The Effect of Low-Level Laser Therapy on the Healing of Open Wounds in Dogs.

OBJECTIVE: To evaluate the effects of low-level laser therapy (LLLT) on acute, full-thickness wound healing in dogs. STUDY DESIGN: Randomized block (dog); historical control. ANIMALS: Adult male Beagles (n = 10). METHODS: Two 2 × 2 cm(2) wounds were surgically created bilaterally on the trunk of each dog. Each side was randomized to receive LLLT (laser, LAS) or standard-of-care management (control, CON), 3 times weekly for 32 days. The LLLT consisted of a dual diode laser (7.5 mW/diode) at 635 nm and total energy density of 1.125 J/cm(2). Wound planimetry was performed on the caudal wounds, from which percent contraction and percent epithelialization were calculated. Histologic features were evaluated at 7 time points from cranial wound biopsies. Experimental data were also compared to wounds from a historical female control cohort (historical control, HCON). RESULTS: There was no difference between LAS and CON wounds for all parameters, including histology. The HCON wounds had significantly greater contraction and epithelialization compared to LAS and CON wounds. The LAS and CON wounds had significantly less inflammation than HCON wounds early in wound healing, but inflammation was significantly greater in LAS and CON wounds by day 21. Fibroblast infiltration and collagen deposition were significantly less in LAS and CON wounds than HCON wounds. CONCLUSION: There are no apparent beneficial effects of LLLT on the healing of acute wounds in healthy dogs using this LLLT protocol. Gender may influence wound healing in intact dogs.

Effects of negative pressure wound therapy on healing of free full-thickness skin grafts in dogs.

OBJECTIVE: To compare healing of free, full-thickness, meshed skin grafts under negative pressure wound therapy (NPWT) with bolster dressings in dogs. STUDY DESIGN: Randomized, controlled experimental study, paired design. ANIMALS: Dogs (n = 5) METHODS: Full-thickness skin wounds (4 cm × 1.5 cm) were created bilaterally on the antebrachia of 5 dogs (n = 10). Excised skin was grafted to the contralateral limb. Grafts were randomized to NPWT or bolster dressings (control; CON). NPWT was applied continuously for 7 days. Grafts were evaluated on Days 2, 4, 7, 10, 14, and 17, biopsied on days 0, 4, 7, and 14, and had microbial culture on Day 7. Outcome variables were: time to first appearance of granulation tissue, percent graft necrosis, and percent open mesh. Significance was set at P < .05. Histologic findings, culture results, and graft appearance were reported. RESULTS: Granulation tissue appeared earlier in the NPWT grafts compared with CON grafts. Percent graft necrosis and remaining open mesh area were both greater in CON grafts compared with NPWT grafts at most time points. Histologic results showed no significant difference in all variables measured, and all cultures were negative. CONCLUSIONS: Variables of graft acceptance were superior when NPWT was used in the first week post-grafting. Fibroplasia was enhanced, open meshes closed more rapidly and less graft necrosis occurred with NPWT application. More preclinical studies are required to evaluate histologic differences.

Comparison of hair follicle histology between horses with pituitary pars intermedia dysfunction and excessive hair growth and normal aged horses.

BACKGROUND: Pituitary pars intermedia dysfunction (PPID) in older equids is commonly recognized by a long hair coat that fails to shed. OBJECTIVE: The aim of this study was to compare hair follicle stages in PPID-affected horses with excessively long hair coats with the stages of normal aged horses (controls) and to compare hair follicle stages in PPID-affected horses after 6 months of treatment with pergolide mesylate with those of control horses. ANIMALS: Eight PPID-affected horses and four normal, age-matched, control horses. METHODS: Skin biopsies were collected from the neck and rump of PPID-affected and control horses. A diagnosis of PPID was established based on hair coat changes and supportive overnight dexamethasone suppression test results. Skin biopsies were repeated after 6 months of treatment with pergolide. The number of hair follicles in anagen (A) or telogen (T) was counted for each skin biopsy using transverse sections. RESULTS: Pretreatment biopsies had a greater percentage of A follicles (neck 96%, rump 95%) and a lower percentage of T follicles (neck 4%, rump 5%) in PPID-affected horses than in control horses (A, neck 15%, rump 25%; and T, neck 85%, rump 75%). After treatment with pergolide, all PPID-affected horses had improved shedding, and the percentages of A follicles (neck 69%, rump 70%) and T follicles (neck 31%, rump 30%) were not different from untreated control horses (A, neck 68%, rump 82%; and T, neck 32%, rump 18%). CONCLUSIONS: These findings document that excessive hair growth (hypertrichosis) in PPID-affected horses is due to persistence of hair follicles in A. Furthermore, treatment with pergolide improved shedding and reduced the percentage of A follicles in PPID-affected horses.

Effects of a cross-linked hyaluronic acid based gel on the healing of open wounds in dogs.

OBJECTIVE: To compare effects of a cross-linked hyaluronic acid (HA) based gel (CMHA-S) to a standard wound management protocol on the healing of acute, full-thickness wounds in dogs. STUDY DESIGN: A prospective, controlled, experimental study. ANIMALS: Purpose-bred, adult, female beagles (n = 10). METHODS: Two 2 × 2 cm wounds were surgically created bilaterally on the trunk of each dog and each side randomized to treatment (CMHA-S) or control (CON) groups. Total and open wound areas were measured with digital image planimetry at 15 time points. From these data, percent contraction and percent epithelialization were calculated. Tissue biopsies were obtained at 6 time points and histologic features were scored. RESULTS: Total wound area was significantly larger and percent contraction was significantly less in CMHA-S compared to CON wounds at all data points between days 9 and 18. At day 25, and for the remainder of the study, CMHA-S wounds were smaller and contracted more than CON wounds, reaching significance at day 32. Percent epithelialization was significantly less in CMHA-S compared to CON wounds at all data points after day 11. Histologically, fibroblastic cellular infiltration was significantly higher in CMHA-S wounds at day 21. CONCLUSIONS: CMHA-S wounds healed more slowly than CON wounds. This HA-based gel is not indicated in acute, full-thickness skin wounds in dogs as administered in this study. However, treatment may be beneficial in the mid-to-late repair stage of healing, or if scar minimization is desired. Further studies to evaluate the effects of the CMHA-S gel on canine wounds are indicated.

Development of antihuman IgG antibodies and hematologic deficits but not clinical abnormalities in C57BL/6 mice after repeated administration of human intravenous immunoglobulin.

Intravenous immunoglobulin (IvIg) preparations consist of purified human immunoglobulins collected from large numbers of healthy persons and are used to treat autoimmune, immunodeficiency, and inflammatory disorders. Studying the effects of IvIg effects in experimental animal models might clarify its mechanisms of action in these disorders, but whether 'serum sickness' or other abnormalities occur after repeated IvIg administration to immunocompetent animals is unknown. In the current study, male C57BL/6 mice (8 to 10 wk old; n = 27) received IvIg (1 g/kg IP) weekly for 6 wk. They were observed for clinical abnormalities, and body weight, temperature, renal function, hematologic parameters, and serum antihuman IgG antibodies were measured before and during treatment. Postmortem evaluations were performed on kidney, spleen, liver, and heart. No clinical or histologic abnormalities were noted despite a transient increase in BUN. Mean antibody levels to human IgG on days 21 and 43 after IvIg administration were increased by 23-fold compared with pretreatment levels. 88% and 89% of the mice were antibody responders on those days. Unexpectedly, hemoglobin, hematocrit, and RBC, WBC, lymphocyte, and platelet counts decreased after IvIg administration. These findings suggest that although it does not produce serum sickness, repeated IvIg administration to immunocompetent mice induces a strong humoral immune response and hematologic deficits of unknown etiology. These factors could cause the effects of IvIg preparations in mouse models of human disease to differ from their effects in the human disorders.

Effects of negative pressure wound therapy on healing of open wounds in dogs.

OBJECTIVE: To compare the effect of negative pressure wound therapy (NPWT) with standard-of-care management on healing of acute open wounds in dogs. STUDY DESIGN: Prospective, controlled, experimental study. ANIMALS: Adult dogs (n=10). METHODS: Full-thickness 4 m × 2 m wounds were surgically created on each antebrachium and in each dog were randomized to receive either NPWT or standard wound dressings (CON) for 21 days. Dressing changes and wound evaluations were made at 8 time points. First appearance of granulation tissue, smoothness of granulation tissue, exuberance, percent epithelialization, and percent contraction were compared. Biopsies for histopathology were taken, and histologic scores determined, at 5 time points, and aerobic bacterial wound cultures performed at 2 time points. RESULTS: Granulation tissue appeared significantly earlier, and was smoother and less exuberant in NPWT wounds compared with CON wounds. Percent contraction in NPWT wounds was less than CON wounds after Day 7. Percent epithelialization in NPWT wounds was less than CON wounds on Days 11, 16, 18, and 21. Histologic scores for acute inflammation were higher in NPWT on Day 3, and lower on Day 7, than CON wounds. Bacterial load was higher in NPWT on Day 7. CONCLUSION: NPWT accelerated appearance of smooth, nonexuberant granulation tissue; however, prolonged use of NPWT impaired wound contraction and epithelialization.

Ocular melanosis in the Cairn Terrier: histopathological description of the condition, and immunohistological and ultrastructural characterization of the characteristic pigment-laden cells.

OBJECTIVE: To describe the microscopic features and lineage of proliferating/infiltrating pigmented cells in ocular melanosis of Cairn Terriers. Animals studied Forty-nine globes removed from 45 Cairn Terriers with ocular melanosis and three globes from control dogs were available for microscopic examination. PROCEDURES: All globes were examined histologically, eight affected and three control globes were also examined by immunohistochemistry, and three affected and three control globes by transmission electron microscopy. RESULTS: Large round pigment-laden cells infiltrated the anterior uvea, obscured the drainage angle and were present within the sclera and episclera of affected globes. Similar pigmented cells were present in lower numbers in the posterior segment of the globe, the optic nerve meninges and periphery of the optic nerve. Changes due to chronic glaucoma were present in many globes and some had evidence of uveitis. Many of the pigmented cells were immunoreactive to HMB45 and some were MITF and vimentin positive. One globe, which was inflamed when removed, had many pigmented cells that were CD18 immunoreactive. The other eyes had lower numbers of CD18 positive cells. The pigmented cells were not immunoreactive to smooth muscle actin, S-100, MART/Melan A, chromogranin A/B, PGP 9.5, synaptophysin, MNF116, AE1/AE3, and CD45. Ultrastructurally many of the pigmented cells had features typical of melanocytes while a smaller number appeared to be melanophages. CONCLUSIONS: Ocular melanosis in Cairn Terriers is characterized by an infiltration of pigment-laden cells predominantly, but not exclusively, within the anterior uvea and anterior sclera. Most of these cells appear to be melanocytes although a variable proportion are pigment-laden melanophages.

Effect of porcine small intestinal submucosa on acute full-thickness wounds in dogs.

OBJECTIVE: To evaluate the effects of porcine small intestinal submucosa (PSIS) on the healing of full-thickness wounds in dogs, specifically the appearance of granulation tissue, percent epithelialization and contraction, histologic variables of inflammation and repair, and aerobic culture results. STUDY DESIGN: Prospective, controlled, experimental study. ANIMALS: Purpose-bred, female dogs (n=10). METHODS: Wounds were created bilaterally on the trunk; 1 side as a control and 1 treated with PSIS. First appearance of granulation tissue was recorded. Total wound area, open wound area, and epithelialized area were measured at 21 time points-wound contraction and percent epithelialization were calculated. Aerobic cultures were taken at 4 time points and wound biopsies at 8. Histologic features were graded into an Acute Inflammation Score and Repair Score. RESULTS: There was no difference in first appearance of granulation tissue between PSIS-treated and control wounds. Wound contraction was significantly faster in control wounds as was percent epithelialization after day 21. Histologic Acute Inflammation Scores were significantly higher in PSIS-treated wounds compared with control wounds on days 2 and 6. There were no differences in Histologic Repair Scores between PSIS-treated and control wounds or in aerobic culture results. CONCLUSION: Wounds treated with PSIS contract more slowly, epithelialize less, and have more pronounced acute inflammation after implantation than control wounds. CLINICAL RELEVANCE: Acute, full-thickness wounds in dogs do not benefit from treatment with PSIS.

Hemangiosarcoma and squamous cell carcinoma in the third eyelid of a horse.

A 12-year-old Belgian draft horse presented for a right eye third eyelid mass and red-tinged ocular discharge of 3 months' duration. The third eyelid was excised and submitted for histopathology. On histopathologic examination, the mass was composed of both hemangiosarcoma and squamous cell carcinoma. The horse developed thickened eyelids and hemorrhagic ocular discharge from the right eye approximately 16 months following surgery, and was euthanized. Necropsy and histopathology confirmed local recurrence and regional metastasis of the hemangiosarcoma. This was an unusual case because there were two distinct neoplastic processes composing the same mass that could not be differentiated grossly.

Multiple endocrine neoplasia type I in a cat.

A 13-year-old 4.6-kg (10.2-lb) neutered male domestic long hair cat was evaluated because of a history of lethargy, exercise intolerance, and ventroflexion of the cervical portion of the vertebral column. After extensive assessment at the Veterinary Teaching Hospital at Michigan State University, the clinical signs were attributed to an aldosterone-secreting tumor of the adrenal gland. Subsequently, an insulin-secreting tumor of the pancreas as well as a functional parathyroid gland adenoma were diagnosed. All 3 masses were surgically removed, and the cat made a full recovery with complete resolution of clinical signs. The syndrome of multiple endocrine neoplasia is well described in humans, and the heritability of the condition has been confirmed. In cats and other species with 1 or more endocrine neoplasms, it is important to perform thorough clinical assessments of patients to identify other endocrine organs that may also be affected concurrently with neoplastic disease.