Development of renal adenocarcinoma in a ferret with renal cortical cysts (Mustela putorius furo).

CASE DESCRIPTION: A 5.5-year-old 0.929-kg spayed female domestic ferret (Mustela putorius furo) underwent serial abdominal ultrasonographic and clinicopathologic examinations after multiple renal cysts were detected bilaterally during a routine examination. CLINICAL FINDINGS: The ferret was apparently healthy at the start of the monitoring period and had no clinical signs for > 20 months. Four months after the initial examination, the largest cyst became increasingly mineralized; 17 months after detection, it had increased in size and become amorphous, and the ferret's plasma BUN concentration was mildly high. Within 21 months after the first visit, a nodule was detectable, and hydronephrosis developed in the kidney with the largest cyst. Findings for fine-needle aspirates from the nodule were consistent with renal carcinoma. TREATMENT AND OUTCOME: Contrast-enhanced CT revealed severe unilateral nephromegaly with no contrast uptake in the affected ureter. Following surgical removal of the affected kidney, histologic examination identified renal adenocarcinoma replacing the entire renal cortex and medulla. The ferret was euthanized postoperatively because of declining condition. On necropsy, metastasis to a mesenteric lymph node was identified; comorbidities included 2 other neoplasms and acute, severe injury of the contralateral kidney. CLINICAL RELEVANCE: Neoplastic transformation of a renal cyst was suspected in the ferret of this report on the basis of observed ultrasonographic changes over time and extensive infiltration of the neoplasm throughout the affected kidney. Renal cysts are linked to renal neoplasia in other species, and the findings for this patient supported the need for periodic monitoring of renal cysts in ferrets.

Evaluation of the thermal antinociceptive effects of subcutaneous administration of butorphanol tartrate or butorphanol tartrate in a sustained-release poloxamer 407 gel formulation to orange-winged Amazon parrots (Amazona amazonica).

OBJECTIVE: To determine the thermal antinociceptive effects of butorphanol tartrate and butorphanol tartrate in a sustained-release 25% poloxamer 407 (P407) gel formulation (But-P407) in parrots. ANIMALS: 13 orange-winged Amazon parrots (Amazona amazonica). PROCEDURES: First, butorphanol tartrate (5 mg/kg) or saline (0.9% NaCl) solution was administered IM to birds in a randomized complete crossover design. The temperature prompting a foot withdrawal response to a thermal stimulus (ie, the thermal threshold) was determined 30 minutes before (baseline) and at various points after treatment administration. Second, But-P407 (12.5 mg/kg) or P407 was administered SC in a similar crossover design. Thermal threshold was determined before and at various points after treatment administration. Third, But-P407 (12.5 mg/kg) or saline solution was administered SC and evaluated as in the second trial. Sedation was scored immediately before each time point in all 3 trials. RESULTS: In the first trial, a significant increase in thermal threshold was noted 30 minutes after butorphanol tartrate (vs saline solution) administration. No sedation was noted. In the second and third trials, no significant difference was identified between results for But-P407 and those for either control treatment (saline solution or P407). Mild sedation was noted in the second trial following But-P407 administration. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested a small but significant thermal antinociceptive effect of butorphanol tartrate lasting between 30 minutes and 1.5 hours in orange-winged Amazon parrots. No antinociceptive effect of butorphanol tartrate was demonstrated when delivered in P407. Further research is needed to evaluate the potential analgesic effects of But-P407.

Diagnosis and long-term management of post-traumatic seizures in a white-crowned pionus (Pionus senilis).

CASE DESCRIPTION: A 13-year-old female white-crowned pionus (Pionus senilis) was examined because of seizures 22 months after it was treated for a traumatic brain injury (TBI) characterized by vision loss, hemiparesis, nystagmus, circling, and head tilt. CLINICAL FINDINGS: Bloodwork performed during the initial seizure workup revealed hypercalcemia and hypercholesterolemia, which were attributed to vitellogenesis given the bird's previous egg-laying history and recent onset of reproductive behavior. Magnetic resonance imaging of the brain revealed diffuse right pallium atrophy with multifocal hydrocephalus ex vacuo, which were believed to be the result of the previous TBI. Findings were most consistent with post-traumatic seizures (PTS). TREATMENT AND OUTCOME: Levetiracetam (100 mg/kg [45 mg/lb], PO, q 12 h) was initiated for PTS management. A 4.7-mg deslorelin implant was injected SC to suppress reproductive behavior. The bird was reexamined for presumed status epilepticus 5 times over 22 months. Seizure episodes coincided with onset of reproductive behavior. The levetiracetam dosage was increased (150 mg/kg [68 mg/lb], PO, q 8 h), and zonisamide (20 mg/kg [9.1 mg/lb], PO, q 12 h) was added to the treatment regimen. Additional deslorelin implants were administered every 2 to 6 months to suppress reproductive behavior. The owner was trained to administer midazolam intranasally or IM as needed at home. The treatment regimen helped control but did not eliminate seizure activity. The bird was euthanized 22 months after PTS diagnosis for reasons unrelated to the TBI or PTS. CLINICAL RELEVANCE: Long-term management of PTS in a pionus was achieved with levetiracetam and zonisamide administration.

Advances in Therapeutics and Delayed Drug Release.

Reducing the frequency of drug administration in the treatment of exotic pets is advantageous because it may decrease handling frequency and thus potential stress and injury risk for the animal, increase owner compliance with the prescribed treatment, and decrease need for general anesthesia in patients that cannot be handled safely. Increasing efficient drug plasma concentration using sustained-released delivery systems is an appealing solution. Potential candidates that could provide a promising solution have been investigated in exotic pets. In this article, the technologies that are the closest to being integrated in exotic pet medicine are reviewed: osmotic pumps, nanoparticles, and hydrogels.

Multiple fractures and luxations of palatofacial bones in a hawk-headed parrot (Deroptyus accipitrinus).

CASE DESCRIPTION A 16-year-old female hawk-headed parrot (Deroptyus accipitrinus) was evaluated because of beak trauma and difficulty eating. CLINICAL FINDINGS Physical examination revealed a lateral tissue protrusion in the left half of the oropharyngeal cavity ventral to the proximal aspect of the maxillary tomium as well as a small bony prominence on the left jugal arch. Range of motion of the beak appeared normal. A CT scan of the skull revealed rostroventral displacement of the left palatine bone from the maxilla and left lateral subluxation and lateral luxation of the pterygoid-parasphenoid-palatine complex and pterygoid-palatine articulation, respectively; and transverse fractures of the ipsilateral pterygoid bone, jugal arch, and palatine bone. TREATMENT AND OUTCOME Palatine bone displacement was reduced, and surgical fixation was achieved with an interfragmentary wire inserted through the rostral aspect of the affected palatine bone, maxilla, and rhinotheca. The lateral aspect of the wire was covered with dental acrylic. The wire was removed 2 weeks later owing to concerns over local vascular compromise and potential for infection. The bird started eating pelleted food approximately 3 months after surgery; full return of apparently normal beak function was regained by 10 months after surgery. CLINICAL RELEVANCE To the authors' knowledge, the described beak trauma and surgical approach have not previously been reported for Psittaciformes. Use of CT imaging was invaluable in diagnosing multiple traumatic bone abnormalities and planning surgical correction.

Perforating foreign body in the ventriculus of a pet pigeon (Columba livia domestica).

CASE DESCRIPTION A 2-year-old female pigeon was evaluated because of a 5-day history of lower than typical activity level, weight loss, and polyuria. CLINICAL FINDINGS Whole-body radiography revealed a linear metallic foreign body in the area of the ventriculus. Fluoroscopy followed by contrast-enhanced CT was performed to further characterize the lesion location, revealing that the foreign body had perforated the ventral aspect of the ventriculus wall and that the ventral extremity of the foreign body was surrounded by a mass, consistent with a granuloma. TREATMENT AND OUTCOME A midline celiotomy was performed, and a large granuloma was identified ventral to the ventriculus, adherent to the dorsal aspect of the keel bone. The metallic foreign body (a nail) was removed, and the content of the granuloma was debrided. Amoxicillin-clavulanic acid (150 mg/kg [68.2 mg/lb], PO, q 12 h for 10 days), meloxicam (1 mg/kg [0.45 mg/lb], PO, q 12 h for 5 days), and sucralfate (100 mg/kg [45 mg/lb], PO, q 8 h for 10 days) were prescribed. The pigeon made a successful recovery and was still doing well at a 1-year recheck evaluation. CLINICAL RELEVANCE Although traumatic gastritis in pigeons has been reported, use of advanced diagnostic imaging for the pigeon of this report facilitated identification of the precise nature of the lesion and, therefore, surgical planning. The outcome for this pigeon suggested that successful resolution of traumatic gastritis may be possible in other affected birds with surgery.

In vitro characterization of a formulation of butorphanol tartrate in a poloxamer 407 base intended for use as a parenterally administered slow-release analgesic agent.

OBJECTIVE To assess rheological properties and in vitro diffusion of poloxamer 407 (P407) and butorphanol-P407 (But-P407) hydrogels and to develop a sustained-release opioid formulation for use in birds. SAMPLE P407 powder and a commercially available injectable butorphanol tartrate formulation (10 mg/mL). PROCEDURES P407 and But-P407 gels were compounded by adding water or butorphanol to P407 powder. Effects of various concentrations of P407 (20%, 25% and 30% [{weight of P407/weight of diluent} × 100]), addition of butorphanol, and sterilization through a microfilter on rheological properties of P407 were measured by use of a rheometer. In vitro diffusion of butorphanol from But-P407 25% through a biological membrane was compared with that of a butorphanol solution. RESULTS P407 20% and 25% formulations were easily compounded, whereas it was difficult to obtain a homogenous P407 30% formulation. The P407 was a gel at avian body temperature, although its viscosity was lower than that at mammalian body temperature. The But-P407 25% formulation (butorphanol concentration, 8.3 mg/mL) was used for subsequent experiments. Addition of butorphanol to P407 as well as microfiltration did not significantly affect viscosity. Butorphanol diffused in vitro from But-P407, and its diffusion was slower than that from a butorphanol solution. CONCLUSIONS AND CLINICAL RELEVANCE But-P407 25% had in vitro characteristics that would make it a good candidate for use as a sustained-release analgesic medication. Further studies are needed to characterize the pharmacokinetic and pharmacodynamic properties of But-P407 25% in vivo before it can be recommended for use in birds.

Pharmacokinetics of butorphanol tartrate in a long-acting poloxamer 407 gel formulation administered to Hispaniolan Amazon parrots (Amazona ventralis).

OBJECTIVE To determine pharmacokinetics of butorphanol tartrate incorporated into poloxamer 407 (P407) after SC administration to Hispaniolan Amazon parrots (Amazona ventralis). ANIMALS 11 adult Hispaniolan Amazon parrots (6 males and 5 females; 11 to 27 years old). PROCEDURES A sterile formulation of butorphanol in P407 (But-P407) 25% (percentage determined as [weight of P407/weight of diluent] × 100]) was created (8.3 mg/mL). Five preliminary experiments (2 birds/experiment) were performed to determine the ideal dose for this species. The formulation then was administered (12.5 mg/kg, SC) to 8 birds. Blood samples were collected before (time 0) and 0.08, 0.5, 1, 2, 4, 8, 12, and 24 hours after drug administration. Some birds were used more than once, with a washout period of ≥ 3 months between subsequent treatments. Butorphanol concentrations were quantitated by use of liquid chromatography-tandem mass spectrometry. Pharmacokinetic analysis was performed by use of noncompartmental analysis. RESULTS Maximal plasma butorphanol concentration was reached at 1.31 hours. Plasma concentrations of butorphanol remained > 100 ng/mL for > 3 hours (all birds) or > 4 hours (5/8 birds) but < 8 hours (all birds). Half-life of the terminal slope was 3.41 hours. No adverse effects were detected. CONCLUSIONS AND CLINICAL RELEVANCE Butorphanol was absorbed well from the But-P407 25% by Hispaniolan Amazon parrots, and absorption followed a pharmacokinetic profile compatible with a sustained-release drug. A dose of 12.5 mg/kg, SC, would theoretically provide analgesia for 4 to 8 hours. No adverse effects were detected. Studies on the pharmacodynamics of this formulation are necessary to confirm the degree and duration of analgesia.

Generalized Tetanus in a Gyrfalcon ( Falco rusticolus ) with Pododermatitis.

A 2-yr-old male gyrfalcon ( Falco rusticolus ) was presented for severe and generalized muscle spasticity and pododermatitis. The falcon had been treated for pododermatitis over the previous 4 mo. Muscle rigidity and spasms involved the entire bird but were more severe on the right leg. The bird was also tachypneic and hyperthermic at 45 C. While the plantar pododermatitis lesions had healed, there was still a small abscess on the lateral aspect of the right foot. Clinical signs were consistent with tetanus. Several bacteria were isolated from the abscess including Clostridium tetani . The isolate was confirmed to be toxigenic by PCR. Attempts to detect tetanus toxin in the bird's plasma were unsuccessful. The abscess was debrided. The gyrfalcon received equine tetanus antitoxin, intravenous metronidazole, methocarbamol, midazolam, a constant-rate infusion of Fentanyl, active cooling, and supportive care. Inhalant anesthesia with isoflurane was the only treatment that would lower the body temperature and reduce the clinical signs. The gyrfalcon died a few hours after admission. The characteristic clinical signs and isolation of toxigenic C. tetani from a wound were strong supportive evidence for a diagnosis of tetanus. This case constitutes the first reported natural occurrence of tetanus in an avian species. Further information is needed to determine whether gyrfalcons are more susceptible to tetanus than are other avian species and whether pododermatitis lesions may be risk factors.

Ventral rhinotomy in a pet rabbit (Oryctolagus cuniculus) with an odontogenic abscess and sub-obstructive rhinitis.

A rabbit was presented for severe dyspnea and was diagnosed with an odontogenic abscess obstructing the rostral nasopharynx using CT scan and oral endoscopy. The offending tooth was extracted intraorally, but due to persistent dyspnea, an endoscopic-guided ventral rhinotomy was performed. The dyspnea subsequently resolved, but the rabbit died 5 weeks later from a seemingly unrelated cause.

Rhinotomie ventrale chez un lapin de compagnie(Oryctolagus cuniculus)atteint d'un abcès odontogène et d'une rhinite causant une subocclusion. Un lapin a été présenté pour une dyspnée grave et a été diagnostiqué avec un abcès odontogène bloquant le nasopharynx rostral par tomodensitométrie et endoscopie orale. La dent en cause a été extraite intra-oralement, mais, en raison d'une dyspnée persistante, une rhinotomie ventrale guidée par endoscopie a été réalisée. La dyspnée s'est subséquemment résorbée, mais le lapin est mort 5 semaines plus tard d'une cause apparemment non reliée.(Traduit par Isabelle Vallières).

Diagnosis and Management of Polycythemia Vera in a Ferret (Mustela putorius furo).

A 5-y-old female ferret (Mustela putorius furo) was evaluated for diarrhea, anorexia, and lethargy for 1 wk. Only mild dehydration was detected on physical examination. CBC analysis revealed marked erythrocytosis with an unremarkable plasma biochemistry panel; follow-up CBC analyses revealed a consistent primary erythrocytosis. Whole-body radiographs and abdominal ultrasonography were unremarkable except for a small nephrolith in the right kidney and a small cyst in the left kidney. The plasma erythropoietin level was 17.0 mIU/mL and considered normal. In light of the diagnostic work-up and consistent erythrocytosis, a diagnosis of polycythemia vera (primary erythrocytosis) was made. The initial presentation of diarrhea resolved after treatment with oral metronidazole (20 mg/kg PO BID for 7 d). Treatment for the polycythemia consisted of a phlebotomy initially followed by chemotherapy with hydroxyurea (10 mg/kg PO BID). During the subsequent 12 mo, the hydroxyurea dose adjusted according to follow-up CBC results, and finding an optimal dosage regimen proved to be challenging. One year after the initial diagnosis, the ferret presented to an emergency clinic for acute and severe hemorrhagic diarrhea and died shortly thereafter. The postmortem diagnosis was acute venous infarction of the small and large intestine. To our knowledge, this report is the first to describe the diagnosis and long-term management of polycythemia vera in a ferret and the use of hydroxyurea for this purpose.

Identification of avian bornavirus in a Himalayan monal (Lophophorus impejanus) with neurological disease.

A one-year-old male Himalayan monal (Lophophorus impejanus) was presented for veterinary attention with a history of chronic wasting, weakness and ataxia. The bird died, and post-mortem findings included mild non-suppurative encephalitis and degenerative encephalopathy, lymphoplasmacytic myenteric ganglioneuritis (particularly of the proventriculus), and Wallerian degeneration of the sciatic nerves. Avian bornavirus (ABV) was identified in the brain by immunohistochemistry and reverse-transcriptase polymerase chain reaction. Sequencing of the reverse-transcriptase polymerase chain reaction product indicated the presence of ABV genotype 4, which is generally associated with disease in psittacine birds. Subsequent to the death of the pheasant, ABV genotype 4 was identified at autopsy from a juvenile white-bellied caique (Pionites leucogaster) in the same collection. We hypothesize that the pheasant became infected through contact with psittacine birds with which it shared an aviary. We believe this to be the first reported case of natural ABV infection in a bird in the Order Galliformes.

Tetralogy of Fallot in a 6-year-old albino ferret (Mustela putorius furo).

Tetralogy of Fallot associated with bidirectional shunting across a large ventricular septal defect, was found in a 6-year-old ferret. The prognosis associated with tetralogy of Fallot is usually poor. This case is interesting given the advanced age of the ferret. The bidirectional shunting, responsible for an acyanotic disease, may explain the unexpected prolonged survival in this ferret.

Tétralogie de Fallot chez un furet de 6 ans(Mustela putorius furo) . Une tétralogie de Fallot, associée à un shunt bidirectionnel au travers d'une communication interventriculaire béante, a été découverte chez un furet de six ans. Le pronostic de la tétralogie de Fallot est habituellement sombre. La survie prolongée de l'animal est intéressante. Il est probable que le shunt bidirectionnel, responsable d'une maladie acyanotique, explique l'espérance de vie prolongée de ce furet.(Traduit par les auteurs).