Maureen C. Gates

Endoparasite prevalence and recurrence across different age groups of dogs and cats

The apparent prevalence of endoparasite infections across different age groups was calculated from 6555 dogs and 1566 cats that had a fecal examination performed upon presentation to the Veterinary Hospital of the University of Pennsylvania between 1997 and 2007. Based on notations from the medical history indicating prior parasite infections, estimates of recurrence were generated for each common group of parasites, including Trichuris, Giardia, ascarids, hookworms, Cystoisospora, and tapeworms. Endoparasitism was predominantly a disease of younger animals, with peak prevalence observed almost uniformly in dogs under 6 months old, with the exception of Trichuris with its longer pre-patent period, and in cats less than 18 months old. Furthermore, nearly 50% of dogs under 6 months old with a history of parasites, were diagnosed with at least one species of parasite on subsequent fecal examination. The percentage dropped to 18.4% in animals aged 1-4 years, but again increased to 31.5% in animals over 10 years old. There was no reported recurrence of Giardia or Cystoisospora from canine or feline patients older than 1 year. The recurrence of whipworm rose steadily with age, while hookworm and roundworm recurrence peaked in patients 1-4 years old. Findings from the study emphasize the importance of follow up fecal examinations and treatments in patients diagnosed with endoparasites.

Relative associations of cattle movements, local spread, and biosecurity with bovine viral diarrhoea virus (BVDV) seropositivity in beef and dairy herds

The success of bovine viral diarrhoea virus (BVDV) eradication campaigns can be undermined by spread through local transmission pathways and poor farmer compliance with biosecurity recommendations. This work combines recent survey data with cattle movement data to explore the issues likely to impact on the success of BVDV control in Scotland. In this analysis, data from 249 beef suckler herds and 185 dairy herds in Scotland were studied retrospectively to determine the relative influence of cattle movements, local spread, and biosecurity on BVDV seropositivity. Multivariable logistic regression models revealed that cattle movement risk factors had approximately 3 times greater explanatory power than risk factors for local spread amongst beef suckler herds, but approximately the same explanatory power as risk factors for local spread amongst dairy herds. These findings are most likely related to differences in cattle husbandry practices and suggest that where financial prioritization is required, focusing on reducing movement-based risk is likely to be of greatest benefit when applied to beef suckler herds. The reported use of biosecurity measures such as purchasing cattle from BVDV accredited herds only, performing diagnostic screening at the time of sale, implementing isolation periods for purchased cattle, and installing double fencing on shared field boundaries had minimal impact on the risk of beef or dairy herds being seropositive for BVDV. Only 28% of beef farmers and 24% of dairy farmers with seropositive herds recognized that their cattle were affected by BVDV and those that did perceive a problem were no less likely to sell animals as replacement breeding stock and no more likely to implement biosecurity measures against local spread than farmers with no perceived problems. In relation to the current legislative framework for BVDV control in Scotland, these findings emphasize the importance of requiring infected herds take appropriate biosecurity measures to prevent further disease transmission and conducting adequate follow-up to ensure that biosecurity measures are being implemented correctly in the field.

Factors influencing heartworm, flea, and tick preventative use in patients presenting to a veterinary teaching hospital

The introduction of modern heartworm, flea, and tick preventatives has provided a safe and effective means of controlling companion animal endoparasites, but achieving good owner compliance remains an ongoing challenge for the veterinary profession. Based on a sample of patients from the veterinary teaching hospital at the University of Pennsylvania, this study retrospectively examined factors associated with preventative use and areas of potential weakness in client communication. Between 1999 and 2006, records of 5276 canine and 1226 feline patients were searched for signalment, survey results for heartworm, flea, and tick preventative use, date of visit, presenting complaint, vaccination history, and owner zip code. Data were analyzed using bivariate and multivariate techniques. Overall, only 13-23% of patients were questioned about heartworm, flea, or tick preventative use during routine medical history taking. Patients with a prior history of parasites, younger patients, or those presenting with signs of cardiac disease were no more likely to be questioned about preventative use than healthy animals. Patients presenting to a specialty service were also less likely to be questioned. Approximately 74-79% of dogs and 12-38% of cats in the sample were on preventative products at any given time. There was a distinct seasonality to preventative use corresponding to the heartworm transmission season from June through November in the northeastern United States. Only 50% of patients seen for a yearly physical examination in winter were reported to be using preventative products when surveyed later in the year, compared to the roughly 85% on patients in heartworm preventatives when they received their routine physical examination in spring. Month of presentation and neuter status were the only signalment factors significantly (P<0.05) associated with preventative use in the multivariate analysis. Findings from this study emphasize target areas for increasing owner compliance.

Impact of changes in cattle movement regulations on the risks of bovine tuberculosis for Scottish farms.

Legislation requiring the pre- and post-movement testing of cattle imported to Scotland from regions with high bovine tuberculosis (bTB) incidence was phased in between September 2005 and May 2006 as part of efforts to maintain Officially Tuberculosis Free (OTF) status. In this analysis, we used centralized cattle movement records to investigate the influence of the legislative change on import movement patterns and the movement-based risk factors associated with new bTB herd breakdowns identified through routine testing or slaughter surveillance. The immediate reduction in the number of import movements from high incidence regions of England and Wales into Scotland suggests that pre- and post-movement testing legislation has had a strong deterrent effect on cattle import trade. Combined with the direct benefits of a more stringent testing regime, this likely explains the observed decrease in the odds of imported cattle subsequently being identified as reactors in herd breakdowns detected through routine surveillance compared to Scottish cattle. However, at the farm-level, herds that recently imported cattle from high incidence regions were still at increased risk of experiencing bTB breakdowns, which highlights the delay between the introduction of disease control measures and detectable changes in incidence. With the relative infrequency of routine herd tests and the insidious nature of clinical signs, past import movements were likely still important in determining the present farm-level risk for bTB breakdown. However, the possibility of low-level transmission between Scottish cattle herds cannot be ruled out given the known issues with test sensitivity, changes in import animal demographics, and the potential for on-farm transmission. Findings from this analysis emphasize the importance of considering how farmer behavioural change in response to policy interventions may influence disease transmission dynamics.

Irrigation linked to a greater incidence of human and veterinary West Nile virus cases in the United States from 2004 to 2006.

Identifying risk factors for West Nile virus transmission is vital for future public health control measures. This study investigated the effect of irrigation, expressed as percent irrigated land, and population density on the incidence of human and veterinary West Nile virus (WNV) cases using a sample of 2827 counties from the United States over a 3-year period. Zero-inflated Poisson regression models were selected because of the large number of counties reporting zero cases. The mean percentage of irrigated land for the entire sample was approximately 0.029, while counties reporting both human and veterinary cases had an average of 0.054. As the level of irrigation rose by 0.1% of the total county land area, the incidence rate of WNV cases increased by 50% in the human model (RR: 1.50, 95% CI: 1.46-1.53) and 63% in the veterinary model (RR: 1.63, 95% CI: 1.57-1.68). Higher equine and human population densities were associated with a slightly decreased incidence of WNV cases. In the logistic portion of the Zero-inflated model, the presence of irrigation significantly decreased the odds of a county reporting zero cases. Future research is warranted to determine the exact nature of the relationship between irrigation and increased disease incidence in human and veterinary populations.

Evaluating the reproductive performance of British beef and dairy herds using national cattle movement records

National cattle movement databases provide a valuable opportunity to monitor the reproductive performance of breeding cattle on an industry-wide scale. In this analysis, records from the Cattle Tracing System database were used to derive key measures of reproductive efficiency for British beef and dairy herds, including calving spread, age at first calving, calving interval, culling rate and calf mortality rate. At the animal level, only 8.5 per cent of beef heifers and 6.9 per cent of dairy heifers calved by the target age of 24 months. The average calving interval was 394 days for beef dams (median: 371) and 426 days for dairy dams (median: 400). Differences in performance were noted between cattle breeds. An estimated 43.9 per cent calves born in dairy herds were crossbreed beef animals, which may limit the availability of replacement dairy heifers. At the herd level, calving spread and calf mortality rates increased with herd size, while average age at first calving, calving interval, and crossbreeding generally decreased with herd size. Dam age, calving month, breed and twinning were significant risk factors for culling and calf mortality at the animal level. Wide variation in performance between individual herds highlights the potential for improving the efficiency of British cattle production.

Associations between bovine viral diarrhoea virus (BVDV) seropositivity and performance indicators in beef suckler and dairy herds.

Data from 255 Scottish beef suckler herds and 189 Scottish dairy herds surveyed as part of national bovine viral diarrhoea virus (BVDV) prevalence studies from October 2006 to May 2008 were examined retrospectively to determine the relationship between serological status and key performance indicators derived from national cattle movement records. On average, calf mortality rates were 1.35 percentage points higher in seropositive beef herds and 3.05 percentage points higher in seropositive dairy herds than in negative control herds. Seropositive beef herds were also more likely to show increases in calf mortality rates and culling rates between successive years. There were no discernible effects of BVDV on the average age at first calving or calving interval for either herd type. Accompanying questionnaire data revealed that only 27% of beef farmers and 25% of dairy farmers with seropositive herds thought their cattle were affected by BVDV, which suggests that the clinical effects of exposure may be inapparent under field conditions or masked by other causes of reproductive failure and culling. Beef farmers were significantly more likely to perceive a problem when their herd experienced acute changes in calf mortality rates, culling rates, and calving intervals between successive years. However, only 35% of these perceived positive herds were actually seropositive for BVDV. These findings emphasize both the importance of routinely screening herds to determine their true infection status and the potential for using national cattle movement records to identify herds that may be experiencing outbreaks from BVDV or other infectious diseases that impact herd performance.

Efficacy of heartworm preventatives against ascarids and hookworms in client-owned dogs: a retrospective case control study

The efficacy of heartworm preventatives against ascarids and hookworms was assessed in a retrospective analysis of 1329 dogs that received a fecal examination and were surveyed about heartworm preventative use upon presentation to the veterinary teaching hospital at the University of Pennsylvania. To remove confounding due to age, patients under 6 months old were analyzed separately from the remaining population. Although there were no reported cases of ascarids or hookworms in patients under 6 months old receiving monthly heartworm prevention, the prevalence reached 5.2% and 11.7%, respectively, in patients that were not using any products. For patients over 6 months old, there were no apparent associations between parasites and heartworm preventative use. Of the 75.5% of dogs that were administered heartworm preventatives, 16.1% reported seasonal use and 83.9% reported using the products year round. Patients using heartworm preventatives seasonally were no more likely to be harboring nematode parasites than patients using preventatives year round (OR = 0.70, 95% CI: 0.19-2.55). Overall efficacy rates were consistent with prior studies on the active ingredients. Heartworm preventative have the greatest value for controlling nematode endoparasites in patients under 6 months old.

One Health continuing medical education: an avenue for advancing interdisciplinary communication on One Health issues

JAVMA, Vol 234, No. 11, June 1, 2009 C ago, prominent members of the medical community recognized the link between the health of humans and that of other animals. Although there was considerable collaboration between practitioners of human and veterinary medicine in the late 19th century, particularly with regard to education and research, there are limited collaborative efforts in place today. Globalization of economies, emerging infectious diseases, and bioterrorism are rapidly changing the needs of public health and medical education. Of particular concern to both the human and veterinary medical professions is the threat of zoonotic diseases from livestock, companion animals, and wildlife. The encroachment of housing developments into rural areas has brought people and domestic animals into greater contact with wildlife diseases. With a growing number of US households owning at least one pet, millions of families are placed at further risk, albeit limited in proportion to the risks of other contagious diseases. Via contamination of the food and water supplies with pathogens such as Cryptosporidium and Giardia spp, close contact with live animals is no longer required for humans to develop zoonotic diseases. Millions of consumers in the United States are at risk of developing serious health problems from improperly handled meat, poultry, and egg products. Many zoonoses are preventable through public education programs that target simple measures to reduce disease transmission, such as proper hand washing after handling pets, vaccination of dogs and cats against rabies, routine screening of pets for zoonotic parasites, and observation of leash laws. However, it can be difficult for veterinarians to provide appropriate guidance for several reasons: appointment time is often too limited to discuss all relevant issues with clients, certain pet owners may never seek veterinary care for their animals, and the public does not generally perceive veterinarians to be a source of information on human health. In a research study of parents’ and pediatricians’ knowledge of pet-associated hazards, most parents obtained information regarding animal disease from magazines, newspapers, and television, whereas only 5% (11/231) sought advice from a veterinarian. Physicians and nurses may therefore be the only sources One Health continuing medical education: an avenue for advancing interdisciplinary communication on One Health issues

Preliminary description of aging cats and dogs presented to a New Zealand first-opinion veterinary clinic at end-of-life

Abstract AIMS To conduct a preliminary investigation into the chronic disease conditions and clinical signs present in aging New Zealand companion animals at end-of-life and to describe the timing, circumstances, and manner of death. METHODS The medical records database of a first-opinion, companion animal, veterinary practice in Auckland, New Zealand was searched to identify all canine and feline patients ≥7 years of age that were subjected to euthanasia or cremated in the period between July 2012–June 2014. The free-text medical notes were analysed for information on the circumstances surrounding the death, previous diagnoses of chronic disease conditions, and the presence of clinical signs associated with decreased quality-of-life at the time of euthanasia. RESULTS The median age at death was 15 (max 22) years for the 130 cats and 12 (max 17) years for the 68 dogs in the study sample. Euthanasia at the clinic was carried out for 119/130 (91%) cats and 62/68 (91%) dogs, with the remainder recorded as having an unassisted death. The frequency of deaths was highest during December for both cats and dogs. Cost was mentioned as an issue in the medical records for 39/181 (21.6%) patients that were subjected to euthanasia. At the time of euthanasia, 92/119 (77.3%) cats and 43/62 (69.4%) dogs were recorded as having >1 clinical sign associated with a decreased quality-of-life. Inappetence and non-specific decline were the two most commonly recorded clinical signs for both dogs and cats. Cardiovascular disease (44/130, 34%), renal failure (40/130, 31%), and malignant neoplasia (36/130, 28%) were the most common chronic disease conditions recorded for cats. Degenerative joint disease (22/68, 32%), malignant neoplasia (14/68, 21%), and cardiovascular disease (8/68, 12%) were the most common chronic disease conditions recorded for dogs. CONCLUSIONS AND CLINICAL RELEVANCE These preliminary findings highlight that aging companion animals in New Zealand frequently have chronic disease conditions and clinical signs that may potentially be associated with decreased quality-of-life at the time of death. Further in-depth studies are required to determine whether there is a greater role for veterinarians in counselling owners about end-of-life care and euthanasia decisions.