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was approved by the research committee of the Veterinary Society of Surgical Oncology. Participating members of the Veterinary Society of Surgical Oncology were asked to search their medical record databases for cats with a histopathologic diagnosis of

Full access
in Journal of the American Veterinary Medical Association

dogs was accomplished by soliciting participation via veterinarians (veterinary oncologists) and owners. Samples were submitted from the Washington State University College of Veterinary Medicine; Veterinary Oncology Services PLLC, Hopewell Junction, NY

Full access
in American Journal of Veterinary Research

Abstract

Objective—To investigate subjective and computerized methods of evaluation of color Doppler (CD) and power Doppler (PD) ultrasonographic images (obtained before and after administration of contrast medium) for quantitative assessment of vascularity and perfusion of various naturally occurring tumors in dogs.

Sample Population—34 tumors in 34 dogs.

Procedure—Tumors in dogs were examined via CD and PD ultrasonography before and after IV injection of a microbubble contrast agent (pre- and postcontrast examinations, respectively). Images were digitized for subjective assessment of vessel density and vascular pattern and computer-aided assessment of parameters of vascularity (fractional area [FA]) and perfusion (color-weighted FA [CWFA] and mean color level).

Results—With both analysis methods, more vessels were identified in precontrast PD ultrasonographic images than in precontrast CD ultrasonographic images. Moreover, compared with values for precontrast PD ultrasonography, FA, CWFA, and mean color level were higher for postcontrast PD ultrasonography. In postcontrast images, there was a significant association between vessel densities determined through subjective and computerized assessments. Although sample size was small, vascularity of squamous cell carcinomas was significantly greater than that of other tumor types. Ten of the 19 soft tissue sarcomas had low vessel density with minor contrast enhancement. With increasing gross tumor volume, FA and CWFA decreased for all Doppler ultrasonographic methods.

Conclusions and Clinical Relevance—Higher values of the ultrasonographic parameters representing vascularity and perfusion of tumors in dogs were determined via PD ultrasonography after administration of contrast medium than via PD or CD ultrasonography without administration of contrast medium. (Am J Vet Res 2005;66:21–29)

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To examine bicarbonate (HCO3 ) secretion ex vivo in the equine large colon to determine any differences between the right dorsal colon (RDC) and right ventral colon (RVC). The effect of phenylbutazone (PBZ) on HCO3 secretion was examined in the RDC.

ANIMALS

14 healthy horses.

PROCEDURES

In anesthetized horses (n = 10), segments of mucosa from RDC and RVC were harvested to measure HCO3 secretion ex vivo with the pH Stat method. The effect of PBZ on HCO3 secretion in the RDC was studied in 4 additional horses.

RESULTS

Three distinct mechanisms of HCO3 secretion previously described in a murine model were confirmed in the equine colon. The RDC had a greater capacity for electrogenic, Cl-independent HCO3 secretion than the RVC (P = 0.04). In the RDC, all HCO3 secretion was decreased by PBZ (P < 0.02) but was not studied in the RVC because of low baseline secretion.

CLINICAL RELEVANCE

Secretion of HCO3 by the RDC could play a pivotal role in equine colon physiology, because intense microbial fermentation in this site could require HCO3 secretion to buffer short-chain fatty acids. Inhibition of this secretion by PBZ could interfere with mucosal buffering and predispose to changes associated with right dorsal colitis.

Open access
in American Journal of Veterinary Research

In recent years, extracellular vesicles (EVs) have emerged as prominent mediators of the homeostasis, repair, and regeneration of musculoskeletal tissues including bone, skeletal muscle, and cartilage. Accordingly, the therapeutic potential of EVs for regenerative medicine applications has not gone unnoticed. The use of EVs for the treatment of musculoskeletal injury and disease in veterinary species is a nascent but rapidly expanding area of research. Recent studies in this area have demonstrated the safety and feasibility of EV products in dogs and horses. While early clinical responses to EV-based therapeutics in companion animals have been favorable, more rigorously designed, sufficiently powered, and placebo-controlled clinical trials are required to fully elucidate the clinical benefits and best-use scenarios for EV therapeutics in veterinary medicine. Additionally, clinical translation of EV-based therapeutics will require Good Manufacturing Practice–compliant methods to scale up and purify EV products. Despite these challenges, EVs hold great promise in the regenerative medicine landscape, particularly in the treatment of musculoskeletal injury and disease in companion animals.

Open access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

Right dorsal colitis causes chronic colic associated with long-term treatment with nonsteroidal antiinflammatory drugs (NSAIDs). This study was designed to determine if NSAIDs could inhibit anion transporters that protect against intestinal mucosal injury in other species.

ANIMALS

20 healthy horses.

METHODS

The effects of indomethacin (INDO) and firocoxib (FIR), on short-circuit current (Isc) in mucosa from the right dorsal colon (RDC) and right ventral colon (RVC) were measured in Ussing chambers by standard electrophysiological techniques. Immunohistochemical methods were used to detect apoptosis (caspase-3) with these NSAIDs and phenylbutazone (PBZ) and to locate the NKCC1 transporter.

RESULTS

The Isc in RDC and RVC incubated with INDO or FIR was increased almost 3-fold (P < .0001) by prostaglandin E2 (PGE2) through a system inhibited by loop diuretics (P < .0001). Although these findings and anion replacement studies were consistent with anion secretion, the RDC also displayed an Isc response suggestive of a unique transporter apparently absent in RVC or NSAID-free solutions. In RDC, FIR, INDO, and PBZ induced apoptosis in the lower half of crypts. However, significant differences in apoptotic index were recorded in the RDC between NSAID-treated and control tissues (no NSAID).

CLINICAL RELEVANCE

The effects of NSAIDs on Isc were consistent with reduced anion secretion, which could represent the pharmacological equivalent of the transport failure responsible for Cystic Fibrosis (CF) in other species. Failure of anion secretion could interfere with buffering acid from intraluminal fermentation, which could suggest a treatment target for right dorsal colitis.

Open access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Summary

Analogues of a melanocyte-stimulating hormone (α-msh) have been documented to be effective in inducing integumental melanogenesis in several species. These melanotropin analogues are more potent than the natural hormone and have prolonged biological activity, without apparent teratogenic or other toxic effects, at least in rodents. In a pilot study, a cyclic α-msh analogue, Ac-[Nle 4 , Asp 5 , D _ -Phe 7 , Lys 10 ] α-msh 4-10-NH2, was administered sc to a dog at a dose of 1 mg of analogue in 1 ml of 0.9 % NaCl for 3 weeks, without noticeable adverse effects. There was gradual and extensive darkening of the coat, which originally was predominantly tan, with tips of black. Initially, the darkening involved face and extremities, then gradually expanded to include the trunk and tail hair. Visual pigmentation peaked approximately 2 months after injections were completed. As new hair growth continued subsequent to the injections, the original tan color appeared at the proximal end of the hair shaft, leaving a dark terminal band on all affected hairs. These observations clearly indicated that follicular melanogenesis can be induced in dogs by treatment with a melanotropic peptide.

Free access
in American Journal of Veterinary Research