Objective—To detect and characterize the full range
of chlamydial infections in cats with ocular disease by
use of polymerase chain reaction (PCR) assays, cytologic
examination, immunohistochemical analysis,
and evaluation of clinical information including status
for feline herpesvirus-1 (FeHV-1).
Sample Population—DNA extracted from 226 conjunctival
samples obtained from cats with clinically
diagnosed keratitis or conjunctivitis and 30 conjunctival
samples from healthy cats.
Procedure—PCR assays for the 16S rRNA gene specific
for the order Chlamydiales and a new
Chlamydophila felis (formerly Chlamydia psittaci)
species-specific 23S rRNA gene were performed.
Seventy-four conjunctival samples were prepared
with Romanowsky-type stain, grouped on the basis of
inflammatory pattern, and screened for chlamydial
inclusions by use of immunohistochemical analysis.
Clinical information and FeHV-1 status were recorded.
Results—26 (12%) specimens had positive results
for the only known feline chlamydial pathogen, C felis.
Surprisingly, an additional 88 (39%) were positive for
non-C felis chlamydial DNA. Identification of non-
C felis chlamydial DNA by direct sequencing revealed
16S rRNA gene sequences that were 99% homologous
to the sequence for Neochlamydia hartmannellae,
an amebic endosymbiont. Chlamydial prevalence
was significantly higher in cats with ocular disease.
Conclusions and Clinical Relevance—Application of
a broad-range detection method resulted in identification
of a new agent associated with ocular disease in
cats. Finding chlamydia-like agents such as N hartmannellae
in coinfections with their obligate amebic
host, Hartmannella vermiformis, raises questions
about the potential role of these microorganisms in
causation or exacerbation of ocular disease in cats.
(Am J Vet Res 2003;64:1421–1428)
Objective—To evaluate whether determination of
parathyroid gland size by use of ultrasonography is
helpful in differentiating acute renal failure (ARF) from
chronic renal failure (CRF) in dogs.
Animals—20 dogs with renal failure in which serum
creatinine concentration was at least 5 times the
upper reference limit. Seven dogs had ARF, and 13
dogs had CRF. Twenty-three healthy dogs were used
Procedure—Dogs were positioned in dorsal recumbency
for ultrasonographic examination of the ventral
portion of the neck, A 10-MHz linear-array high-resolution
transducer was used. The size of the parathyroid
gland was determined by measuring the maximal
length of the gland on the screen when it was imaged
in longitudinal section. For comparison among
groups, the longest linear dimension of any of the
parathyroid glands of each dog was used.
Results—Size of the parathyroid glands in the control
dogs varied from 2.0 to 4.6 mm (median, 3.3 mm). In the
dogs with ARF, gland size ranged from 2.4 to 4.0 mm
(median, 2.7), which was not significantly different from
controls. In dogs with CRF, the glands were more distinctly
demarcated from the surrounding thyroid tissue,
than those of controls and dogs with ARF. Sizes ranged
from 3.9 to 8.1 mm (median, 5.7 mm), which was significantly
larger, compared with controls and dogs with
Conclusion and Clinical Relevance—In dogs with
severe azotemia, ultrasonographic examination of the
parathyroid glands was helpful in differentiating ARF
from CRF. Size of the parathyroid glands appeared to
be related to body weight. (J Am Vet Med Assoc