Therapeutics of companion exotic marsupials.

Exotic marsupials are becoming popular companion pets, yet little pharmacologic information is available to the practitioner. Species include sugar gliders (Petarus breviceps), South American (Brazilian) short-tailed opossums (Monodelphis domestica), brushtail possum or "phalanger" (Trichosurus vulpecula), and wallabies: Bennett's (Macropus rufogriseus rufogriseus) and Tammar or Dama (Macropus eugenii). Guidelines for logical choices of medications based on allometric scaling, gastrointestinal tract anatomy and physiology, and liver metabolism are given. An example of scaling and a formulary based on anecdotal, published medications are provided.     

Metabolic and mitogenic activities of insulin-like growth factor-1 in interleukin-1-conditioned equine cartilage

OBJECTIVE: To determine response of interleukin-1alpha (IL-1alpha)-conditioned equine articular cartilage explants to insulin-like growth factor-1 (IGF-1). Sample Population-Cartilage from the trochlea and condyles of the femur of a clinically normal 4-year-old horse. PROCEDURE: Effects of IGF-1 (0 to 500 ng/ml) after addition of IL-1alpha were evaluated by assessing matrix responses, using a sulfated glycosaminoglycan (GAG) assay, matrix 35SO4 GAG incorporation, and release of GAG. Mitogenic response was assessed by 3H-thymidine incorporation into DNA and fluorometric assay of total DNA concentration. RESULTS: Human recombinant IL-1alpha (40 ng/ml) increased the amount of labeled GAG released and decreased labeled and total GAG remaining in explants, and IL-1alpha decreased mitogenic response. Addition of IGF-1 counteracted effects seen with IL-1alpha alone. In general, IGF-1 decreased total and labeled GAG released into the medium, compared with IL-1alpha-treated explants (positive-control sample). Values for these variables did not differ significantly from those for negative-control explants. A significant increase in total and newly synthesized GAG in the explants at termination of the experiment was observed with 500 ng of IGF-1/ml. Labeled GAG remaining in explants was greater with treatment at 50 ng of IGF-1/ml, compared with treatment with IL-1alpha alone. Concentrations of 200 ng of IGF-1/ml abolished actions of IL-1alpha and restored DNA synthesis to values similar to those of negative-control explants. CONCLUSIONS AND CLINICAL RELEVANCE: IGF-1 at 500 ng/ml was best at overcoming detrimental effects associated with IL-1alpha in in vitro explants. These beneficial effects may be useful in horses with osteoarthritis.     

Epitope-tagged insulin-like growth factor-I expression in muscle

Development of a recombinant insulin like growth factor I (IGF-I) that is distinguishable from its endogenous counterpart would provide a powerful tool for delineating the role of IGF in myogenesis. Therefore, the objective of this study was to create an epitope-tagged IGF-I that retains biological activity and determine whether expression of this construct is possible in muscle tissue following direct DNA injection. Expression vectors were created that encoded porcine IGF-I containing a T7 (11-amino acid) epitope-tag (TIGF). Immunoreactivity of the purified recombinant TIGF was confirmed using monoclonal antibodies. Biological activity was evaluated by examining differentiation of myoblasts cultured with TIGF or transfected with TIGF plasmid DNA. Addition of purified TIGF to myoblast cultures stimulated (P < 0.05) muscle creatine kinase levels similar to insulin (10(-5) M). Likewise, transfection of L6A1 with TIGF DNA hastened (P < 0.01) differentiation compared to control pcDNA-transfected myoblasts. The integrity of the recombinant protein was confirmed using a sandwich-configured enzyme linked immunosorbent assay. Finally, recombinant TIGF DNA was injected in porcine muscle and the ability to detect TIGF protein was evaluated. TIGF expression was detected in muscle fibers of injected porcine muscle. These data show that a T7 amino acid tag placed on the amino terminus of the IGF-I protein remains intact during processing and does not interfere with the biological activity of the molecule. Use of this DNA construct is an excellent tool for investigating the role of IGFs in control muscle development and provides a model to investigate other regulators of animal growth.     

Evaluation of intratesticular injection of glycerol for nonsurgical sterilization of dogs

OBJECTIVE: To determine efficacy of intratesticular injection of glycerol as a means to sterilize dogs. ANIMALS: Six 2- to 4-year-old sexually intact male dogs. PROCEDURE: Testicular volume, serum testosterone concentration, and number of sperm in ejaculate were determined before and at weekly intervals for 12 weeks following intratesticular injection of a 70% glycerol solution (1 ml/testis). Testicular tissue specimens for histologic evaluation were obtained 4, 8, and 12 weeks following injection. RESULTS: Number of sperm in ejaculate following glycerol injection was not significantly different from number before injection. Compared with preinjection values, serum testosterone concentrations were significantly less 5, 9, and 10 weeks following injection, although libido and ejaculate characteristics were unchanged. Testicular swelling was evident 24 to 48 hours following injection, and testicular volume decreased starting on week 5 following treatment. Seminiferous tubules and evidence of normal spermatogenesis were detected in testicular biopsy specimens obtained from all dogs 12 weeks following injection. CONCLUSION AND CLINICAL RELEVANCE: Intratesticular injection of a 70% glycerol solution did not result in azoospermia and sterility in dogs.     

Dose dependency of prednisolone on the establishment of Echinococcus multilocularis infection in an alternative definitive host, Mongolian gerbil

This study revealed the dose dependency of prednisolone tertiary-butylacetate (PTBA) treatment on the establishment of Echinococcus multilocularis in the small intestine of Mongolian gerbil (Meriones unguiculatus) and that some of the physiological parameters of host were correlated with the doses of PTBA and establishment of the worm. Twenty Mongolian gerbils were divided into 5 groups, according to the doses of PTBA; 0 mg, 0.5 mg, 2 mg, 5 mg and 10 mg per head. All animals were injected intraperitoneally with PTBA every other day from 6 days before to 6 days after infection. Doses of PTBA and the number of worms recovered at 7 days post-infection showed a positive correlation (r = 0.929, P < 0.0001). The increase of total protein (TP) and the decrease of the percentage of lymphocytes in the peripheral leukocytes were dependent on doses of PTBA (TP: r = 0.811, P < 0.0001, percentage of lymphocyte: r = -0.92, P < 0.0001). The TP and the percentage of lymphocyte also correlated with the number of worms recovered (TP: r = 0.617, P = 0.0049; percentage of lymphocyte: r = -0.800, P < 0.0001).     

Morphology and amplitude values of the electrocardiogram of Spanish-bred horses of different ages in the Dubois leads system

The aim of this work was to record the modifications of the form and amplitude of the electrocardiographic tracings during growth using the Dubois system and to study its sensibility to these physiological changes. This work was carried out on 179 healthy, young and adult Spanish-bred horses (98 females and 81 males). One electrocardiogram (ECG) was obtained from each horse using the Dubois leads system. The bifid shape deflection of the P wave was generally more frequent than the simple one in animals at 4 months of age or older. Amplitudes of the P2 component and of the simple positive wave presented significant differences (p < 0.01) between the age groups studied: animals up to 3 months in age and older than 2 years of age (highest amplitudes), and the rest of the animals (lowest amplitudes). Significant variations (p < 0.05) were found for the QS amplitude between animals of 1 month of age, and all the other groups. The multiple range analysis did not define a clear distribution of age groups for the amplitude of the T wave. It may therefore be concluded, that in the Spanish-bred horse up to 1 month of age, the form and amplitude of the QRS complex in the Dubois leads system differ from those of older animals. Thus, this study shows the sensibility of the Dubois leads system for detecting the electrocardiographic changes related to the growing process in the Spanish-bred horse. In addition, it provides standard values of electrocardiographic parameters in the Spanish-bred horse at different stages of growth.     

Pheasant ataxia: a new condition in pheasant poults

Between 1995 and 1997 a neurological condition in pheasant poults from 24 sites in England and Scotland was investigated. Affected birds showed varying degrees of ataxia and incoordinated movements and, in severe cases, recumbency, but generally remained alert with their heads held upright. The condition characteristically affected poults from seven weeks of age and the incidence on any one site was low. No significant bacteria were isolated consistently from brain tissue. The condition was characterised histologically by a non-suppurative meningoencephalitis, in which lesions were found predominantly in the cerebellum in 61 of 81 samples examined (75.3 per cent). A non-suppurative myelitis was recorded in 16 of 20 spinal cords examined. No lesions were recorded in peripheral neural tissue and lesions were rare in other tissues. The condition appeared not to have been recorded previously in pheasants. A viral aetiology was suspected but Newcastle disease virus was not involved.     

The antifungal activity of natamycin toward molds isolated from commercially manufactured poultry feed

The antifungal activity of natamycin, a polyene antifungal compound, was evaluated on molds isolated from commercial poultry feed. The antifungal activity was measured by determination of the minimal inhibitory concentration (MIC) for natamycin on molds growing on semisolid microbiological medium (potato dextrose agar) containing pure natamycin at concentrations ranging from 0 to 200 mg/liter. Natamycin exhibited a high degree of antifungal activity against the 191 isolates of aspergilli used in this study, with average MIC values ranging from 5.08 to 40.1 mg/liter for Aspergillus fumigatus and Aspergillus parasiticus, respectively. Natamycin was also equally effective in inhibiting the growth of nonaflatoxigenic compared with aflatoxigenic isolates of Aspergillus flavus and A. parasiticus. Natamycin was also efficacious against molds other than aspergilli, with MIC values ranging from 2.15 to 5.80 mg/liter for Paecilomyces and Rhizopus spp., respectively. Natamycin exhibited apparent sporicidal activity against spores of toxigenic strains of Fusarium moniliforme and A. parasiticus but not Penicillium rubrum. This sporicidal activity was evident only when spores were exposed to an in vitro concentration of natamycin of 25 mg/liter or higher for a period of time of at least 12 hr. The growth inhibiting activity of natamycin was more pronounced compared with the sporicidal activity.     

On the morphology of the liver in the two-humped camel (Camelus bactrianus)

The liver of a two-humped camel (Camelus bactrianus) was examined by means of gross anatomy and histology. The liver appeared characteristically as an enlarged triangle in visceral aspect, and showed the following lobation: the left lateral and medial lobes, the right lobe, the caudate lobe and the quadrate lobe. These findings were similar to those for the one-humped camel. Histologically, a distinct lobulation, a typical arrangement of the interlobular connective tissue, and the trias was confirmed.     

Radial carpal bone fractures in 15 dogs

Between 1977 and 1992, 15 adult dogs were presented to the Universities of Bristol, Glasgow, Liverpool and London with fractures of the radial carpal bone which had occurred without a known episode of violent trauma. Eleven of the dogs were boxers and the other breeds affected were a Pharaoh hound, rottweiler, springer spaniel and a greyhound. The condition was bilateral in three cases. Eleven dogs were treated surgically by cast immobilisation (four cases), fragment removal (one case), lag screw fixation (three cases), pan-carpal arthrodesis (one case) and lag screw reduction followed by pan-carpal arthrodesis (two cases). The remaining four dogs were treated conservatively with rest and tactical use of non-steroidal anti-inflammatory drugs. Follow-up periods ranged from two months to 11 years. Varying degrees of lameness, which tended to be exacerbated by exercise, persisted in all cases. The radial carpal bone appears to have at least three separate centres of ossification which eventually fuse; their planes of fusion correspond approximately to the two main fracture lines. These areas of fusion could be weak points within the radial carpal bone.