Female Labrador Retriever Research Articles

Cosmetic Rostral Nasal Reconstruction After Nasal Planum and Premaxilla Resection: Technique and Results in Two Dogs

To describe a novel reconstructive technique after nasal planum and premaxilla resection. Case report. Dogs (n=2) with squamous cell carcinoma (SCC) of the nasal planum. A 9-year-old neutered female Labrador retriever (dog 1) and an 11-year-old neutered male Golden retriever (dog 2) had resection of the nasal planum and premaxilla for treatment of locally invasive SCC. Reconstruction of a nasal planum facsimile was based on use of the nonhaired pigmented margins of bilateral labial mucocutaneous rotation-advancement flaps. Reconstruction of the premaxilla by construction of a nasal planum facsimile resulted in uncomplicated wound healing and improved cosmesis. There was no tumor recurrence at 1290 (dog 1) and 210 (dog 2) days after surgery. Reconstruction of a nasal planum facsimile was successfully performed without complications in 2 dogs with high owner satisfaction with cosmetic appearance. This technique represents a significant advancement in surgical cosmetic outcome, may potentially reduce postoperative complications, and should be considered for dogs requiring nasal reconstruction after nasal planum resection with premaxillectomy.

Combined xeno/auto-grafting of a benign osteolytic lesion in a dog, using a novel bovine cancellous bone biomaterial

CASE HISTORY: A 4-year-old female Labrador Retriever was diagnosed with an osteolytic lesion of the right distal radius. CLINICAL FINDINGS: Radiographs indicated a well-circumscribed radiolucent area 18 × 15 × 8 mm, centred on the distal radial physeal scar. DIAGNOSIS: Histopathology, performed via Jamshidi needle biopsy and following surgical curettage, was inconclusive but suggested either an aneurysmal bone cyst or fibrous dysplasia. CLINICAL RELEVANCE: A novel processed cancellous bovine bone xenograft was used in conjunction with autogenous cancellous bone (at a ratio of approximately 4:1) to fill the curetted defect. There were no observed complications associated with the use of this new biomaterial. Osteointegration of the bone graft was followed using conventional radiographs and peripheral quantitative computed tomography (pQCT) for 10 months post-operatively. Radiographically, the osteolytic lesion modelled to resemble metaphyseal trabeculation. The cross-sectional area and the average bone density of the grafted lesion determined using pQCT data increased over time, suggesting healthy osteoconduction and native bone production.

IMAGING DIAGNOSIS—INFILTRATIVE LIPOMA CAUSING SPINAL CORD COMPRESSION IN A DOG

An 11-year-old, 43 kg neutered female Labrador retriever dog developed acute pelvic limb paraparesis. In magnetic resonance images there was a T1- and T2-hyperintense extradural at the fifth thoracic intervertebral space that was causing marked compression of the spinal cord. In short tau inversion recovery and fat suppressed T1-weighted images the signal from the mass was decreased indicating it was of fatty origin. The mass was removed via a dorsal hemilaminectomy in the thoracic area. Histopathologic analysis confirmed the mass was an infiltrative lipoma. The dog recovered and is fully ambulatory 24 months after surgery. This report provides additional evidence that lipomas in the vertebral canal may be the source of pelvic limb neuropathy and also illustrates the value of magnetic resonance imaging in establishing the fatty nature of some soft tissue masses.

Idiopathic primary chylopericardium in a dog

A 7-year-old spayed female Labrador Retriever was evaluated because of pericardial effusion. The dog had a history of decreased appetite and exercise intolerance of 3 days' duration. Thoracic radiography performed by the referring veterinarian revealed a large cardiac silhouette. Heart sounds were muffled. Echocardiographic findings were indicative of severe pericardial effusion with cardiac tamponade; no pleural effusion was identified. Pericardiocentesis yielded a considerable amount of chylous fluid. A diagnosis of chylopericardium in the absence of pleural effusion was made. Conservative management was not effective, and subtotal pericardectomy and thoracic duct ligation were recommended. Surgery was postponed by the owners for 25 days, at which time the dog had both chylopericardium and chylothorax. The dog underwent subtotal pericardectomy and thoracic duct ligation; to delineate the thoracic duct, intraoperative lymphangiography was performed by injection of a radiopaque contrast agent directly into a mesenteric lymph node and subsequent injection of methylene blue solution into another mesenteric lymph node. Surgical treatment resulted in complete resolution of the clinical signs and pleural effusion. To the authors' knowledge, this is the first report of the development of chylopericardium prior to development of chylothorax in a dog. Treatment with thoracic duct ligation and pericardectomy resulted in complete resolution of the effusion and clinical signs.

Rectovaginal fistula following colectomy with an end‐to‐end anastomosis stapler for a colorectal adenocarcinoma

An 11-year-old, female neutered Labrador retriever was presented with a micro-invasive differentiated papillar adenocarcinoma at the colorectal junction. A colorectal end-to-end anastomosis stapler device was used to perform resection and anastomosis using a transanal technique. A rectovaginal fistula was diagnosed two days later. An exploratory laparotomy was conducted and the fistula was identified and closed. Early dehiscence of the colon was also suspected and another colorectal anastomosis was performed using a manual technique. Comparison to a conventional manual technique of intestinal surgery showed that the use of an automatic staple device was quicker and easier. To the authors' knowledge, this is the first report of a rectovaginal fistula occurring after end-to-end anastomosis stapler colorectal resection-anastomosis in the dog. To minimise the risk of this potential complication associated with the limited surgical visibility, adequate tissue retraction and inspection of the anastomosis site are essential.

Detection of Neospora caninum Tachyzoites in Canine Cerebrospinal Fluid

4-year-old female Labrador Retriever was referred to the Veterinary Teaching Hospital of the Autonomous University of Barcelona because of progressive, generalized ataxia and depressed mental status of 5 days’ duration. Before the onset of signs of neurologic dysfunction, the dog had been anorexic, lethargic, and hyperthermic for 7–10 days. The dog had been treated with doxycycline (5 mg/kg of body weight PO q12h) by the referring veterinarian without clinical improvement. During that time, general attitude, condition, and gait had progressively worsened. Over the 12 hours before presentation, the dog experienced a generalized seizure. Routine vaccinations were current, the owners did not report any previous medical history, and the possibility of exposure to toxins was considered unlikely.

Detection of Neospora caninum Tachyzoites in Canine Cerebrospinal Fluid

4-year-old female Labrador Retriever was referred to the Veterinary Teaching Hospital of the Autonomous University of Barcelona because of progressive, generalized ataxia and depressed mental status of 5 days’ duration. Before the onset of signs of neurologic dysfunction, the dog had been anorexic, lethargic, and hyperthermic for 7–10 days. The dog had been treated with doxycycline (5 mg/kg of body weight PO q12h) by the referring veterinarian without clinical improvement. During that time, general attitude, condition, and gait had progressively worsened. Over the 12 hours before presentation, the dog experienced a generalized seizure. Routine vaccinations were current, the owners did not report any previous medical history, and the possibility of exposure to toxins was considered unlikely.

Cardiac Toxicity From Phenylpropanolamine Overdose in a Dog

A 5-year-old, 29-kg, female Labrador retriever developed tachypnea, tachycardia, and ataxia following ingestion of approximately 48 mg/kg of phenylpropanolamine. Initial diagnostic tests showed multiform ventricular tachycardia, left ventricular dilatation with a focal dyskinetic region in the dorsal interventricular septum, and elevations in creatinine kinase and cardiac troponin I. All abnormalities resolved within 6 months. The transient electrocardiographic, echocardiographic, and biochemical abnormalities were consistent with myocardial necrosis from infarction or direct catecholamine-induced myocardial toxicity.

Chromosome Rearrangements in Canine Fibrosarcomas

We have previously reported the use of six- and seven-color paint sets in the analysis of canine soft tissue sarcomas. Here we combine this technique with flow sorting of translocation chromosomes, reverse painting, and polymerase chain reaction (PCR) analysis of the gene content of the reverse paint in order to provide a more detailed analysis of cytogenetic abnormalities in canine tumors. We examine two fibrosarcomas, both from female Labrador retrievers, and show abnormalities in chromosomes 11 and 30 in both cases. Evidence of involvement of TGFBR1 is presented for one tumor.

犬の線維軟骨塞栓症の1症例

Abstract. A five-year-old female Labrador Retriever was referred for the diagnosis of acute onset of tetraplegia with a three-week history. A neurological examination demonstrated lower motor neuron signs on the left forelimb and upper neuron signs on the both hindlimbs, suggesting a lesion at the spinal cord segments C6-T2. Radiographs of the cervical area did not show any pathological changes. MR images demonstrated a lesion at the C6, as a high intensity area on T2-weighted images, with minimal contrast-enhancement both on T1- and T2-weighted images. As a fibrocartilaginous embolism was the most likely diagnosis for the tetraplegia of the dog, a poor prognosis was given. Euthanasia and necropsy were performed and a definitive diagnosis of fibrocartilaginous embolism was made through a histopathological examination, since an ischemic infarction with a fibrocartilaginous tissue in the vessels around the lesion was observed.

Diagnosis of Rapid Eye Movement Sleep Disorder With Electroencephalography and Treatment With Tricyclic Antidepressants in a Dog

A 9-month-old, female Labrador retriever mix was presented for two types of seizure-like episodes, one of which occurred only during sleep. The two types of episodes were morphologically distinct. An electroencephalogram (EEG) demonstrated that the sleep-associated episodes occurred during rapid eye movement (REM) sleep, supporting a diagnosis of a REM behavior disorder. Based on their morphology and response to antiseizure medications, the waking episodes were diagnosed as seizures. The animal was also diagnosed with an obsessive-compulsive and generalized anxiety disorder. The REM behavior disorder and anxiety-related behaviors improved with tricyclic antidepressant therapy.

P‐66 Disseminated histiocytic sarcoma in a dog receiving long‐term immunosuppressive therapy

A 4‐year‐old female Labrador retriever that had been receiving prednisolone for over 8 months because of severe pruritus developed iatrogenic Cushing's syndrome and was referred to our hospital. After complete withdrawal of prednisolone, atopic dermatitis was diagnosed, based on clinical signs, history, an elimination diet test and an intradermal test. Immunotherapy was started, but it was discontinued 3 months later due to lack of improvement. Several drugs, including prednisolone and cyclosporine, were used in an attempt to control the pruritus, and amitriptyline was added for psychogenic treatment. When the dog was 5.5 years old, dome‐shaped and nonpainful nodules were detected on the digits, neck and shoulder. Three months after the first nodule was detected, nodules had developed all over the body, and most were ulcerated. The nodules were examined histopathologically and the diagnosis was disseminated histiocytic sarcoma. As disseminated histiocytic sarcoma has a reportedly poor prognosis, only antibiotic therapy in addition to continuous amitriptyline and prednisolone administration was pursued. The dog died 6 months after the first nodule was detected. The dog received immunosuppressive agents long‐term to control severe pruritus due to atopic dermatitis. There is a possibility that a long‐term immunocompromised state may lead to the development of neoplasms, such as disseminated histiocytic sarcoma. Funding: Self‐funded.

犬のエプスタイン奇形の1例

A 3-year-old female Labrador retriever was presented because of dyspnea caused by severe pleural effusion. Cardiac auscultation revealed a grade III/VI systolic murmur over the tricuspid-valve area. Echocardiographic examination demonstrated typical tricuspid-valve malformations, dilation of the right atrium and severe tricuspid-valve regurgitation. On the basis of these results, the dog was diagnosed as having Ebstein's anomaly and was treated with orally administered vasodilators, β-adrenergic receptor blockers and diuretics. Clinical signs improved immediately. The patient was doing well and demonstrating no clinical signs 13 months after diagnosis. In this case, medication successfully treated congestive heart failure caused by Ebstein's anomaly

Acute severe hemorrhage secondary to arterial invasion in a dog with thyroid carcinoma

A 7-year-old spayed female Labrador Retriever was referred because of progressive swelling and bruising of the neck, hemothorax, a possible mediastinal mass, and stridor. At the time of admission, the dog was recumbent, mentally dull, tachycardic, and hypothermic. Fluid therapy with hydroxyethyl starch and a balanced electrolyte solution was administered because of presumed hypovolemic shock secondary to hemorrhage; multiple units of packed RBCs and fresh frozen plasma were also administered. On the basis of the computed tomographic images, extensive subcutaneous, subfascial, and cranial mediastinal hemorrhage; hemothorax; prescapular lymphadenopathy; and a contrast-enhancing mass in the left cranioventral aspect of the neck were diagnosed. Exploratory surgery of the neck was performed. All subcutaneous structures were encased in a large blood clot. During dissection of the clot, pulsatile bleeding was observed just caudal to and to the left of the larynx; ligation of the left common carotid artery resulted in immediate cessation of the pulsatile bleeding. Further surgical exploration revealed a 2.5 x 2.5-cm mass adhered to the left common carotid artery at the level of the branching to the left cranial thyroid artery. The mass was removed; the histologic diagnosis was thyroid carcinoma. Three weeks after surgery, treatment with a combination of radiation and chemotherapy (doxorubicin and carboplatin) was begun. Thirteen months after surgery, the dog continued to be free from clinical signs of disease.

Urinary Bladder Rhabdomyosarcoma (Botryoid Rhabdomyosarcoma) in a Labrador Retriever Dog

Urinary bladder rhabdomyosarcoma from a 9-month-old female Labrador retriever dog is described. Grossly reddish black multiple friable multinodular masses filled the lumen of the urinary bladder. Histologically, the masses consisted of round, fusiform and polygonal cells with various consistencies. There were also some strap-like cells with chained nuclei and cross-striations. It was diagnosed as a urinary bladder rhabdomyosarcoma. Additionally, the diagnosis was confirmed by immunoreactivity of tumor cells for canine myoglobin.

Breed and sex differences in growth curves for two breeds of dog guides.

A desirable dog guide weighs 18 to 32 kg as an adult. Male and female German shepherd dogs and male and female Labrador retrievers were weighed between birth and 18 mo of age, with at least one weight recorded after 290 d of age. Growth curves were constructed from 10,484 observations on 880 dogs using the Gompertz function in the form Wt = W(max)exp(-e[-(t-c)/b]), where Wt is weight at time t, Wmax is mature body weight, b is proportional to duration of growth, c is age at point of inflection, and t is age in days. Estimates for mature body weight were 2.4 +/- .3 kg higher for Labrador retrievers than for German shepherd dogs and 4.7 +/- .2 kg higher for males than for females. Male Labrador retrievers were closest to the upper limit for desirable weight, with an average estimated mature weight of 31.4 +/- .3 kg. Duration of growth, 4b + c, was not different between the breeds; however, the estimate for males was 8 +/- 5d longer than for females. Female Labrador retrievers had the shortest estimate for growth of 319 +/- 6 d. The estimate for age at the point of inflection was 3.6 +/- 1.2 d greater for males than for females, but not different between breeds. A better understanding of growth curves for dog guides may aid in estimating mature weight at a young age, thus allowing earlier breeding and training decisions to be made and increasing genetic change per year.

Influence of restricted food intake on estrous cycles and pseudopregnancies in dogs

Abstract Objective To examine effects of restricted food intake on estrous cycle frequency, interestrus interval, and pseudopregnancy prevalence in dogs. Animals 28 female Labrador Retrievers. Procedure Dogs were paired by body weight when they were 6 weeks old and fed so that the limit-fed pair-mate received 75% of the amount of food offered to its maintenance-fed counterpart. Estrous cycle, interestrus interval, and pseudopregnancy data were recorded. Results Mean annual frequency of estrous cycles and duration of interestrus intervals did not differ between feeding groups. Prevalence of clinically evident pseudopregnancy was significantly greater among females that were maintenance fed, although results of endocrinologic testing did not identify a mechanism for this observation. Conclusions and Clinical Relevance Pseudopregnancy in dogs can be influenced by physiologic factors related to nutrition. Clinicians should consider a variety of physiologic and environmental factors when evaluating reproductive function in dogs. (Am J Vet Res 1999;60:820–825)

Acute Water Intoxication in a Dog

SummaryA one‐year‐old female labrador Retriever dog was admitted to the Emergency Service after playing in a lake for several hours. Physical examination revealed coma, hypothermia, and bradycardia. Marked diuresis was noted. A serum biochemical profile revealed hyposmolality, hyponatremia, and hypoproteinmia suggestive of dilution of serum constituents. Acute water intoxication was diagnosed. Recovery was complete and occurred without specific therapy. Acute water intoxication should be considered in the differential diagnosis of coma. (Vet Emerg & Crit Care, 1999, 9: 19–25)

The effect of dietary changes on plasma lipids and lipoproteins of six Labrador Retrievers

Six healthy, spayed female Labrador Retrievers (aged 5·5 to 11 years), kept under controlled conditions of exercise and housing, were fed a diet of 15 per cent fat, 24 per cent carbohydrate and 33 per cent protein for two weeks before and between each of three test diets, of differing fat to carbohydrate ratios (A 13:44, B 20:33, C 25:26 fat:carbohydrate gm per cent dry weight) given in a predetermined order for four weeks each. Fasting plasma lipoproteins and total fatty acids were measured weekly. In the fourth week of each test period post-prandial plasma lipoproteins were measured. Diets B and C increased total (P<0·001) and LDL cholesterol (P<0.05) whilst diet A increased HDL triglyceride (P<0·05). Eicosapentaenoic acid (C20:5) increased on diets B and C, and oleic acid (C18:1) on diet A. Post-prandial hypertriglyceridaemia occurred on all diets. Chylomicron clearance was slower on higher fat diets. Relatively small dietary changes produced significant alterations of plasma lipids, lipoproteins and chylomicron clearance.

Body Composition of Male and Female Labrador Retriever Puppies at 20 wk of Age

Body Composition of Male and Female Labrador Retriever Puppies at 20 wk of Age