Objective—To compare effectiveness and complications associated with peribulbar and retrobulbar anesthesia with bupivacaine in cats.
Animals—6 healthy adult cats.
Procedures—Cats were sedated with dexmedetomidine and received a peribulbar injection of 0.5% bupivacaine (1.5 mL), iopamidol (0.5 mL), and saline (0.9% NaCl) solution (1 mL) or retrobulbar injection of 0.5% bupivacaine (0.75 mL) and iopamidol (0.25 mL) in a crossover study with ≥ 2 weeks between treatments. The contralateral eye was the control. Injectate distribution was evaluated with CT. After atipamezole administration, periocular and corneal sensations, intraocular pressure (IOP), and ocular reflexes and appearance were evaluated for 24 hours.
Results—All peribulbar and 3 of 6 retrobulbar injections resulted in CT evidence of intraconal injectate. Corneal sensation and periocular skin sensation were absent or significantly reduced relative to that for control eyes for 3 hours after peribulbar injection. Mean ± SD IOP immediately after injection was significantly higher for eyes with peribulbar injections (33 ± 12 mm Hg) than for control eyes or eyes with retrobulbar injections (both 14 ± 4 mm Hg) but 10 minutes later decreased to 18 ± 3 mm Hg. Exophthalmos, chemosis, and ptosis were evident in most injected eyes, and irritation was evident in 3 of 6 peribulbar-injected and 1 of 6 retrobulbar-injected eyes. All conditions resolved within 14 hours.
Conclusions and Clinical Relevance—Peribulbar injection resulted in intraconal deposition of bupivicaine in a higher percentage of cats than did retrobulbar injection and induced notable anesthesia relative to that for the control eye; however, IOP increased temporarily.
Objective—To determine the expression and distribution of a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4), its substrates aggrecan and versican, and their binding partner hyaluronan in laminae of healthy horses.
Sample—Laminae from the forelimb hooves of 8 healthy horses.
Procedures—Real-time quantitative PCR assay was used for gene expression analysis. Hyaluronidase, chondroitinase, and keratanase digestion of lamina extracts combined with SDS-PAGE and western blotting were used for protein and proteoglycan analysis. Immunofluorescent and immunohistochemical staining of tissue sections were used for protein and hyaluronan localization.
Results—Genes encoding ADAMTS-4, aggrecan, versican, and hyaluronan synthase II were expressed in laminae. The ADAMTS-4 was predominantly evident as a 51-kDa protein bearing a catalytic site neoepitope indicative of active enzyme and in situ activity, which was confirmed by the presence of aggrecan and versican fragments bearing ADAMTS-4 cleavage neoepitopes in laminar protein extracts. Aggrecan, versican, and hyaluronan were localized to basal epithelial cells within the secondary epidermal laminae. The ADAMTS-4 localized to these cells but was also present in some cells in the dermal laminae.
Conclusions and Clinical Relevance—Within digital laminae, versican exclusively and aggrecan primarily localized within basal epithelial cells and both were constitutively cleaved by ADAMTS-4, which therefore contributed to their turnover. On the basis of known properties of these proteoglycans, it is possible that they can protect the basal epithelial cells of horses from biomechanical and concussive stress.
Objective—To quantify changes in endothelium-derived factors and relate those changes to various aspects of digital hemodynamics during the prodromal stages of carbohydrate overload (CHO)-induced laminitis in horses.
Animals—20 adult horses without abnormalities of the digit.
Procedures—Digital and jugular venous blood samples were collected at 1-hour intervals (for assessment of endothelin-1 [ET-1] immunoreactivity and measurement of glucose, insulin, and nitric oxide [NO] concentrations) or 4-hour intervals (CBC and platelet-neutrophil aggregate assessment) for 8 hours or 16 hours after induction of CHO-associated laminitis in horses treated with an ET-1 antagonist. Effects of treatment, collection site, and time and the random effects of horse on each variable were analyzed by use of a repeated-measures model. Where treatment and collection site had no significant effect, data were combined.
Results—Compared with baseline values, CHO resulted in changes in several variables, including a significant increase from baseline in digital blood ET-like immunoreactivity at 11 hours; digital blood ET-like immunoreactivity was significantly greater than that in jugular venous blood at 8, 9, 11, and 12 hours. Digital and jugular venous blood concentrations of glucose increased from baseline significantly at 3, 4, and 5 hours; insulin concentration increased significantly at 5 hours; and the number of platelet-neutrophil aggregates increased significantly at 12 hours.
Conclusions and Clinical Relevance—In horses, concurrent increases in venous blood ET-1 immunoreactivity, insulin and glucose concentrations, and platelet-neutrophil aggregates support a role of endothelial dysfunction in the pathogenesis of CHO-induced laminitis.
Objective—To correlate gene transcription of
cytokines and chemokines with histologic inflammation
in nasal biopsy specimens of cats.
Animals—25 study cats and 4 specific pathogen–free
Procedure—One nasal biopsy specimen from each
cat was submitted for routine histologic evaluation; a
second was submitted for evaluation by use of a
quantitative real-time polymerase chain reaction
analysis with a fluorogenic probe (ie, TaqMan) for
detection of cytokines and chemokines (interleukin
[IL]-4, IL-5, IL-6, IL-10, IL-12 p40, IL-16, IL-18, interferon
[IFN]-γ, tumor necrosis factor [TNF]-α, and the regulated
on activation normal T cell expressed and secreted
[RANTES] protein). Specimens were grouped histologically
by degree of inflammation (none, mild,
moderate, or severe). Linearized TaqMan signals for
each gene were compared among histologic groups.
Results—Nasal biopsy specimens from specific
pathogen–free cats were histologically normal, and
cytokine transcription was low in these samples. As
nasal inflammation in study cats worsened from
absent (n = 3) to mild (4) to moderate (8) or severe
(10), progressively and significantly increasing transcription
of IL-6, IL-10, IL-12 p40, IFN-γ, TNF-α, and the
RANTES protein was detected. Transcription of IL-4, IL-
5, IL-16, and IL-18 did not correlate with worsened histologic
Conclusions and Clinical Relevance—Transcription
of specific cytokines and chemokines in nasal tissue
of cats progressively increased with severity of histologic
evidence of inflammation, and IL-6, IL-10, IL-12
p40, IFN-γ, TNF-α, and the RANTES protein were
markers of inflammation. Our data suggest that the
nasal cavity of cats is biased toward a Th1 cytokine
profile that is augmented by inflammation. (Am J Vet
Objective—To determine the prevalence of pedunculated
lipomas and identify risk factors affecting postoperative
complications and survival in horses at a
veterinary teaching hospital undergoing surgery for
colic caused by pedunculated lipomas.
Animals—102 horses with a diagnosis of pedunculated
Procedure—Age, breed, weight, and sex of horses
with pedunculated lipomas were compared with the
total equine hospital population and the population of
horses admitted for abdominal surgery during the
same period. Follow-up information was obtained by
reevaluation or contact with owners via telephone or
Results—Prevalence of pedunculated lipomas as a
reason for abdominal surgery in horses, compared with
the population of horses with and without lipomas
admitted for abdominal surgery, was 10%. Castrated
male Saddlebred and Arabian horses > 14 years old
were identified as being at risk for developing pedunculated
lipomas. Postoperative complications were
detected in 72% of horses with pedunculated lipomas.
Variables associated with low survival rates included
surgery before 1992, heart rate > 80 beats/min, abnormal
color of abdominal fluid, pale mucous membranes,
surgery requiring intestinal resection, and inability to
attain a mean arterial pressure ≥ 100 mm Hg. Horses
undergoing surgery from 1992 to 1996, weighing < 409
kg (900 lb), or requiring jejunojejunal anastomosis had
a high survival rate.
Conclusions and Clinical Relevance—Although
many of the variables reflected the health of the horse
at the time of surgery, results may help veterinarians
recognize risk factors associated with development of
pedunculated lipomas and better predict the outcome
of horses undergoing surgery for colic caused by
pedunculated lipomas. (J Am Vet Med Assoc2005;
Case Description—13 equids (10 horses, 2 donkeys, and 1 pony) were examined for signs of colic (n = 7), weight loss (6), anorexia (3), and diarrhea (2). Ten equids were evaluated in the fall (September to November). Seven equids had a history of persimmon ingestion.
Clinical Findings—A diagnosis of phytobezoar caused by persimmon ingestion was made for all equids. Eight equids had gastric persimmon phytobezoars; 5 had enteric persimmon phytobezoars. Gastroscopy or gastroduodenoscopy revealed evidence of persimmon ingestion in 8 of 10 equids in which these procedures were performed.
Treatment and Outcome—2 of 13 equids were euthanatized prior to treatment. Supportive care was instituted in 11 of 13 equids, including IV administration of fluids (n = 8) and treatment with antimicrobials (5), NSAIDs (5), and gastric acid suppressants (4). Persimmon phytobezoar–specific treatments included dietary modification to a pelleted feed (n = 8); oral or nasogastric administration of cola or diet cola (4), cellulase (2), or mineral oil (2); surgery (4); and intrapersimmon phytobezoar injections with acetylcysteine (1). Medical treatment in 5 of 7 equids resulted in resolution of gastric persimmon phytobezoars. Seven of 8 equids with gastric persimmon phytobezoars and 1 of 5 equids with enteric persimmon phytobezoars survived > 1 year after hospital discharge.
Clinical Relevance—Historical knowledge of persimmon ingestion in equids with gastrointestinal disease warrants gastroduodenoscopy for evaluation of the presence of persimmon phytobezoars. In equids with gastric persimmon phytobezoars, medical management (including administration of cola or diet cola and dietary modification to a pelleted feed) may allow for persimmon phytobezoar dissolution.
Objective—To evaluate the safety and efficacy of a vaccine containing plasmid DNA with an insert encoding human tyrosinase (ie, huTyr vaccine) as adjunctive treatment for oral malignant melanoma (MM) in dogs.
Animals—111 dogs (58 prospectively enrolled in a multicenter clinical trial and 53 historical controls) with stage II or III oral MM (modified World Health Organization staging scale, I to IV) in which locoregional disease control was achieved.
Procedures—58 dogs received an initial series of 4 injections of huTyr vaccine (102 μg of DNA/injection) administered transdermally by use of a needle-free IM vaccination device. Dogs were monitored for adverse reactions. Surviving dogs received booster injections at 6-month intervals thereafter. Survival time for vaccinates was compared with that of historical control dogs via Kaplan-Meier survival analysis for the outcome of death.
Results—Kaplan-Meier analysis of survival time until death attributable to MM was determined to be significantly improved for dogs that received the huTyr vaccine, compared with that of historical controls. However, median survival time could not be determined for vaccinates because < 50% died of MM before the end of the observation period. No systemic reactions requiring veterinary intervention were associated with vaccination. Local reactions were primarily limited to acute wheal or hematoma formation, mild signs of pain at the injection site, and postvaccination bruising.
Conclusions and Clinical Relevance—Results support the safety and efficacy of the huTyr DNA vaccine in dogs as adjunctive treatment for oral MM.
Impact for Human Medicine—Response to DNA vaccination in dogs with oral MM may be useful in development of plasmid DNA vaccination protocols for human patients with similar disease.