Digital-image Analysis of the Brain-base Arteries in Chinchilla, Chinchilla laniger (Molina)

This paper attempts to quantitatively characterize the cerebral arterial circle in the chinchilla using a computerized image-analysis system. The sole source of the blood supply to the brain in this animal is the vertebral arteries and the basilar arteries. It was found that the diameter and volume of the basilar artery were over twofold larger than those of cerebral-circle arteries. The total length of the cerebral-circle arteries was approximately two times greater than the length of the basilar artery. A strong correlation between the parameters of the basilar artery and the total volume of the arterial circle was observed, as might be expected. These results suggest that if appropriate geometrical parameters are maintained, the brain can be adequately vascularized, even in the absence of additional blood supply.     

Organisation of Autonomic Nervous Structures in the Small Intestine of Chinchilla (Chinchilla laniger,Molina)

Using histochemical, histological and immunocytochemical methods, organisation of the autonomic nerve structures in small intestine of chinchilla was investigated. Myenteric plexus was localised between circular and longitudinal layers of the smooth muscles. Forming network nodes, the small autonomic, cholinergic ganglia were linked with the bundles of nerve fibres. Adrenergic structures were visible as specific varicose, rosary‐like fibres forming bundles of parallel fibres connecting network nodes. Structures of the submucosal plexus formed a finer network than those of the myenteric plexus. Moreover, in ‘whole‐mount’ specimens, fibres forming thick perivascular plexuses were also observed. Immunocytochemical studies confirmed the cholinergic and adrenergic character of the investigated structures. VAChT‐positive neurones were found only in myenteric plexus, and numerous VAChT‐positive and DBH‐positive fibres were found in both plexuses.     

Lumbar osteosarcoma in a chinchilla (Chinchilla laniger)

An 11-year-old male chinchilla was presented for investigation of progressive weight loss, apathy, anorexia, changes in faecal quality and alopecia on the tip of the tail. On clinical examination, a stiffness of the back legs was noted. Abdominal palpation revealed a hard immobile, irregular structure in the region of the last lumbar vertebrae. Subsequent radiography and ultrasonography suggested the presence of neoplasia. The following day the chinchilla was showing hindlimb paralysis, and there was severe self-trauma to the distal 5 cm of the tail. In view of the rapid clinical deterioration, the chinchilla was euthanased with the owner's consent. Macroscopic examination supported the clinical suspicion of neoplasia. Histopathological examination revealed a reactive osteoblastic osteosarcoma. To the author's knowledge, this is the first report of osteosarcoma in chinchillas.     

Use of computed tomography to investigate cheek tooth abnormalities in chinchillas (Chinchilla laniger)

Computerised tomographic scanning was used to investigate tooth structure in chinchillas ( Chinchilla laniger ), both cheek tooth crown and root abnormalities being common in this species. This paper describes a common form of dental disease affecting species with continuously growing teeth, with particular reference to the chinchilla, and confirms the potential role of computed tomography (CT) in its early diagnosis. CT imaging is compared with previously available methods of investigation which frequently fail to detect early pathological changes.     

Drinking preferences in chinchillas (Chinchilla laniger), degus (Octodon degu) and guinea pigs (Cavia porcellus)

Chinchilla (Chinchilla laniger), degus (Octodon degus) and guinea pigs (Cavia porcellus) are South American rodents living in a semi‐arid habitat with varying, species‐specific adaptations to water deprivation. Nonetheless, several diseases have been linked to insufficient water intake when these species are kept as pets, such as urolithiasis or obstipation. This study evaluated preferences for drinking systems. Six animals of each species were given a choice between an open dish and a nipple drinker. Food intake and water intake were measured daily for 13 days. Chinchillas in this study had significantly lower water intakes than the other two species, indicating particular species‐specific adaptations to aridity. All chinchillas favoured open dishes, whereas the degus and guinea pigs had variable individual preferences. Water intake of chinchillas was similar or higher in this study than in previous studies where nipple drinkers were used. The results indicate that degus and guinea pigs can meet their drinking water needs with nipple drinkers; for chinchillas, other drinking systems may be more adequate.     

Effects of Ultraviolet Radiation on Serum 25-Hydroxyvitamin D Concentrations in Captive Chinchillas (Chinchilla laniger)

Vitamin D is an important hormone in vertebrates, and most animals acquire this hormone through their diet and/or exposure to ultraviolet B (UVB) radiation. To date, no study has determined how chinchillas (Chinchilla laniger) acquire vitamin D. The objective of this study was to determine whether exposure to UVB radiation had an effect on serum 25-hydroxyvitamin D levels in captive chinchillas. Overall, 10 juvenile chinchillas were used for this scientific investigation. Baseline blood samples were collected from the animals while under isoflurane anesthesia to determine their serum 25-hydroxyvitamin D concentrations. The chinchillas were then randomly assigned to 2 treatment groups: Group A, 12 hours of UVB exposure per day and Group B, no UVB exposure. At the end of the study (Day 16), a second blood sample was collected from each animal while again under isoflurane anesthesia to measure serum 25-hydroxyvitamin D concentrations. Mean ± standard deviation serum 25-hydroxyvitamin D concentrations differed significantly (P = 0.048) between juvenile chinchillas provided supplemental UVB radiation (189.0 ± 102.7 nmol/L) and those not provided supplemental UVB radiation (87.8 ± 34.4 nmol/L). This study found that exposing juvenile chinchillas to UVB radiation significantly increased their circulating serum 25-hydroxyvitamin D levels. Because vitamin D is an essential hormone in vertebrates, these findings suggest that the provision of UVB radiation to captive chinchillas may be important. Further research to elucidate the importance of 25-hydroxyvitamin D and UVB radiation in captive chinchillas is required.     

Isolation of a Campylobacter lanienae‐like Bacterium from Laboratory Chinchillas (Chinchilla laniger)

Routine necropsies of 27 asymptomatic juvenile chinchillas revealed a high prevalence of gastric ulcers with microscopic lymphoplasmacytic gastroenteritis and typhlocolitis. Polymerase chain reaction (PCR) analysis using Campylobacter genus‐specific partial 16S rRNA primers revealed the presence of Campylobacter spp. DNA in the faeces of 12 of 27 animals (44.4%). Species‐specific partial 16S rRNA PCR and sequencing confirmed that these animals were colonized with Campylobacter lanienae, a gram‐negative, microaerophilic bacterium that was first identified on routine faecal screening of slaughterhouse employees and subsequently isolated from faeces of livestock. Campylobacter lanienae was isolated from the faeces of six PCR‐positive animals and identified with species‐specific PCR and full 16S rRNA sequencing. Phylogenetic analysis showed that these isolates clustered with C. lanienae strain NCTC 13004. PCR analysis of DNA extracted from gastrointestinal tissues revealed the presence of C. lanienae DNA in the caecum and colon of these chinchillas. Gastrointestinal lesions were scored and compared between C. lanienae‐positive and C. lanienae‐negative animals. There was no correlation between colonization status and lesion severity in the stomach, liver, duodenum, or colon. Possible routes of C. lanienae infection in chinchillas could include waterborne transmission and faecal–oral transmission from wild mice and rats or livestock. Based on these findings, the authors conclude that C. lanienae colonizes the lower bowel of chinchillas in the absence of clinical disease. This is the first report of C. lanienae in any rodent species. Campylobacter lanienae isolates from different mammalian species demonstrate heterogeneity by 16S rRNA sequence comparison. Analysis using rpoB suggests that isolates and clones currently identified as C. lanienae may represent multiple species or subspecies.     

Cleft Palate in a Chinchilla (Chinchilla lanigera)

A 5-month-old female chinchilla (Chinchilla lanigera) was evaluated for failure to thrive, difficulty drinking, and respiratory signs. Physical examination demonstrated a thin body condition score, purulent nasal and ocular discharge, and an abnormal facial appearance. Endoscope-guided oral examination and computed tomography (CT) scan demonstrated a cleft soft palate, absent nasal turbinates, and bilateral otitis media. The animal was euthanized and necropsy confirmed the diagnosis of palatoschisis (cleft palate) of the soft palate. Other relevant postmortem findings included otitis media, interna, and externa, bony bullae proliferative changes, absent nasal turbinates and rhinosinusitis. Congenital abnormalities are rarely reported in chinchillas. While cleft palates have been reported in many other domestic animals, there are no published reports of this condition in chinchillas to the best of the authors’ knowledge.     

A Review of Disorders of the Gallbladder and Extrahepatic Biliary Tract in the Dog and Cat

Disorders of the gallbladder and extrahepatic biliary tract in the dog and cat can easily be confused with other intra-abdominal disorders. This confusion results because many times the clinical course and signs of biliary tract disease are similar to these other intra-abdominal disorders. This review discusses the normal anatomy and physiology of the gallbladder, bile duct, and bile in the dog and cat and then summarizes the historic, physical examination, clinicopathologic, diagnostic, histologic and therapeutic aspects of all the cases of extrahepatic biliary tract disease reported in the veterinary literature.     

Semen-Matrix Calculi in a Juvenile Chinchilla (Chinchilla lanigera)

A 10-month-old, intact male chinchilla (Chinchilla lanigera) was diagnosed with urolithiasis, unilateral hydroureter, and hydronephrosis secondary to ureteral obstruction confirmed by radiography and ultrasonography. Nephrectomy and cystotomy were performed, and the urolith was suspected to be a semen-matrix calculus (mineralized copulatory plug) based on the discovery of sperm within the renal pelvis of the nephrectomized kidney on histopathology; this was later confirmed through a postmortem examination. Three months after initial presentation the chinchilla was diagnosed with recurrent urolithiasis, hydroureter, and hydronephrosis of the remaining kidney and ureter, and euthanized due to poor prognosis. Necropsy confirmed the presence of semen-matrix calculi in the ureter and urinary bladder. Veterinary clinicians should consider semen-matrix calculi as a differential diagnosis for radiopaque calculi within the bladder or urethra of male chinchillas. Pathogenesis may be formation of a coagulum secondary to retrograde ejaculation.     

Ultrasonographic Features of the Chinchilla (Chinchilla lanigera) Kidney

Nine healthy chinchillas (Chinchilla lanigera) were used to characterize the ultrasonographic size and anatomical structure of the kidneys. Sonographic evaluations were performed with the aid of a 12-MHz linear probe. Kidney measurements included total width and length, total organ area, cortex and medullary thickness, and width and length of the renal pelvis. Based on the results of this study, normal chinchilla kidneys are located retroperitoneally, with the right kidney in a more cranial location than the left. Statistical analysis showed that measurements were similar between contralateral kidneys and between sexes. Chinchilla kidneys have a single papilla and a wider renal pelvis compared with the renal pelvis of dogs and cats. Moreover, chinchilla kidneys have a longer medullary area. The data herein may aid diagnosis of renal disease in chinchillas, avoiding misinterpretations of ultrasonic findings involving the kidneys of this species.     

Pressure Distribution Under Paws of Chinchilla (Chinchilla Laniger)

The purpose of this study was to estimate the pressure distribution under the paws of chinchilla ( Chinchilla laniger ) using static pedobarography. We included in our study three healthy chinchilla aged 1–3 year, both sexes, weighted 480–570 g. We performed static pedobarography (PEL 38 podometer) in each chinchilla and we took into account standing on four legs or two hind legs. We found that on standing on four legs, two types of contact area with base in chinchilla exist: first type – the ring shape of contact area with base of forefeet with maximal pressure in forefeet at their central part and elliptic shape of foot contact area with base of hind legs (paws) with longer diameter about twice longer than the shorter one and with maximal pressure in hind legs at their posterior part (greater than pressure under forefoot paws), that a value was 98 g/cm² In the second type of foot contact area with base a pattern of hind legs was similar to that of forefeet. During standing on two hind legs we distinguished the another type (third) of foot contact area with base that was similar to the first type with the difference made by the fact that animal was standing only on hind paws. In each animal we found also the contact area with base of a tail – the contact area was similar to that of forefeet but the value of pressure was twice decreased. Concluding, the most frequent manner of contact area with base in chinchilla is 4 points contact with hind paws contact area twice greater than contact area of forefeet. Moreover, the fifth point of support can exist – a tail, which is mainly important during standing on the hind paws.     

黄牛植黄期间胆道压力与胆汁粘度的关系

28头黄牛施以双胆囊植黄术,即在胆囊内的牛黄床和腹腔内的模拟胆囊内同时培植牛黄。植黄期间,测定了胆囊和模拟胆囊内的压力及胆汁粘度,胆囊和模拟胆囊内的压力差△P与胆汁粘度η的回归方程为：△P＝－0．127＋0．498η。