrospective study of 676 cases (1986–2010)

The objective of this study was to determine common tumor types that occur on the canine scrotum in relation to other cutaneous locations and to identify potential risk factors for specific scrotal tumor development. A retrospective study was conducted and the database of pathology reports from the Surgical Pathology Service of the Department of Pathology and Toxicology, School of Veterinary Medicine, University of Pennsylvania from 1986 to 2010 was searched for canine neoplastic scrotal and non-scrotal cutaneous lesions. Neoplastic lesions were evaluated based on diagnosis, breed, age, and number and location of tumors (scrotal versus non-scrotal cutaneous). Mast cell tumor, melanocytoma, malignant melanoma, vascular hamartoma, hemangiosarcoma, hemangioma, and cutaneous histiocytoma were the most common tumor types identified on the canine scrotum. Breed predispositions and mean age at diagnosis were identified for each tumor type and should be considered when planning surgical excision of a canine scrotal tumor.     

Owner complaints of canine behavior in Iran–A preliminary survey

The current survey assessed 17 common behavioral complaints reported by 234 dog owners attending the Small Animal Hospital, University of Tehran using a questionnaire. According to the results, nearly 95% of dog owners reported at least 1 undesirable behavior in their dogs. Aggression toward other dogs and people, jumping up, and excessive barking were the most common behavioral complaints. Owners of large-breed dogs were more likely to complain about their dogs’ aggressive behaviors toward people/dogs and excessive barking compared with owners of small-breed dogs. Dogs without access to a yard were more likely to show phobia-associated behaviors, fearfulness, and separation-related behaviors, whereas those having access to a yard were more likely to show aggressive behaviors toward people/dogs and excessive barking. Interaction of dogs with people and type of reaction used by owners in response to the behavior were also related with some other behavioral characteristics of the animals.     

A Descriptive Study of Urban Rabies during the Civil War in Sierra Leone: 1995–2001

A study was conducted to assess the effects of the breakdown in internal infrastructure on the incidence of canine-transmitted human rabies in urban areas of Sierra Leone during the course of the civil war between 1995 and 2001. Data from provincial hospitals in the Western Area and Southern Province indicated that there was a significant increase in the incidence of canine-transmitted urban human rabies chi2 = 39.63, p < 0.0001, particularly among children chi2 = 23.73, p < 0.0001, over the course of the war. In the Western Area in 2001, towards the end of the war, there was a significant increase in adult cases, which was reflected in the observed versus the expected chi2 ratio (70 versus 53). Interview-based questionnaire surveys in Freetown administered between 2001 and 2002 indicated that dogs were commonly kept for security reasons, and were largely unrestrained and unlicensed, regardless of the socioeconomic status of the owner. Virtually all dogs were unvaccinated and were mainly living in close proximity with humans. This study indicated that there is an urgent requirement for appropriate mass rabies vaccination campaigns for pet dogs and for campaigns to manipulate the urban habitat to control free-roaming and wandering but owned dog populations in Freetown and other urban areas in the provinces of Sierra Leone. Interview-based questionnaires administered in three districts of Freetown indicated a relatively high degree of uniformity in dog husbandry and veterinary care habits across a wide range of socioeconomic status categories in dog owners.     

Arterial Thromboembolism in 250 Cats in General Practice: 2004–2012

Background

Population characteristics and outcome of cats with arterial thromboembolism (ATE) managed in general practice (GP) have been poorly described.

Hypothesis

Cats with ATE presenting to GP are usually euthanized at presentation, but survival times >1 year are possible.

Animals

Cats with ATE managed by 3 GP clinics in the United Kingdom.

Methods

Records of cases presenting to GP over a 98‐month period (2004–2012) were reviewed. Cats with an antemortem diagnosis of limb ATE were included. Outcome information was obtained.

Results

Over 98 months, 250 cats were identified with ATE. Prevalence was approximately 0.3%. At presentation, 153 cats (61.2%) were euthanized, with 68/97 (70.1%) of the remaining cats (27.2% of the total population) surviving >24 hours after presentation. Of these, 30/68 (44.1%) survived for at least 7 days. Hypothermia (HR, 1.44; 95% CI, 1.002–2.07; P = .049) and management by Clinic 2 (HR, 5.53; 95% CI, 1.23–24.8; P = .026) were independent predictors of 24‐hour euthanasia or death. For cats surviving >24 hours, hypothermia (HR, 2.25; 95% CI, 1.12–4.48; P = .021) and failure to receive aspirin, clopidogrel, or both (HR, 8.26; 95% CI, 1.39–50; P = .001) were independent predictors of euthanasia or death within 7 days. For cats that survived ≥7 days, median survival time was 94 (95% CI, 42–164) days, with 6 cats alive 1 year after presentation.

Conclusions

Although 153/250 cats were euthanized at presentation, 6 cats survived >12 months. No factors were identified that predicted euthanasia on presentation.     

Encephalitozoon cuniculi–Associated Equine Encephalitis: A Case Report

A case of encephalitis of unknown origin in the horse was investigated. Postmortem examination findings revealed a nonsuppurative granulomatous meningoencephalitis in the right hemisphere of the cerebral cortex. Testing for West Nile virus, equine herpes virus, equine infectious anemia, Toxoplasma gondii, Neospora caninum, and Sarcocystis neurona were negative. The horse had a titer for Encephalitozoon cuniculi, and sections from the affected area of the brain tested positive for the organism using both polymerase chain reaction (PCR) and immunohistochemistry. Amplicons generated using PCR were sequenced, and E. cuniculi genotype II was identified. This is the first case of E. cuniculi genotype II associated with encephalitis in the horse.     

Human‐infecting influenza A (H9N2) virus: A forgotten potential pandemic strain?

Continuously emergence of human infection with avian influenza A virus poses persistent threat to human health, as illustrated in H5N1, H7N9 and recent surge of H9N2 infections. Long‐term prevalence of H9N2 avian influenza A virus in China and adjacent regions favours the interspecies transmissions from avian to human. Establishment of multiple genotypes of H9N2 variants in this region contributes to the emergence of novel H7N9 and H10N8 viruses which caused human fatalities. Recent increasing human infection with H9N2 virus in China highlights the necessity to closely monitor the interspecies transmission events. Available human H9N2 sequences revealed that Y280/G9 lineage was responsible for the most of human cases. Presence of adaptive mutations beyond the human‐like receptor binding was indicative of the capacity of readily infecting new hosts without prior adaptation. Moreover, enlarged host range of H9N2 virus in this region substantially increased the transmission among mammals. Meanwhile, serological surveys implied human was more susceptible to H9N2 infection, compared with panzootic H5 and H7 subtype avian influenza virus. Thus, control at the source will be the ultimate and effective option for H9N2 pandemic preparedness. This review comprehensively summarized recent updates on H9N2 human infections, aiming to shed light on the prevention strategies against this strain with pandemic potential.     

Biofilms: A role in recurrent mastitis infections?

Mastitis remains one the most important diseases in dairy cattle despite the progress made in improving general udder health in recent years. Epidemiological studies have revealed that following treatment with antimicrobials, bacteriological cure rates vary between 0% and 80% but with no evidence of a significant loss of activity of the major classes of antibiotics licensed for the treatment of bovine mastitis. Recurrent infections are often attributable to biofilm growth of bacteria and this review provides an overview of those mechanisms related to bacterial biofilm growth in mastitis. Biofilm formation is accompanied by significant genetic and subsequent physiological changes in the microorganisms resulting, inter alia, in a loss of sensitivity to virtually all classes of antibiotics.     

Frequency of group A rotavirus in diarrhoeic calves in Brazilian cattle herds, 1998–2002

The frequency of group A bovine rotavirus (gpA BRV) in calves from 1998 to 2002 was determined by the polyacrylamide gel electrophoresis technique in 2177 faecal samples, of which 1898 samples were diarrhoeic and 279 were of normal consistency (control group) that were collected from asymptomatic calves for comparative purposes. The animals were from beef and dairy cattle herds (n = 321) from 158 counties in seven States (Paraná, São Paulo, Minas Gerais, Mato Grosso do Sul, Mato Grosso, Goiás and Rondônia) and four Brazilian geographical regions (south, south-east, centre-west, and north). GpA BRV was detected in 19.4% (369/1898; p = 0.0001) of the samples collected in calves with diarrhoea and in only 2.2% (6/279; p = 0.0001) of the faeces with normal consistency. The proportion of positive samples collected from beef and dairy cattle herds was 22.8% (205/899; p = 0.0001) and 16.4% (169/999; p = 0.0005), respectively. In relation to age, a higher prevalence of infections was found in calves up to 30 days old, where 33.0% (189/573; p = 0.0001) and 20.2% (138/683; p = 0.0001) of the diarrhoeic faecal samples from beef and dairy cattle herds, respectively, were positive for gpA BRV. These results show the possible importance of inclusion of gpA BRV in the management of neonatal calf diarrhoea in Brazilian cattle herds.     

White line disease: A review (1998–2018)

White line disease (WLD) is a significant pathological condition that affects the equine hoof. White line disease continues to frustrate veterinarians and farriers due to the diversity regarding the aetiology, diagnosis and especially treatment. Furthermore, WLD lacks a definitive definition as the disease becomes apparent only when the hoof wall is compromised with an extensive separation, a hoof capsule distortion is present or when lameness exists. Clinical signs can range from a minor hoof wall separation to an extensive disruption of the external laminar bond resulting in displacement of the distal phalanx within the hoof capsule. There has been a myriad of treatments and topical preparations proposed for treating WLD, but most remain controversial with few having any scientific documentation or evidence of efficacy. This review of WLD is based on the sparse information available in the veterinary literature, the large number of WLD cases treated successfully in the authors’ combined practices using conventional farriery and the relevant questions that hopefully can be answered in the future.