Dermoid cysts presenting as enlarged thyroid glands in a cat.

A 5-year-old spayed female cat was evaluated for hyperthyroidism based on an elevated free thyroxine (T(4)) measurement and bilaterally enlarged symmetric subcutaneous masses in the area of the thyroid glands. Physical examination revealed bilateral subcutaneous masses on either side of the cervical trachea. Blood was obtained for serum biochemical profile and thyroid function analysis. Mild hyperalbuminemia, mild hypercalcemia, and mildly increased alanine aminotransferase activity were identified. Serum concentrations of total and free thyroxine were within the reference interval. Cytologic analysis of fine-needle aspirates from one of the masses was suspicious for neoplasia. Nuclear scintigraphy revealed no abnormalities. Surgically obtained excisional biopsies of both masses were submitted for histopathology and diagnosed as bilateral dermoid cysts. After excisional biopsy, the patient recovered without incident. The histopathologic diagnosis of completely excised bilateral dermoid cysts indicated that no further medical or surgical intervention was required. This is the first report of a cat presenting with bilateral dermoid cysts in the area of the thyroid glands. Histopathologic examination was necessary to make a definitive diagnosis. Practitioners should include cysts in their list of differential diagnoses for ventral neck masses in cats.

Genetic variability of Cytauxzoon felis from 88 infected domestic cats in Arkansas and Georgia.

Although cytauxzoonosis has historically been nearly 100% fatal in domestic cats, increasing number of reports of infected cats that demonstrate less-severe disease suggest the existence of different strains of Cytauxzoon felis. To test this hypothesis, the genetic variability of C. felis was examined in blood samples from naturally infected domestic cats from Arkansas and Georgia by using the first and second ribosomal internal transcribed spacer regions (ITS1, ITS2) as markers to assess genotypic variability. In addition, the clinical outcome of infection (survival vs. fatal disease) was analyzed. Within the C. felis ITS1 region, there were a total of 8 single nucleotide polymorphisms (SNP) and a single nucleotide insertion. Within the ITS2 region, there were a total of 4 SNPs and a single 40 base pair insertion. When taken together, the ITS1 and ITS2 sequence data defined a total of 11 different sequences and 3 unique genotypes. One unique ITS1-ITS2 genotype was detected in samples submitted exclusively from Arkansas, and a second unique genotype was submitted exclusively from Georgia. There was a significant association between infection with C. felis that contained particular ITS genotypes and survival of the infected domestic cat. The identification of unique C. felis genotypes obtained from different geographic areas and the association of particular ITS genotypes with the outcome of infection suggest the existence of parasite strains that may vary in pathogenicity to the domestic cat and offer an explanation for the survival of some infected cats in more recent case studies.

Cytologic diagnosis of diseases of ferrets.

Cytology is a useful, rapid, inexpensive diagnostic technique that is particularly suitable for ferrets because of their small size and readily accessible organs and tissues. This article begins with a brief discussion of general cytologic information. The remainder of the article concentrates on the cytologic features of common diseases that affect ferrets.

Avian cytology.

An overview of avian cytology is presented, discussing more common abnormalities that are encountered in routine clinical practice. The general cytologic features of inflammatory, infectious, and neo-plastic lesions are described. The remainder of the article covers major cytologic abnormalities by anatomic site of origin of the specimens.

Gastrointestinal pythiosis in two cats.

Two young adult male Domestic Shorthair cats living in the southeastern United States were evaluated for signs attributable to partial intestinal obstruction. Physical examination indicated a palpable abdominal mass in each animal. Exploratory laparotomy revealed a large extraluminal mass involving the ileum and mesentery with adjacent mesenteric lymphadenopathy in cat No. 1 and an abscessed mass in the distal duodenum in cat No. 2. Mass resection and intestinal anastomosis were performed in both cats. Histologic evaluation indicated that the intestinal lesions involved primarily the outer smooth muscle layer and serosa and consisted of eosinophilic granulomatous inflammation with multifocal areas of necrosis. In Gomori methenamine silver-stained sections, broad (2.5-7.5 microm), occasionally branching, infrequently septate hyphae were observed within areas of necrosis. A diagnosis of Pythium insidiosum infection was confirmed in both cats by immunoblot serology and by immunoperoxidase staining of tissue sections using a P. insidiosum-specific polyclonal antibody. Cat No. 1 was clinically normal for 4 months after surgery but then died unexpectedly from an unknown cause. Cat No. 2 has been clinically normal for at least 9 months after surgery and appears to be cured on the basis of follow-up enzyme-linked immunosorbent assay serology.

Variation among pathologists in histologic grading of canine cutaneous mast cell tumors.

Ten veterinary pathologists at 1 veterinary institution independently assigned histologic grades to the same 60 canine cutaneous mast cell tumors (MCTs). There was significant variation among pathologists in grading the MCTs (P < 0.001). The probability of assigning a low grade was significantly higher for the pathologists in this study who use a published reference for histologic grading of canine cutaneous MCTs that allows subcutaneous MCTs or MCTs with mitotic figures to be included in the low-grade category (P < 0.0001 and P < 0.0001, respectively).

Molecular diagnosis of paramyxovirus infection in snakes using reverse transcriptase-polymerase chain reaction and complementary deoxyribonucleic acid:ribonucleic acid in situ hybridization.

Identification of ophidian paramyxovirus (OPMV) nucleic acid was accomplished in 11 of 14 snakes by a reverse transcriptase-polymerase chain reaction (RT-PCR) assay that detected a 153-bp region of the OPMV genome in total RNA extracted from paraffin-embedded tissues and cell culture. The RT-PCR protocol amplified a portion of the OPMV RNA genome, producing a 153-bp complementary DNA (cDNA) product from both fresh and paraffin-embedded tissue samples. In addition, cDNA:RNA in situ hybridization localized OPMV in formalin-fixed, paraffin-embedded tissue specimens to specific tissues and cells. This latter technique increased the degree of specificity with which a diagnosis of OPMV could be made.

Investigation of parrot papillomavirus in cloacal and oral papillomas of psittacine birds.

Cloacal and oral papillomas from 27 psittacine birds of various species were examined for the presence of parrot papillomavirus by DNA in situ hybridization, DNA in situ polymerase chain reaction, and nested polymerase chain reaction. Parrot papillomavirus was detected in one oral papilloma from an African grey parrot by all three techniques. In addition, rare basophilic intranuclear inclusions were observed by light microscopy in tissue sections of the oral papilloma from this parrot. The remaining lesions were negative for parrot papillomavirus DNA. This study suggests that parrot papillomavirus may be involved in the development of papillomas in African grey parrots, but apparently is not responsible for development of similar lesions in unrelated species of psittacine birds.