Brood parasitism and host-parasite relationships: Cuckoos adapt to reduce the time of hatching ahead of host nestlings by increasing egg thickness.

The phenomenon of cuckoos' brood parasitism is well known and can be investigated using applied mathematical techniques. Among adaptive features of this phenomenon are certain egg parameters that ensure their shortened incubation period (I) and thus the successful survival of their offspring. In particular, the volume of a cuckoo egg is not less than, or exceeds, that of the host species, which should, in theory, increase I. Also, cuckoo eggs have thicker shell than that of nest hosts. Here, we analyzed the available geometric dimensions of eggs in 447 species and found an inverse correlation (-0.585, p < 0.05) between I and the shell thickness-to-egg surface area ratio (T/S). A mathematical relationship was derived to calculate I depending on T/S. This premise was confirmed by comparative calculations using egg images of two parasitic species, common (Cuculus canorus) and plaintive cuckoo (Cacomantis merulinus) and their hosts: great reed warbler (Acrocephalus arundinaceus), European robin (Erithacus rubecula), rufescent prinia (Prinia rufescens), and common tailorbird (Orthotomus sutorius). An average calculated I value for cuckoo eggs was one day less than that for host eggs. Our findings unravel additional details of how cuckoos adapt to brood parasitism and specific host-parasite relationships.

TERBINAFINE PHARMACOKINETICS FOLLOWING SINGLE-DOSE ORAL ADMINISTRATION IN RED-EARED SLIDER TURTLES (TRACHEMYS SCRIPTA ELEGANS): A PILOT STUDY.

In this pilot study, the pharmacokinetics of terbinafine were determined in six apparently healthy red-eared slider turtles (Trachemys scripta elegans) after a single PO administration. Terbinafine suspension (15 mg/kg, once) was administered via gavage tube to all turtles. Blood samples were collected immediately before (time 0) and at 1, 2, 4, 8, 24, and 48 h after drug administration. Plasma terbinafine concentrations were quantified by ultra-performance liquid chromatography-mass spectrometry, and noncompartmental pharmacokinetic analysis was performed. None of the animals showed any adverse responses following terbinafine administration. Mean area under the curve from time 0 to 24 h was 1,213 h × ng/ml (range 319-7,309), mean peak plasma concentration was 201.5 ng/ml (range 45.8-585.3), mean time to maximum plasma concentration was 1.26 h (range 1-4), mean residence time was 7.71 h (range 3.85-14.8), and mean terminal half-life was 5.35 h (range 2.67-9.83). The administration of terbinafine (15 mg/kg, PO) may be appropriate for treatment of select fungal organisms with low minimum inhibitory concentrations in red-eared slider turtles but may require q12h administration even for organisms with low minimum inhibitory concentrations. Multiple-dose studies as well as clinical studies are needed to determine ideal dosages and efficacy.

Treatment with chloroquine is retinotoxic in captive African penguins (Speniscus demersus). Attenuation and recovery of electroretinographic responses.

PURPOSE: To evaluate the effect of prophylactic anti-malarial chloroquine treatment, and its cessation, on electroretinographic (ERG) responses of captive African penguins. METHODS: A brief ERG protocol ("QuickRetCheck") was recorded under mesopic conditions with manual restraint and no sedation or pupil dilation. Birds were recorded on two separate occasions, first while being treated with a daily chloroquine dose of 10 mg/kg for 12 days (n = 15, treatment group) and second after 4 months without chloroquine treatment (n = 6, off-treatment group). Three birds were recorded on both occasions. Three other birds from the flock that died were studied histopathologically. RESULTS: Scotopic responses were unmeasurable in either recording and therefore were not analyzed. Mean a- and b-wave amplitudes of the mixed rod-cone responses to standard (3 cd·s/m2 ) and high (10 cd·s/m2 ) intensity flashes were higher in the off-treatment group. No difference in implicit times was observed. Sex, age, and number of previous chloroquine treatments did not affect ERG responses. Histopathology revealed Plasmodium spp.in the lungs, liver, and brain, but not in the eyes, of the necropsied birds, and there were no signs of retinitis or retinopathy. CONCLUSIONS: Daily chloroquine treatment was associated with attenuated ERG responses in penguins, which improve following cessation of treatment. Further work is warranted to establish a chloroquine dose that is efficacious yet has minimal adverse effects. Our results suggest that ERG responses of captive penguins undergoing ERG for any indication (such as prior to cataract surgery), must be evaluated in light of the birds' anti-malaria treatment status.

Immobilization of captive Persian fallow deer (Dama dama mesopotamica) using medetomidine-ketamine or medetomidine-midazolam.

OBJECTIVE: To establish and compare the effectiveness of two medetomidine-based immobilization protocols in Persian fallow deer (Dama dama mesopotamica). STUDY DESIGN: Prospective, randomized, blinded clinical study. ANIMALS: A group of 31 captive Persian fallow deer. METHODS: Deer scheduled for translocation were immobilized with a combination of medetomidine (76 ± 11 µg kg-1) and ketamine (1.0 ± 0.2 mg kg-1) (MK; n = 15) or medetomidine (77 ± 11 µg kg-1) and midazolam (0.10 ± 0.01 mg kg-1) (MM; n = 16) administered intramuscularly. An observer unaware of group assignments recorded times to immobilization and recovery, monitored physiologic variables and scored the quality of induction, immobilization and recovery (scale 1-5: 1, poor; 5, excellent). Atipamezole was administered for reversal. Data analysis was performed using the t test, the Mann-Whitney U test, the chi-square test and the Fisher's exact test. Significance was set at p < 0.05. RESULTS: Data are presented as mean ± standard deviation or median (range). Time to induce immobilization was 9 ± 4 and 10 ± 4 minutes in the MK and MM groups, respectively. Immobilization quality score was 5 (1-5) following both combinations. Hemoglobin oxygen saturation (SpO2) was significantly lower in the MK (80 ± 8%) than in the MM group (87 ± 8%) although respiratory frequency did not differ between MK and MM (11 ± 5 and 10 ± 2 breaths minute-1, respectively). Recovery times were 13 ± 6 (MK) and 14 ± 7 minutes (MM) and did not differ between groups. No morbidities or mortalities were recorded during 1 month after immobilization. CONCLUSIONS AND CLINICAL RELEVANCE: The MK and MM combinations produced sufficient immobilization in captive Persian fallow deer for short nonpainful procedures. Based on the SpO2 values, the MM combination may be associated with less respiratory depression; nevertheless, both combinations may result in a decrease in SpO2.

Pathological and molecular characterisation of peste des petits ruminants in Nubian ibex (Capra nubiana) in Israel.

Peste des petits ruminants (PPR) is a devastating disease that generally affects sheep and goats, mostly in Asia, the Middle East and Africa. The disease has been declared a target for global eradication. Despite its high prevalence in domestic flocks and its high seroprevalence among wildlife, it is rarely reported as a fulminant disease in wild ruminant species (with the exception of Central Asia). In this report, we describe a severe PPR outbreak in a zoo herd of Nubian ibex (Capra nubiana), causing the deaths of 2/3 of the herd. The clinical onset was acute with morbid animals exhibiting lethargy and watery-to-bloody diarrhea and death usually within 48 h. The most consistent gross pathologic findings were hemorrhagic abomasitis and enteritis. Oral lesions and pulmonary lesions were rare. Histology revealed necrohemorrhagic enteritis and abomasitis with myriad nuclear and cytoplasmic viral inclusion bodies. Molecular examinations confirmed the diagnosis of PPR and determined that the causative agent belongs to lineage IV. Further molecular examination showed that the virus belongs to the Asian clade of lineage IV and is closely related to a virus described in Turkey.

Effects of time and storage temperature on selected biochemical analytes in plasma of red-eared sliders (Trachemys scripta elegans).

OBJECTIVE To investigate effects of storage duration and temperature on biochemical analytes in plasma from red-eared sliders (Trachemys scripta elegans). ANIMALS 8 red-eared sliders. PROCEDURES Blood samples were collected. Plasma was harvested and analyzed at room temperature (approx 23°C; time = 1 hour) and then fractioned into 0.1-mL aliquots that were stored at room temperature or were refrigerated (4°C) or frozen (-20°C). Biochemical analysis of stored samples was performed at 4 (room temperature), 8 (4°C), 24 (4°C), 48 (4° and -20°C), and 72 (-20°C) hours and at 7 days (-20°C). For each time point for each storage temperature, bias was calculated by subtracting values from the value obtained at 1 hour. Bias was modeled by use of a linear mixed model. RESULTS Storage temperature had a significant effect on several plasma biochemical analytes. In general, aspartate aminotransferase activity and uric acid, total protein, and potassium concentrations increased after storage at 4° and -20°C. Differences in values after storage were mostly within the acceptable range for allowable total error, except for calcium and potassium concentrations for samples stored at -20°C. Both storage temperatures increased variability of measurement results. Results for samples stored at room temperature for 4 hours did not differ significantly from values at 1 hour. Results differed significantly between refrigerated and frozen samples stored for 48 hours. CONCLUSIONS AND CLINICAL RELEVANCE Short-term storage conditions influenced results for some biochemical analytes. These effects should be considered when performing biochemical analyses of plasma samples obtained from red-eared sliders.

Postnatal Exocrine Pancreas Growth by Cellular Hypertrophy Correlates with a Shorter Lifespan in Mammals.

Developmental processes in different mammals are thought to share fundamental cellular mechanisms. We report a dramatic increase in cell size during postnatal pancreas development in rodents, accounting for much of the increase in organ size after birth. Hypertrophy of pancreatic acinar cells involves both higher ploidy and increased biosynthesis per genome copy; is maximal adjacent to islets, suggesting endocrine to exocrine communication; and is partly driven by weaning-related processes. In contrast to the situation in rodents, pancreas cell size in humans remains stable postnatally, indicating organ growth by pure hyperplasia. Pancreatic acinar cell volume varies 9-fold among 24 mammalian species analyzed, and shows a striking inverse correlation with organismal lifespan. We hypothesize that cellular hypertrophy is a strategy for rapid postnatal tissue growth, entailing life-long detrimental effects.

RETROSPECTIVE EVALUATION OF A NOVEL SUSTAINED-RELEASE IVERMECTIN VARNISH FOR TREATMENT OF WOUND MYIASIS IN ZOO-HOUSED ANIMALS.

Myiasis is a major disease condition in human and veterinary medicine. Domestic, free-ranging, and zoo-housed animals can be severely affected by myiasis. Depending on case severity, multiple treatment episodes may be indicated and can lead to recurrent capturing, handling stress, and anesthetics, all of which increase the risk of adverse responses (including death) individually and also in the herd. As an insecticide, ivermectin is often used for larval control. A total of 28 individual myiasis cases were retrospectively evaluated, out of which 11 cases were also treated using an ivermectin sustained-release varnish (SRV). The clinical outcome of all cases was assessed and the results suggest that the use of a topical ivermectin SRV (with or without concurrent injectable ivermectin) can reduce handling and treatments, has no adverse effects, and has minimal recurrence of the disease when compared with cases treated without it.

The retina of the collared peccary (Pecari tajacu): structure and function.

OBJECTIVE: To study retinal morphology and function in the collared peccary, an ungulate species distantly related to the domestic pig. ANIMAL STUDIES: Twenty captive peccaries anesthetized for routine health examinations. Procedures No abnormalities were noted on a complete ophthalmic examination. Fundi were examined ophthalmoscopically and photographed. The eyes of an individual that died of unrelated, nonocular reasons were studied histologically and by immunohistochemistry. Scotopic, mixed rod-cone, and photopic electroretinography (ERG) responses were recorded using the 'QuickRetCheck' (n = 6) and 'Dog diagnostic' (n = 5) protocols of the Handheld Multispecies ERG (HMsERG). RESULTS: The fundus of the peccary is atapetal, with varying amounts of pigmentation seen ophthalmoscopically, and histologically in the retinal pigment epithelium (RPE) and choroid. The retina is holangiotic with dichotomously branching vessels. These cross, and apparently loop on, the optic disk surface, but no venous circle was seen. Immunohistochemistry suggests a high concentration of cone photoreceptors with red/green cones being more abundant than blue cones. Rod ERG responses were very low with no evident dark adaptation. Mixed rod-cone and cone ERG response amplitudes were low compared to those of domestic pigs, but quite similar to those of minipigs. CONCLUSIONS: To the best of our knowledge, this study describes the collared peccary's retinal features for the first time. A comparison of our findings with data from other ungulate species shows some similarities between the peccary and pig retinas. Further studies are warranted to determine whether the peccary can be used alongside the pig as an animal model in retinal studies.

EVALUATION OF THE EFFECTS OF STERNAL VERSUS LATERAL RECUMBENCY ON TRENDS OF SELECTED PHYSIOLOGIC PARAMETERS DURING ISOFLURANE ANESTHESIA IN ZOO-HOUSED BLACK-TAILED PRAIRIE DOGS (CYNOMYS LUDOVICIANUS).

Isoflurane gas anesthesia is often used for immobilization of prairie dogs in field studies, laboratory research, and veterinary clinical purposes. The goals of this prospective study were to evaluate the effects of sternal versus right lateral recumbency on trends of selected physiologic parameters during isoflurane anesthesia in black-tailed prairie dogs ( Cynomys ludovicianus ). Fourteen adult, zoo-housed black-tailed prairie dogs were tested during the study. Animals were anesthetized using isoflurane and randomly placed in either sternal or right lateral recumbency to evaluate changes in trends of physiologic parameters, measured selectively every 30 min throughout a 60-min anesthesia period. Results were analyzed using linear mixed modeling. Right lateral recumbency resulted in a decrease in anion gap of about 4.6 mEq/L (95% confidence interval [95% CI]: 3.1-6.0, P < 0.001), whereas sternal recumbency resulted in a lower decrease of 2.1 mEq/L (95% CI: 0.7-3.6, P = 0.02). However, the absolute values at the beginning and at the end of the anesthesia time were not significantly different between the right lateral and sternal recumbency (all P > 0.57). Body position did not have any effect on any other variables, and most of the observed physiologic changes were due to the duration of anesthesia. Our results indicate no significant effect on trends of selected physiologic parameters between sternal recumbency and right lateral recumbency during 1 hr of isoflurane anesthesia in black-tailed prairie dogs.

SELECTED HEMATOLOGIC AND PLASMA BIOCHEMISTRY ANALYSIS OF FERRUGINOUS DUCKS (AYTHYA NYROCA) IN ISRAEL.

The ferruginous duck (Aythya nyroca) is a medium-sized chestnut-colored diving duck that inhabits wetlands of Europe and Asia. In recent years, this species has been declining throughout much of Europe--a decline that is attributed mainly to destruction of natural habitats, and to hunting and pollution. The ferruginous duck is listed as "near threatened" by the International Union for Conservation of Nature, and as a critically endangered nesting species in Israel. In 2009, a captive-breeding/reintroduction program was established in Israel, aiming to increase the species' population. The objective of this study was to collect data on normal hematology and plasma biochemistry analytes of ferruginous ducks in order to promote the species' conservation. Blood was collected from 49 birds, and 27 analytes were quantified. Compared to most other anseriformes studied, the ferruginous ducks in this study had lower white blood cell counts, which were dominated by heterophils rather than by lymphocytes.

SELECTED PLASMA BIOCHEMISTRY ANALYTES OF HEALTHY CAPTIVE SULCATA (AFRICAN SPURRED) TORTOISES (CENTROCHELYS SULCATA).

The sulcata or African spurred tortoise (Centrochelys sulcata) is a large tortoise species that is commonly kept in zoologic collections and as a pet. The objectives of this study were to establish reference intervals for selected biochemical analytes in clinically healthy captive sulcata tortoises and to evaluate the impact of blood sampling site and sex. Blood samples were collected from 60 tortoises from either the dorsal coccygeal (tail) vein or the subcarapacial venous plexus based on their body size. The packed cell volume and refractometric total solids (TS) were determined. The concentrations of selected plasma biochemical analytes were determined using the VetScan VS2 analyzer and included albumin, aspartate aminotransferase, bile acids, calcium, creatine kinase, globulins, glucose, potassium, sodium, phosphorous, total proteins (TP), and uric acid. The calcium-to-phosphorous ratio was calculated. Reference intervals were determined and evaluated for the potential effects of blood sampling site and sex. There were significant differences (P < 0.05) associated with the blood sampling site in TS, TP, phosphorus, and globulins, with higher values in samples from the tail versus the subcarapacial sampling site. No significant statistical differences were noted in the plasma biochemistry analytes between the sexes. Reading of the globulins by the analyzer failed in 36 of 60 of the samples and was largely associated with the subcarapacial plexus sampling site. The reference intervals defined by the VetScan analyzer in this study can be used for clinical medicine and conservation of this tortoise species. Sampling site was identified as a factor significantly affecting some blood analytes in this study; this factor should thus be taken into consideration when assessing sulcata tortoise health status and using this testing methodology.

Hematologic, plasma biochemistry, and acid-base analysis of adult Negev Desert tortoises (Testudo werneri) in Israel.

The Negev Desert tortoise (Testudo werneri) is one of the smallest tortoise species in the Mediterranean region. This is a critically endangered species (CITES I) in its native habitat, which includes the Saharo-Arabian sands of northern Egypt, Sinai, and the Negev Desert in Israel. Great efforts have been invested in captive breeding and reintroduction of this tortoise to the wild. The purpose of this study was to collect blood samples from healthy Negev Desert tortoises kept in well-managed zoologic collections in order to describe hematologic, plasma biochemistry, and acid-base analytes for this species. Data of 36 different blood analytes were collected using the Abaxis Vetscan bench-top analyzer and i-STAT handheld analyzer, and a significant difference was observed between males and females in 13 of the measured analytes. To the authors' knowledge, this is the first report of blood analytes for the Negev Desert tortoise; however, the data do not fully meet the strict ASVCP guidelines required for reference range determination and thus can only provide a rough estimate for evaluating the health status of Negev Desert tortoises using similar testing methodology.

Use of a sustained release chlorhexidine varnish as treatment of oral necrobacillosis in Macropus spp.

Oral necrobacillosis or lumpy jaw is a common cause of morbidity and mortality affecting captive macropods. This article describes several cases of a new treatment regimen using a sustained release chlorhexidine varnish applied locally to the teeth and the gingivae of two Macropus species, eastern grey kangaroos (Macropus gigantus) from Gan-Garoo Australian Park and a red-necked wallaby (Macropus rufogriseus fruticus) from The Tisch Family Zoological Gardens in Jerusalem. The varnish was applied using a horsehair paint brush as three 1- to 2-mm thick layers. The active ingredient in the varnish was the disinfectant chlorhexidine. Results indicated that use of an intraoral sustained release varnish significantly shortens the treatment time and may prevent recurrence.

Use of a sustained release preparation of clotrimazole to treat dermatophytosis in a siamang (Hylobates syndactylus).

In November 2004, an adult male siamang (Hylobates syndactylus) from The Tisch Family Zoological Gardens-Jerusalem Biblical Zoo (Israel) presented with skin lesions on various body parts. Lesions consisted of alopecia and dry, crusty areas of hyperkeratosis. A diagnosis of dermatophytosis due to Microsporum canis was determined by fungal culture of skin scraping taken from the edge of several lesions. Treatment with various oral and topical antifungal agents such as griseofluvin, itraconozole, and lufenuron resulted in the resolution of most lesions and a decrease in size of the single remaining lesion, which continued to be culture positive for M. canis. The animal was anesthetized and an experimental sustained-release clotrimazole varnish was painted directly on the lesion. Initially there was no change in the lesion, and 2 months later a slightly altered formula was applied under anesthesia. One month later, the lesion began to reduce in size; 3 months after the start of treatment, although 2 years after the onset of clinical signs, the lesion resolved. Minimizing the number of treatments is always an advantage when dealing with exotic animals or zoological collections.