Comparison of carfentanil-xylazine and thiafentanil-medetomidine in electroejaculation of captive gaur (Bos gaurus).

Carfentanil citrate and thiafentanil oxalate have been used successfully to immobilize captive and free-ranging ungulates. The objective of this study was to compare the efficacy and certain physiologic parameters of protocols by using the 2 opioids in gaur (Bos gaurus). Eight adult gaur bulls were immobilized for electroejaculation at Omaha's Henry Doorly Zoo (Omaha, Nebraska, USA). All the animals were immobilized twice, by using each of the following protocols one time: 10 mg carfentanil combined with 100 mg xylazine (CX), reversed with 1,000 mg naltrexone and 24 mg yohimbine; and 12 mg thiafentanil combined with 20 mg medetomidine (TM), reversed with 120 mg naltrexone and 100 mg atipamezole. Immobilization drugs were delivered intramuscularly into the shoulder area via pole syringe. Electroejaculation was carried out by a standardized protocol to duplicate procedural stimulation on each animal. Induction and recovery times, initial rectal temperature, heart rate, respiratory rate, anesthetic depth, oxygen saturation, indirect blood pressure, and arterial blood gases were recorded at the time of initial handling, before ejaculation, and after ejaculation. Antagonists were administered 1/4 i.v. and 3/4 s.q. Both protocols require a small volume of drug for a large ungulate, provide smooth induction, and adequate anesthesia. Both protocols produced a significant hypoxemia, although the animals on CX showed slightly better blood gas values (based on lower partial pressure of carbon dioxide) and numerically lower blood pressure values. Animals on TM had better muscle relaxation and smoother recoveries, with no renarcotization noted. The results of the present study indicate the TM and CX protocols used for immobilizing gaur result in similar quality ejaculates that can be used for fertility examination as well as for assisted reproduction such as artificial insemination. Additional immobilizations need to take place to further compare these 2 combinations in this species.

Influence of feeding raw or extruded feline diets on nutrient digestibility and nitrogen metabolism of African wildcats (Felis lybica).

The African wildcat is one of the closest ancestors to the domestic cat and is believed to have similar nutrient requirements, but research is lacking. The objective of this study was to determine the effects of feeding a high-protein extruded kibble diet vs. a raw meat diet on nutrient digestibility, nitrogen metabolism, and blood metabolite concentrations in African wildcats. Five wildcats were randomized onto either a high-protein (>50% crude protein) extruded kibble diet or a raw meat diet. The study was executed as a crossover design, with 21-d periods, consisting of a 16-d adaptation phase followed by a 4-d total fecal and urine collection phase. Cats were housed individually in metabolism cages and fed to maintain body weight (BW). A fresh fecal sample was collected for short-chain fatty acid (SCFA) and branched-chain fatty acid (BCFA) analyses. Blood was analyzed for serum chemistry and leptin concentration. Food intake (as is) did not differ (P>0.05) between diets. Food intake and fecal output (g/d DMB) were greater (P<0.05) when cats consumed the kibble diet. Protein digestibility was higher (P<0.05) when cats were fed the raw meat diet vs. the kibble diet. Nitrogen intake was greater (P<0.05) when cats consumed the kibble diet, and more (P<0.05) nitrogen was present in the feces; however, the percentage of nitrogen retained and nitrogen balance did not differ (P>0.05). Fecal scores, ammonia, SCFA, and BCFA concentrations did not differ (P>0.05) between diets. Fecal butyrate molar ratio was higher (P<0.01) when cats consumed the kibble diet. Blood analyses demonstrated few differences between diets, but alanine aminotransferase activity and bicarbonate were higher (P<0.05) when cats consumed the commercial raw meat diet. Owing to lack of differences, these data indicate that African wildcats can readily utilize a high protein extruded kibble diet, and may be able to replace a commercial raw meat diet.

Evaluation of nutrient digestibility and fecal characteristics of exotic felids fed horse- or beef-based diets: use of the domestic cat as a model for exotic felids.

The objective of this study was to determine the effects of feeding commercially available beef- and horse-based diets on nutrient digestibility and fecal characteristics of large captive exotic felids and domestic cats. Four species of large exotic felids including cheetahs, Malayan tigers, jaguars, and Amur tigers, and domestic cats were utilized in a crossover design. Raw meat diets included a beef-based diet (57% protein; 28% fat) and a horse-based diet (51% protein; 30% fat). All cats were acclimated to the diet for 16 days followed by a 4 day collection period, where total feces, including one fresh sample, were collected. All feces were scored on collection. Intake did not differ due to diet, but fecal output was greater when cats consumed the horse-based diet. Total tract apparent dry matter (DM) digestibility was higher (P<0.05) and organic matter (OM) and crude protein (CP) digestibilities were lower (P<0.05) when cats were fed the beef-based diet compared with the horse-based diet. CP digestibility was similar in domestic cats and cheetahs, and greater (P<0.05) than Amur tigers. Fecal scores were lower and fecal DM was greater (P<0.05) when cats consumed the horse-based diet compared with the beef-based diet. Domestic cats had lower (P<0.05) fecal ammonia concentrations compared with all other species. Fecal ammonia concentrations were lowest (P<0.05) when cats were fed the horse-based diet. Fecal total short-chain fatty acid (SCFA), branched-chain fatty acid (BCFA), and butyrate concentrations were higher (P<0.05) when cats consumed the beef-based diet. Our results suggest that the domestic cat serves as an appropriate model for large exotic felid species, but differences among the species exist. Decreased nutrient digestibility by tigers and jaguars should be considered when developing feeding recommendations for these species based on domestic cat data.

An outbreak of avian mycobacteriosis caused by Mycobacterium intracellulare in little blue penguins (Eudyptula minor).

Mycobacterium intracellulare (MIT) was diagnosed postmortem by culture and supporting histopathology in seven birds from a flock of little blue penguins (Eudyptula minor) at the Henry Doorly Zoo (HDZ). These birds represented 20% of the deaths in the population over a 4 yr period. Clinical signs in affected birds included severe respiratory distress characterized by open-mouth breathing with chronic debilitation. On exam, plaques were noted in the larynx, trachea, and soft tissue of the caudal oropharynx. Index cases were identified on necropsy in two birds on loan to another institution in 2003. Following a case confirmed antemortem at the HDZ, a three-drug protocol of rifampin (15 mg/kg p.o. s.i.d.), ethambutol (15 mg/kg p.o. s.i.d.), and clarithromycin (10 mg/kg p.o. s.i.d.) was started on this bird in 2004 and extended to the entire flock in 2005. Gastric wash, fecal samples, and throat plaques were obtained antemortem on five birds within the flock, selected because of the presence of oral plaques, and tested by culture followed by a polymerase chain reaction assay. MIT was detected in gastric washes from four birds and in throat plaques from all five. Three more birds died during treatment. After the seventh bird died, antimicrobial susceptibility testing performed in July 2007 indicated that the MIT was now resistant to most antibiotics tested, including rifampin and ethambutol. The treatment regimen was changed to minocycline (10 mg/kg p.o. b.i.d.) and clarithromycin (10 mg/kg p.o. s.i.d.). Oral plaques were not seen on monthly rechecks of the flock through November 2008. The proposed mechanism of transmission is exposure to wild birds but the source has not been determined. These cases of avian mycobacteriosis caused by MIT are the first known cases reported in little blue penguins.

Nutrient digestibility and fecal characteristics are different among captive exotic felids fed a beef-based raw diet.

Nutrient digestibility has not been well characterized in exotic felids. The objective of this experiment was to evaluate differences in nutrient digestibility and fecal characteristics in five large exotic captive felid species, including bobcats, jaguars, cheetahs, Indochinese tigers, and Siberian tigers. All animals were individually housed and adapted to a beef-based raw diet (Nebraska Brand((R)) Special Beef Feline, North Platte, NE) for 16 d. Total fecal collections were conducted from days 17 to 20. Fecal samples were weighed and scored on collection. Diet and fecal samples were evaluated for dry matter, organic matter, protein, fat, and energy to determine total tract digestibility. Fresh fecal samples were collected to determine fecal pH, ammonia, phenol, indole, short-chain fatty acid, and branched-chain fatty acid concentrations. Fecal scores were greater (P<0.01) in Indochinese tigers when compared with all other species, and cheetahs had greater (P<0.01) fecal scores than jaguars and bobcats. Fat digestibility was greater (P<0.01) in Siberian tigers, Indochinese tigers, and bobcats (96%) compared with cheetahs and jaguars (94%). Digestible energy was greater (P<0.05) in bobcats and Indochinese tigers at 93.5 and 92.9%, respectively, compared with cheetahs and jaguars, 91.6%. Fecal pH was greater (P<0.01) in bobcats compared with all other species evaluated. Indole concentrations were greater (P<0.05) in cheetahs and jaguars compared with bobcats and Indochinese tigers. Fecal ammonia concentrations were increased (P<0.05) in cheetahs compared with all other species. The beef-based raw diet was highly digestible; however, differences in fat and digestible energy suggest that species should be considered when determining caloric needs of exotic felids. Zoo Biol 27:126-136, 2008. (c) 2008 Wiley-Liss, Inc.

Xylazine-midazolam-ketamine versus medetomidine-midazolam-ketamine anesthesia in captive Siberian tigers (Panthera tigris altaica).

Two alpha2-adrenoceptor agents, xylazine and medetomidine, in combination with midazolam and ketamine safely and effectively immobilized Siberian tigers (Panthera tigris altaica). The medetomidine protocol used smaller drug volumes, and induction and recovery times were shorter. Although cardiopulmonary abnormalities were noted, none were likely to be life threatening.