Increase in Lead Concentraion in the Drinking Water of an Animal Care Facility. Contemporary Topics 37 (1): 51.
Ingested lead accumulates in the body resulting in haematological, gastrointestinal and neurological dysfunction. Metal alloys used in plumbing may cause lead in the drinking water. This article describes a facility which had increased lead concentration in the drinking water due to a brass fitting connecting the drinking spout in each animal cage to PVC water pipes.
When the the lead concentration exceeds the EPA current action level, additional samples must be collected and tested to confirm the existence of contamination. Results from the additional samples are ranked from highest to lowest lead concentration. If the 90th percentile concentration is greater than the EPA action level, corrective action is required.
QUESTIONS:
1. What do the following acronyms stand for?
EPA
PVC
2. What is the action level set by EPA for lead in water?
a) 0 ppb
b) 0.05 mg/L
c) 0.015 mg/L
3. What is the maximum containment level for lead in water?
a) 0 ppb
b) 0.05 mg/L
c) 0.015 mg/L
4. What regulation governs water quality?
ANSWERS:
1. EPA - Environmental Protection Agency
PVC - Polyvinyl Chloride
2. c
3. b
4. The Safe Drinking Water Act

Naturally Developing Virus-Induced Lethal Pneumonia in Two Guinea Pigs (Cavia porcellus). Contemporary Topics 37 (1): 54.
This paper describes the clinical signs, gross and histological lesions seen in two guinea pigs who succumbed to pneumonia. One animal was found dead, the other was acutely dyspneic and tachypneic. The animals had been at the facility for 3 weeks, and were part of a colony of 250 animals. Gross necropsy lesions included well-demarcated areas of pulmonary parenchymal consolidation primarily in the right cranioventral and hilar regions and compensatory emphysema. All other organs were normal, and bacteriologic cultures from the lungs and trachea did not yield growth. Histological lesions included severe multifocal, acute necrotizing bronchitis and bronchiolitis. Oval basophilis intranuclear inclusion bodies were seen in the sloughed epithelial lining. Based on ultrastructural examination, an adenovirus was diagnosed.
Adenovirus has been reported as a cause of moribity in all ages of guinea pigs. Stress triggers the onset of disease. The disease is characterized by low morbidity, but up to 100+ACU- mortality.
Questions:
1. The differential diagnosis for pneumonia in guinea pigs should include:
a. Bordetella bronchiseptica
b. Strep. zooepidemicus
c. Strep pneumoniae
d. Klebsiella pneumoniae
e. Pasteurella multocida
f. viral diseases, including GPCMV, GPHLV, SV, PVM, SV-5, PI2 +ACY-3 and adenovirus
g. all of the above
2. T/F Adenoviruses are relatively host specific.
3. T/F Adenoviruses usually affect the respiratory and enteric systems.
4. Adenoviral pneumonia in guinea pigs is characterized by:
a. low morbidity
b. high mortality
c. consolidation of dorsal lung fields
d. epistaxis
e. a +ACY- b
Answers:
1. g
2. T
3. T
4. e

Elimination of an infestation of Infestation of Rat Fur Mites (Radofoerdia ensifera) from a Colony of Long Evans Rats, Using Microdot technique for Topical Adminstration of 1% Ivermectin. Contemporary Topics 37 (1): 58.
The distinguishing feature of rat fur mite is the paired and equal claws on the tarsi of the second pair of legs, which differentiates it from mouse fur mite, which have paired but unequal claws on second pair of legs and single empoidal claw on these segments.
In this study the investigators chose the microdot technique, using Ivermectin to treat fur mites in rats which were used for behavior research. This colony of rats was also infected with fur mites, pin worms and was positive for mycoplasma pulmonis.
Three treatments of Ivermcetin were applied at 2 week intervals and rats were found to be free of fur mites for 129 days. Ivermectin toxicity was not observed.
Question:
1. Which of the following methods is the most accurate to Dx. fur mites in
rats:
skin scrapping
gross examination of coat
washing method.
dorsal test tape

Silicon Crystals in Water of Autoclaved Glass Bottles. Contemporary Topics 37 (1): 62.
This note describes crystals detected in glass bottles filled with tap water that had been autoclaved and were used for barrier-maintained rodents. These crystals were observed twice at approximately a 6 month interval. Affected bottles had sipper tubes and stoppers. Crystals were identified as being silicon by analysis with Transmission Electron Microscopy and inductively coupled plasma (ICP) and energy X-ray analysis. Procedures and processes involved with water bottle preparation were analyzed to determine the source or factors involved with silicon contamination. Specifically, silicon analysis was performed on samples of tap water, tap water autoclaved in polycarbonate, glass and polycarbonate bottles after purposeful contamination of tap water with various amounts of alkaline detergent, and on steam condensate from the autoclave. Water from autoclaved glass bottles had greater concentration of silicon, compared with water from non-autoclaved glass bottles. Siliconized rubber stoppers and stainless-steel sipper tubes were not found to be a source of silicon. A small amount of crystals were observed in glass bottles that contained stopper pieces, but crystals were not present in polycarbonate bottles with stopper pieces. Detergent contamination did not influence silicon concentrations.
The bottom line for this note is: autoclaving glass water bottles in some circumstances, leads to increased silicon concentrations and may cause conditions that favor crystallization.
Questions
1. What is silicon solubility greatly dependent on?
2. What disease can develop in humans from chronic ingestion of silicon?
Answers
1. Temperature
2. Balkan nephropathy

Peripheral Primitive Neuroectodermal Tumor (Peripheral Neuroepithelioma) in a Dog. Contemporary Topics 37 (1): 66.
Primitive neuroectodermal tumors (PNET) in human beings are morphologically similar to malignant neoplasms arising from intracrainial and peripheral sites of the nervous system and have been characterized by site and the degree of cellular differentiation. Peripherally located PNET's include neuroblastomas that arise from the adrenal medulla or sympathetic ganglia (conventional neuroblastomas). Conventional neruoblastomas probably arising from the adrenal glands or sympathetic ganglia have been described in dogs and cattle. In this article neoplasms detected initially as round palpable masses about 10 mm in diameter, were located in the subcutaneous tissue of the abdominal and thoracic wall of a 5 year old female Beagle maintained in a laboratory colony. Three months later, the tumors grew to about 20-30 mm in diameter and sometimes became ulcerated. The animal was euthanized and a necropsy was performed.
Gross examination revealed well circumscribed, white neoplastic masses of up to 30mm in diameter within the subcutaneous tissue that were distributed throughout the body, mainly the trunk and femoral region. The largest mass was located in the femoral region. On cut surface, the tumors were grayish in color with large necrotic or hemorrhagic areas at their centers. Small tumors were also seen in the right kidney, pancreas, mesenteric lymph nodes, and in small intestinal Peyer's patches. The adrenal glands were normal. Almost all tissues were submitted for histopath including tumors fixed in neutral buffered 10% formalin. Paraffin-embedded sections were stained with H&E and selected tumor sections were stained with PAS (with/without diastase digestion), AzanMallory method, and Watanabe's silver strain impregnation method for reticulin. Selected tumor specimens were subjected to immunohistochemical analysis as well as for ultrastructual examination.
Histopathologically, the tumor consisted of small, closely packed round or polygonal cells with a high nuclear-to-cytoplasmic ratio and finely granular clear cytoplasms. Mitotic figures and necrotic, hemorrahgic areas were frequently evident. The tumor's boundary was obscure, as it appeared to infiltrate surrounding tissue and invade blood and lymphatic vessels. The reticulin preparation revealed a lobular arrangement of the tumor. PAS positive tumor cells contained numerous diatase-digestible materials in the cytoplasm; therefore they contained abundant glycogen and often had a vacuolated appearance. Immunohistochemical evaluations revealed that tumor cells were strongly positive for vimentin and weakly positive for neurogenic markers (NSE/S-100 protein). They were negative for cytokeratin, neurofilament, and synaptophysin, even though normal tissue around the tumor was positive for these antibodies (i.e. cytokeratin-sqamous epi., neurofilament and synaptophysin- nerve fibers). Ultrastructurally, tumor cells were closely situated with little intracellular collagenous matrix. Most cells were euchromatic (oval-elongate nuclei w/small nucleolus). Tumor cell cytoplasms contained a few cytoplasmic organelles, but numerous free ribosomes, polyribosomes, and glycogen particles. Dark cells were observed with marginally situated nuclei and many pleomorphic lysosomal dense bodies in the cytoplasm. A psuedorosette arrangement of the tumor cells was confirmed ultrastructurally.
The neoplasm in this dog was considered to be of primitive neuroectoderm origin as determined on the basis of morphological and immunohistochemical features. The dark cells that were recognized were considered to be evidence of ganglionic differentiation of the tumor cells. The neoplasm was highly aggressive, spread rapidly, and metastasized to many organs. The most developed tumor was in the femoral region. Therefore, the neoplasm was considered to originate in the subcutaneous tissue more than likely from a peripheral nerve. This type of neoplasm can be compared and contrasted to human conventional neuroblastomas and peripheral PNET, and Ewing's sarcoma. Furthermore, peripheral PNET should be included in the list of differential diagnoses of soft-tissue tumors in dogs.
No questions

Renal Cell Carcinoma in Two Siberian Hamsters (Phodopus sungorus). Contemporary Topics 37 (1): 70.
Renal cell carcinoma is a rare condition in Siberian hamsters. More common neoplasms include tumors of the mammary gland, skin, lungs, and thyroid gland. The sex and age of the first hamster was unknown. Diagnosis was a unilateral solitary papillarytubular carcinoma. The second hamster was a 2.5 yr old male diagnosed with a clearcell, a papillarytubular, and mixed type carcinoma in the left kidney and a cysticpapillarytubular type of carcinoma in the right kidney. (Gross & histologic pictures in Figures 14) Renal cell carcinomas arise from the renal tubular epithelium. There are two major histologic types: papillarytubular carcinoma and clearcell carcinoma, mixed types may develop. The first histologic type is common in domestic animals, with the second type being more prevalent in humans, especially men. Causes for the development of renal carcinoma is unknown in humans, possibilities include environment and genetics. A viral cause has been identified in leopard frogs, chickens, and gray squirrels. Environmental toxicants (lead) have been implicated in rodents.
Questions:
1. What are the other common names for Siberian hamsters?
Answers:
1. Russian hamster, Small Asiatic hamster, Striped hairyfooted hamster, Dzungarian (Zungarian or Djungrain) hamster.

Lipoma in the Mediastinum of a Prairie Dog (Cynomys ludovicianus). Contemporary Topics 37 (1): 74.
A necropsy was performed on a 3 yr old obese female blacktailed prairie dog kept as a pet. A large pale, yellowtan, wellcircumscribed softtissue mass was identified in the chest cavity. (Figure 1) Histopathology revealed the lesion to be a lipoma. (Figure 2). Death was apparently caused by hypoxia due to the effect of a spaceoccupying mass. This is the first documented case of a lipoma in a prairie dog. Previously only hepatocellular carcinoma and epiglottal fibrosarcoma have been reported in this species.
Questions:
1. What order and family do prairie dogs belong to?
2. What animal model are blacktailed prairie dogs used for?
3. List two other neoplasms of fat, in addition to lipomas, found in other species?
Answers:
1. Order Rodentia, Family Sciuridae
2. Used to study cholesterol gallstones, with specific emphasis on gallbladder contractility.
3. Hibernomas (rodents) and liposarcomas