Objective—To characterize and quantitatively assess the typical pulmonary anatomy of healthy adult alpacas with multidetector row CT.
Animals—10 clinically normal adult female alpacas.
Procedures—CT examination of the thorax was performed before and after IV administration of iodinated contrast medium in sedated alpacas in sternal recumbency. Measurements of the trachea, bronchi and related blood vessels, and selected vertebrae as well as the extent and density of lung parenchyma were performed with a Digital Imaging and Communications in Medicine (DICOM) viewer. Morphometric and quantitative data were summarized.
Results—Separation of individual lung lobes could not be identified, except for the accessory lung lobe. In all alpacas, both lungs extended farther caudally at the medial aspect than at the lateral aspect. The right lung extended farther in both cranial and caudal directions than did the left lung. The branching pattern of the bronchial tree varied only slightly among alpacas and consisted of 1 cranial bronchus and 3 caudal bronchi bilaterally, with a right accessory bronchus. Luminal diameters of first-generation bronchi ranged from 3 to 9 mm. Mean ± SD parenchymal lung density was −869 ± 40 Hounsfield units (HU) before contrast injection and −825 ± 51 HU after contrast injection. Mean difference in diameter between bronchi and associated arteries or veins was 0.8 ± 0.9 mm.
Conclusions and Clinical Relevance—Knowledge of the typical anatomy of the lungs and bronchial tree in healthy alpacas as determined via CT will aid veterinarians in clinical assessment and bronchoscopic evaluation of alpacas.
Procedure—Llamas were allocated to 1 of 3 groups
(3 llamas/group). Fentanyl patches (each providing
transdermal delivery of 75 µg of fentanyl/h) were
placed on shaved areas of the antebrachium of all llamas.
In group 1, llamas were treated with 1 patch
(anticipated fentanyl dosage, 75 µg/h). In group 2, llamas
were treated with 2 patches (anticipated fentanyl
dosage, 150 µg/h). In group 3, llamas were treated
with 4 patches (anticipated fentanyl dosage,
300 µg/h). For each llama, the degree of sedation was
assessed by use of a subjective scoring system and a
blood sample was collected for determination of
serum fentanyl concentration at 12, 24, 36, 48, 60,
and 72 hours after patch placement.
Results—Following the placement of 4 patches,
mean ± SD serum fentanyl concentration in group 3
llamas reached 0.3 ± 0.08 ng/mL within 12 hours. This
concentration was sustained for 72 hours. In group 2,
application of 2 patches provided inconsistent results;
in group 1, application of 1 patch rarely provided measurable
serum fentanyl concentrations. No llamas
became sedated at any time.
Conclusions and Clinical Relevance—Results suggest
that application of four 75 µg/h fentanyl patches
provides consistent, sustained serum fentanyl concentrations
without sedation in llamas. However, the
serum concentration of fentanyl that provides analgesia
in llamas is not known. (Am J Vet Res
Objective—To determine the minimum alveolar concentration
(MAC) of sevoflurane in spontaneously
breathing llamas and alpacas.
Animals—6 healthy adult llamas and 6 healthy adult
Procedure—Anesthesia was induced with sevoflurane
delivered with oxygen through a mask. An endotracheal
tube was inserted, and a port for continuous
measurement of end-tidal and inspired sevoflurane
concentrations was placed between the endotracheal
tube and the breathing circuit. After equilibration at an
end-tidal-to-inspired sevoflurane concentration ratio
> 0.90 for 15 minutes, a 50-Hz, 80-mA electrical stimulus
was applied to the antebrachium until a response
was obtained (ie, gross purposeful movement) or for
up to 1 minute. The vaporizer setting was increased or
decreased to effect a 10 to 20% change in end-tidal
sevoflurane concentration, and equilibration and stimulus
were repeated. The MAC was defined as the
mean of the lowest end-tidal sevoflurane concentration
that prevented a positive response and the highest
concentration that allowed a positive response.
Results—Mean ± SD MAC of sevoflurane was 2.29 ±
0.14% in llamas and 2.33 ± 0.09% in alpacas.
Conclusions and Clinical Relevance—The MAC of
sevoflurane in llamas and alpacas was similar to that
reported for other species. (J Am Vet Med Assoc
Case Description—20 alpaca crias (13 females and 7 males) were examined for diarrhea (n = 20), weight loss (15), and poor appetite (5). Fourteen crias were between 8 and 18 days of age at time of admission.
Clinical Findings—Cryptosporidiosis was diagnosed in all crias. Common biochemical abnormalities included acidemia, hyperlactemia, azotemia, and hyperglycemia and increases in aspartate transaminase and γ-glutamyltransferase activities. Serum sodium and chloride concentrations were high or low. Other potential gastrointestinal tract pathogens were identified in only 7 crias.
Treatment and Outcome—Supportive care was instituted, including IV administration of fluids with partial parenteral administration of nutrients (n = 19 crias), antimicrobials (19), supplemental orally administered nutrients (11), administration of plasma (10), and insulin treatment (9). Other palliative treatments used by attending clinicians were sucralfate, flunixin meglumine, vitamin A/D/E/B complex, antiparasitic agents, antidiarrheal agents, and azithromycin. Three crias with inadequate urine production and severe azotemia were treated with furosemide administered IV as a bolus or as a constant-rate infusion. Treatment resulted in a successful outcome in 16 of 20 crias. Weight loss and refractory azotemia were common in nonsurvivors but not in surviving crias.
Clinical Relevance—Findings suggested that Cryptosporidium spp may be a diarrheal pathogen of unweaned alpaca crias that may be more widespread than has been recognized and can become endemic on some farms. Metabolic derangements were unpredictable and should be determined by biochemical analysis before fluid and electrolyte replacement is initiated. Cryptosporidiosis has zoonotic potential, and the infection can be self-limiting in alpacas receiving supportive treatment.
Case Description—15 llamas and 34 alpacas between 3 weeks and 18 years old with fecal oocysts or intestinal coccidial stages morphologically consistent with Eimeria macusaniensis were examined. Nineteen of the camelids were admitted dead, and 30 were admitted alive. Camelids admitted alive accounted for 5.5% of all camelid admissions during this period.
Clinical Findings—Many severely affected camelids had signs of lethargy, weight loss, decreased appetite, and diarrhea. Camelids with clinical infection also commonly had evidence of circulatory shock, fat mobilization, and protein loss. Nonsurviving camelids also had evidence of shock, edema, bile stasis, renal insufficiency, hepatic lipidosis, muscle damage, relative hemoconcentration, and sepsis. Postmortem examination frequently re-vealed complete, segmental replacement of the mucosa of the distal portion of the jejunum with coccidial meronts and gamonts. For 17 of 42 camelids, results of initial fecal examinations for E macusaniensis were negative.
Treatment and Outcome—Most camelids admitted alive were treated with amprolium hydrochloride, plasma, and various supportive treatments. Fifteen of the 30 treated camelids died or were euthanized.
Clinical Relevance—Findings suggest that E macusaniensis may be an important gastrointestinal tract pathogen in camelids of all ages. Clinical signs were frequently nonspecific and were often evident before results of fecal examinations for the parasite were positive. As with other coccidia, severity of disease was probably related to ingested dose, host immunity, and other factors. The clinical and herd relevance of positive fecal examination results must be determined.