To report history, clinical examination findings, clinicopathologic findings, diagnostic test results, treatment, and outcome in horses with a novel idiopathic hepatitis syndrome.
13 client-owned horses.
Medical records of horses that were presented with fever and increased blood liver enzyme activity over a 16-month period were reviewed (December 1, 2020, to April 1, 2022). Collected data included signalment, history, clinical and clinicopathologic findings, diagnostic test results, treatment, clinical progression, and short-term outcome.
Affected horses were presented between December and April of each of the 2 seasons investigated. The majority of horses developed cyclic fevers over the course of 3 weeks, during which time histologic evidence of hepatitis was observed. Histologic lesions included hepatic necrosis, neutrophilic to lymphohistiocytic inflammation, biliary epithelial injury, and portal fibrosis. Systemic inflammation was evidenced by increased serum amyloid A concentration and leukon changes. No horse developed signs of hepatic insufficiency, and all horses clinically recovered. Return of serum activity of GGT to within the reference range occurred within 16 weeks in most horses. Histologic lesions remained evident up to 27 weeks after initial presentation in 1 horse.
Although an etiologic agent has not been identified, an apparently seasonal equine hepatitis syndrome was characterized by fever, systemic inflammation, increased liver enzyme activity, and histologic evidence of hepatitis. An infectious cause is suspected on the basis of histology and outcome.
Objective—To determine expression of folate receptors (FRs) and folate uptake in multicentric lymphomas in dogs.
Sample—10 dogs with histopathologically confirmed multicentric lymphoma and 20 archival lymph node biopsy specimens from dogs with multicentric lymphoma.
Procedures—Multicentric lymphomas in 10 dogs were prospectively evaluated for FR expression by use of immunohistochemical analysis and for in vivo folate uptake by use of nuclear scintigraphy. Dogs with FR-expressing tumors were eligible for FR-targeted chemotherapy. Twenty archival lymphoma biopsy specimens were also evaluated with immunohistochemical analysis.
Results—FRs were not detected with immunohistochemical analysis in lymph node samples obtained from the 10 dogs or in archival biopsy specimens. However, nuclear scintigraphy revealed uptake of radioactive tracer in 6 of 10 dogs. Five of these 6 dogs were treated with an FR-targeted chemotherapeutic agent; results of treatment were complete remission in 1 dog, stable disease in 2 dogs, and progressive disease in 2 dogs. Treatment-related toxicoses generally were mild.
Conclusions and Clinical Relevance—This study provided strong evidence for folate uptake in a substantial portion of multicentric lymphomas of dogs and indicated the antitumor activity of FR-targeted chemotherapeutics for these cancers. Use of FR-targeted chemotherapeutics may be promising for the treatment of FR-expressing multicentric lymphomas in dogs. Further studies are needed to determine reasons for lack of immunoreactivity to currently identified anti-FR antibodies and to develop improved methods for detecting FRs in lymphomas of dogs.
Objective—To determine the effects of diode laser palatoplasty on the soft palate in horses.
Animals—6 clinically normal horses and 6 euthanized horses from another study.
Procedures—6 horses underwent diode laser palatoplasty (treated horses); 3 received low-dose laser treatment (1,209 to 1,224 J), and 3 received high-dose treatment (2,302 to 2,420 J). Six other horses received no treatment (control horses). The upper respiratory tracts of all treated horses were evaluated immediately following surgery (day 0) and on days 2, 7, 14, 21, 30, and 45. Horses were euthanized on day 45, and magnetic resonance imaging (MRI) of the head was performed. The soft palate was removed from treated and control horses, evaluated grossly, and scored for edema, inflammation, and scarring. Soft palates from all horses were sectioned for histologic and biomechanical evaluations.
Results—Endoscopic examination revealed a significant increase in soft palate scarring and decrease in edema and inflammation in treated horses by day 7. Gross postmortem findings corresponded with MRI findings. Gross and histologic examination revealed a significant increase in scarring, edema, and inflammation at day 45. Histologic evaluation of palatal tissue from high-dose–treated horses revealed full-thickness injury of skeletal muscle, with atrophy of muscle fibers; findings in low-dose–treated horses indicated superficial injury to skeletal muscle. After surgery, treated horses had a significant decrease in soft palate elastic modulus, compared with control horses.
Conclusions and Clinical Relevance—Laser palatoplasty resulted in soft palate fibrosis and skeletal muscle loss; however, the fibrosis did not result in an increase in soft palate elastic modulus.
Case Description—2 cats were examined because of congestive heart failure secondary to heartworm infection.
Clinical Findings—One cat had severe abdominal distention and the other had dyspnea secondary to chylothorax. Both had loud right-sided heart murmurs, precordial thrills, and jugular distension. Thoracic radiography revealed cardiomegaly and enlarged caudal pulmonary arteries. Echocardiography revealed tricuspid regurgitation and multiple hyperechoic structures consistent with adult Dirofilaria immitis within the right atrium, right ventricle, and main pulmonary artery. Pulmonary hypertension was documented by means of Doppler echocardiography in 1 cat.
Treatment and Outcome—Cats were anesthetized, and a nitinol gooseneck snare catheter was introduced into the right side of the heart via a jugular venotomy. In the first cat, the snare was used to retrieve 5 female and 2 male adult D immitis. The catheter was then passed into the main pulmonary artery in an unsuccessful attempt to retrieve remaining heartworms. In the second cat, 2 adult female D immitis were removed from the right atrium with the nitinol snare. In both cats, clinical signs resolved within 4 weeks after the procedure.
Clinical Relevance—Findings suggested that use of a nitinol gooseneck snare catheter may be a safe and effective technique for removing adult D immitis from the right atrium and ventricle in cats and that successful removal of adult heartworms in infected cats may resolve clinical signs of right-sided congestive heart failure and chylothorax. In addition, findings in 1 cat suggested that removal of all adult heartworms may not be necessary for clinical signs to resolve.
Objective—To evaluate the clinical and pathologic
characteristics of mammary duct ectasia in dogs.
Animals—51 dogs with mammary duct ectasia.
Procedure—Information regarding body condition,
history, number and location of affected mammary
glands, appearance of lesions, surgical treatment,
nonsurgical treatment, and evidence of recurrence or
development of mammary neoplasia was obtained
from surveys sent to referring veterinarians. Results
of information from examination of histologic sections
and referring veterinarians were evaluated for all
mammary duct ectasia biopsies performed between
1992 and 1999.
Results—Duct ectasia was the primary diagnosis in
51 of 1,825 (2.8%) mammary biopsy specimens and
comprised 48% of nonneoplastic mammary diseases.
Affected dogs were evenly distributed over a range of
1 to 13 years of age, with a mean age at the time of
diagnosis of 6.1 ± 3.1 years. All dogs were female (31
sexually intact, 20 spayed); 10 of 26 had whelped.
Duct ectasia was described as nodular (26 dogs), cystic
(13), and multiglandular (11) and located in caudal
(31) more often than cranial (14) or middle glands (10).
Ectasia recurred in 3 dogs. One dog had a history of
previously excised mammary adenocarcinoma; another
subsequently developed mammary carcinoma.
Conclusions and Clinical Relevance—Duct ectasia
affected mature, sexually intact and spayed female
dogs over a wide age range. Certain breeds were
affected more commonly than expected. Increased
risk for mammary neoplasia was not evident. Duct
ectasia should be considered as a cause for mammary
enlargement, especially in young dogs or when its
cystic nature is evident. Mastectomy is usually curative,
and neoplasia should be ruled out in dogs with
ectasia. (J Am Vet Med Assoc 2001;218:1303–1307)
Objective—To determine immunoreactivity of matrix
metalloproteinase (MMP)-1, -3, and -13 in cartilaginous
tumors of dogs, correlate expression of MMP
with histologic grade of tumors and clinical outcome
of dogs, and compare MMP immunoreactivity
between chondrosarcomas and chondromas.
Sample Population—Formalin-fixed, paraffin-embedded
tissues obtained from samples of naturally occurring
chondrosarcomas (n = 31) and chondromas (8) of
dogs that were submitted to our veterinary medical
Procedure—Histologic sections from each sample
were stained with H&E and monoclonal antibody to
MMP-1, -3, and -13 by use of an avidin-peroxidase
immunohistochemical technique. For each section, histologic
grade (I, II, or III) and immunohistochemical
expression (0, 1, 2, or 3) were evaluated. Clinical outcome
was obtained from medical records or interviews
with referring veterinarians and scored as a good outcome,
moderate outcome, or poor outcome.
Correlations among variables and differences between
chondrosarcomas and chondromas were analyzed.
Results—Samples from chondrosarcomas had significantly
higher immunoreactivity of MMP-1 and -13,
compared with immunoreactivity in samples from
chondromas. In chondrosarcomas, a significant positive
correlation (r, 0.386) was found between MMP-1
and -13 immunoreactivities, and a significant negative
correlation (r, –0.390) was detected between MMP-3
and -13 immunoreactivities.
Conclusion and Clinical Relevance—A significant
increase in expression of collagenases (MMP-1 and -
13) in chondrosarcomas, compared with expression in
chondromas, suggests that collagenases may play an
important role in tumor progression, and possibly
metastasis, in chondrosarcomas of dogs. (Am J Vet