Within-day and between-day variability of transthoracic anatomic M-mode echocardiography in the awake bottlenose dolphin (Tursiops truncatus)

The use of transthoracic echocardiography in dolphins has been limited so far owing to technical and anatomical specificities. Anatomic M-mode (AMM) is a postprocessing echocardiographic technique generating M-mode studies from two-dimensional (2D) cineloops independently of the ultrasound beam orientation. The aim of the present study was to determine the within-day (repeatability) and between-day (reproducibility) variability of AMM echocardiography in awake healthy bottlenose dolphins (BN, Tursiops truncatus). Four adult BN trained to lie in left recumbency at the water surface were involved in the protocol. A total of 96 echocardiographic examinations were performed on 4 different days by a trained observer examining each BN 6 times per day. Video clips of 2D left parasternal long-axis views showing the left ventricle (LV) ventrally and the aortic root dorsally were recorded at each examination and analyzed for AMM measurements in a random order. A general linear model was used to determine the within-day and between-day coefficients of variation (CV). All examinations were interpretable allowing calculation of 10 AMM variables (i.e., end-diastolic and end-systolic ventral and dorsal LV myocardial wall thicknesses as well as LV and aortic diameters, mean aortic diameter, and LV shortening fraction). Most within- and between-day CV values (18/20) were <15%, the lowest being observed for the end-diastolic LV diameter (1.6%). In conclusion, AMM provides a simple non-invasive evaluation of heart morphology and function in the awake BN with good repeatability and reproducibility of the measurements. Further studies are required to determine the corresponding reference intervals.     

Creatinine in the dog: a review

Creatinine is the analyte most frequently measured in human and veterinary clinical chemistry laboratories as an indirect measure of glomerular filtration rate (GFR). Although creatinine metabolism and the difficulties of creatinine measurement have been reviewed in human medicine, similar reviews are lacking in veterinary medicine. The aim of this review is to summarize information and data about creatinine metabolism, measurement, and diagnostic significance in the dog. Plasma creatinine originates from the degradation of creatine and creatine phosphate, which are present mainly in muscle and in food. Creatinine is cleared by glomerular filtration with negligible renal secretion and extrarenal metabolism, and its clearance is a good estimate of GFR. Plasma and urine creatinine measurements are based on the nonspecific Jaffé reaction or specific enzymatic reactions; lack of assay accuracy precludes proper interlaboratory comparison of results. Preanalytical factors such as age and breed can have an impact on plasma creatinine (P-creatinine) concentration, while many intraindividual factors of variation have little effect. Dehydration and drugs mainly affect P-creatinine concentration in dogs by decreasing GFR. P-creatinine is increased in renal failure, whatever its cause, and correlates with a decrease in GFR according to a curvilinear relationship, such that P-creatinine is insensitive for detecting moderate decreases of GFR or for monitoring progression of GFR in dogs with severely reduced kidney function. Low sensitivity can be obviated by determining endogenous or exogenous clearance rates of creatinine. A technique for determining plasma clearance following IV bolus injection of exogenous creatinine and subsequent serial measurement of P-creatinine does not require urine collection and with additional studies may become an established technique for creatinine clearance in dogs.     

The use of concentrated bovine serum albumin in canines.

In humans it has been estimated that for each 2.5 g L^–1 decrease in serum albumin, risk of death increases by 24–56%. Clinical impression suggests this may be similar in veterinary patients. Species‐specific albumin (plasma) is often unavailable and concentrated solutions are not. Our experience using 25% human serum albumin (HSA) in critically ill dogs suggests a positive effect (results submitted), however it is expensive. Bovine serum albumin (BSA) may be a more cost effective and readily available alternative. The purpose of this study was to assess the immediate and long‐term safety of an intravenous dose (500 mg kg^–1) of bovine albumin administered to healthy dogs. Ten mature dogs (eight males, two females, 28 ± 6 kg) were to receive BSA (250 mg mL^–1) twice (BSA1 and BSA2) with 14 days between treatments. Temperature, blood pressure, and pulse and respiration rate were continuously monitored to identify a reaction to BSA. All dogs received BSA1. One dog immediately developed mild urticaria and pruritus, otherwise the infusion was well tolerated. No immediate reaction was noted in the other nine dogs. Two dogs received BSA2. One dog developed a mild immediate reaction similar to that occurring with BSA1, and one dog (the dog immediately reacting to BSA1) developed a severe anaphylactic reaction. Due to these reactions, no other dogs received BSA2. During a two‐week observation of the remaining eight dogs given BSA1, five developed a mild or severe generalized type‐III hypersensitivity reaction. The dog experiencing a mild reaction during BSA2 administration also developed a generalized type‐III hypersensitivity reaction. Delayed reactions occurred 15 ± 2.7 days after BSA exposure. Three dogs did not develop a reaction. All reacting dogs recovered fully. The severity of reactions, and the number of dogs affected, suggests prior (natural) exposure and immunological sensitization to bovine albumin. Bovine serum albumin is not suitable for therapeutic use in dogs.     

The use of vascular access ports in nonanesthetized green iguanas (iguana iguana) to collect baseline arterial blood gas parameters.

The green iguana, Iguana iguana, is used as a model in reptile anesthesia research because of its size, availability, and the body of knowledge characterizing its physiology. Arterial blood gas values in nonanesthetized green iguanas have not been determined because of the technical difficulty involved. Vascular access port (VAP) placement to facilitate blood sampling has been described in other species, but not lacertilians. This abstract describes the technique for placement of VAPs and the values for arterial blood gas parameters in seven 1 kg adult green iguanas. Using sterile technique, a 1.5 cm incision was made on the lateral side of the neck. Blunt dissection ventral to the external jugular vein revealed the internal and external carotid arteries near their bifurcation. The catheter was inserted into the internal carotid artery and then guided to the common carotid artery. The other end of the catheter was tunneled below the skin to a subcutaneous location, caudal‐dorsal to the iSPSilateral scapula. The skin was closed and the port was flushed twice a week with heparinized saline. Post‐operatively, the VAPs were well tolerated by the iguanas. Difficulties included port disconnection (n = 1), inability to aspirate blood after a few weeks (n = 2), and infection (n = 1). The iguanas were breathing room air prior to and during blood collection. From the five functional VAPs, the blood pH, PCO₂, PO₂, HCO^‐₃, and BE (measured at 37 °C) were 7.45 ± 0.06; 37.5 ± 7.0 mm Hg, 99.0 ±16.6 mm Hg, 25.4 ± 2.5 mmol L^–1, and 1.5 ±2.4 mmol L^–1 respectively (mean ± SD). VAPs can be successfully used to facilitate collection of arterial blood gas samples in green iguanas. These values are similar to those reported for most mammalian species. This technique should facilitate research in anesthesiology and respiratory physiology of iguanas and other lacertilians.     

Ovarian vascular hamartoma in a cow

A 5-year-old Holstein cow was examined for a unilateral enlarged ovary. A clinical diagnosis of ovarian tumor was established before a histological diagnosis of ovarian vascular hamartoma was made. Ovarian vascular hamartoma has not been reported previously in a live animal.     

Computed tomography as an aid in the diagnosis of chronic nasal disease in dogs

OBJECTIVES: To assess the use of computed tomography (CT) in the diagnosis of chronic nasal disease in dogs. METHODS: A retrospective study of 85 dogs with chronic nasal discharge due to primary nasal disease, which had undergone nasal CT and biopsy, was carried out. Medical records were reviewed for signalment, clinical signs, CT findings, endoscopic findings and histopathology. The results obtained via CT were correlated with nasal histopathology and gross anatomical observations were recorded at the time of rhinoscopy. RESULTS: Neoplasia was diagnosed in 37 dogs for which CT typically revealed a soft tissue density associated with extensive turbinate destruction. Inflammatory rhinitis was diagnosed in 40 dogs. CT disclosed either normal turbinate structures or mild to moderate turbinate destruction, with or without the presence of soft tissue densities (mucopus) within the nasal passages. Fungal rhinitis was diagnosed in seven dogs for which CT disclosed extensive turbinate destruction with hyperlucency of the nasal passages. One dog had normal CT and histopathology findings. CLINICAL SIGNIFICANCE: CT greatly enhanced the ability to diagnose chronic nasal disease in dogs, providing detailed Information regarding the extent of the disease, accurate discrimination of neoplastic versus non-neoplastic diseases, and identification of areas of the nose to examine rhinoscopically and suspicious regions to target for biopsy.     

Plasma exogenous creatinine clearance test in dogs: comparison with other methods and proposed limited sampling strategy

Plasma clearance of creatinine was evaluated for assessment of glomerular filtration rate (GFR) in dogs. In 6 healthy dogs (Experiment 1), we determined 24-hour urine clearance of endogenous creatinine, plasma, and urine clearances of exogenous creatinine administered at 40, 80, and 160 mg/kg in a crossover design (linearity study), plasma iothalamate clearance, and plasma and urine clearances of 14C-inulin. In Experiment 2, plasma creatinine and iothalamate clearances were compared, and a linearity study was performed as for Experiment 1 in 6 dogs with surgically induced renal impairment. Experiment 3 compared plasma creatinine clearance with plasma iothalamate clearance before and 3 weeks after induction of moderate renal impairment in 6 dogs. Plasma creatinine clearances were calculated by both noncompartmental and compartmental analyses. In Experiment 1, plasma inulin clearance was higher (P < .001) than other clearance values. Plasma creatinine clearances at the 3 dose rates did not differ from urine inulin clearance and each other. In Experiment 2, plasma creatinine clearances were about 14% lower than plasma iothalamate clearance (P < .05). In Experiment 3, decreases in GFR assessed by plasma clearances of iothalamate and creatinine were similar. Renal failure decreased the daily endogenous input rate of creatinine by 25%. Limiting sampling strategies for optimizing GFR calculation were proposed, allowing an error lower than 6.5% with 4 blood samples. These results suggest that determination of plasma creatinine clearance by a noncompartmental approach offers a reliable, inexpensive, rapid, and convenient means of estimating GFR in routine practice.     

Use of plasma ionized calcium levels and Ca(2+) substitution response patterns as prognostic parameters for ileus and survival in colic horses

Summary Objective: Hypocalcaemia is a common finding in horses with enterocolitis and severe gastrointestinal disorders. The aims of this study were to investigate in colic horses (!))the parameters related to hypocalcaemia, (2))the influence of hypocalcaemia on outcome and (3))the possible beneficial effect of Ca(2+ )substitution. Design: Randomized controlled trial. Setting: Intensive care unit. Patients: One hundred forty-four horses that were admitted with an acute abdomen during a 1.5 year period were enrolled and daily evaluated for clinical criteria and whole blood ionized Ca levels. Colic horses with hypocalcaemia were randomly assigned to receive Ca(2+). Interventions: Analysis of heparinised whole blood samples. Horses that were assigned to be treated received 400 mEq Ca(2+) diluted in 10L of Ringer's lactate solution every 24 h until low reference range limits were obtained or until death. Measurements and main results: 88% of all colic patients showed blood ionized Ca levels below the reference range at the time of admission. Multivariable analysis revealed that the presence of reflux signs of endotoxaemia increased Packed Cell Volume (PCV) alkalinization of pH and the interaction PCV/pH all predispose colic horses to low ionized Ca(2+) levels at the time of admission. The Odds for developing ileus during hospitalization are ± 11.94 times larger for horses in the "very low" calcaemia interval in comparison with normocalcaemic horses. The Odds for fatal outcome are respectively ± 9.82 and 8.33 times larger for horses in the "very low" and "low" calcaemia interval. Ca(2+) substitution increased the probability of survival provided that Ca(2+) levels could be normalized. The lack of an upward calcaemia response despite repetitive Ca(2+) substitutions can be guarded as a poor ominous sign. Conclusions: Hypocalcaemia in colic horses is of prognostic relevance both with regard to survival as to the probability of development of ileus during hospitalization. This study shows the importance of routine measurement of ionized calcium levels in colic horses. Moreover correction of hypocalcaemia seems to improve clinical outcome.     

Polymerase chain reaction and other laboratory techniques in the diagnosis of long incubation rabies in Australia

SUMMARY Blood and post-mortem tissues from a 10-years-old girl were submitted to the Australian Animal Health Laboratory. Clinical signs and histopathological lesions had suggested a diagnosis of rabies, but, an unusually long incubation period of at least 5 years did not encourage such a diagnosis. Serological examinations by the rapid fluorescent focus inhibition test revealed a dramatic increase in rabies virus-neutralising antibody during the 10-day period of hospitalisation. The results of a fluorescent antibody test on brain smears, and an immunoperoxidase test on formalin-fixed sections of brain were also consistent with a diagnosis of rabies. Attempts to isolate virus were unsuccessful. Polymerase chain reactions (PCRs) were conducted on a 10% suspension of a post-mortem sample from the patient's brain, using primers based on the published sequence of the Pasteur virus strain of rabies virus. 413 and 513 bp fragments from the nucleoprotein gene and a 403 bp fragment from the glycoprotein gene were amplified. Subsequent sequencing of these fragments, and comparison with equivalent regions of known rabies viruses, confirmed that the fragments originated from a virus belonging to the rabies virus serotype. This case demonstrated the advantage of using a range of laboratory techniques to obtain a definitive diagnosis. In particular, a PCR-based test may allow a diagnosis, even in the face of conditions that preclude virus isolation such as apparently occurred in this case. Finally, this case demonstrated that an unusually long incubation period should not discourage a tentative clinical diagnosis of rabies.