Pharmacokinetics of paroxetine, a selective serotonin reuptake inhibitor, in Grey parrots (Psittacus erithacus erithacus): influence of pharmaceutical formulation and length of dosing.

Paroxetine, a selective serotonin reuptake inhibitor, may be beneficial in the treatment of behavioural disorders in pet birds. The lack of pharmacokinetic data and clinical trials currently limits the use of this drug in clinical avian practice. This paper evaluates the pharmacokinetic properties and potential side effects of single and repeated dosing of paroxetine in Grey parrots (Psittacus erithacus erithacus). Paroxetine pharmacokinetics were studied after single i.v. and single oral dosing, and after repeated oral administration during 1 month. Plasma paroxetine concentrations were determined by liquid chromatography-tandem mass spectrometry. No undesirable side effects were observed during the study. Pharmacokinetic analysis revealed a quick distribution and rapid elimination after i.v. administration. Oral administration of paroxetine HCl dissolved in water resulted in a relatively slow absorption (T(max)=5.9±2.6 h) and a low bioavailability (31±15%). Repeated administration resulted in higher rate of absorption, most likely due to a saturation of the cytochrome P450-mediated first-pass metabolism. This study shows that oral administration of paroxetine HCl (4 mg/kg twice daily) in parrots results in plasma concentrations within the therapeutic range recommended for the treatment of depressions in humans. Further studies are needed to demonstrate the clinical efficacy of this dosage regimen in parrots with behavioural disorders.

Ethanol poisoning as a differential diagnosis in a hunter's dog with tetraplegia.

A 4.5-month-old German pointer was presented with tetraplegia. Based on the physical examination, a tentative diagnosis of idiopathic polyneuropathy or synaptic disorder was made. Later that day additional information from the owner revealed that the dog might have ingested sloe berries that had been used to make sloe gin. Ethanol poisoning was added to the differential diagnosis. The dog's locomotion recovered in the course of 24 hours. Faecal analysis revealed that the animal had ingested at least 127 gin-saturated sloe berries and it was estimated that the blood ethanol concentration would have been at least 0.75 per thousand. The aetiology, diagnosis, and treatment of ethanol poisoning in dogs is reviewed.

[Numbers of dogs, cats, birds, and exotic animals in veterinary practices in the Netherlands 1994-2005 and possible consequences for the veterinary curriculum]. / Aanbod van honden, katten, vogels en bijzondere dieren in de Nederlandse diergeneeskundige praktijk in 1994 en 2005 en consequenties voor het veterinaire curriculum.

The species of pets owned in the Netherlands are constantly changing, and it is important that veterinary practitioners have information about the number and species of pets presented in veterinary practice. Using the same methodology as in 1994, we determined the relative importance of the various pet species in 2005 and compared these data with those for 1994. The most notable findings were a 25% increase in the number of birds and exotic animals seen in small and large animal practices (from about 10% to about 12.5%), a doubling of the number of birds and tripling of the number of pigeons seen in mixed practices, a doubling of the number of reptiles seen in small animal practices, and a 10-fold increase in the number of fish seen in veterinary practices in general. There was a significant decrease in the proportion of cats (from 46% to 40.7%) and an increase in the proportion of dogs (from 44% to 46.7%). These trends in veterinary practice consultations did not parallel those seen in pet ownership. The increase in the number of birds (especially pigeons), reptiles, and fish seen in veterinary practice emphasizes the need to pay attention to these species in the standard companion animal curriculum.

Giant cell tumor of the bone in a scarlet macaw (Ara macao).

A 6-mo-old female scarlet macaw (Ara macao) was presented after a 2-mo period of anorexia and weakness. The bird was reluctant to fly 1 wk before referral due to a painful left wing. Physical examination revealed a firm swelling around the left shoulder. On radiographs, the diaphysis and proximal metaphysis of the left scapula were radiolucent. Computer tomography revealed an osteolytic process, suggestive of a bone tumor, affecting the left scapula. Cytology of a fine needle aspiration biopsy of the mass showed erythrocytes, a proliferation of spindle-shaped mesenchymal cells, and multinucleated giant cells (osteoclasts) suggestive of a giant cell tumor. The left wing, including the scapula, was amputated. The bird showed a fast recovery but died 1 hr later. Findings during the pathological examination were compatible with shock due to blood loss. The shoulder process was characterized as a giant cell tumor. To our knowledge, this is the first complete report of a giant cell tumor of the bone in a bird.

Exocrine pancreatic insufficiency in pigeons.

Exocrine pancreatic insufficiency (EPI) is a well-studied syndrome in domestic animals. EPI occurs when severe progressive loss of tubulo-acinar tissue from atrophy or inflammatory destruction results in insufficient secretion of digestive enzymes and clinical signs of malabsorption. However, the literature on EPI in birds is limited. The syndrome has been previously described in several cases where the diagnosis was based on clinical signs due to malabsorption-like light-coloured voluminous faeces, voracious appetite, coprophagia and weight loss, and on the response to treatment with pancreatic enzyme formulas. To enable a more scientific approach to the diagnosis of pancreatic functional disorders in pigeons, reference values of plasma amylase (382 to 556 IU/l), lipase (0 to 5 IU/l), and faecal activities of amylase (13 to 16 IU/l) and trypsin (11 to 14 IU/l) were determined in 24 adult pigeons. A case of EPI in a racing pigeon (Columba livia domestica) is reported, based on the clinical signs and the measurement of faecal amylase and trypsin activity.

Urinary glucocorticoid excretion in the diagnosis of hyperadrenocorticism in ferrets.

Hyperadrenocorticism in ferrets is usually associated with unaltered plasma concentrations of cortisol and adrenocorticotropic hormone (ACTH), although the urinary corticoid/creatinine ratio (UCCR) is commonly elevated. In this study the urinary glucocorticoid excretion was investigated in healthy ferrets and in ferrets with hyperadrenocorticism under different circumstances. In healthy ferrets and in one ferret with hyperadrenocorticism, approximately 10% of plasma cortisol and its metabolites was excreted in the urine. High-performance liquid chromatography (HPLC) revealed one third of the urinary corticoids to be unconjugated cortisol; the other peaks mainly represented cortisol conjugates and metabolites. In 21 healthy sexually intact ferrets, the UCCR started to increase by the end of March and declined to initial values halfway the breeding season (June). In healthy neutered ferrets there was no significant seasonal influence on the UCCR. In two neutered ferrets with hyperadrenocorticism the UCCR was increased, primarily during the breeding season. In 27 of 31 privately owned ferrets with hyperadrenocorticism, the UCCR was higher than the upper limit of the reference range (2.1 x 10(-6)). In 12 of 14 healthy neutered ferrets dexamethasone administration decreased the UCCR by more than 50%, whereas in only 1 of the 28 hyperadrenocorticoid ferrets did the UCCR decrease by more than 50%. We conclude that the UCCR in ferrets primarily reflects cortisol excretion. In healthy sexually intact ferrets and in ferrets with hyperadrenocorticism the UCCR increases during the breeding season. The increased UCCR in hyperadrenocorticoid ferrets is resistant to suppression by dexamethasone, indicating ACTH-independent cortisol production.

Morphology of the pituitary gland in ferrets (Mustela putorius furo) with hyperadrenocorticism.

Pituitary tumours are the cause of hyperadrenocorticism in a variety of species, but the role of the pituitary gland in hyperadrenocorticism in ferrets is not known. In this species, the disease is mediated by the action of excess gonadotrophins on the adrenal cortex and is characterized by an excessive secretion of sex steroids. In this study, the pituitary gland of four healthy control ferrets, intact or neutered, and 10 neutered ferrets with hyperadrenocorticism was examined histologically following immunohistochemical labelling for adrenocorticotrophic hormone, alpha-melanocyte-stimulating hormone, growth hormone, thyroid-stimulating hormone, luteinizing hormone, follicle-stimulating hormone, and prolactin. Immunohistochemistry revealed that somatotrophs, thyrotrophs and lactotrophs were the most abundant cell types of the pars distalis of the pituitary gland in the healthy ferrets. The distribution of corticotrophs was similar to that in the dog and man. In ferrets, as in dogs, the melanotrophic cell was almost the only cell type of the pars intermedia. Gonadotrophs were found in the pars distalis of neutered, but not intact ferrets. All the ferrets with hyperadrenocorticism had unilateral or bilateral alterations of the adrenal gland. In addition, in the pituitary gland of two of these ferrets a tumour was detected. These tumours were not immunolabelled by antibodies against any of the pituitary hormones, and had characteristics of the clinically non-functional gonadotroph tumours seen in man. In some of the other ferrets low pituitary immunoreactivity for gonadotrophic hormones was detected, which may have been due to the feedback of autonomous steroid secretion by the neoplastic transformation of the adrenal cortex. It is concluded that initially high concentrations of gonadotrophins resulting from castration may initiate hyperactivity of the adrenal cortex. The low incidence of pituitary tumours and the low density of gonadotrophin-positive cells in non-affected pituitary tissue in this study suggest that persistent hyperadrenocorticism is not dependent on persistent gonadotrophic stimulation.