Serum biochemistry of captive and free-ranging gray wolves (Canis lupus).

Normal serum biochemistry values are frequently obtained from studies of captive sedentary (zoo) or free-ranging (wild) animals. It is frequently assumed that values obtained from these two populations are directly referable to each other. We tested this assumption using 20 captive gray wolves (Canis lupus) in Minnesota, USA, and 11 free-ranging gray wolves in Alaska, USA. Free-ranging wolves had significantly (P < 0.05) lower sodium, chloride, and creatinine concentrations and significantly higher potassium and blood urea nitrogen (BUN) concentrations; BUN to creatinine ratios; and alanine aminotransferase, aspartate aminotransferase, and creatine kinase activities relative to captive wolves. Corticosteroid-induced alkaline phosphatase activity (a marker of stress in domestic dogs) was detected in 3 of 11 free-ranging wolves and in 0 of 20 captive wolves (P = 0.037). This study provides clear evidence that serum biochemical differences can exist between captive and free-ranging populations of one species. Accordingly, evaluation of the health status of an animal should incorporate an understanding of the potential confounding effect that nutrition, activity level, and environmental stress could have on the factor(s) being measured.     

Antibody response to rabies vaccination in captive and free-ranging wolves (Canis lupus).

Fourteen captive and five free-ranging Minnesota gray wolves (Canis lupus) were tested for the presence of rabies virus neutralizing antibodies (RVNA) after vaccination with an inactivated canine rabies vaccine. Blood was collected from all wolves prior to vaccination and at 1 mo postvaccination (PV) and from all captive and three wild wolves at 3 mo PV. In addition, one free-ranging wolf was sampled at 4 mo PV, and two free-ranging wolves were sampled at 6 mo PV. All wolves were seronegative prior to vaccination. RVNA were detected in 14 (100%) captive wolves and in four of five (80%) free-ranging wolves. The geometric mean titer of the captive wolves at 1 mo PV was significantly higher (P = 0.023) than in the free-ranging wolves. Five of 13 (38.5%) captive wolves and none of the three (0%) free-ranging wolves had measurable RVNA at 3 mo PV. No measurable RVNA were detected in the serum samples collected from the free-ranging wolves at 4 and 6 mo PV. These results should be interpreted with caution because of the small number of free-ranging wolves tested. Further research is needed to properly assess immune function and antibody response to vaccination in captive wolves in comparison with their free-ranging counterparts.     

Hematology and serum clinical chemistry reference intervals for free‐ranging Scandinavian gray wolves (Canis lupus)

Background: Scandinavian free‐ranging wolves (Canis lupus) are endangered, such that laboratory data to assess their health status is increasingly important. Although wolves have been studied for decades, most biological information comes from captive animals. Objectives: The objective of the present study was to establish reference intervals for 30 clinical chemical and 8 hematologic analytes in Scandinavian free‐ranging wolves. Methods: All wolves were tracked and chemically immobilized from a helicopter before examination and blood sampling in the winter of 7 consecutive years (1998–2004). Seventy‐nine blood samples were collected from 57 gray wolves, including 24 juveniles (24 samples), 17 adult females (25 samples), and 16 adult males (30 samples). Whole blood and serum samples were stored at refrigeration temperature for 1–3 days before hematologic analyses and for 1–5 days before serum biochemical analyses. Reference intervals were calculated as 95% confidence intervals except for juveniles where the minimum and maximum values were used. Results: Significant differences were observed between adult and juvenile wolves for RBC parameters, alkaline phosphatase and amylase activities, and total protein, albumin, γ‐globulins, cholesterol, creatinine, calcium, chloride, magnesium, phosphate, and sodium concentrations. Conclusion: Compared with published reference values for captive wolves, reference intervals for free‐ranging wolves reflected exercise activity associated with capture (higher creatine kinase activity, higher glucose concentration), and differences in nutritional status (higher urea concentration).     

Clinical feasibility of cognitive testing in dogs (Canis lupus familiaris)

Several cognitive tests have been developed to evaluate specific aspects of human and animal learning and memory. These tests have been used for early detection of cognitive deficits and to monitor the treatment of dogs with cognitive impairment. Thus, this article evaluated the feasibility of cognitive tests for use in canine neurology clinical routines and the suitability of the different tests to accomplish this aim. Fifteen healthy adult dogs were used for the cognitive tests of reward approach learning, object approach learning, object discrimination learning, reversal learning, delayed non-matched to position, and delayed non-matched to sample to assess different aspects of memory. No difference was observed between tests of delayed non-matched to position (3.13 ± 2.23 days) and delayed non-matched to sample (3.20 ± 2.40 days) (P = 0.944). However, dogs had greater difficulty in reversal learning (8.47 ± 2.61 days) than in object discrimination learning (4.60 ± 1.64 days) (P ≤ 0.001). Based on the tests performed, the delayed non-matched to position test may be performed in clinical routine if the owner and the veterinarian have time available, because this test is sensitive to evaluate dogs with cognitive impairments, but requires approximately 10 days of training. Thus, elderly dogs are excellent experimental models to study pathological aging based on their similarities with some human brain diseases, such as Alzheimer disease.     

M-mode,two-dimensional and Doppler echocardiographic findings in 40 healthy domestic pet rabbits

ObjectivesThe aim of the study was to report normal two-dimensional, M-mode, and Doppler echocardiographic findings from a large cohort of healthy, manually restrained, adult pet rabbits.Animals and methodsForty healthy pet rabbits [22 Dwarf Lops (DL), 14 French Lops (FL) and 4 Alaskan (AL)] underwent a full physical examination and conscious two-dimensional, M-mode, and Doppler echocardiography.ResultsThe median age of the rabbits was 21.5 months, the median weight was 2.9 kg (DL: 2.4 kg, AL: 4.35 kg, FL: 6.0 kg). Echocardiography with ECG monitoring was feasible in all rabbits. Left atrial and ventricular dimensions were significantly larger in FL as compared to DL; overall, a positive correlation with weight was present. No significant differences between breeds were identified for flow velocities. Trace regurgitation was detected at the aortic valve in 7/40 (17.5%) rabbits, at the tricuspid valve in 5/40 (12.5%) and at the pulmonic valve in 1/40 (2.5%) rabbits. Mitral inflow E and A waves were summated in 60% of cases.ConclusionsThe results of this study can be used as echocardiographic values in FL and DL for comparison with clinical cases, and may also be applicable for other breeds of similar sizes. Breed specific values should be used when measuring left atrial and ventricular sizes. However, no breed or size differences were found for the rest of the echocardiographic parameters, which may therefore be applicable for the general pet rabbit population.     

Cardiorespiratory effects of medetomidine-butorphanol, medetomidine-butorphanol-diazepam, and medetomidine-butorphanol-ketamine in captive red wolves (Canis rufus).

Safe, effective, and reversible immobilization protocols are essential for the management of free-ranging red wolves (Canis rufus). Combinations using an alpha2-adrenoceptor agonist and ketamine have been shown to be effective for immobilization but are not reversible and can produce severe hypertension and prolonged or rough recoveries. To minimize hypertension and provide reversibility, 24 red wolves were immobilized using three medetomidine-butorphanol (MB) combinations without the use of ketamine in the initial injection. All wolves were administered medetomidine (0.04 mg/kg i.m.) and butorphanol (0.4 mg/kg i.m.). Seven wolves received no other immobilization agents (MB wolves), nine received diazepam (0.2 mg/kg i.v.) at the time they were instrumented (MBD wolves), and eight received ketamine (1 mg/kg i.v.) 30 min after instrumentation (MBK30 wolves). Physiologic parameters were monitored during immobilization. The heart rate was similar among the three groups for the first 30 min, and marked bradycardia was noted in one wolf from each group. Hypertension was observed initially in all three groups but was resolved within 10-30 min. The MBK30 wolves had significant elevations in heart rate and transient hypertension after intravenous ketamine administration. Most wolves had mild to moderate metabolic acidemia. Immobilizing drugs were antagonized in all wolves with atipamezole (0.2 mg/kg i.m.) and naloxone (0.02 mg/kg i.m.). The medetomidine-butorphanol-diazepam wolves were also given flumazenil (0.04 mg/kg i.v.). All wolves were standing within 12 min and were fully recovered within 17 min. Medetomamine-butorphanol and MBD combinations provided effective and reversible immobilization of red wolves without the sustained hypertension associated with the use of alpha2-adrenoceptor agonist-ketamine combinations. Delaying the administration of ketamine reduced its hypertensive effects.     

Survey of necropsy results in captive red wolves (Canis rufus), 1992-1996.

Through the Red Wolf Species Survival Plan, the captive red wolf (Canis rufus) population was developed with the intent of reestablishing wild populations. One part of the plan was a survey for diseases that might occur as a result of population homogeneity or that might impede breeding success and reintroduction. For this survey, complete necropsies and histopathologic analyses were performed on 62 red wolves from 1992 to 1996. Major causes of 22 neonatal deaths were parental trauma, parasitic pneumonia, and septicemia. Common neonatal lesions included pododermatitis and systemic ascariasis. Cardiovascular anomalies and systemic parasitism were found in two juveniles. Causes of death in the 38 adults included conspecific trauma, neoplasia, or gastrointestinal diseases such as necrotizing enteritis, intestinal perforation, and gastric volvulus. Lymphosarcoma represented 50% of the fatal neoplasms. Three adults died from cardiovascular failure or hyperthermia during handling, and several adults were euthanized for suspected genetic diseases. Overall, the captive population had few significant health problems, but population fitness might be improved by continued removal of potentially deleterious genes from the breeding population and by modifying the husbandry of neonates and adults.     

Gray wolf (Canis lupus) is a natural definitive host for Neospora caninum

The gray wolf (Canis lupus) was found to be a new natural definitive host for Neospora caninum. Neospora-like oocysts were found microscopically in the feces of three of 73 wolves from Minnesota examined at necropsy. N. caninum-specific DNA was amplified from the oocysts of all three wolves. Oocysts from one wolf were infective for the gamma interferon gene knock out (KO) mice. Viable N. caninum (designated NcWolfUS1) was isolated in cell cultures seeded with tissue homogenate from the infected mouse. Typical thick walled tissue cysts were found in outbred mice inoculated with the parasite from the KO mouse. Tissue stages in mice stained positively with N. caninum-specific polyclonal antibodies. Our observation suggests that wolves may be an important link in the sylvatic cycle of N. caninum.     

Echocardiographic findings in a dog with vegetative bacterial endocarditis (Case report)

Definitive diagnosis of mitral and aortic valvular endocarditis in a dog was based on echocardiograpic findings and was then confirmed by positive blood culture. Abdominal ultrasound examination revealed a renal abcess. This case illustrates that echocardiography associated with abdominal ultrasound has become an essential tool for the diagnosis of bacterial endocarditis and for the detection of sequela or initial source of bacteriemia, while waiting for blood culture results. A short review of echocardiographic and Doppler abnormalities associated with bacterial endocarditis is presented.     

Echocardiographic and radiographic findings in a cohort of healthy adult green iguanas (Iguana iguana)

ObjectivesTo describe characteristics of echocardiography and cranial coelomic radiography in a cohort of iguanas.AnimalsTwenty apparently healthy adult green iguanas (Iguana iguana) from a reptile sanctuary.MethodsPhysical examination, radiography, two-dimensional and color Doppler echocardiography were performed to assess cardiac structures and function, and any related normal or abnormal findings were recorded.ResultsEchocardiographic examination was possible without sedation and allowed visualization of the great vessels, atria, and ventricle. Some structures could not be evaluated in a minority of the iguanas due to individual differences in bony conformation and imaging quality. Suspected abnormal echocardiographic findings in 3 iguanas included pericardial effusion (n = 1) and enlarged caudal vena cava and/or sinus venosus (n = 2). Objective measurements were repeatable as assessed by within-subject coefficient of variation, and reliable as assessed by intra-observer intraclass correlation coefficient. Left atrial and ventricular measurements were significantly correlated with body weight. Valve regurgitation was common, with atrioventricular valve regurgitation present in 53% (9/17) and aortic or pulmonic valve regurgitation in 71% (12/17) of otherwise normal iguanas. A heart murmur was not appreciated during examination of any of the iguanas. Heart size cannot be measured radiographically due to superimposition and silhouetting of other coelomic structures. Echocardiographic or radiographic findings consistent with mineralization of the great vessels were present in 76% of iguanas (13/17).ConclusionsEchocardiography in iguanas is well tolerated without sedation and allowed both subjective evaluation and structural measurements. Valve regurgitation and great vessel mineralization were commonly observed in this cohort of apparently healthy adult iguanas.     

Das Blutgefäßsystem des Enddarms vom Hund (Canis lupus f. familiaris)

The Vascular System in the Large Intestine of Dog (Canis lupus f. familiaris) The vascular System of the large intestine of 10 dogs was examined by means of vascular corrosion casts, histology and transmission-electron microscopy. The tela submucosa contains an arterial and a venous vascular plexus. In broader areas of the submucosa, a deep and a superficial vascular plexus, which are interconnected, can be found. The plexus are orientated parallel to the layers of the intestinal wall. On the one hand, these vessels naturally provide self-sufficiency and drainage of the submucosa, and, moreover, direct branches to the stratum circulare of the muscular layer. On the other hand, the submucosal vascular plexus is the ‘distributional network’ for the functional plexus of the tunica mucosa. The arteries, which ascend to the tunica mucosa, supply a flat arterial network underneath the intestinal glands. Bundles of only a few arteriolae originate from this in order to supply the pericryptal capillaries. In the vicinity of the cryptai orifices, these turn into a network of subepithelial capillaries, which is post-connected to the periglandular capillary plexus. From this ‘terminal circulatory pathway’, the blood is drained off by veins that enter the submucosal plexus. It is characteristic that the postcapillary venules often begin as part of the capillary network. As in other species, the subepithelial capillaries are predominantly lined with a ‘fenestrated endothelium’, whereas the capillaries of the pericryptal areas show a continuous endothelium. The latter contains multiple vesicles that may fuse in order to form transcytoplasmic channels as a morphological equivalent for transcappillar-epithelial and vice versa occurring transport of substances.     

Echocardiographic findings in 103 cats with hyperthyroidism

Using M-mode echocardiography, cardiac abnormalities were studied in 103 cats with untreated hyperthyroidism. In addition, follow-up echocardiography was performed on 24 of these cats to assess the long-term (4 to 21 months) effect of treatment (thyroidectomy or radioiodine) on thyrotoxic cardiac disease. The most common echocardiographic abnormality in the 103 untreated hyperthyroid cats was hypertrophy of the left ventricular caudal wall (71.9%). Hypertrophy of the interventricular septum also was documented in 39.8% of the 103 cats. Other abnormalities included high values for left atrial diameter (70.0%), aortic root diameter (18.5%), and left ventricular diameter at end diastole (45.6%). In some of these cats, indices of contractility were enhanced; in 21.4% and 14.6% of the cats, values for shortening fraction and velocity of circumferential fiber shortening, respectively, were greater than those values measured in clinically normal cats. After treatment of the hyperthyroidism, left ventricular hypertrophy resolved or improved in many of the cats, as indicated by decreases in left ventricular caudal wall and interventricular septum thicknesses. Hyperdynamic wall motion resolved in all cats after treatment, as evidenced by consistent decreases in shortening fraction and velocity of circumferential fiber shortening. Despite these improvements, some cats had one or more persistently abnormal echocardiographic values after treatment. These results suggested that in cats, hyperthyroidism commonly is associated with largely reversible cardiomyopathy. In those cats in which cardiomyopathy persists or worsens after treatment, underlying primary cardiomyopathy or thyroid hormone-induced cardiac structural damage may exist.