Positive effect of spring advance on the diet quality of an alpine herbivore

Changes in vegetation phenology related to global warming are having alarming effects on the life history traits of many herbivore species. Such changes are particularly critical in alpine ecosystems, where strong climate limitations on plant growth make seasonal synchronization imperative for the growth, reproduction and survival of herbivores. However, despite the pivotal role of resource-use strategies on the performances of such species, few studies have explicitly assessed the mechanistic impact of climate change on their diets. We aimed to fill this gap by studying the effect of spring onset on the dietary composition and quality of a medium-size alpine herbivore while considering density-dependent processes and age- and sex-specific differences in foraging behavior. Using an exceptional, long-term (24 years) direct individual-based dietary monitoring of a Pyrenean chamois population (Rupicapra pyrenaica pyrenaica), we showed that ongoing earlier onsets of spring are leading to an earlier access to high-quality forage and therefore a higher diet quality at a fixed date, without apparent changes in diet composition. We also showed that at high densities, intraspecific competition reduced diet quality by driving animals to feed more on woody plants and less on nutritious forbs and graminoids. By assessing the mechanistic effects of global warming on the dietary patterns of species at the center of trophic networks, this study is an essential step for predictive models aiming at understanding the ongoing ecosystem consequences of the global climatic crisis.

Temporal changes in clinical and radiographic variables in dogs with preclinical myxomatous mitral valve disease: The EPIC study

Background

The Evaluation of pimobendan in dogs with cardiomegaly caused by preclinical myxomatous mitral valve disease (EPIC) study monitored dogs with myxomatous mitral valve disease (MMVD) as they developed congestive heart failure (CHF).

Objectives

To describe the changes in clinical and radiographic variables occurring as dogs with MMVD and cardiomegaly develop CHF, compared to similar dogs that do not develop CHF.

Animals

One hundred and thirty‐five, and 73 dogs that did or did not develop CHF, respectively.

Materials and methods

The following variables were evaluated in 2 groups of dogs (dogs that did or did not develop CHF): Heart rate (HR), clinic respiratory rate (RR), home‐measured resting respiratory rate (RRR), rectal temperature (RT), body weight (BW), and vertebral heart sum (VHS). Absolute value and rate of change of each variable were calculated for each day a dog was in study. Daily means were calculated and plotted against time. The onset of CHF or last visit before leaving the study were set as reference time points.

Results

The most extreme values and rate of change occurred in variables immediately before onset of CHF. Vertebral heart sum increased earliest. Heart rate, RR, and RRR also increased. Rectal temperature and BW decreased. Increases in RR and RRR were most extreme and occurred immediately before CHF.

Conclusions and Clinical Importance

Dogs with MMVD and cardiomegaly experience increases in HR, RR, RRR, and VHS, and decreases in BW and RT as they develop CHF. The variables with highest absolute change and rate of change were RR and RRR. These findings reinforce the value of RR and RRR as indicators of impending or incipient CHF.

Longitudinal Analysis of Quality of Life, Clinical, Radiographic, Echocardiographic, and Laboratory Variables in Dogs with Preclinical Myxomatous Mitral Valve Disease Receiving Pimobendan or Placebo: The EPIC Study

Background

Changes in clinical variables associated with the administration of pimobendan to dogs with preclinical myxomatous mitral valve disease (MMVD) and cardiomegaly have not been described.

Objectives

To investigate the effect of pimobendan on clinical variables and the relationship between a change in heart size and the time to congestive heart failure (CHF) or cardiac‐related death (CRD) in dogs with MMVD and cardiomegaly. To determine whether pimobendan‐treated dogs differ from dogs receiving placebo at onset of CHF.

Animals

Three hundred and fifty‐four dogs with MMVD and cardiomegaly.

Materials and Methods

Prospective, blinded study with dogs randomized (ratio 1:1) to pimobendan (0.4–0.6 mg/kg/d) or placebo. Clinical, laboratory, and heart‐size variables in both groups were measured and compared at different time points (day 35 and onset of CHF) and over the study duration. Relationships between short‐term changes in echocardiographic variables and time to CHF or CRD were explored.

Results

At day 35, heart size had reduced in the pimobendan group: median change in (Δ) LVIDDN −0.06 (IQR: −0.15 to +0.02), P < 0.0001, and LA:Ao −0.08 (IQR: −0.23 to +0.03), P < 0.0001. Reduction in heart size was associated with increased time to CHF or CRD. Hazard ratio for a 0.1 increase in ΔLVIDDN was 1.26, P = 0.0003. Hazard ratio for a 0.1 increase in ΔLA:Ao was 1.14, P = 0.0002. At onset of CHF, groups were similar.

Conclusions and Clinical Importance

Pimobendan treatment reduces heart size. Reduced heart size is associated with improved outcome. At the onset of CHF, dogs treated with pimobendan were indistinguishable from those receiving placebo.

Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study-A Randomized Clinical Trial

Background

Pimobendan is effective in treatment of dogs with congestive heart failure (CHF) secondary to myxomatous mitral valve disease (MMVD). Its effect on dogs before the onset of CHF is unknown.

Hypothesis/Objectives

Administration of pimobendan (0.4–0.6 mg/kg/d in divided doses) to dogs with increased heart size secondary to preclinical MMVD, not receiving other cardiovascular medications, will delay the onset of signs of CHF, cardiac‐related death, or euthanasia.

Animals

360 client‐owned dogs with MMVD with left atrial‐to‐aortic ratio ≥1.6, normalized left ventricular internal diameter in diastole ≥1.7, and vertebral heart sum >10.5.

Methods

Prospective, randomized, placebo‐controlled, blinded, multicenter clinical trial. Primary outcome variable was time to a composite of the onset of CHF, cardiac‐related death, or euthanasia.

Results

Median time to primary endpoint was 1228 days (95% CI: 856–NA) in the pimobendan group and 766 days (95% CI: 667–875) in the placebo group (P = .0038). Hazard ratio for the pimobendan group was 0.64 (95% CI: 0.47–0.87) compared with the placebo group. The benefit persisted after adjustment for other variables. Adverse events were not different between treatment groups. Dogs in the pimobendan group lived longer (median survival time was 1059 days (95% CI: 952–NA) in the pimobendan group and 902 days (95% CI: 747–1061) in the placebo group) (P = .012).

Conclusions and Clinical Importance

Administration of pimobendan to dogs with MMVD and echocardiographic and radiographic evidence of cardiomegaly results in prolongation of preclinical period and is safe and well tolerated. Prolongation of preclinical period by approximately 15 months represents substantial clinical benefit.

Erythrocyte pyruvate kinase deficiency in three West Highland white terriers in Ireland and the UK

Erythrocyte pyruvate kinase (PK) deficiency is described for the first time in three apparently unrelated West Highland white terriers (WHWT) from Ireland and the UK. All three dogs were diagnosed with markedly regenerative but persistent anaemia and had been treated for presumed immune-mediated haemolytic anaemia (IMHA) before hereditary erythrocyte PK-deficiency was confirmed by breed-specific DNA mutation analysis. This hereditary erythroenzymopathy causes haemolytic anaemia and affects several canine breeds with varying degrees of severity. Although eventually causing osteosclerosis, haemosiderosis and death, PK-deficient dogs can adapt to their anaemia for many years.PK-deficiency should be considered in anaemic WHWTs worldwide particularly in dogs with haemolytic anaemia where evidence for an immune-mediated, infectious or toxic underlying cause is lacking.

Circulating natriuretic peptide concentrations in hyperthyroid cats

OBJECTIVES

To assess the influence of thyroid function on natriuretic peptide concentration in hyperthyroid cats before and after treatment.

METHODS

Serum natriuretic peptide concentration was measured in 61 hyperthyroid cats recruited from first-opinion clinics before and after treatment.

RESULTS

Following successful treatment, total thyroxine, heart rate, systolic blood pressure and packed cell volume all decreased and bodyweight and creatinine concentrations increased. Furthermore, a significant (P < 0·001) decline in NT-proBNP concentration but not NT-proANP was identified.

CLINICAL SIGNIFICANCE

Thyroid function has a modest but significant effect on NT-proBNP concentration. Thyroid status should be taken into account when interpreting NT-proBNP concentrations in cats.

Transmission of a pestivirus infection in a population of Pyrenean chamois

Outbreaks of a previously unrecorded disease have recently affected Pyrenean chamois (Rupicapra pyrenaica pyrenaica) populations across the mountain range. A pestivirus was hypothesized to be the cause of this emerging disease and this type of virus can cross the species barrier and be transmitted to or from wildlife. Using an epidemiological survey conducted from 1995 to 2004 at Orlu, France, we characterized the virus and analyzed its transmission. A phylogenetic analysis of viral sequences and virus neutralization tests showed that the virus belonged to the newly described border disease virus-4 group. The increase of seroprevalence with age indicated that infection can occur at any age and resulted in lifelong immunity. Overall, 70.3% of 323 samples were positive for anti-p80 antibodies and 10.2% of 167 samples showed viremia, as demonstrated by either positive ELISA antigen test or RT-PCR. Infection has thus been widespread in this population since 1995, whereas no mass mortality or clinical signs have been observed. Incidence and seroprevalence varied seasonally and according to number of individuals aged less than 2 years old in the population, so viral transmission was dependent on host population age structure. We propose that the virus is now endemic in this population and is likely detrimental for reproduction and juveniles. Further investigation is needed to estimate the impact of pestivirus on host population dynamics and the risk of cross-transmission to farm animals.

Atrial fibrillation in dogs with and without structural or functional cardiac disease: A retrospective study of 109 cases

OBJECTIVES

To determine if the heart rate and survival of dogs with atrial fibrillation (AF) varied amongst those: (1) without structural and functional disease (Group NoDz), (2) with structural or functional disease without pulmonary edema or ascites (Group DzNoF), and (3) with structural or functional disease with pulmonary edema or ascites (Group DzF).

ANIMALS, MATERIALS AND METHODS

The records of 109 dogs from the Veterinary Teaching Hospital of the University of Montreal (n=30) and the Cornell University Hospital for Animals (n=79) were examined.

RESULTS

Large and giant breed dogs were most commonly affected (95.5%) with the Irish Wolfhound, Mastiff, Newfoundland, and Rottweiler overrepresented (P<0.01) in Group NoDz and the Irish Wolfhound, Boxer, English Sheepdog, Great Dane and Doberman Pincher overrepresented (P<0.01) in Groups DzNoF and DzF. Males (73.4%) were more commonly affected (P<0.001). Heart rate (mean+/-SD) on presentation was different amongst the 3 groups of dogs (P<0.001) (Group NoDz: 120+/-8.0bpm, Group DzNoF: 155+/-7.6bpm, and Group DzF: 203+/-6.2bpm). Kaplan-Meier survival analysis revealed a longer survival for dogs in Group NoDz (P=0.006) and large and giant breeds (P=0.02). Initial heart rate could not be separated from diseased group as an independent determinant of survival.

CONCLUSIONS

Results suggest that dogs with AF and no demonstrable cardiac disease have a slower presenting heart rate and greater survival than dogs with structural disease with and without heart failure.

[Air-conditioner disease. Results of an industrial medicine survey (author's transl)]

The results of a survey conducted in a company employing 1850 persons working in air-conditioned premises are reported. One hundred and five persons were examined, including 790 who mostly complained of respiratory disorders and 20 controls. Regular check-ups during the last two years have failed to reveal any serious disease. The most frequent complaints were rhinitis and tracheitis, especially among female employees. No alveolitis was observed. The finding of Bacillus subtilis in samples of ambient air and air-conditioner filters in conjunction with the presence of precipitating antibodies against crude extracts from these samples, suggested that the respiratory disorders might have been due to this microorganism. A multifactorial analysis demonstrated a statistically significant correlation between clinical symptoms and immunological disorders. The air-conditioner disease, therefore, may present as a benign condition.