Oestrogen receptor antagonist and hair regrowth in dogs with hair cycle arrest (alopecia X)

An oestrogen receptor pathway that regulates the telogen-anagen hair follicle transition in mice has been described. The purpose of this study was to investigate whether fulvestrant, a pure oestrogen receptor antagonist, would cause hair regrowth in Pomeranian dogs with hair cycle arrest (alopecia X). Eleven Pomeranian dogs with hair cycle arrest were randomly assigned to receive two intramuscular injections of either 10 mg kg(-1) fulvestrant (n = 6) or an equal volume of saline (n = 5) 1 month apart. Complete blood count, chemistry panel, and urinalysis were monitored prior to the first injection and monthly for 2 months. Dogs were evaluated each month for degree of hair growth, percentage of body affected, and quality of new hair growth. Three control dogs received fulvestrant after the completion of the study. In addition, one control dog and one treatment dog received two subcutaneous injections of 20 mg kg(-1) fulvestrant 1 month apart. No dogs that received 10 mg kg(-1) fulvestrant had any evidence of hair regrowth. The control dog that received 20 mg kg(-1) fulvestrant had substantial hair regrowth 1 month after the first injection. No adverse effects from the treatment were noted. Fulvestrant does not appear to be a feasible treatment for dogs with hair cycle arrest (alopecia X) when administered intramuscularly at 10 mg kg(-1). A higher dose of fulvestrant requires more investigation but may be cost-prohibitive.     

Adrenal steroid hormone concentrations in dogs with hair cycle arrest (Alopecia X) before and during treatment with melatonin and mitotane

The purpose of the study was to evaluate intermediate adrenal steroid hormones (ISH) in neutered dogs with hair cycle arrest (Alopecia X) during treatment with melatonin, and to see if hair re-growth is associated with sex hormone concentrations within the normal ranges. Twenty-nine neutered, euthyroid, and normo-cortisolemic dogs were enrolled in the study (23 Pomeranians, three keeshonds, two miniature poodles, and one Siberian husky). Coat assessment and an ACTH stimulation test were performed pre-treatment and approximately every 4 months for a year post treatment. Melatonin was administered initially at 3-6 mg, every 12 h. Based on clinical progression, each dog was continued on the current dose of melatonin, given an increased dose of melatonin or changed to mitotane. Partial to complete hair re-growth occurred in 14/23 Pomeranians, and partial re-growth in 3/3 keeshond and 1/2 poodle dogs. A Siberian husky dog failed to re-grow hair. Fifteen dogs had partial hair re-growth at the first re-evaluation. Melatonin dosage was increased in eight dogs but only one had improved hair re-growth. On mitotane treatment, partial to complete hair re-growth was seen in 4/6 dogs and no re-growth in 2/6 dogs. No significant decrease in sex hormone concentrations were seen during melatonin or mitotane treatment. Concentrations of ISH in dogs with hair re-growth did not differ significantly from pre-treatment values. At the completion of the study, androstenedione, progesterone and 17-hydroxyprogesterone were still above reference ranges in 21, 64 and 36%, respectively, of dogs with partial to complete hair re-growth. In conclusion, 62% of dogs had partial to complete hair re-growth. However, not all dogs with hair re-growth had concentrations of ISH within the normal range.     

Retrospective evaluation of sex hormones and steroid hormone intermediates in dogs with alopecia

The purpose of this study was to determine if there are specific steroid hormone aberrations associated with suspect endocrine alopecias in dogs in whom hypothyroidism and hyperadrenocorticism have been excluded. Steroid hormone panels submitted to the UTCVM endocrinology laboratory over a 7.5-year period (783 samples) from dogs with alopecia were reviewed. During this period, 276 dogs met the criteria for inclusion and were comprised of 54 different breeds. Approximately 73% of dogs had at least one baseline or post-ACTH stimulation steroid hormone intermediate greater than the normal range. The most frequent hormone elevation noted was for progesterone (57.6% of samples). When compared with normal dogs, oestradiol was significantly greater in Keeshond dogs and progesterone was significantly greater in Pomeranian and Siberian Husky dogs. Not all individual dogs had hormone abnormalities. Chow Chow, Samoyed and Malamute dogs had the greatest percentage of normal steroid hormone intermediates of the dogs in this study. Baseline cortisol concentrations were significantly correlated with progesterone, 17-hydroxyprogesterone (17-OHP) and androstenedione. Results of this study suggest that the pathomechanism of the alopecia, at least for some breeds, may not relate to steroid hormone intermediates and emphasizes the need for breed specific normals.     

Hair cycle in dogs with different hair types in a tropical region of Brazil

Hair cycle activity has been extensively studied in humans, sheep and laboratory animals, but there is a lack of information in dogs. Besides varying according to species, breed, sex and general health, hair growth is mainly affected by climatic variations. The aim of the study was to evaluate the follicle activity in three breeds of dogs with different hair types, in the city of Viçosa, Minas Gerais (latitude 20°45′S), Brazil. Twenty‐one male dogs of boxer, labrador and schnauzer breeds were trichographically analysed monthly over 12 consecutive months. Hair percentage of telogen and anagen hairs at the different stages of the hair cycle in boxers and labradors was not significantly different, but both differed from the schnauzers. A significant correlation between hair follicle cycle and environmental temperature and photoperiod was noted in the boxers and labradors. In these breeds, a larger number of telogen hairs were observed during the hottest months of the year, and an increase in anagen hairs during the coldest months. The mean percentage of telogen hairs was 93, 90 and 55.3% for boxer, labrador and schnauzer, respectively.     

Clinical evaluation of methoximorpholino-doxorubicin (FCE 23762) in dogs with spontaneous malignancies

We conducted a clinical evaluation of FCE 23762, a methoxymorpholino analog of doxorubicin, in 48 dogs with metastatic, nonresectable, or chemotherapy-resistant spontaneous malignancies at an initial dosage of 50-60 microg/kg IV every 3 weeks. Clinical evidence of toxicity was minimal; 6 dogs developed grades I, II, and III hematologic toxicities after the 1st treatment, and 1 dog developed grade II gastrointestinal toxicity. One dog became pancytopenic 4 months after discontinuation of FCE 23762. No other adverse effects were noted. Partial or complete remissions were observed in 32% of the dogs. Responses were observed both in previously untreated dogs and in those that had received prior chemotherapy, including doxorubicin. FCE 23762 is a promising new antineoplastic agent that can be used safely in dogs with cancer; doses higher than those used in this study may be used eventually in practice.     

Retrospective evaluation of postoperative nasotracheal tubes for oxygen supplementation in dogs following surgery for brachycephalic syndrome: 36 cases (2003–2007)

Objective – To assess the utility of nasotracheal tubes in postoperative oxygen supplementation in dogs following corrective surgery for brachycephalic syndrome. Design – Retrospective study 2003–2007. Setting – University teaching hospital. Animals – Thirty‐six client‐owned dogs that underwent corrective surgery for brachycephalic syndrome. Interventions – None. Measurements and Main Results – Medical records were reviewed for animals that underwent surgical interventions for brachycephalic syndrome including palatoplasty, ventriculectomy, and rhinoplasty. Data collected included signalment, presenting complaints, analgesic and surgical interventions, type of supplemental oxygen therapy, complications and mortality occurring during hospitalization. A nasotracheal tube (NTT) was placed in 20 dogs at the end of surgery; 16 dogs received other forms of oxygen supplementation (8) or no oxygen supplementation (8) during recovery. The total number of postoperative complications was similar in both groups (8/20 dogs with NTTs and 7/16 in those without NTTs). However, respiratory distress was observed in 5 dogs without NTTs but was not observed in any dog while an NTT was in place. One dog in each group died postoperatively. Conclusion – Placement of an NTT was found to be easy and may offer benefit in dogs with brachycephalic syndrome as a noninvasive means of delivering oxygen. The use of NTT may minimize severe postoperative morbidity, in particular by reducing postoperative respiratory distress.     

Retrospective evaluation of the use of amiodarone in dogs with arrhythmias (from 2003 to 2010)

Objectives : To evaluate the efficacy of amiodarone in dogs with refractory supraventricular and ventricular arrhythmias and to document the side effects in treated dogs. Methods : Records of 28 dogs were retrospectively searched to document indication for amiodarone administration, heart rate, alkaline phosphatase, alanine aminotransferase, thyroxine (T4) and thyroid stimulating hormone values before and after starting treatment and during follow‐up periods. Results : Sixteen dogs with supraventricular and 12 dogs with ventricular arrhythmias were treated with amiodarone. Amiodarone treatment significantly reduced the heart rate (P<0.001) and resulted in improvement in the severity of the arrhythmia and clinical signs in 26 dogs. There were no significant differences in alkaline phosphatase (P=0.596), alanine aminotransferase (P=0.842), T4 (P=0.789) and thyroid stimulating hormone (P=0.064) before and after starting amiodarone. On maintenance therapy, median amiodarone blood levels were within the accepted reference range (0.5 to 2.0 mg/L) at 0.8 mg/L (range 0.2 to 11.6 mg/L), but the majority of the desethylamiodarone levels were below normal at 0.1 mg/L (range 0.1 to 0.9 mg/L), based on human reference intervals (0.5 to 2.0 mg/L). Clinical Significance : Amiodarone may be an effective and safe alternative to treat supraventricular and ventricular arrhythmias in dogs, when common anti‐arrhythmic drugs are not effective or contraindicated.     

Efficacy evaluation of epsiprantel (Cestex) against Echinococcus mutilocularis in dogs and cats

Helminth-free dogs and cats were experimentally infected with protoscoleces of Echinococcus multilocularis and used in controlled trials for efficacy evaluation of the cestodicide epsiprantel. In two separate trials each 4 dogs were treated at day 20 post infection (p.i.) with average oral dosages of 5.1 (4.9-5.3) and 5.4 (5.2-5.8) mg/kg body weight (b.w.) epsiprantel, respectively, and necropsied at day 24 p.i. Among each 4 dogs of the two untreated control groups all animals were infected and had high intestinal worm burdens with averages of 33.575 and 100.725 E. multilocularis specimens per animal (individual worm burdens in group Ib 59,500-149,800, group IIb 20,500-43,200); in the two groups of treated dogs the average worm burdens were reduced by 99.6 and 99.9%. Among 8 treated dogs 4 were helminth-free, the other 4 had residual worm burdens (10-70 in 3 dogs, 1480 in 1 dog). In each 5 cats single oral treatments with average doses of 2.7 (2.7-2.8) and 5.5 (5.5-5.5) mg/kg b.w. epsiprantel were 100% effective against E. multilocularis 20 days p.i. and eliminated the worm burdens from all 10 animals. In the untreated group of 5 cats the average worm burden was 2864 per animal (individual worm burdens 20-6830). Side effects of the drug treatment were not observed. The results of the study show that in single therapeutic dosages recommended by the producer (dogs 5.5 mg, cats 2.75 mg/kg b.w.) epsiprantel eliminates E. multilocularis to over 99% or completely, but residual worm burdens may persist in some animals.     

Effects of dietary fiber supplementation on glycemic control in dogs with alloxan-induced diabetes mellitus.

The effect of a high insoluble-fiber (IF) diet containing 15% cellulose in dry matter, high soluble-fiber (SF) diet containing 15% pectin in dry matter, and low-fiber (LF) diet on glycemic control in 6 dogs with alloxan-induced insulin-dependent diabetes mellitus was evaluated. Each diet contained greater than 50% digestible carbohydrate in dry matter. A crossover study was used with each dog randomly assigned to a predetermined diet sequence. Each dog was fed each diet for 56 days. Caloric intake was adjusted weekly as needed to maintain each dog within 1.5 kg of its body weight measured prior to induction of diabetes mellitus. All dogs were given pork lente insulin and half of their daily caloric intake at 12-hour intervals. Mean (+/- SEM) daily caloric intake was significantly (P less than 0.05) less when dogs consumed the IF diet vs the SF and LF diets (66 +/- 3 kcal/kg, 81 +/- 5 kcal/kg, and 79 +/- 4 kcal/kg, respectively). Serum alkaline phosphatase activity was significantly (P less than 0.05) higher when dogs consumed the LF diet vs the IF and SF diets (182 +/- 37 IU/L, 131 +/- 24 IU/L, and 143 +/- 24 IU/L, respectively). Mean postprandial plasma glucose concentration measured every 2 hours for 24 hours, beginning at the time of the morning insulin injection, was significantly (P less than 0.05) lower at most blood sampling times in dogs fed IF and SF diets, compared with dogs fed the LF diet.(ABSTRACT TRUNCATED AT 250 WORDS)     

Post-mortem evaluation of expanded polytetrafluoroethylene (ePTFE) used in mitral valve repair in dogs

Mitral valve repair is one of the treatment options for mitral regurgitation. Expanded polytetrafluoroethylene (ePTFE) is a polymer that has been widely used in cardiovascular surgery. In this case series, we report the autopsy and histological findings in 6 dogs that underwent cardiopulmonary bypass for mitral annuloplasty using ePTFE sheets and chordoplasty using ePTFE sutures.From May 2005 to October 2009, 3 female and 3 male dogs with severe mitral regurgitation underwent mitral valve repair. This case series included 3 Cavalier King Charles spaniels, 2 Maltese, and 1 Shih Tzu. The survival period after surgery was 19–72 (35 ± 19) months.In all the cases, autopsy revealed that the ePTFE sheets and sutures were not damaged and well integrated into the surrounding highly differentiated, connective tissues. Low-power microscopy revealed that in all cases, the tissues surrounding the ePTFE sheet in the mitral valve annulus had almost completely been covered by granulation tissue. No inflammatory infiltrate or thrombogenesis was observed around the ePTFE in any of the cases.There was no evidence of reactive changes in the region surrounding the ePTFE. These results suggest that ePTFE has excellent tissue compatibility and durability and can be effectively used for canine mitral valve repair.     

Effects of dietary supplementation with sodium chloride on urinary relative supersaturation with calcium oxalate in healthy dogs

OBJECTIVE: To evaluate the effect of dietary supplementation with sodium chloride (NaCl) on urinary calcium excretion, urine calcium concentration, and urinary relative supersaturation (RSS) with calcium oxalate (CaOx). ANIMALS: 6 adult female healthy Beagles. PROCEDURE: By use of a crossover study design, a canned diet designed to decrease CaOx urolith recurrence with and without supplemental NaCl (i.e., 1.2% and 0.24% sodium on a dry-matter basis, respectively) was fed to dogs for 6 weeks. Every 14 days, 24-hour urine samples were collected. Concentrations of lithogenic substances and urine pH were used to calculate values of urinary RSS with CaOx. RESULTS: When dogs consumed a diet supplemented with NaCl, 24-hour urine volume and 24-hour urine calcium excretion increased. Dietary supplementation with NaCl was not associated with a change in urine calcium concentration. However, urine oxalate acid concentrations and values of urinary RSS with CaOx were significantly lower after feeding the NaCI-supplemented diet for 28 days. CONCLUSIONS AND CLINICAL RELEVANCE: Dietary supplementation with NaCl in a urolith-prevention diet decreased the propensity for CaOx crystallization in the urine of healthy adult Beagles. However, until long-term studies evaluating the efficacy and safety of dietary supplementation with NaCl in dogs with CaOx urolithiasis are preformed, we suggest that dietary supplementation with NaCl be used cautiously.     

Photodynamic hyperthermal therapy with indocyanine green (ICG) induces apoptosis and cell cycle arrest in B16F10 murine melanoma cells

We examined the effects of photodynamic hyperthemal therapy (PHT), which is a combination of photodynamic therapy (PDT) and hyperthermia (HT), on the apoptosis and cell cycle progression of murine melanoma B16F10 cells. The percentage of apoptotic cell was determined by flow cytometry using fluorescein isothiocyanate (FITC)-conjugated Annexin V and propidium iodide (PI) double staining. The cell cycle analysis was performed by PI staining with flow cytometry. The expression of cyclins and heat shock protein 70 (Hsp70) were examined by a Western blotting analysis. PHT induces death in B16F10 cells, and PHT-mediated apoptosis occurred acutely and persistently in vitro. Our study demonstrated that PHT using indocyanine green (ICG) and near infrared (NIR) light source induces apoptosis and G0/G1 cell cycle arrest in the B16F10 cells.     

Effects of different dietary protein levels and DL‐methionine supplementation on hair growth and pelt quality in mink (Neovision vision)

The effect of different dietary protein levels and DL‐methionine (Met) supplementation on hair growth and the resulting pelt quality in mink was studied. Four groups of male mink were fed with four isocaloric diets containing 32% (P32), 24% (P24), 16% (P16) or P24+Met (0.8%) crude protein of dry matter (DM) from September to December. Skin biopsies were taken at the pelting. Histological techniques and computer‐assisted light microscopy were used to determine the ratio of activity (ROA) of under hairs and guard hairs respectively. The results showed that when the dietary protein level reduced from 32% to 16%, body length, number and diameter of under hairs and guard hairs of minks declined, and pelt length and pelt weight of minks decreased significantly (p < 0.05). These parameters were similar between P32 and P24 with Met supplementation (p > 0.05). The hair follicle density of the winter coat was not influenced by the dietary protein levels and Met supplementation (p > 0.05). Low‐protein diets content led to a reduction of hair follicle developing to next phase. It was documented that 24% crude protein of DM with Met supplementation during growing‐furring period was sufficient for minks to express their genetic capacity to develop hair follicles and achieve the prime fur characteristics. Overall this study demonstrated that hair growth and hair properties in pelts are very dependent on the dietary protein and Met supply in the growing‐furring period of minks.