VITAMIN C DEFICIENCY-ASSOCIATED LESIONS IN A COLONY OF COMMON VAMPIRE BATS (DESMODUS ROTUNDUS) IN A ZOO FACILITY.

The Milwaukee County Zoo has housed common vampire bats (Desmodus rotundus) since 1973. The bats are fed defibrinated cow's blood supplemented with a liquid pediatric multivitamin. From July 2013 to May 2014, multiple deaths occurred in colony bats, including five juveniles with multiple bone fractures and failure of endochondral ossification, three adults with cerebellar necrosis, and one adult with subcutaneous hemorrhage. In November 2013, an adult bat developed a nonhealing left wing hematoma and eventually succumbed 9 mo later. A postmortem examination revealed multifocal extensive necrohemorrhagic and suppurative ulcerative dermatitis with no underlying cause determined. From July to December 2014, five of nine adult bats in the colony developed similar hematomas along with gingival bleeding. One euthanized bat had a serum ascorbic acid level of 0.08 mg/dl and marked generalized subcutaneous hemorrhage. A therapeutic trial was initiated in which two bats received defibrinated cow's blood supplemented only with oral vitamin C, 100 mg/kg PO q24h for 3 d, and then 50 mg/kg PO q24h. Two other bats received nonsupplemented defibrinated cow's blood and were given vitamin K 3.3 mg/kg SC q12h for 3 d, and then 3.3 mg/kg SC q24h for 7 d. The bats supplemented with vitamin C improved, supporting a diagnosis of vitamin C deficiency. All bats were subsequently supplemented with vitamin C leading to resolution of all lesions within 10 d to 2 mo. Vitamin C is necessary for collagen synthesis, which is required for proper wound healing, capillary and cartilage strength, osteoid production, and pial membrane formation of the cerebellum. Several bat species cannot synthesize vitamin C and require a dietary source. This is the first report of vitamin C deficiency in a colony of vampire bats leading to severe chronic subcutaneous hemorrhage, bone fragility, microfractures, cerebellar necrosis, and death.

Primary amebic meningoencephalomyelitis caused by Naegleria fowleri in a south-central black rhinoceros (Diceros bicornis minor).

CASE DESCRIPTION A 20-year-old female south-central black rhinoceros (Diceros bicornis minor) was evaluated because of an acute onset of CNS deficits. CLINICAL FINDINGS The rhinoceros had no history of illness. Clinical signs included acute lethargy, ataxia, and decreased appetite. Hematologic abnormalities included leukocytosis with neutrophilia and a profound left shift. Results of serum biochemical analysis revealed hypophosphatemia but no other abnormalities. Results of a quantitative PCR assay for West Nile virus and an assay for anti-Neosporum caninum antibodies in serum were negative; the patient was seropositive for multiple Leptospira serovars. TREATMENT AND OUTCOME Antimicrobials and anti-inflammatory agents were administered, but the condition of the rhinoceros worsened overnight; despite treatment with additional anti-inflammatory and antimicrobial agents, IV fluids, and thiamine, it became obtunded and died of respiratory arrest ≤ 24 hours later. Necropsy revealed severe, diffuse, suppurative, and histiocytic meningo-encephalomyelitis involving the cerebrum, cerebellum, and spinal cord. Amebic trophozoites were observed on histologic examination of affected tissue. Infection with Naegleria fowleri was confirmed by results of immuno-histochemical analysis and a multiplex real-time PCR assay. CLINICAL RELEVANCE Findings suggested that south-central black rhinoceros are susceptible to the free-living ameba N fowleri. Ameba-induced meningoencephalomyelitis should be considered as a differential diagnosis for rhinoceros that have an acute onset of neurologic signs. Diagnosis of N fowleri infection in an animal has a profound public health impact because of potential human exposure from the environment and the high fatality rate in people with N fowleri infection.

Definitive Hosts of Versteria Tapeworms (Cestoda: Taeniidae) Causing Fatal Infection in North America.

We previously reported fatal infection of a captive Bornean orangutan with metacestodes of a novel taeniid tapeworm, Versteria sp. New data implicate mustelids as definitive hosts of these tapeworms in North America. At least 2 parasite genetic lineages circulate in North America, representing separate introductions from Eurasia.

Fatal metacestode infection in Bornean orangutan caused by unknown Versteria species.

A captive juvenile Bornean orangutan (Pongo pygmaeus) died from an unknown disseminated parasitic infection. Deep sequencing of DNA from infected tissues, followed by gene-specific PCR and sequencing, revealed a divergent species within the newly proposed genus Versteria (Cestoda: Taeniidae). Versteria may represent a previously unrecognized risk to primate health.

Accessory carpal bone luxation in two gray wolves (Canis lupus).

Two sibling male castrated gray wolves (Canis lupus) developed acute onset right forelimb lameness, one at 8 and the other at 11 yr of age. In both cases, the right carpus was swollen, carpal hyperextension was notable, and the wolves exhibited significant intermittent lameness of the affected limb. Radiographs revealed right accessory carpal bone luxation in both cases, with type III fracture of the accessory carpal bone in one wolf. Although carpal bone luxation in domestic dogs is frequently treated surgically, conservative medical management resolved the lameness in both wolves with no further complications.

Alternative therapeutic options for medical management of epilepsy in apes.

Phenobarbital has been the primary antiepileptic drug used in primates, but the dosage required for seizure control is frequently associated with significant side effects. Newer antiepileptic drugs and adjunctive therapies currently being used in human medicine provide additional options for treatment of nonhuman primates. This report describes different drug regimes used for control of epileptic seizures in apes at the Milwaukee County Zoo (Milwaukee, Wisconsin, U.S.A.), including the addition of acetazolamide to phenobarbital, levetiracetam, carbamazepine, and the use of extended cycle oral contraceptives to assist seizure control in female apes with catamenial epilepsy.

Effects of anesthesia and surgery on serial blood gas values and lactate concentrations in yellow perch (Perca flavescens), walleye pike (Sander vitreus), and koi (Cyprinus carpio).

OBJECTIVE-To evaluate serial blood gas values and lactate concentrations in 3 fish species undergoing surgery and to compare blood lactate concentrations between fish that survived and those that died during the short-term postoperative period. DESIGN-Prospective cohort study. Animals-10 yellow perch, 5 walleye pike, and 8 koi. PROCEDURES-Blood samples were collected from each fish at 3 time points: before anesthesia, during anesthesia, and immediately after surgery. Blood gas values and blood lactate concentrations were measured. Fish were monitored for 2 weeks postoperatively. RESULTS-All walleye and koi survived, but 2 perch died. Blood pH significantly decreased in perch from before to during anesthesia, but increased back to preanesthesia baseline values after surgery. Blood Pco(2) decreased significantly in perch from before anesthesia to immediately after surgery, and also from during anesthesia to immediately after surgery, whereas blood Pco(2) decreased significantly in koi from before to during anesthesia. Blood Po(2) increased significantly in both perch and koi from before to during anesthesia, and also in koi from before anesthesia to immediately after surgery. For all 3 species, blood lactate concentrations increased significantly from before anesthesia to immediately after surgery. Blood lactate concentration (mean +/- SD) immediately after surgery for the 8 surviving perch was 6.06 +/- 1.47 mmol/L, which was significantly lower than blood lactate concentrations in the 2 nonsurviving perch (10.58 and 10.72 mmol/L). CONCLUSIONS AND CLINICAL RELEVANCE-High blood lactate concentrations following surgery in fish may be predictive of a poor short-term postoperative survival rate.

Coccidioidomycosis in a black rhinoceros (Diceros bicornis).

A 5-yr-old female black rhinoceros (Diceros bicornis) was euthanized 11 mo after arrival at the Milwaukee County Zoo (Milwaukee, Wisconsin, USA) from Glen Rose, Texas (USA) for a severe progressive rear leg lameness of 6-mo duration. Gross necropsy revealed complete rupture of the capital ligament of the left femur with synovitis and osteomyelitis. Multifocal lymphadenopathy with chronic suppurative lymphadenitis of the tracheobronchial, left supramammary, and iliac lymph nodes was present. Granulomatous pneumonia with a focal abscess was also noted. Histologically, fungal elements were seen in the lung, lymph nodes, and synovium, and Coccidioides immitis was isolated on fungal culture. Coccidioides immitis is not endemic to Wisconsin; therefore, the animal had to have been infected, although asymptomatic, at the time of arrival at the Milwaukee County Zoo. Whether the disease was active at the time of arrival or whether it was quiescent and then became active with the stress of shipment or injury is unknown.

Visceral and presumptive neural baylisascariasis in an orangutan (Pongo pygmaeus).

A 32.5-year-old female hybrid orangutan (Pongo pygmaeus) developed hind-limb stiffness that progressed to tetraparesis over 2 wk. Repeated diagnostic evaluations, including serial magnetic resonance imaging of the central nervous system, revealed nonspecific lesions involving both the deep white and gray matter with an intact blood-brain barrier. Multiple empirical treatments failed to produce improvement and the animal was humanely euthanized. Histology of a granuloma in the ileum contained a nematode parasite, most consistent with Baylisascaris procyonis. Additionally, neuropil vacuolization, rarefaction, astrocytic scarring, and an eosinophilic granuloma and lymphoeosinophilic perivascular cuffing in the brain were suggestive of nematode migration. These findings confirm the presence of visceral larval migrans and support the presence of neural larval migrans. This case report of Baylisascaris procyonis confirms the presentation for the first time in an ape and documents the difficulty in antemortem diagnosis of neural larval migrans.

Erythema multiforme in a spotted hyena (Crocuta crocuta).

A 10.5-yr-old male spotted hyena (Crocuta crocuta) developed acute, severe erythematous and ulcerative dermatitis of the hindquarters, feet, face, and ears 19 days after receiving a recombinant canary pox vectored canine distemper vaccine. Biopsies of the lesions supported a diagnosis of erythema multiforme (EM), which is an immune-mediated disorder that can occur days to months after exposure to antigenic stimuli. During the lengthy recovery, esophageal regurgitation and ulceration developed either as complications of the disease or secondary to therapy. The esophageal disease was managed with metoclopramide, sulcrafate, omeprazole, and frequent feedings. The distemper vaccine is postulated to have been the inciting cause of EM in this animal.