Veterinary Medical Teaching Hospital Research Articles

Gonadectomy effects on the risk of immune disorders in the dog: a retrospective study.

BackgroundGonadectomy is one of the most common procedures performed on dogs in the United States. Neutering has been shown to reduce the risk for some diseases although recent reports suggest increased prevalence for structural disorders and some neoplasias. The relation between neuter status and autoimmune diseases has not been explored. This study evaluated the prevalence and risk of atopic dermatitis (ATOP), autoimmune hemolytic anemia (AIHA), canine myasthenia gravis (CMG), colitis (COL), hypoadrenocorticism (ADD), hypothyroidism (HYPO), immune-mediated polyarthritis (IMPA), immune-mediated thrombocytopenia (ITP), inflammatory bowel disease (IBD), lupus erythematosus (LUP), and pemphigus complex (PEMC), for intact females, intact males, neutered females, and neutered males. Pyometra (PYO) was evaluated as a control condition.ResultsPatient records (90,090) from the William R. Pritchard Veterinary Medical Teaching Hospital at the University of California, Davis from 1995 to 2010 were analyzed in order to determine the risk of immune-mediated disease relative to neuter status in dogs. Neutered dogs had a significantly greater risk of ATOP, AIHA, ADD, HYPO, ITP, and IBD than intact dogs with neutered females being at greater risk than neutered males for all but AIHA and ADD. Neutered females, but not males, had a significantly greater risk of LUP than intact females. Pyometra was a greater risk for intact females.ConclusionsThe data underscore the importance of sex steroids on immune function emphasizing a role of these hormones on tissue self-recognition. Neutering is critically important for population control, reduction of reproductive disorders, and offers convenience for owners. Despite these advantages, the analyses of the present study suggest that neutering is associated with increased risk for certain autoimmune disorders and underscore the need for owners to consult with their veterinary practitioner prior to neutering to evaluate possible benefits and risks associated with such a procedure.

Transpalpebral exenteration in cattle: a retrospective study of 115 cases.

To describe the indications for exenteration and complications associated with the procedure. 115 cattle. Medical records of cattle presented for unilateral exenteration evaluated at the University of California, Davis Veterinary Medical Teaching Hospital from January 1985 through December 2015 were reviewed. Median (range) age at presentation for all cattle was 6 (0.2-30) years. The most prevalent (80.9%) indication for exenteration was squamous cell carcinoma (SCC). Cattle >5 years had higher odds (OR = 11.2, 95% CI, 2.8-45.8) for undergoing exenteration due to SCC compared to cattle ≤5 years. Herefords had higher odds (OR = 4.6, 95% CI, 1.5-14.6) for undergoing exenteration for SCC compared to other breeds. Holsteins had higher odds (OR = 140.7, 95% CI, 7.5-2644) for undergoing exenteration for retrobulbar lymphoma compared to other breeds. Complications following exenteration were reported in 15 cases (13.0%). The postsurgical complications were orbital abscesses (6/15), recurrence of SCC (5/15), wound dehiscence (3/15), and excessive hemorrhage (1/15). Median (range) time to occurrence of postsurgical complications was 19 (5-205) days. There was no significant association (P > 0.05) between ocular diagnosis, age, anesthetic technique or the suture pattern used to close the skin postsurgically, and occurrence of postsurgical complications. Early clinical diagnosis of SCC by owners and veterinarians may prevent the need for exenteration. Owners should be made aware of the possible postsurgical complications following exenteration in cattle.

Prospective study evaluating the incidence of bacteraemia and bacteruria in afebrile and febrile neutropaenic dogs undergoing chemotherapy.

The purpose of this prospective study was to determine the incidence and character of bacteraemia and bacteruria in afebrile and febrile neutropaenic dogs undergoing cytotoxic chemotherapy. Fifty‐five neutropaenic dogs presenting to the University of Wisconsin Veterinary Medical Teaching Hospital were enrolled for a total of 57 neutropaenic episodes. The overall incidence of bacteraemia was 12.3% (n = 7/57). Three afebrile dogs and four febrile dogs were bacteraemic; this difference was not significant (P = 0.6968). The overall incidence of bacteruria was 7.5% (n = 4/53). Two afebrile dogs and two febrile dogs were bacteruric; this difference was not significant (P = 1.0). Of the positive blood cultures, the majority of organisms cultured (n = 6/7) were gram‐positive organisms with one gram‐negative organism. Three of the positive blood cultures showed in vitro resistance to more than one antimicrobial agent. Clinical parameters (age, body weight, heart rate, rectal temperature, neutrophil count, haematocrit and platelet count) were not predictive of bacteraemia. The results of this study were not sufficient to justify the use of blood cultures as a first‐line diagnostic test for neutropaenic patients. Blood cultures may have utility in individual case management for a minority of patients in guiding antibiotic choice in the case of resistant bacterial infections. Blood cultures may serve as a tool for antimicrobial de‐escalation, although further study is needed.

림프종 이환견에서 Cyclophosphamide 치료에 의한 무균성 출혈성 방광염 발생 증례

A 12-years-old Maltese (castrated male) dog with jaundice and purulent discharge from the shoulder was referred to the Veterinary Medical Teaching Hospital of Chungnam National University. A physical and laboratory examination revealed that the mucosa of the conjunctiva and the sclera were icteric, and the liver functional enzyme level and the total bilirubin level were increased. Duodenal caudal deviation caused by suspected masses in diameter of about 2 cm was shown by radiographic and ultrasonographic examinations. Using fine needle aspiration (FNA) and computed tomography (CT), the dog was diagnosed with alimentary lymphoma. The dog was treated with chemotherapy. Hematuria was discovered and dysuria occurred because of sterile hemorrhagic cystitis, which is a unique complication resulting from the use of cyclophosphamide.

Clinicopathologic and Histopathologic Renal Abnormalities in Dogs with Coccidioidomycosis.

BackgroundWe observed evidence of protein‐losing nephropathy in some dogs with coccidioidomycosis, suggestive of immune complex glomerulonephritis (ICGN). The goal of this study was to understand the prevalence of renal histopathologic lesions and proteinuria in dogs with coccidioidomycosis.HypothesisBiochemical and histopathological evidence of glomerular lesions is present in dogs with coccidioidomycosis.AnimalsHundred and fifty‐six dogs with naturally occurring coccidioidomycosis.MethodsRetrospective case series. Clinical information and results of clinicopathologic testing were retrieved from the University of California, Davis Veterinary Medical Teaching Hospital (VMTH). Microscopic sections of renal tissue procured from necropsy of dogs with coccidioidomycosis were examined to evaluate the nature and distribution of lesions.ResultsA total of 156 dogs with coccidioidomycosis were identified; 87 dogs had serum biochemistry and a urinalysis performed, 17 had urine protein:creatinine ratios (UPCs), and 24 had renal tissue available for histopathology. Eleven (13%) of the 87 dogs were azotemic, 55 (63%) were proteinuric (of which 14 [25%] had clinically relevant proteinuria defined as ≥3+ or ≥500 mg/dL), and 14 dogs had UPC ≥0.5 (range, 0.5–21.5, median 4.2). Thirteen (54%) of 24 dogs had renal histopathologic lesions suggestive of ICGN. Seven of these dogs had urinalyses performed; 5 (71%) had clinically relevant proteinuria as described above. Two dogs (33%) with normal glomeruli had granulomatous nephritis, 1 of which had intralesional Coccidioides spherules.Conclusions and Clinical ImportanceCoccidioidomycosis should be considered as a possible contributor to glomerular disease in dogs. Whether similar lesions occur in other mammalian hosts, including humans, warrants further investigation.

Seizure Disorders in Goats and Sheep.

BackgroundGoats and sheep are more likely to be presented for examination for seizures than are cattle, possibly as a consequence of their relatively smaller body size. Currently, no reports describing seizure disorders in goats and sheep are available.ObjectivesTo describe clinical features and treatment outcomes of sheep and goats presented for seizures.AnimalsA total of 59 goats and 21 sheep presented for seizures.MethodsRetrospective study. Medical records from 1994 to 2014 at the Veterinary Medical Teaching Hospital, University of California, Davis, were reviewed. Descriptive statistics were used to summarize data. Logistic regression was performed to determine whether variables were associated with mortality.ResultsThe majority of seizures in goats and sheep had structural or metabolic causes. Polioencephalomalacia (PEM) secondary to ruminal lactic acidosis or PEM of undetermined cause was the most frequently diagnosed cause of seizures in goats and sheep. The proportions of mortality in goats and sheep were 49.2 and 42.9%, respectively. Age increased the odds mortality (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.07, 2.14) in goats. Goats with structural or metabolic causes of seizures had higher odds for mortality (OR, 37.48; 95% CI, 1.12, 99.10) than those with unknown causes. Age and etiological diagnosis were not significant (P > .05) predictors of mortality in affected sheep.Conclusions and Clinical RelevanceSeizure disorders in goats and sheep are associated with high mortality, despite treatment. Current treatment in goats and sheep with seizures warrants further investigation to determine whether treatments are beneficial or detrimental to survival.

Skin diseases in companion guinea pigs (Cavia porcellus): a retrospective study of 293 cases seen at the Veterinary Medical Teaching Hospital, University of California at Davis (1990-2015).

Guinea pigs (Cavia porcellus) are popular companion animals with reported skin diseases, but most reports are accessed from textbooks or review articles. To document skin diseases and their prevalence in companion guinea pigs in northern California, USA, and to investigate predilections for the most common conditions over a 25 year period. Two hundred and ninety three guinea pigs from the hospital population met inclusion criteria. A retrospective study was performed by searching computerized medical records seen at the Veterinary Medical Teaching Hospital (VMTH), School of Veterinary Medicine, University of California from 1 January 1990 to 31 July 2015 using key words relevant to dermatology. Of the 580 guinea pigs seen at the VMTH, 50% (293) had skin disease. Of the 293 cases, 154 (52%) presented for nondermatological reasons. Guinea pigs with skin disease were significantly older than those without skin disease (P = 0.0002); females with skin disease were more likely to have cystic ovaries (P = 0.0203), although these were not always associated with alopecia. Pododermatitis and infestation with Trixacarus caviae or lice were the most common skin diseases. Ivermectin or selamectin was used for ectoparasite treatment. Abscesses unassociated with pododermatitis were the most common nodules. Benign follicular tumours were the most common neoplasm. Despite the frequent mention of dermatophytosis in the veterinary literature, only two cases of Trichophyton mentagrophytes were diagnosed. Cutaneous conditions in companion guinea pigs in the USA are common. Clinicians should include a dermatological examination when examining these rodents regardless of the reason for presentation.

Treatment of MRI-Diagnosed Trigeminal Peripheral Nerve Sheath Tumors by Stereotactic Radiotherapy in Dogs.

BackgroundStereotactic radiotherapy (SRT) is an emerging technique for treating tumors in animals.ObjectivesTo assess the outcome of dogs with suspected intracranial trigeminal nerve peripheral nerve sheath tumors (PNST) treated with SRT.AnimalsEight dogs with presumptive PNST.MethodsThis was a retrospective study of dogs identified by searching UC Davis Veterinary Medical Teaching Hospital medical records for dogs treated with SRT for a presumed PNST. Presumptive diagnosis was based on magnetic resonance imaging. SRT was delivered in 3 dose fractions of 8 Gray (Gy) on consecutive days or every other day to a total dose of 24 Gy.ResultsMedian disease‐specific survival was 745 days (range: 99–1375 days, n = 6). No signs of acute adverse effects of radiation treatment were recorded. Late radiation effects versus tumor progression could not be confirmed histopathologically because of few animals undergoing necropsy.Conclusions and Clinical ImportanceThis study provides preliminary evidence that dogs with PNST benefit from SRT in terms of long‐term survival. The treatment appears to be well tolerated and requires fewer anesthetic events for animals compared to full‐course radiation.

Use of a percutaneous transabdominal catheter for management of obstructive urolithiasis in goats, sheep, and potbellied pigs: 69 cases (2000-2014).

OBJECTIVE To evaluate the use of a percutaneous transabdominal catheter (PTC) for urinary bladder drainage in goats, sheep, and potbellied pigs with obstructive urolithiasis. DESIGN Retrospective case series. ANIMALS 43 goats, 10 sheep, and 16 potbellied pigs (all males) with obstructive urolithiasis evaluated at the University of California-Davis Veterinary Medical Teaching Hospital. PROCEDURES Medical records of goats, sheep, and potbellied pigs examined because of obstructive urolithiasis from January 2000 through December 2014 were reviewed. Records of animals for which a standard PTC had been placed into the urinary bladder as part of disease management were selected. Data were collected regarding signalment, complications associated with PTC placement, and duration of PTC placement prior to removal. RESULTS 42 of 43 goats, 5 of 10 sheep, and all potbellied pigs were castrated. Median (range) duration of PTC placement was 2 (1 to 4) days for goats, 1 (1 to 4) day for sheep, and 1 (1 to 3) day for potbellied pigs. Complications associated with PTC placement included blockage of the catheter by urine sediment, perforation of the cecum, and migration of the catheter out of the urinary bladder. CONCLUSIONS AND CLINICAL RELEVANCE Placement of a PTC into the urinary bladder allowed for effective stabilization of goats, sheep, and potbellied pigs with obstructive urolithiasis while acid-base and electrolyte imbalances were corrected. Use of a PTC should be considered for urinary bladder drainage during medical management or prior to surgical management of obstructive urolithiasis for these species.

A Huge Intra-Abdominal Mass Associated with Long-Term Surgical Gauze Retention in a Toy Breed Dog

A 1.83 kg, 9-year-old, spayed female Yorkshire Terrier was referred to the Veterinary Medical Teaching Hospital of Konkuk University for evaluation of an intra-abdominal mass with a week history of vomiting and diarrhea. On physical examination, survey radiography, abdominal ultrasonography, and computed tomography, a huge firm mass was identified in the mid-caudal abdomen. Surgical exploration of the abdominal cavity was performed to remove the mass. The encapsulated mass adhered to the mesentery, tail of the spleen, small intestine, omentum, and right lobe of the pancreas was removed using blunt dissection with dry gauze and cotton swabs. Macroscopic and histopathological examination revealed that the mass was foreign-body granuloma consistent with gauze fiber. Plain abdominal radiography demonstrated no remarkable findings 8 months post-operatively. There was no evidence of vomiting, diarrhea, coughing, difficulty breathing, and cyanosis on exertion 13 months post-operatively.

Aberrant Ancylostoma sp. in the brain of a dog

A 14-month-old, male American Bulldog presented to Texas A&M University Veterinary Medical Teaching Hospital in August of 2012 for anorexia, hydrophobia and gradually worsening neurologic signs. Grossly hemorrhage on the left side of the caudal cerebrum and cerebellum was observed and histologically corresponded with necrohemorrhagic and lymphoplasmacytic encephalitis associated with adult nematodes. Based on morphology and molecular analysis, these were identified as Ancylostoma sp.

Excision and Subsequent Treatment of a Leiomyoma From the Periventiduct of a Koi (Cyprinus carpio koi)

A 10-year-old female koi subspecies (Cyprinus carpio) was presented with bilateral, asymmetric, sessile masses of the periventiductal tissue. The owner had first observed the masses for approximately 1 year before seeking a veterinary evaluation of the fish. Over the past year, the sessile masses continued to grow and develop in size. An incisional biopsy was performed under general anesthesia to further assess the abnormal tissue structures. Based on the histologic evaluation of the submitted biopsy sample, the growth was determined to be a benign spindle cell neoplasm. The koi also was diagnosed with a concurrent genital tract infection based on cytological examination of the reproductive tract fluid. Following transport to the Veterinary Medical Teaching Hospital for further evaluation, a coelomic ultrasound revealed local infiltration of the tissue to the surrounding tissue. To decrease the risks of recurrence following surgical debulking, chemotherapy was recommended to treat the tissue adjacent to the tumor. Cultures obtained from the genital pore resulted in the isolation of Aeromonas spp. susceptible to ceftiofur, which was elected as a preemptive antibiotic. Surgical debulking of the mass was performed, and bleomycin was administered intralesionally and at the periphery of the surgical site. The koi recovered successfully from anesthesia and was discharged later the same day and prescribed an analgesic regimen of meloxicam. After further histological examination of the submitted tissue samples from the periventiductal growths, the tumor was identified as a leiomyoma. No recurrence of the mass was detected 6 months following the surgical procedure and chemotherapy.

Abnormal Buoyancy in a Convict Cichlid (Amatitlania Nigrofasciata) Associated With an Ovarian Carcinoma Invading the Swim Bladder

An 8-year-old female convict cichlid (Amatitlania nigrofasciata) was presented to the University of Wisconsin Veterinary Medical Teaching Hospital with a 2-month history of abnormal buoyancy; the fish spent most of its time in lateral recumbency on the aquarium substrate. During the initial visual examination of the patient in its transport aquarium, the fish was laterally recumbent on the bottom of the tank and had a mildly distended coelom. A transient response to empirical florfenicol therapy was reported, but the cichlid presented 1 month later in poor body condition and, again, in lateral recumbency. Owing to the poor prognosis, the fish was humanely euthanized and a necropsy was performed. The histopathologic results were consistent with a papillary carcinoma originating in the ovary, which invaded the caudal kidney and the swim bladder. The infiltration of the carcinoma into the swim bladder was suspected to be the primary cause of the clinically observed buoyancy abnormality.

Evaluation of a virtual pet visit system with live video streaming of patient images over the Internet in a companion animal intensive care unit in the Netherlands.

To evaluate the impact of a virtual pet visit system ("TelePet" System, TPS) on owners and staff of a companion animal ICU. Longitudinal interventional study (2010-2013). Companion animal ICU at a university veterinary medical teaching hospital. Pet owners, ICU technicians. The introduction of the TPS, with live video streaming of patient images over the Internet, in a companion animal ICU. Pet owners experienced TPS as a valuable extra service. Most TPS users (72.4%) experienced less anxiety and felt less need (40.4% of TPS users) to visit their hospitalized pet in person. Most users (83.5%) shared TPS access with their family. The introduction of the TPS did not improve overall owner satisfaction, except for the score on "quality of medical treatment." Seven of 26 indicators of owner satisfaction were awarded higher scores by TPS users than by TPS nonusers in the survey after the introduction of the system. However, the lack of randomization of owners might have influenced findings. The enthusiasm of the ICU technicians for the system was tempered by the negative feedback from a small number of owners. Nevertheless they recognized the value of the system for owners. The system was user friendly and ICU staff and TPS users experienced few technical problems. As veterinary healthcare is moving toward a more client-centered approach, a virtual pet visit system, such as TPS, is a relatively simple application that may improve the well-being of most owners during the hospitalization of their pet.

Correction of Tooth-to-tooth Contact and Class IV Mesiodistocclusion by Orthodontic Tooth Movement in Three Dogs

Three Maltese dogs, 5 to 7 months old, were admitted to the Veterinary Medical Teaching Hospital, Chonnam National University with malocclusion including Class IV mesiodistocclusion. In the first case, the treatment was performed by moving the mandibular canine teeth caudally with orthodontic buttons and Masel chains. The second patient was treated for rostroverted mandibular canines using buttons and chains. When distal movement of the mandibular canine teeth was completed, a maxillary arch wire with finger springs was applied to push the incisor teeth forward. In the third case, the treatment began by moving the mandibular canine teeth caudally with buttons and chains. An arch wire with finger springs was applied at maxilla to move the maxillary incisor teeth labially. Additionally, the mandibular incisor teeth were moved lingually by an elastic band attached to the buttons cemented to mandibular canine teeth. As a result, all patients successfully regained a normal occlusion.

The use of a hydrocolloid dressing in the facial wound healing process of a horse - case report

Hydrocolloid dressing is a bioactive product used to improve the healing process of large open wounds. InMarch 2011, a horse was evaluated at the Veterinary Medical Teaching Hospital- UNICENTRO, Guarapuava,Brazil. The animal presented with epistaxis and inspiratory dyspnoea associated with fracture of the orbitalpart of the frontal bone with a comminuted fracture of the zygomatic process and bone loss of the articulartubercle of the temporal bone reaching the zygomatic process, tooth fracture and a partial laceration of theleft cheek with avulsion of the eyeball. After the reconstructive facial surgery and enucleation we used thehydrocolloid dressing during the repair phase. It helped re-establish the epithelial layer, avoided excessivegranulation tissue formation and decreased the healing time. Seven days after surgery and the use ofbiological membrane we verified the production of intense and controlled granulation tissue, beyond thatthe membrane was a viable and low cost alternative.

Risk Factors and Spatial Distribution of Canine Coccidioidomycosis in California, 2005-2013

Given the predisposition of dogs to coccidioidomycosis, identification of high-risk regions for coccidioidomycosis in dogs may improve early recognition of emerging human disease. We sought to identify risk factors for canine coccidioidomycosis and to produce a risk map for coccidioidomycosis occurrence. Forty-one dogs seen at the Veterinary Medical Teaching Hospital at the University of California, Davis, between 2005 and 2013 with coccidioidomycosis were identified together with a control population of 79 dogs. Owners were surveyed about potential risk factors including younger age, digging behaviour, and travel to Arizona or the California central valley. Risk factors were analysed using logistic regression analysis. Outcomes were used to generate a risk map for coccidioidomycosis in California. There was a significant correlation between the reported rate of coccidioidomycosis in humans and our risk map for canine coccidioidomycosis in California, supporting the idea of dogs as sentinels for emerging geographic areas for coccidioidomycosis in humans.

Fibrocartilaginous Embolism Associated with the Extrusion of the Intervertebral Disc in a Dog

Background: Intervertebral disc disease is a usual neurological disorder in dogs, which the spinal cord is compressed by intervertebral disc extrusion or protrusion. Fibrocartilaginous embolic myelopathy isan acute infarction disease of spinal cord caused by fibrocartilaginous emboli histologically identical to the nucleus pulposus of intervertebral discs. The aim of this report is present two cases of fibrocartilaginous embolic myelopathy in dogs with intervertebral disc disease.Cases: Two dogs - dachshund breed - were referred to the Veterinary Medical Teaching Hospital of the UFSM. In the first case, the dog was three years old and the owner described complete inability to move the pelvic limbs. The neurological examination revealed paraplegia, postural reactions deficits, normal spinal reflexes and muscle tonus in the hind limbs, pain on palpation in T12-T11 region and loss of deep pain in hind limbs. In the other case, the dog was seven years old and the owner described partial inability to move four limbs. The neurological examination revealed non-ambulatory tetraparesis, postural reactions deficit, normal spinal reflexes in four limbs and pain on palpation in cervical spine. In both cases, the presumptive diagnosis was intervertebral disc disease and surgical treatment was indicated. The dog with thoracolumbar injury died during the anesthesia and the dog with cervical injury was euthanized, after decision of owner. During the necropsy was observed intervertebral disc extrusion between L1-L2 vertebrae in a dog and between C3-C4 vertebrae in the other case with cartilaginous fragments in the spinal canal. Histopathology revealed marked diffuse necrosis with multifocal hemorrhage and cartilaginous emboli.Discussion: Fibrocartilaginous embolic myelopathy is commonly reported in large and giant breed dogs, though also occur in small and medium-sized breeds of dogs. One hypothesis is the pulpous nucleus remains soft for a longer period in large breed dogs, empowering to infiltration in the spinal cord vessels. The intervertebral disc extrusion occurs predominantly in dogs with age between three and six years old, in the cervical, thoracolumbar (T11-L3) and lumbar regions. Chondroid or fibroid degeneration of the intervertebral disc is the most common cause of spinal cord compression in small animals. In chondrodistrophic breed dogs is frequently chondroid degeneration, which the nucleus pulposus moves into the spinal canal through rupture of the annulus fibrosus (extrusion or Hansen type I), causing acute spinal cord compression. The prevalence of fibrocartilaginous embolism in adult and old dogs increase the possibility of predisposing factors, facilitating the injection intravascular of nucleus pulposus material. One of the most accepted theories about the mechanism of fibrocartilaginous emboli into the vessels is due to increase of inside discal pressure and liberation of fibrocartilaginous emboli from nucleus pulposus into the vertebral artery for retrograde flow, reaching the spinal cord by blood flow. The simultaneous occurrence of intervertebral disc disease and the infarction of spinal cord in the proximate region accentuate the hypothesis that the etiology of fibrocartilaginous embolic myelopathy is mechanical into the vessels of the spinal cord.Keywords: neurology, spinal cord, intervertebral disc disease, dogs.

Facial Paralysis Secondary to Hypothyroidism in a Dog

Background: Secondary neurological disorders hypothyroidism is unusual in dogs, especially when compared with other clinical signs, such as lethargy, weight gain and dermatological alterations. When manifested, these signals refer to the peripheral or central nervous system and the most common include: vestibular disease, seizures, laryngeal paralysis, poly­neuropathy and paralysis of the facial nerve. Several reports of neurological disorders associated with hypothyroidism are found in literature, basically international. In the national literature, however, there are few reports on the subject. Thus, the aim of this study was to report a case of facial paralysis associated with hypothyroidism in a dog.Case: A male canine, the boxer race, with 7-year-old were referred to the Veterinary Medical Teaching Hospital of the UFSM with a history of difficult water and food intake and asymmetry of the face for seven days. On neurological ex­amination, the animal found itself alert and locomotion, postural reactions and segmental reflexes without changes. In the evaluation of the cranial nerves, there was a menace response absent the right side, however with preserved vision, palpebral and lip ptosis of the right side and reflection palpebral absent on the same side. Opposite the historical, clinical, neurological and laboratory test findings, the diagnosis was facial paralysis secondary to hypothyroidism. As differential diagnoses were listed, inner otitis neoplasm in inner ear, trauma and idiopathic facial paralysis. After the diagnosis, clini­cal treatment was instituted with levothyroxine sodium, at a dose of 0.02 mg kg orally every 12 h, being observed total improvement of clinical signs (no changes for water intake and food, menace response and reflection palpebral normal and symmetry of the face) in 32 days.Discussion: The diagnosis of facial paralysis associated with hypothyroidism was based on the history, clinical and neurological examination findings, laboratory assessment of thyroid function by observing low serum free T4 and high concentrations of TSH, the therapeutic response after supplementation levothyroxine sodium, and exclusion of other pos­sible causes, such as otitis interna and traumatic. The pathogenesis of this change associated with hypothyroidism is not completely understood, although it is believed that cranial nerve paralysis (trigeminal, facial and vestibulocochlear) may result from the resulting compression of myxedema deposit nerve or in the tissues of the head and neck, demyelination caused by disordered metabolism of Schwann cells, decreased blood perfusion of the inner ear secondary to hyperlipidemia and increased blood viscosity or metabolic defects ranging from change in axonal transport to severe axonal loss. Treatment consists of supplementation of levothyroxine and most dogs with neurological disorders associated with hypothyroidism will present partial or total improvement of clinical signs between two and four months, generally being observed improve­ment within the first week of treatment. In the dog this report, after the beginning of treatment, improvement was observed partial and total clinical signs in 15 and 32 days, respectively. Therefore, with appropriate treatment, hypothyroidism is a disease with an excellent prognosis. The report brings to clinical relevance, the importance of hypothyroidism in the dif­ferential diagnosis of facial paralysis in dogs with face asymmetry history, the laboratory evaluation of thyroid function and response to therapy with levothyroxine sodium supplementation essential for definitive diagnosis. Keywords: neurology, facial nerve, peripheral neuropathy, dogs.

Evaluation of optimal water fluoridation on the incidence and skeletal distribution of naturally arising osteosarcoma in pet dogs.

Experimental toxicological studies in laboratory animals and epidemiological human studies have reported a possible association between water fluoridation and osteosarcoma (OSA). To further explore this possibility, a case-control study of individual dogs evaluated by the UC Davis Veterinary Medical Teaching Hospital was conducted using ecologic data on water fluoridation based on the owner's residence. The case group included 161 dogs with OSA diagnosed between 2008-2012. Two cancer control groups included dogs diagnosed with lymphoma (LSA) or hemangiosarcoma (HSA) during the same period (n = 134 and n = 145, respectively). Dogs with OSA were not significantly more likely to live in an area with optimized fluoride in the water than dogs with LSA or HSA. Additional analyses within OSA patients also revealed no significant differences in age, or skeletal distribution of OSA cases relative to fluoride status. Taken together, these analyses do not support the hypothesis that optimal fluoridation of drinking water contributes to naturally occurring OSA in dogs.