SERIAL CHANGES IN METABOLIC ACID-BASE STATUS IN THREE SPECIES OF ANESTHETIZED CAPTIVE LARGE FELID.

Determination of acid-base status contributes important information about patient health, including for patients under anesthesia. There is a paucity of information about the determinants of acid-base status of large felids managed under anesthesia, and advancement of such knowledge may contribute to patient safety. This study serially monitored the individual metabolic acid-base status of 11 large felids, including lions (Panthera leo), tigers (Panthera tigris), and cheetahs (Acinonyx jubatus), under general anesthesia. We analyzed the contributions of measured strong ions (sodium, chloride, potassium, lactate), weak acids and buffers (albumin, phosphate and bicarbonate), and unmeasured anions to standardized extracellular base excess (SBE). A general linear model assessed for species differences in these parameters, with time since immobilization, SBE, and mean arterial pressure as covariates. By employing a Stewart-based analytical approach, it was possible to separate chloremic and unmeasured anion contributions to metabolic acid base status. This provided a basis for identifying mixed metabolic processes, generating differentials for underlying causes. Using normal acid base parameters for domestic felids, metabolic acidosis was found to be prevalent. Frequent evidence of unmeasured anion accumulation was also found, with unmeasured anions occasionally exceeding 5mmol/L. These findings warrant further inquiry into the drivers and clinical significance of metabolic acidosis and unmeasured anion accumulations in anesthetized large felids, encouraging further anion identity studies to elucidate possible causes. Reference ranges need to be established for acid-base parameters in large felids as a foundation for interpreting more controlled, prospective research into determinants of metabolic acid-base status in these animals under anesthesia.

MYCOBACTERIAL DISEASE AND SUBSEQUENT DIAGNOSTIC INVESTIGATIONS IN A GROUP OF CAPTIVE PINNIPEDS IN NEW ZEALAND.

This case series includes a single case of disseminated tuberculous disease due to Mycobacterium pinnipedii in a New Zealand fur seal (Arctocephalus forsteri), which was being cared for by a zoo in New Zealand. The remaining five pinnipeds in the colony underwent extensive mycobacterial disease surveillance over the following 4 yr, involving a total of 26 anesthetic procedures and numerous diagnostic tests that included comparative intradermal tuberculin skin tests, mycobacterial antibody serology, respiratory and gastric lavages, and computed tomography (CT) scans. An additional case of chronic sinusitis due to Mycobacterium marinum and Pseudomonas aeruginosa was identified in a California sea lion (Zalophus californianus). Results from CT and the respiratory lavages were the most helpful antemortem diagnostic tests for active mycobacterial disease in this case series. Of the remaining four animals, two were euthanatized and two remain alive, and none of them had evidence of active mycobacterial disease. Further mycobacterial disease surveillance in staff and animals was performed, and no other case was identified. There are no validated mycobacterial surveillance tests available for pinnipeds and so it remains unknown whether the two surviving pinnipeds are truly negative or whether they have latent mycobacterial infection that could develop into active mycobacterial disease in the future. For this reason, increased levels of biosecurity and quarantine remain permanently in place for the pinniped colony.

UROLITHIASIS IN A GROUP OF VISAYAN WARTY PIGS (SUS CEBIFRONS NEGRINUS).

Four cases of obstructive urolithiasis occurred in male Visayan warty pigs (Sus cebifrons negrinus) during a 12-mo period. One animal died, two were euthanized, and one was treated successfully with a tube cystotomy procedure and a subsequent urinary acidification diet. Uroliths from two cases of urethral obstruction were analyzed and confirmed as calcium carbonate. A fifth nonobstructive case was suspected in an adult female in which calcium carbonate crystalluria was diagnosed, and that case was resolved with medical management. Possible causes of these uroliths included reduced water intake, increased calcium in the diet through use of lucerne hay, and concurrent urinary tract infections. Changes to the diet and access to water were correlated with cessation of further cases, and no recurrence has been seen to date. To the authors' knowledge, this is the first report of calcium carbonate urolithiasis and the first use of a tube cystotomy in a nondomestic pig species.

Really mixed practice - a career in conservation medicine.

James Chatterton is veterinary services manager at Auckland Zoo. Part of his role involves providing veterinary care for the kakapo, one of the most endangered birds in New Zealand. He regularly provides onsite help on two protected islands off the South Island of New Zealand as part of his role as veterinary coordinator to the Kakapo Recovery Group.

SUCCESSFUL SURGICAL TREATMENT OF OBSTRUCTIVE LIVER DISEASE CAUSED BY A BILIARY CALCULUS IN A CAPTIVE CHIMPANZEE (PAN TROGLODYTES).

A 40-yr-old female chimpanzee (Pan troglodytes) presented with intermittent, short-duration episodes of nonspecific clinical signs that included lethargy and reduced responsiveness to external stimuli. Clinical examination and diagnostics suggested obstructive hepatic disease, which was confirmed by subsequent ultrasonographic examination. During routine laparotomy, a biliary calculus was removed from the distal common bile duct and the gallbladder was removed, which resulted in complete clinical recovery. The biliary calculus was analyzed as a mixed composition of predominantly cholesterol, bilirubin, and calcium.

Management of severe respiratory tract disease caused by human respiratory syncytial virus and Streptococcus pneumoniae in captive chimpanzees (Pan troglodytes).

Chimpanzees (Pan troglodytes) are susceptible to many viral and bacterial pathogens of human origin. This case series reports an acute outbreak of respiratory disease due to human respiratory syncytial virus and Streptococcus pneumoniae in a single group of 30 captive chimpanzees. Both pathogens are potentially zoonotic. The diagnosis was made antemortem and enabled a targeted response to the outbreak; but it more importantly, prompted improvements to the disease surveillance, biosecurity for risk mitigation and risk communication protocols within the zoo. A defined zoonotic disease risk communication pathway provides a model for management and compliance requirements for other collections.

Renal trematode infection due to Paratanaisia bragai in zoo housed Columbiformes and a red bird-of-paradise (Paradisaea rubra).

Trematode infections affect a diverse range of avian species and the organs that are parasitised are also very varied. The family Eucotylidae contains seven genera of renal flukes that parasitise various birds. In birds, mild to severe lesions have been reported for species of the genus Paratanaisia, which was originally described from columbiform and galliform specimens collected in South America and has been identified in a number of wild avian species. This paper investigates eight cases of renal trematode infection at Chester Zoo in the UK due to Paratanaisia bragai in five previously unreported species: red bird-of-paradise, Socorro dove, Mindanao bleeding heart dove, laughing dove and emerald dove. Pathological changes, which varied between species, are discussed. A known intermediate snail host Allopeas clavulinum was present in the enclosures but there was no direct evidence of trematode infection. The size of the snails, possible low prevalence and the difficulty of visualising sporocysts contributed to this. Thus the development and application of further molecular diagnostic markers that can be applied to snail tissues is warranted. Parasite identification was confirmed utilizing DNA amplification from formalin-fixed paraffin-embedded tissues using PCR and trematode specific primers. Sequencing full ssrDNA and D1-D3 lsrDNA confirmed the identity in all cases as P. bragai. However, the short 310 bp fragment used provides insufficient variation or sequence length for wider application. The epidemiology, pathology and consequences for the management of these endangered species are discussed. Preliminary work on developing an effective ante mortem diagnostic PCR test kit is also highlighted.