Toxoplasma gondii antibodies in exotic wild felids from Brazilian zoos.

Serum samples from 37 captive exotic felids in 12 zoos from six Brazilian states were assayed for antibodies to Toxoplasma gondii by the modified agglutination test using formalin-fixed whole tachyzoites. Titers greater than or equal to 1:20 were considered positive. Antibodies to T. gondii were found in 24 of 37 (64.9%) felids, including one European lynx (Lynx lynx), two jungle cats (Felis chaus), two servals (Leptailurus serval), two tigers (Panthera tigris), three leopards (Panthera pardus), and 14 of 27 lions (Panthera leo). This is the first serologic analysis for T. gondii infection in exotic wild felids from Brazilian zoos.     

The effects of a probiotic on blood urea nitrogen and creatinine concentrations in large felids

Chronic kidney disease is a common finding in older captive exotic felids. The purpose of this study was to evaluate the effectiveness of a probiotic to reduce blood urea nitrogen and creatinine in large felids. Fifteen adult, large felids (6 tigers [Panthera tigris], 5 lions [Panthera leo], 3 cougars [Puma concolor], and 1 leopard [Panthera pardus]) were administered a probiotic twice daily after a baseline complete blood cell count and plasma chemistry panel was obtained. Plasma chemistry values were rechecked at 2 mo (n = 14) and 6 mo (n = 9). There was no significant change in blood urea nitrogen over time; however, there was a significant change in creatinine over time (P = 0.04). Creatinine concentration decreased significantly between 2 and 6 mo (P = 0.02), and a decrease was seen between 0 and 6 mo, but this change was not significant (P = 0.05). There was no significant difference noted for creatinine concentration between 0 and 2 mo (P = 0.35). This probiotic may be helpful in large felids with elevated creatinine concentrations because of chronic kidney disease; however, further studies are warranted.     

Intervertebral disc extrusion in six cats

Existing reports concerning intervertebral disc disease (IVDD) have focused almost exclusively on dogs, although a small number of individual case reports of IVDD of cats has been published. The medical records of six cats with IVDD were reviewed. Radiographic studies confirmed narrowed intervertebral disc spaces, mineralised intervertebral discs, and one or more extradural compressive lesions of the spinal cord in each cat. All disc extrusions were located in the thoracolumbar region. Surgical decompression of the spinal cord was achieved in all cats by means of hemilaminectomy and removal of compressive extradural material confirmed to be degenerative disc material. Good to excellent neurological recovery was noted in five of the six cats included in this report. Based on this review, it appears that IVDD of cats has many similarities to IVDD of dogs, and that healthy cats with acute intervertebral disc extrusion(s) respond favourably to surgical decompression of the spinal cord.     

Irradiation of diets fed to captive exotic felids: microbial destruction, consumption, and fecal consistency.

Two frozen, raw horse meat-based diets fed to captive exotic felids at Brookfield Zoo were irradiated to determine the extent of microbial destruction and whether radiation treatment would affect consumption and/or fecal consistency in exotic cats. Fifteen cats, two African lions (Panthera leo), two Amur tigers (Panthera tigris altaica), one Amur leopard (Panthera pardus orientalis), two clouded leopards (Neofelis nebulosa), two caracals (Felis caracal), one bobcat (Felis rufus), and five fishing cats (Felis viverrinus), housed at Brookfield Zoo were fed nonirradiated and irradiated raw diets containing horse meat with cereal products and fortified with nutrients: Nebraska Brand Feline and/or Canine Diet (Animal Spectrum, North Platte, Nebraska 69103, USA). Baseline data were obtained during a 2-wk control period (nonirradiated diets), which was followed by a 4-wk period of feeding comparable irradiated diets. Feed intake and fecal consistency data were collected. An estimated radiation dose range of 0.5-3.9 kilograys reduced most microbial populations, depending on specific diet and microbe type. Irradiation had no overall effect on either feed consumption or fecal consistency in captive exotic cats, regardless of species, age, sex, or body mass. Data indicate that irradiation of frozen horse meat-based diets (packaged in 2.2-kg portions) result in microbial destruction in these products but that product storage time between irradiation and sampling may also affect microbial reduction. However, irradiation would be an appropriate method for reducing potentially pathologic bacteria in raw meat fed to exotic cats.     

Blastomycosis in nondomestic felids.

Blastomycosis was diagnosed in six nondomestic felids from eastern Tennessee, including two Asian lions (Panthera leo persicus), one African lion (Panthera leo), one Siberian tiger (Panthera tigris), one cheetah (Acinonyx jubatus), and one snow leopard (Panthera uncia). Clinical signs included lethargy, anorexia, weight loss, dyspnea, sneezing. ataxia, and paresis. Variable nonspecific changes included leukocytosis, monocytosis, moderate left shift of neutrophils, moderate hypercalcemia, hyperproteinemia, and hyperglobulinemia. Thoracic radiographs revealed interstitial and alveolar changes, consolidation or collapse of a lung lobe, bullae formation, and a pulmonary mass. Agar gel immunodiffusion (AGID) serology for Blastomyces dermatitidis was performed in five felids and was positive in three. The tiger had cerebral blastomycosis and was positive for AGID serologic tests of both cerebrospinal fluid and serum. One percutaneous lung aspirate in the snow leopard and one bronchial aspirate in an Asian lion demonstrated B. dermatitidis organisms. whereas tracheal wash samples and a nasal discharge were nondiagnostic in others. Treatment with itraconazole was attempted in four cats. The tiger improved before euthanasia, whereas the others did not survive beyond initial treatments. In four felids, B. dermatitidis was found in the lungs and tracheobronchial lymph nodes associated with a florid pyogranulomatous reaction; the tiger had a pyogranulomatous encephalomyelitis, and the cheetah had a single pulmonary granuloma. Thoracic radiography, cytologic examination of lung lesion aspirates, and B. dermatitidis AGID serology should be performed on clinically ill zoo felids in endemic areas to rule out blastomycosis.     

Identification of Haemobartonella felis (Mycoplasma haemofelis) in captive nondomestic cats.

This study was undertaken to determine whether Haemobartonella felis (Mycoplasma haemofelis), the causative bacterial agent of feline infectious anemia, infects nondomestic cats. Routine complete blood count and polymerase chain reaction (PCR) were performed to detect the gene for 16S ribosomal RNA for the organism. Sixty-four blood samples were collected from 54 nondomestic cats, including tigers (Panthera tigris), cheetahs (Acinonyx jubatus), lions (P. leo), mountain lions (Felis concolor), snow leopards (P. unica), and a jaguar (P. onca). Some cats were sampled on two or three different dates. Two tigers were positive for H. felis by PCR analysis. As previously described in domestic cats, the parasitemia appears to be intermittent in nondomestic cats.     

Antibody response to vaccines for rhinotracheitis, caliciviral disease, panleukopenia, feline leukemia, and rabies in tigers (Panthera tigris) and lions (Panthera leo)

This article presents the results of a study of captive tigers (Panthera tigris) and lions (Panthera leo) vaccinated with a recombinant vaccine against feline leukemia virus; an inactivated adjuvanted vaccine against rabies virus; and a multivalent modified live vaccine against feline herpesvirus, calicivirus, and panleukopenia virus. The aim of the study was to assess the immune response and safety of the vaccines and to compare the effects of the administration of single (1 ml) and double (2 ml) doses. The animals were separated into two groups and received either single or double doses of vaccines, followed by blood collection for serologic response for 400 days. No serious adverse event was observed, with the exception of abortion in one lioness, potentially caused by the incorrect use of the feline panleukopenia virus modified live vaccine. There was no significant difference between single and double doses for all vaccines. The recombinant vaccine against feline leukemia virus did not induce any serologic response. The vaccines against rabies and feline herpesvirus induced a significant immune response in the tigers and lions. The vaccine against calicivirus did not induce a significant increase in antibody titers in either tigers or lions. The vaccine against feline panleukopenia virus induced a significant immune response in tigers but not in lions. This report demonstrates the value of antibody titer determination after vaccination of nondomestic felids.     

Spondylosis deformans and diffuse idiopathic skeletal hyperostosis (dish) resulting in adjacent segment disease

Spondylosis deformans and diffuse idiopathic skeletal hyperostosis (DISH) are usually incidental findings and in most dogs are either asymptomatic or associated with mild clinical signs. Severe spondylosis deformans and DISH can result in complete bony fusion of consecutive vertebral segments. One of the recognised complications following vertebral fusion in human patients is the development of adjacent segment disease, which is defined as degenerative changes, most commonly degenerative intervertebral disc disease, in the mobile vertebral segment neighboring a region of complete vertebral fusion. A similar syndrome following cervical fusion in dogs has been termed the domino effect. The purpose of this retrospective study was to investigate the hypothesis that vertebral fusion occurring secondary to spondylosis deformans or DISH in dogs would protect fused intervertebral disc spaces from undergoing degeneration, but result in adjacent segment disease at neighbouring unfused intervertebral disc spaces. Eight dogs with clinical signs of thoracolumbar myelopathy, magnetic resonance imaging of the thoracolumbar vertebral column, and spondylosis deformans or DISH producing fusion of > or = 2 consecutive intervertebral disc spaces were evaluated. Vertebral fusion of > or = 2 consecutive intervertebral disc spaces was correlated (P = 0.0017) with adjacent segment disease at the neighbouring unfused intervertebral disc space. Vertebral fusion appeared to protect fused intervertebral disc spaces from undergoing degeneration (P < 0.0001). Adjacent segment disease should be considered in dogs with severe spondylosis deformans or DISH occurring in conjunction with a thoracolumbar myelopathy.     

Molecular characterization of Hepatozoon spp. infection in endangered Indian wild felids and canids

Hepatozoon species are parasites that infect a wide variety of domestic and wild animals. The objective of this study was to perform the molecular detection and characterization of Hepatozoon spp. in Asiatic lion, Indian tiger, Indian leopard, Indian wild dog, Indian domestic dog and cat based on partial 18S rRNA gene sequences from Hepatozoon spp. in the naturally infected animals. Hepatozoon spp. could be detected in blood samples of 5 out of 9 Asiatic lions, 2 out of 5 Indian tigers, 2 out of 4 Indian leopards and 2 out of 2 Indian wild dogs and, 2 out of 4 domestic cats and 2 out of 3 domestic dog samples by PCR. Sequencing of PCR amplicon and BLAST analysis of partial 18S rRNA gene sequences indicated that the Hepatozoon spp. in Asiatic lion, Bengal tiger, Indian leopard and domestic cat was Hepatozoon felis (98-99% similarity) and in the Indian wild and domestic dog the phylogenetic neighbour was Hepatozoon canis (97-100% similarity). Presence of H. felis and H. canis in both domestic and wild animals suggested that they are not host specific and the same parasite causes infection in domestic and wild felids and canids in India and from different parts of the world. To our knowledge, this is the first report on detection and molecular characterization of H. felis infection in Asiatic lions, Indian tigers, Indian leopards and H. canis in Indian wild dog. Hepatozoon spp. may be a potential pathogen and an opportunistic parasite in immuno-compromised animals and could thus represent a threat to endangered Indian wild felids and canids.     

Spontaneous lumbar intervertebral disc protrusion in cats: literature review and case presentations

Reports on intervertebral disc disease in cats are rare in the veterinary literature. It has been postulated that intervertebral disc protrusion is a frequent finding during necropsy in cats, without having any clinical relevance (King and Smith 1958, King & Smith 1960a, King & Smith 1960b). However, a total of six cases with disc protrusions and clinically significant neurological deficits have been reported over the past decade. (Heavner 1971, Seim & Nafe 1981, Gilmore 1983, Littlewood et al 1984, Sparkes & Skerry 1990, Bagley et al 1995). As in dogs, there are also two types of intervertebral disc disease in cats: Hansen's type I (extrusion), and type II (herniation). Cervical spinal cord involvement was more commonly recognised in cats than the lumbar or the thoraco lumbar area. Cats over 15 years were mainly affected (King & Smith 1958, King & Smith 1960a, King & Smith 1960b). We describe two cats with lumbar intervertebral disc protrusions. Emphasis is placed on differential diagnoses, treatment and follow-up.     

MENISCAL OSSICLES IN LARGE NON-DOMESTIC CATS

Radiographs of the stifles of 6 species of 34 large, non-domestic cats were reviewed foremost for the presence of meniscal ossicles and then for the presence of the other potential four sesamoids. The animals in the review included 12 lions, 7 tigers, 7 cougars, 3 leopards, 3 bobcats, and 2 jaguars. Fluoroscopy, arthrography, computed tomography, necropsy, and histology were also used to evaluate the stifles of one tiger after euthanasia. Ossicles were found in the region of the cranial horn of the medial meniscus in most of the lions, tigers, leopards, and jaguars. These ossicles were found in half of the cougars but in none of the bobcats. Among the large, non-domestic cats, meniscal ossicles had been reported previously only in Bengal tigers. The lions, tigers, and leopards having meniscal ossicles appeared to have a lateral but often not a medial fabella of the gastrocnemius muscle, an observation previously unreported. Popliteal sesamoids and patellas were present in all the skeletally mature cats.     

Yohimbine antagonizes the anaesthetic effects of ketamine–xylazine in captive Indian wild felids

ObjectiveTo determine the effectiveness of yohimbine as an antagonist of ketamine-xylazine anaesthesia in captive Asiatic lions (Panthera leo persica), tigers (Panthera tigris) and leopards (Panthera pardus).Study designProspective clinical trial.AnimalsFifty-two healthy adult lions, 55 adult leopards and 16 adult male tigers.MethodsCaptive wild felids in Indian zoos were anaesthetized with a combination of ketamine (2.2-2.6 mg kg^?1) and xylazine (1.1-1.3 mg kg^?1) using a dart propelled from a blowpipe. Time to onset of anaesthesia, lateral recumbency and induction time were measured, and physiological variables (respiration, heart rate and rectal temperature) were recorded once after the onset of complete anaesthesia. Anaesthesia was antagonized at various time periods with an intravenous administration of either 0.1 or 0.15 mg kg^?1 yohimbine. Onset of arousal and time to complete anaesthetic recovery were recorded.ResultsA total of 123 immobilizations were conducted between 2000 and 2005. Anaesthetic induction was achieved in 15-25 minutes in all animals. Incidents of sudden recovery or life-threatening effects associated with immobilizations were not observed. Yohimbine effectively antagonized anaesthesia in all animals within 10 minutes without any excitatory behaviour compared to control animals. No adverse reactions/side effects to yohimbine were recorded except that a few leopards exhibited seizure-like signs for a short period immediately after yohimbine administration. The duration of anaesthesia had no significant effect on the recovery time in any of the animals.Conclusion and clinical relevanceYohimbine antagonized the xylazine portion of ketamine-xylazine anaesthesia and thereby hastened recovery from anaesthesia in Asiatic lions, tigers and leopards.     

COMPARISON BETWEEN COMPUTED TOMOGRAPHIC AND SURGICAL FINDINGS IN NINE LARGE-BREED DOGS WITH LUMBOSACRAL STENOSIS

In a three-year prospective study, computed tomographic (CT) and surgical findings were compared for nine large breed dogs with lumbosacral stenosis. Surgically-excised tissue was examined histologically in seven dogs and additional necropsy evaluation was performed in one dog. The CT abnormalities observed at sites of confirmed cauda equina compression were: loss of epidural fat, increased soft tissue opacity, bulging of the intervertebral disc margin, spondylosis, thecal sac displacement, narrowed intervertebral foramen, narrowed vertebral canal, thickened articular process, articular process subluxation, articular process osteophyte, and telescoped sacral lamina. The CT characteristics of lumbosacral degenerative disease and discospondylitis were similar to those described in humans. In three dogs, CT findings at the site of cauda equina compression were consistent with congenital or developmental spinal stenosis, but the method of surgical exposure precluded confirmation. Epidural fibrosis (eight dogs) and multi-level CT abnormalities (six dogs) were identified but the cause(s) and significance were unknown.     

Feline asthma syndrome in African lions (Panthera leo).

Feline asthma syndrome, previously recognized only in domestic cats, was diagnosed in three captive African lions (Panthera leo), one of which died as a result of the condition. Two of the lions displayed progressive signs for 7 yr, including severe bouts of coughing, wheezing, dyspnea, rhonchi, and tachypnea that were most severe during the spring and summer, and the third lion displayed acute signs only once. Scattered to diffuse increased interstitial markings, peribronchial cuffing, and focal atelectasis were visible in radiographs. At necropsy, multiple subpleural bullae, 2-3 cm in diameter, were scattered throughout the lung tissue. There were thick-walled bronchi and bronchioles filled with thick grayish mucus, and alveolar spaces were enlarged with severe, diffuse, banded multifocal areas of alveolar wall fibrosis. The lions had significantly elevated IgE type I immediate hypersensitivity responses to recognized aeroallergens. The captive management of lions should address the design and maintenance of allergen-free air supplies. Ventilation systems should be examined routinely and thoroughly cleaned of any residue. The frequency of examination should increase during the summer. Lions and other large cats should be routinely screened for IgE aeroallergen-specific titers, asthma cases should be treated promptly with prednisolone, and investigations of etiology should be initiated.     

Spinal compression due to atlantal vertebral malformation in two African lions (Panthera leo).

Two young (14-mo-old and 6-mo-old), unrelated, male African lions (Panthera leo) were presented to the Veterinary Teaching Hospitals of Oklahoma State University and Kansas State University with progressive ambulatory difficulty. In both cases, limited neurologic evaluation demonstrated pelvic limb paresis and ataxia with conscious proprioceptive deficits. Spinal imaging showed nearly identical lesions in both cases. Radiography and myelography demonstrated cervical stenosis secondary to atlantal (C1) malformation producing a dorsoventral deformity of the laminar arch with atlantoaxial spinal cord compression between the ventrally displaced laminar arch of the atlas and the underlying odontoid process of C2. Computed tomography of the atlanto-axial junction confirmed cervical stenosis and cord compression, showing flattening of the spinal cord between the laminar arch of C1 and the dens of C2. Decompressive surgery consisting of dorsal laminectomy of C1 was performed. Each lion demonstrated progressive improvement of neurologic status to recovery of normal ambulation after surgical intervention. Neurologic disease in large captive felids is rare; atlanto-axial spondylomyelopathy has not been reported previously.     

An outbreak of canine distemper virus in tigers (Panthera tigris): possible transmission from wild animals to zoo animals

Canine distemper virus (CDV), a morbillivirus that causes one of the most contagious and lethal viral diseases known in canids, has an expanding host range, including wild animals. Since December 2009, several dead or dying wild raccoon dogs (Nyctereutes procyonoides) were found in and around one safari-style zoo in Japan, and CDV was isolated from four of these animals. In the subsequent months (January to February 2010), 12 tigers (Panthera tigris) in the zoo developed respiratory and gastrointestinal diseases, and CDV RNA was detected in fecal samples of the examined tigers. In March 2010, one of the tigers developed a neurological disorder and died; CDV was isolated from the lung of this animal. Sequence analysis of the complete hemagglutinin (H) gene and the signal peptide region of the fusion (F) gene showed high homology among these isolates (99.8-100%), indicating that CDV might have been transmitted from raccoon dog to tiger. In addition, these isolates belonged to genotype Asia-1 and had lower homology (<90%) to the vaccine strain (Onderstepoort). Seropositivity of lions (Panthera leo) in the zoo and wild bears (Ursus thibetanus) captured around this area supported the theory that a CDV epidemic had occurred in many mammal species in and around the zoo. These results indicate a risk of CDV transmission among many animal species, including large felids and endangered species.     

MAGNETIC RESONANCE IMAGING OF THE CAUDAL LUMBAR AND LUMBOSACRAL SPINE IN 13 DOGS (1990–1993)

The caudal lumbar and lumbosacral spine of 13 dogs with pain or neurologic deficits were evaluated using magnetic resonance imaging (MRI). Spin echo T1, proton density, and T2 weighted and gradient echo T2* imaging sequences were utilized. MRI permitted direct, multiplanar, tomographic visualization of the spine facilitating evaluation of all components of degenerative caudal lumbar and lumbosacral stenosis. Abnormalities detected included intervertebral disc degeneration, intervertebral disc protrusion involving both the vertebral canal and intervertebral foramina, articular process osteophytosis, articular process fracture, nerve root impingement by spondylosis deformans, and the presence of low signal material within the vertebral canal of 2 dogs with recurrent pain following previous spinal surgery. In all 7 dogs treated surgically, MRI findings were consistent with surgical findings.     

Cervical intervertebral disc protrusion in two horses

Two horses with ataxia of all four limbs were found to have cervical intervertebral disc protrusion. Severe pelvic limb ataxia, proprioceptive deficits and spasticity were present in both horses with similar but less severe signs in the thoracic limbs. Cerebrospinal fluid analysis was within normal limits. Metrizamide myelography allowed definitive diagnosis in one case when a compression of the spinal cord was demonstrated at the level of the second intervertebral space. In the second case, an intervertebral disc protrusion between cervical vertebrae 6 and 7 was found at necropsy. Fiber degeneration with poor myelin staining characterized the spinal cords histologically.     

Traumatic Intervertebral Disc Herniation with Paraplegia in a Black-Tailed Prairie Dog (Cynomys ludovicianus)

A 2-year-old castrated male black-tailed prairie dog (Cynomys ludovicianus) was presented 48 hours after peracute onset of rear limb paraplegia secondary to a traumatic incident. The prairie dog was nonambulatory in the rear legs with absent deep pain; hematuria and pollakiuria were also observed. Diagnostic imaging revealed intervertebral disc herniation with compression of the spinal cord at the L1-L2 disc spaces. Hemilaminectomy at the L1-L2 disc space was performed. After 48 hours, the prairie dog regained anal tone, and a deep pain response was noted. Azotemia developed during the course of hospitalization likely secondary to neuromuscular damage causing an obstruction in the lower urinary tract but resolved with supportive care. The prairie dog recovered complete use of its hind legs and had normal excretory function at a 3-month recheck. Practitioners should consider intervertebral disc herniation secondary to trauma as a differential diagnosis for neurologic deficits affecting the rear limbs of prairie dogs. Surgical management of intervertebral disc herniation is a viable treatment option in appropriate cases.