Of mice and men: olfactory neuroblastoma among animals and humans

Olfactory neuroblastoma (ONB) is a rare tumour of nasal cavity and paranasal sinuses that arises from the olfactory neuroepithelium and has unpredictable clinical course. As the sense of smell is phylogenetically one of the first senses and olfactory neuroepithelium is evolutionary conserved with striking similarities among different species, we performed an extensive analysis of the literature in order to evaluate the similarities and differences between animals and humans on the clinical, morphological, immunohistochemical, ultrastructural and molecular level. Our analysis revealed that ONB was reported mainly in mammals and showed striking similarities to human ONB. These observations provide rationale for introduction of therapy modalities used in humans into the veterinary medicine. Animal models of neuroblastoma should be considered for the preclinical studies evaluating novel therapies for ONB.     

Canine transmissible venereal tumour: a review

Canine transmissible venereal tumour (CTVT) is a contagious venereal tumour of dogs, commonly observed in dogs that are in close contact with one another, or in stray and wild dogs that exhibit unrestrained sexual activity. CTVT represents a unique, naturally transmissible, contagious tumour, where the mutated tumour cell itself is the causative agent and perpetuates as a parasitic allograft in the host. Clinical history, signalment and cytological features are often obvious for establishing a diagnosis though biopsy and histological examination may be needed in atypical cases. Most cases are curable with three intravenous injections of vincristine sulphate at weekly intervals. The role of stray and wild dogs makes the disease difficult to control and necessitates sustained animal birth control in stray dogs along with prompt therapy of the affected dogs. This review captures the manifold developments in different areas embracing this fascinating tumour, including its biology, diagnosis and therapeutic alternatives.     

Anatomical and physiological basis for the allometric scaling of cisplatin clearance in dogs

Cisplatin is a platinum‐containing cytotoxic drug indicated for the treatment of solid tumors in veterinary and human patients. Several of the algorithms used to standardize the doses of cytotoxic drugs utilize allometry, or the nonproportional relationships between anatomical and physiological variables, but the underlying basis for these relationships is poorly understood. The objective of this proof of concept study was to determine whether allometric equations explain the relationships between body weight, kidney weight, renal physiology, and clearance of a model, renally cleared anticancer agent in dogs. Postmortem body, kidney, and heart weights were collected from 364 dogs (127 juveniles and 237 adults, including 51 dogs ≥ 8 years of age). Renal physiological and cisplatin pharmacokinetic studies were conducted in ten intact male dogs including two juvenile and eight adult dogs (4–55 kg). Glomerular filtration rate (GFR), effective renal plasma flow, effective renal blood flow, renal cisplatin clearance, and total cisplatin clearance were allometrically related to body weight with powers of 0.75, 0.59, 0.61, 0.71, and 0.70, respectively. The similar values of these diverse mass exponents suggest a common underlying basis for the allometry of kidney size, renal physiology, and renal drug handling.     

Pharmacokinetic indices for cefovecin after single‐dose administration to adult sea otters (Enhydra lutris)

Seven sea otters received a single subcutaneous dose of cefovecin at 8 mg/kg body weight. Plasma samples were collected at predetermined time points and assayed for total cefovecin concentrations using ultra‐performance liquid chromatography and tandem mass spectrometry. The mean (±SD) noncompartmental pharmacokinetic indices were as follows: C_Max (obs) 70.6 ± 14.6 μg/mL, T_{Max (obs)} 2.9 ± 1.5 h, elimination rate constant (k_el) 0.017 ± 0.002/h, elimination half‐life (t_1/2kel) 41.6 ± 4.7 h, area under the plasma concentration‐vs.‐time curve to last sample (AUC_last) 3438.7 ± 437.7 h·μg/mL and AUC extrapolated to infinity (AUC_0→∞) 3447.8 ± 439.0 h·μg/mL. The minimum inhibitory concentrations (MIC) for select isolates were determined and used to suggest possible dosing intervals of 10 days, 5 days, and 2.5 days for gram‐positive, gram‐negative, and Vibrio parahaemolyticus bacterial species, respectively. This study found a single subcutaneous dose of cefovecin sodium in sea otters to be clinically safe and a viable option for long‐acting antimicrobial therapy.     

Effects of season on the reproductive organs and steroid hormone profiles in guinea hens (Numida meleagris)

1. The study documented gross anatomical and histological differences in the reproductive organs of 28 breeding and non-breeding female guinea fowls. Peripheral progesterone and 17β-oestradiol concentrations were also compared in breeding and non-breeding hens.

2. In non-breeding females, all ovarian and oviducal gross anatomical features had significantly regressed. Histologically, some of the changes in a regressing oviduct include systematic changes in height and size of all epithelial cells in all regions of the duct, absence/sparse ciliation of portions of surface epithelium in the magnum, isthmian and uterine regions, general loss of cytoplasmic mass, reduction in size and degeneration of tubular glands. Mucosal folds in all regions of the oviduct except the infundibular lip were higher in breeding females.

3. No difference was found between the two groups in plasma progesterone concentrations. Breeding females, however, had higher peripheral oestradiol concentrations than non-breeding females. About 2 h prior to oviposition, plasma oestradiol concentrations peaked at 2.4-fold (230 pg/ml) compared with baseline concentration and plasma progesterone concentrations by nearly 9-fold (5.29 ng/ml) of baseline.

4. Significant regression and changes in the histological structure of the ovary and oviduct had occurred in non-breeding females, and lower peripheral oestrogen concentrations may be responsible for this phenomenon.

     

Survival of 4 dogs with persistent atrial standstill treated by pacemaker implantation

Pacemakers were implanted in 4 client-owned female dogs which had persistent atrial standstill. Three dogs were alive after 14 to 39 months and 1 dog was euthanized after 10.5 years. This report demonstrates that some dogs with persistent atrial standstill can survive for extended time periods.     

Effect of supplementing broiler chicken diets with green tea extract on the growth performance,lipid profile,antioxidant status and immune response

1. A trial was conducted to explore the effect of feeding graded concentrations of green tea extract (GTE; 125, 250, 500, 1000 and 2000 mg/kg) on the growth performance, serum lipid profile, liver glutathione-reduced, thigh muscle malondialdehyde and humoral immune response against Newcastle disease virus vaccines of broiler chickens from hatching to 42 d of age. The results of broilers fed on GTE were contrasted to those fed on butylated hydroxytoluene (BHT; 125 mg/kg) or unsupplemented controls.

2. The obtained results revealed no significant difference among treatments in the measured growth performance parameters (body weight, average daily gain, average daily feed intake and feed conversion ratio), per cent liveability and serum lipid profile (total lipid, total cholesterol, high-density, low-density and very low-density lipoprotein cholesterols).

3. Dietary intake of GTE resulted in a significant increase in the liver glutathione-reduced level compared to the control. The glutathione-reduced level of broilers fed on the BHT diet was not significantly different from that of broilers fed on GTE or control diets. Feeding GTE or BHT resulted in a significant decrease in the malondialdehyde level of meat tissue.

4. The specific antibody titre against Newcastle disease virus vaccines was significantly increased at 28 and 35 d of age in broilers fed on diets supplemented with GTE but not with BHT.

5. In conclusion, GTE was found to possess antioxidant and immunostimulant characteristics for broilers when supplemented to their diets, and its optimum inclusion level ranged from 125 to 500 mg/kg.