Patricia M. Dennis

Viral hemorrhagic septicemia virus infection in Yellow perch, Perca flavescens, in Lake Erie

ABSTRACT Viral hemorrhagic septicemia virus (VHSV) infects wild and hatchery fish in Europe, Japan, and the Great Lakes and Pacific regions of North America. The virus was associated with a large die-off of yellow perch, Perca flavescens, in Lake Erie in 2006. To determine the infection pattern of VHSV, we sampled yellow perch during the spring, summer, and fall of 2007 and 2008 in the central basin of Lake Erie during routine sampling by the Ohio Division of Wildlife with bottom trawls in nearshore, mid-depth, and offshore locations near the Chagrin River. The Ohio Department of Agricultures Diagnostic Laboratories and the U.S. Fish and Wildlife Services La Crosse Fish Health Center tested for VHSV from homogenized samples obtained from yellow perch kidney, spleen, and brain. At each lake sample location, we also measured temperature, dissolved oxygen, and conductivity. In both years, we found yellow perch infected with VHSV during a threeweek period starting in the last week of spawning to early June. A high proportion of adult male and female yellow perch tested positive for VHSV during the infection period in our sample population. Infection appeared to be associated with temperatures between 12 and 18 °C and with significantly higher yellow perch densities during spawning. No large mortalities of yellow perch were observed during the VHSV infection period in 2007 and 2008.

INTESTINAL VOLVULUS AND STRICTURE ASSOCIATED WITH A LEIOMYOMA IN A GREEN TURTLE (CHELONIA MYDAS)

Abstract A previously stranded 30-kg female green turtle (Chelonia mydas) was referred to the Veterinary Medical Teaching Hospital at the University of Florida following a 2-mo history of anorexia, intermittent regurgitation, decreased fecal production, and positive buoyancy of the right side. Radiographs confirmed gaseous distension of bowel loops suggestive of intestinal obstruction. The coelom was surgically approached through a plastron osteotomy, and a 540° volvulus of the small intestine was identified and derotated. An intestinal stricture was present at the site of the volvulus, and segments of bowel orad to the stricture were greatly distended. Following resection of abnormal bowel, the osteotomy was stabilized using self-tapping screws and figure-eight wire, and the defect was sealed with fiberglass cloth and fast-drying epoxy resin. A leiomyoma associated with the focal stricture was identified by histology. Appetite and defecation returned to normal. Six months after surgery, the turtle had regained normal buoyancy and showed no further clinical signs of gastrointestinal obstruction.

A REVIEW OF SOME OF THE HEALTH ISSUES OF CAPTIVE BLACK RHINOCEROSES (DICEROS BICORNIS)

Abstract In captivity, black rhinoceroses (Diceros bicornis) are beset by many disease syndromes not described in black rhinoceroses in the wild. Hemolytic anemia, hepatopathy, and ulcerative dermatopathy that lead to increased morbidity and mortality characterize these syndromes. It is uncertain whether these are separate disease syndromes with different etiologies or the same disease with different manifestations. This article offers a brief review of some of the health issues of concern for the captive black rhinoceros population and proposes some possible avenues of research for consideration.

Echocardiographic Parameters of Captive Western Lowland Gorillas (Gorilla gorilla gorilla)

Abstract: A total of 163 echocardiographic studies on western lowland gorillas (Gorilla gorilla gorilla) were submitted for evaluation; 140 from 99 animals were suitable for analysis. Of these, 81 studies (42 studies from 35 males ranging in age from 11–41+ yr and 39 studies from 31 females ranging in age from 11–41+ yr) are reported here. Three studies from 3 females and 56 studies from 30 males were excluded from this report due to cardiac abnormalities. Cardiac parameters measured were aortic root (Ao Rt) diameter and left atrial (L atrium) size. Left ventricular (LV) measurements included left ventricular internal diameter in systole (LVIDs) and diastole (LVIDd) as well as diastolic septal (IVS) and posterior wall thickness (LVPW). Values considered to be normal in females >11 yr of age were: Ao Rt < 3.5 cm, L atrium < 4.0 cm, LVIDd < 5.0 cm, IVS < 1.4 cm, LVPW < 1.4 cm, and ejection fraction (EF) >60%. The data from male gorillas show a separation in animals based on three cardiac parameters: systolic function, LV cavity size, and LV wall thickness. Male gorillas >11 yr of age fall into two groups; unaffected and affected. Unaffected animals are defined as those with no echocardiographic abnormalities and a consistent Ao Rt of <4.0 cm, LVIDd of <6.0 cm, IVS and LVPW of <1.5 cm, and an EF of >58%. The affected group consisted of male gorillas that exhibited changes in echocardiographic parameters representing the presence of cardiovascular disease. The results determined in this database, gathered from data collected from 1999–2009, suggest a sex-based difference between males and females with predominantly males demonstrating evidence of cardiac disease. The most striking finding seen in this study is that of progressive LV hypertrophy and depressed LV EF in affected adult male gorillas.

RISK FACTORS ASSOCIATED WITH A SKEWED NATAL SEX RATIO IN CAPTIVE BLACK RHINOCEROSES (DICEROS BICORNIS) IN THE UNITED STATES

Abstract The skew toward males in the sex ratio of calves is considered to be a problem for the captive population of black rhinoceroses (Diceros bicornis) in North America. This study used a retrospective case-control design to determine whether there was a predisposition toward birth of male calves over female calves and to examine risk factors associated with the occurrence of any detected skewed natal sex ratio in captive black rhinoceroses in the United States. The study population included captive female black rhinoceroses housed in the United States that had given birth to at least one calf of known sex. This study confirmed a skewing of the natal sex ratio toward male calves in the captive black rhinoceros population. The skewed ratio was found in calves born to wild-born dams, for which an increased time in captivity, irrespective of age, was associated with an increased likelihood of a male calf. Dams between 12 and 19 yr of age had a decreased likelihood of a male calf. The data also suggested a possible trend for the southern subspecies of black rhinoceros (Diceros bicornis minor) to be more likely to produce male calves than the eastern subspecies (Diceros bicornis michaeli). No associations were found with the sex of offspring in captive-born dams; however, this lack of association could be a result of low power in the study.

A Survey of Husbandry Practices for Lorisid Primates in North American Zoos and Related Facilities

Zoos and related facilities in North America currently manage five species in the primate family Lorisidae: the greater (Nycticebus coucang), Bengal (N. bengalensis) and pygmy (N. pygmaeus) slow lorises, red slender loris (Loris tardigradus), and potto (Perodicticus potto). We used an online survey to describe institutional housing and husbandry practices for these species and assess the extent to which practices are consistent with established guidelines. Our results show that most captive lorisids are housed solitarily or in pairs. Most individuals occupy a single exhibit space in a building dedicated to nocturnal animals. Facilities are commonly meeting recommendations for abiotic exhibit design and are providing animals with an enriched environment. However, pottos and slender lorises currently occupy exhibit spaces smaller than the recommended minimum, and the impact of cleaning protocols on olfactory communication should be critically evaluated. Few facilities are taking advantage of the benefits of positive reinforcement training for promoting animal welfare. Research is greatly needed on the effects of exhibit lighting on behavior, health, and reproduction; and to determine how best to manage the social needs of lorisids with naturally dispersed social structures. Although captive populations of slender lorises, pottos, and slow lorises are declining, we suggest that improved husbandry knowledge has the potential to positively influence population sustainability and to enhance future efforts to manage the growing pygmy loris population.

Implementing a low-starch biscuit-free diet in zoo gorillas: The impact on behavior: Behavioral Effect of a Diet on Gorillas

In the wild, western lowland gorillas travel long distances while foraging and consume a diet high in fiber and low in caloric density. In contrast, gorillas in zoos typically consume a diet that is low in fiber and calorically dense. Some items commonly used in captive gorilla diets contain high levels of starch and sugars, which are present at low levels in the natural diet of gorillas. Diet items high in simple carbohydrates are associated with obesity and heart disease in humans. Typical captive gorilla diets may also encourage undesirable behaviors. In response to these issues, we tested the behavioral impact of a diet that was biscuit-free, had low caloric density, and which was higher in volume at five institutions. We hypothesized that this diet change would reduce abnormal behaviors such as regurgitation and reingestion (R/R), decrease time spent inactive, and increase time spent feeding. The biscuit-free diet significantly reduced (and in the case of one zoo eliminated) R/R and may have reduced hair-plucking behavior. However, an increase in coprophagy was observed in many individuals following the diet change. The experimental diet caused a general increase in time the gorillas spent feeding, but this increase did not occur across all institutions and varied by individual. Interestingly, the overall time gorillas spent inactive actually increased with this diet change. Future research will examine these behavioral changes in a greater number of individuals to determine if the results remain consistent with these preliminary findings. Additionally, future research will examine the physiological impact of this diet change.

Canine distemper virus infection in binturongs (Arctictis binturong).

prehensile tail. 14 Reports of susceptibility of the binturong to canine distemper are based on clinical observations, but there has been no recovery of the virus or histopathologic documentation of infection. 2 This report documents the light microscopic, ultrastructural, and immunohistochemical findings of canine distemper in binturongs. Four males (ages 1, 2.5, 2, and 7 years) of 7 binturong in a private collection exhibited clinical signs of anorexia and lethargy for 2 weeks and then died. Initially, the binturong passed blood and mucus in feces, followed by mucoid discharge from the eyes and nose. Footpads of all affected animals were thickened. The referring veterinarian treated the affected animals symptomatically. None of the binturong in the collection had been vaccinated for canine distemper. Serum from 1 of the affected animals that had been collected and banked prior to the time of illness was submitted for evaluation of the canine distemper virus (CDV) antibody titer. a

A POTENTIAL LINK BETWEEN INSULIN RESISTANCE AND IRON OVERLOAD DISORDER IN BROWSING RHINOCEROSES INVESTIGATED THROUGH THE USE OF AN EQUINE MODEL

Iron overload disorder afflicts captive rhinoceros but has not been documented in the wild. The specific cause for the disorder has not been identified but is likely associated with diet and management. Compared with wild counterparts, captive rhinoceros eat diets containing more iron, have greater fat stores, and exercise less. It has been suggested that the problem may be linked to development of insulin resistance in the captive population. Given that controlled experiments with sufficient numbers of rhinoceros are logistically not possible, an equine model was used to look for a relationship between iron status and insulin resistance; the nutritional requirements of horses are used as a guide for rhinoceros, because they have similar gastrointestinal tracts. Sixteen horses were tested to determine blood insulin responses to an oral drench of dextrose (0.25 g/kg bodyweight) and a meal of pelleted corn (1.5 g/kg bodyweight). Fasting blood samples were taken 30 and 0 min before administration. Further blood samples were taken every 30 min for 4 hr after administration to determine peak insulin and total area under the insulin curve (AUC). Fasting samples were tested for serum ferritin concentrations. Correlations were determined between ferritin and peak insulin concentrations and insulin AUC after administration of oral dextrose and pelleted corn. The strongest correlation was between ferritin and insulin AUC after dextrose administration (r = 0.61; P = 0.01) followed by AUC after feeding a meal of pelleted corn (r = 0.60; P = 0.01), with the correlation for peak insulin being 0.53 (P = 0.03) after dextrose administration and 0.56 (P = 0.02) after pelleted corn. When evaluating responses by gender, a significant correlation existed only for females, influenced by one insulin resistant individual. These data suggest a potential link between insulin resistance and body stores of iron and also suggest that approaches to reduce the susceptibility to insulin resistance should be incorporated into management of captive browsing rhinoceros.

A Survey of Diabetes Prevalence in Zoo‐housed Primates

In humans, type II diabetes mellitus is a condition in which the pancreas is capable of producing insulin but cells do not appropriately respond to insulin with an uptake of glucose. While multiple factors are associated with type II diabetes in humans, a high calorie diet and limited exercise are significant risk factors for the development of this disease. Zoo primates, with relatively high caloric density diets and sedentary lifestyles, may experience similar conditions that could predispose them to the development of diabetes. We surveyed all Association of Zoos and Aquariums (AZA) facilities with primates in their collections to determine the prevalence of diabetes, diagnosis and treatment methods, and treatment outcomes. Nearly 30% of responding institutions reported at least one diabetic primate in their current collection. Although the majority of reported cases were in Old World Monkeys (51%), all major taxonomic groups were represented. Females represented nearly 80% of the diagnosed cases. A wide variety of diagnosing, monitoring, and treatment techniques were reported. It is clear from these results diabetes should be considered prominently in decisions relating to diet, weight and activity levels in zoo-housed primates, as well as discussions surrounding animal health and welfare.