Gingival thickness in dogs: association with age, gender, and dental arch location

Reduced gingival thickness is one of many factors that might predispose humans to periodontal disease and subsequent gingival recession. Gingival thickness differs between individuals, and is associated with age, gender, and location on the dental arch. Different gingival phenotypes exist in the human population according to the thickness of gingiva. Similar information on gingival phenotypes in dogs is unknown. The aim of this study was to investigate the thickness of the gingiva in dogs and its relation to age, gender and location on the dental arch. For this study, 48 dogs of comparable size (40-cm at withers) were divided into three groups according to their age as follows: < 2-years of age; 2 to 8-years of age; > 8-years of age. Gingival thickness was measured in both the mandible and maxilla using a transgingival probing technique. The graded probe was inserted midway into the attached gingiva at the level of each tooth class region. Young and middle aged dogs had significantly thicker gingiva (1.67 +/- 0.17 mm and 1.68 +/- 0.18 mm, respectively) compared with older dogs (1.54 +/- 0.16 mm). There was no significant difference in gingival thickness based on location or gender Generally, the gingiva was thicker at the level of large teeth such as canine and carnassial teeth. Regions of thinner gingiva at the level of incisor and premolar teeth correlated with the regions of highest prevalence of periodontal disease found in previous studies.     

Dental caries in the dog

The dental records of 435 dogs seen in a dental referral practice were reviewed. Twenty-three dogs (5.3%) had one or more caries lesions. Of the 47 caries lesions, 19 (40%) were pit and fissure caries, 17 (36%) were smooth surface caries, and 11 (23%) were root caries. Twelve dogs had symmetrical lesions. The teeth most commonly involved were the fourth premolar and first and second molar teeth. Twenty affected teeth were extracted and 17 were treated by cavity preparation and restoration with composite or glass ionomer materials. Ten restorations in four dogs were examined one year or more following treatment; all of the restorations were intact and there was no progression of the caries.     

Dental and craniofacial findings in eight miniature schnauzer dogs affected by myotonia congenita: preliminary results

Myotonia is a clinical sign characterized by the delay of skeletal muscle relaxation following the cessation of a voluntary activity or the termination of an electrical or mechanical stimulus. Recently, Miniature Schnauzers with myotonia congenita associated with defective chloride ion conductance across the skeletal muscle membrane were identified. Congenital myotonia in these dogs appears to follow an autosomal recessive mode of inheritance. Craniofacial and dental findings of eight Miniature Schnauzer dogs with myotonia congenita are described in the present paper. These findings include: delayed dental eruption of both deciduous and permanent dentition: persistent deciduous dentition; unerupted or partially erupted permanent teeth: crowding and rotation of premolar and or incisor teeth: missing teeth: increased interproximal space between the maxillary fourth premolar and first molar teeth: decreased interproximal space between the maxillary canine and lateral incisor teeth: inability to fully close the mouth due to malocclusion: distoclusion: and, decreased mandibular range of motion. A long narrow skull with a flattened zygomatic arch and greater mandibular body curvature were also consistent findings in the affected dogs. The small number of dogs studied prevents conclusive statements about the origin of these abnormalities, however it is interesting that only 1 of 45 unaffected Miniature Schnauzer dogs showed similar traits.     

Mapping of the radiographic central point of feline dental resorptive lesions

Intraoral dental radiographs of 217 cats presented for dental treatment were examined. Radiographic signs of dental resorptive lesions were identified in 107 cats, and the apparent central point of each lesion was mapped on a diagram of the tooth. Mapping was only possible on maxillary and mandibular canine teeth and on mandibular third premolar, fourth premolar, and first molar teeth. Resorptive lesions were most common on the molar teeth (n = 103) and maxillary canine teeth (n = 96), and least common on fourth premolar teeth (n = 56). Resorptive lesions on premolar and molar teeth were widely scattered, noted more commonly in the coronal portions of the root. Resorptive lesions in canine teeth had a tendency to be located more apically on the roots.     

Area of desensitization following mental nerve block in dogs

Regional nerve blocks are commonly used to provide analgesia for dental and oral surgical procedures. The purpose of this study was to demarcate the areas of the mandible that would be desensitized by application of the mental nerve block. Seven healthy mixed-breed dogs were anesthetized for an annual dental examination and professional teeth cleaning procedure. Bupivacaine HCl (0.4 ml/ m2) was administered at one middle mental foramen based on previously described techniques for the mental nerve block. A noxious stimulus was applied at 23 predetermined ipsilateral mandibular locations using pressure from a mosquito hemostat on the mucocutaneous junction (MCJ) and a dental curette on the vestibular mucogingival line (MGL) at the incisor canine, and premolar teeth; and, the mesial and distal aspects of the first molar tooth. A thermal stimulus using a refrigerant spray on a cotton ball was applied to the ipsilateral canine, third premolar and fourth premolar teeth; and, the mesial and distal aspects of the first molar tooth. Demonstration of nociception or anesthesia was noted and the responses tabulated. The area of desensitized tissues was smaller than expected and highly variable within the study group. In conclusion, the unilateral mental nerve block does not reliably provide generalized desensitization to tissues of the incisive and rostral regions of the mandible. Although the mental nerve block is recommended, other modes of analgesia should be emphasized for surgical and dental procedures involving these areas.     

A MACROSCOPIC AND RADIOLOGIC INVESTIGATION OF DENTAL DISEASES OF THE DOG

The type and frequency of dental diseases and disorders were determined in 162 randomly selected dogs available for necropsy. There were 82 males and 80 females ranging in age from seven months to 14 years. There were 150 purebred dogs (50 different breeds) and 12 mongrels. Only four breeds were represented by ten individuals or more: Poodles (Miniature and Toy), German Shepherds, Dachshunds, and Boxers. The oral cavity was examined macroscopically, and missing teeth, dental caries, dental calculus (tartar), and gingival epulides were recorded as to frequency and distribution. After macroscopic examination of the oral cavity, the head of each dog was sawed at the midline, fixed in formalin, and radiographed. The frequency, severity, and distribution of marginal periodontitis, periapical destruction, and root resorption were recorded. The most frequently noted disease was periodontitis, which increased in frequency and severity with increasing age of the dogs. The disease varied markedly among and within different breeds. Small dogs were more often affected with periodontitis than large dogs. Periapical destruction was a common finding. Caries and root resorption were less common. Missing teeth was a frequent disorder regardless of age. Most of the dogs had dental calculus.     

A cross-sectional study of Leishmania spp. infection in clinically healthy dogs with polymerase chain reaction and serology in Greece

The prevalence of gastrointestinal parasites in stray dogs, and dogs with owners was investigated by fecal examinations from 271 dogs employing sedimentation, simple flotation and centrifugation-flotation methods. The centrifugation-flotation method, when compared to simple flotation or sedimentation methods was generally more accurate in the diagnosis of all intestinal parasites, but statistical differences were detected only in relation to Giardia spp. and Cystoisospora spp. (synonym Isospora spp.). The following parasites, with their respective prevalence, were diagnosed in the fecal samples: Ancylostoma spp. (23.6%); Toxocara canis (5.5%); Trichuris vulpis (4.8%); Spirocerca lupi (1.9%); Dipylidium caninum (0.7%); Giardia spp. (12.2%); Hammondia heydorni (2.6%); Cystoisospora spp. (8.5%); and Sarcocystis spp. (2.2%). The prevalence of most parasites was similar for dogs of mixed-breed and for dogs of a defined-breed, except for Cystoisospora spp. and T. canis which showed a significantly higher prevalence in mixed-breed dogs. The prevalence of Ancylostoma spp. (17.1%) was significantly lower in stray dogs than in those with an owner (31.9%) and the prevalence of Giardia spp. and Cystoisospora spp. was higher in stray dogs (P < 0.05). No effect of season on the occurrence of the different parasite genera could be observed, except for Ancylostoma spp., for which an increase in the percentage of dogs shedding eggs was observed at the beginning of Summer with a peak occurrence during April and May (Autumn). The prevalence of Ancylostoma spp., T. canis, T. vulpis, Giardia spp. and Cystoisospora spp. was higher in adult males than in adult females, but significant differences between the two groups occurred only with Giardia spp. Young animals were found to more frequently shed Nematode eggs in feces than adult animals.     

Repair of experimental plaque-induced periodontal disease in dogs

Forty mongrel dogs were used in this study for induction of periodontal disease by placing subgingival silk ligatures affecting maxillary and mandibular premolar teeth during a 12-month period. Experimental premolar teeth received monthly clinical, radiographic, and histometric/pathologic assessments. The results demonstrated significant increases in scores and values of periodontal disease parameters associated with variable degrees of alveolar bone loss. The experimental maxillary premolar teeth exhibited more severe and rapid rates of periodontal disease compared with mandibular premolar teeth. Histometric analysis showed significant reduction in free and attached gingiva of the experimental teeth. Histopathological examination of buccolingual sections from experimental premolar teeth showed the presence of rete pegs within the sulcular epithelium with acanthosis and erosive changes, widening of the periodontal ligament, and alveolar bone resorption. Various methods for periodontal repair were studied in 194 experimental premolar teeth exhibiting different degrees of periodontal disease. The treatment plan comprised non-surgical (teeth scaling, root planing, and oral hygiene) and surgical methods (closed gingival curettage, modified Widman flap, and reconstructive surgery using autogenous bone marrow graft and canine amniotic membrane). The initial non-surgical treatment resulted in a periodontal recovery rate of 37.6% and was found effective for treatment of early periodontal disease based on resolution of gingivitis and reduction of periodontal probing depths. Surgical treatment by closed gingival curettage to eliminate the diseased pocket lining resulted in a recovery rate of 48.8% and proved effective in substantially reducing deep periodontal pockets. Open root planing following flap elevation resulted in a recovery rate of 85.4% and was effective for deep and refractory periodontal pockets. Autogenous bone graft implantation combined with canine amniotic membrane as a biodegradable membrane was used in 18 premolar teeth and failed to improve advanced furcation defects in most teeth.     

Stray dog population health in Jodhpur, India in the wake of an animal birth control (ABC) program

Our objectives were to (1) estimate the prevalence of various health indices in the stray dog population in Jodhpur, India and (2) determine if there was an association between an animal birth control (ABC) program and the prevalence of these health indices in this population. A prevalence survey of 323 sexually intact stray dogs >3 months caught from the streets of Jodhpur from September to November, 2005 indicated that low body condition score (70%), skin conditions (69%) and tick infestation (68%) were the most common health problems in this population. An observational study of 888 stray dogs on the streets of Jodhpur from March to April, 2006 revealed that sterilized dogs were more likely to have a higher body condition score (BCS) than sexually intact dogs when controlling for age, based on a multinomial regression model. However, sterilized dogs were more likely to have a skin condition than sexually intact dogs, based on a logistic regression model. Our observations of the surgical/kennel facility indicated that an effective tick control program was needed. Additionally, the current parasite control protocol at the kennel/shelter facility was inadequate to treat mange, a contact-transmitted skin disease. This is the first study to evaluate the associations between an ABC program and stray dog health, apart from rabies.     

Prevalence and epidemiological aspects of Dirofilaria immitis in dogs from Kayseri Province, Turkey

This study was conducted to determine the prevalence of Dirofilaria immitis infection and to investigate the risk factors related to heartworm disease in dogs from Kayseri, Turkey. Blood samples were collected from 280 dogs from May 2005 to March 2006 and were examined by membrane filtration-acid phosphatase histochemical staining and antigen Elisa techniques to detect circulating microfilariae and antigens of D. immitis, respectively. Of the total of 280 dogs, 27 were positive for D. immitis with a prevalence value of 9.6%. In addition 29.6% of positive dogs determined to have occult D. immitis infections. D. immitis was the only canine filarial parasite present in the study area. The mean number of microfilariae in infected dogs was 4730+/-5479 per ml of blood. The highest heartworm prevalence were observed in 7-10 age group (28.6%) followed by 4-6 (17.1%) and 0.5-3 (4.8%) age groups. The differences between 0.5-3 and other age groups were found significant, whereas no statistically significant difference was observed between 4-6 and 7-10 age groups. The infection was more prevalent in males, larger breeds and the dogs not on prophylaxis. No statistically significant difference was observed between stray and owned dogs. Our results suggest that heartworm treatment and prophylaxis should be considered in Kayseri Province.     

Post mortem survey of dental disorders in 349 donkeys from an aged population (2005-2006). Part 1: prevalence of specific dental disorders

REASON FOR PERFORMING STUDY: Donkey dental disorders are being recognised with increased frequency worldwide and have important welfare implications; however, no detailed investigations of dental disorders in donkeys appear to have been published. OBJECTIVES: To determine the prevalence of specified dental disorders in donkeys by performing a prospective post mortem study on donkeys that were subjected to euthanasia or died for other reasons at the Donkey Sanctuary, UK. METHODS: Post mortem examinations were performed on 349 donkeys over an 18 month period, 2005-2006. The presence and extent of specified dental disorders were recorded and these data analysed to determine their prevalence and common locations. RESULTS: A high prevalence (93%) of disorders was noted in the population with a median age of 31 years. In particular, cheek teeth diastemata (85% prevalence) were very common, often associated with advanced periodontal disease. Other disorders observed included missing teeth (in 55.6% of donkeys), displaced teeth (43%), worn teeth (34%), local overgrowths (15%), focal sharp overgrowths (3%) and dental-related soft tissue injuries (8%). CONCLUSIONS AND POTENTIAL RELEVANCE: Aged donkeys have a high prevalence of significant dental disease, especially cheek teeth diastemata. These findings highlight the importance of routine dental examinations and prophylactic dental treatments to improve the dental health and welfare of donkeys.     

Periodontal disease in research beagle dogs--an epidemiological study

Objectives : To estimate the prevalence and describe the extent and severity of periodontal disease and associated periodontal parameters in beagle dogs. Methods : A full‐mouth, site‐specific examination was performed in 98 beagle dogs. Focus was placed on clinical attachment loss, pocket depth and bleeding on probing. Results : The prevalence of clinical attachment loss greater than equal to 1 mm was 20 per cent in the one‐year‐old dogs, increasing to 84 per cent of the dogs aged more than three years. The number of sites affected with clinical attachment loss greater than equal to 1 mm showed a skewed distribution. The prevalence of clinical attachment loss greater than equal to 4 mm was only seven per cent. A probing pocket depth of 4+ mm was observed in 44 to 81 per cent of the dogs, depending on age. Also, the distribution of the number of deepened pockets/dog was skewed. The teeth most prone to clinical attachment loss greater than equal to 1 mm were the P2, the P3 and the P4 of the maxilla. The teeth most prone to pocket depth greater than equal to 4 mm were the maxillary canines. Clinical Significance : Periodontal disease in terms of clinical attachment loss greater than equal to 1 mm and pocket depth greater than equal to 4 mm is common in beagle dogs, but the major disease burden is carried by only a few dogs. The prevalence increases with increased age but is high already at the age of two years.     

Nested PCR-based detection of Toxoplasma gondii in German shepherd dogs and stray cats in South Korea

The prevalence of Toxoplasma gondii was surveyed by using a nested polymerase chain reaction (PCR) that was targeted to T. gondii B1 gene in German shepherd dogs and stray cats. Sixty-four (46.3%) out of 138 German shepherd dogs and 50 (47.2%) out of 106 stray cats were tested positive by the nested PCR assay, respectively. There was no significant difference in gender or age in German shepherd dogs and stray cats. In the five positive dogs and five positive cats, the nucleotide partial sequence of the T. gondii B1 gene was identified by direct sequence analysis. All the sequences were identical to each other and the corresponding sequence, T. gondii B1 gene (Accession No. AF179871). The results suggest that the prevalence of T. gondii is high, and the nested PCR assay is useful for early detection of T. gondii for asymptomatic dogs and cats.     

A retrospective study of dental conditions of captive brown bears (Ursus arctos spp.) compared with free-ranging Alaskan grizzlies (Ursus arctos horribilis).

The teeth of 63 skulls of brown bears (Ursus arctos spp.) that had lived in the Bernese bear pit between 1850 and 1995 were examined and radiographed for occlusion, loss of teeth, calcified dental plaque and calculus, attrition, and caries. Dental pathology and periodontal status were evaluated with respect to age and location in the dentition. Further techniques such as computed tomography, microhardness testing, histologic sectioning, and scanning electron microscopy were used in selected cases to verify the macroscopic and radiographic diagnoses. Fourteen skulls originating from free-ranging wild Alaskan brown bears (Ursus arctos horribilis) were examined as a control group. For zoo bears over 10 yr old, severe enamel and dentinal attrition has been observed in canine teeth, with exposed pulp and proximal lesions in molar teeth. Deposits of calcified dental calculus were found in various locations and increased with age. A much lower degree of calculus deposition was found in the Alaskan grizzlies, whose average caries frequency was higher but with large individual variation and different locations in canine teeth and occlusal lesions in molar and premolar teeth. Radiographic evaluation of perialveolar osteolytic processes revealed a greater frequency of apical and combined apical-marginal lesions of the alveoli in zoo bears over 10 yr old. Stereotypical behavior like cage chewing is a suspected cause of canine tooth and secondary alveolar lesions, whereas a nutritionally inappropriate diet and inadequate opportunities for tooth-cleaning activities are responsible for the lack of natural cleaning and the extensive calculus formation that results. The methods used in this study are useful in assessing and comparing the dental health status of free-ranging bears, and those living in zoological gardens, by evaluating anesthetized bears or bear skull collections representing both groups.     

Morphologic features of the root canal system of the maxillary fourth premolar and the mandibular first molar in dogs

Root canal morphology was evaluated in 72 maxillary fourth premolar and 59 mandibular first molar teeth. An apical delta was present in all roots (n = 334). The apical delta represented approximately 12-18% of the total root length for all roots. Non-apical ramifications from the main canal were observed in 25.1% of roots. Secondary canal(s) were present in 20.6% of roots, while lateral canal(s) were present in 6.9% of roots. The distal root of the maxillary fourth premolar had the highest incidence (47.2%) of non-apical ramifications. Overall, 68.0 and 20.4% of maxillary fourth premolar and mandibular first molar teeth had non-apical ramifications, respectively. The prevalence and location of non-apical ramifications may influence clinical decision making when performing endodontic therapy.     

Seroepidemiology of Toxoplasma gondii in dogs in Trinidad and Tobago

A cross-sectional study was conducted to determine the seroprevalence of Toxoplasma gondii agglutinins and to investigate the relationship between various risk factors and occurrence of toxoplasmosis in dogs in Trinidad. Of a total 250 dogs, comprising domestic, hunting and stray dogs, 80 (32.0%) were positive for T. gondii agglutinins at a titre of > or =1:32 using a latex agglutination test. Stray dogs (60.5%) had statistically significantly higher (P<0.001) seroprevalence for toxoplasmosis than hunting dogs (30.5%) and domestic dogs (25.5%). Amongst dogs whose ages were known, the prevalence of toxoplasmosis was significantly highest (P=0.037) in dogs in the >2-3 years age group compared with other age groups. Dogs that consumed home-cooked foods had a seroprevalence of 32.9% compared with those fed commercial dog foods (17.2%) and dogs fed both home-cooked and commercial foods (21.0%). However, the difference was not statistically significant (P>0.05; chi(2)). The rather high prevalence of toxoplasmosis in stray dogs is a good indication of the extent of the infection in the environment.     

Chronology and sequence of emergence of permanent premolar teeth in the horse: Study of deciduous premolar ‘cap’ removal in Thoroughbred racehorses

Reasons for performing study: There are few published data to support the ages of emergence of permanent dentition widely reported in horses. Objectives: To clarify the chronology and sequence of permanent premolar (PM) tooth emergence in Thoroughbred racehorses. Methods: A prospective study was undertaken in which records were kept of deciduous PM ‘cap’ extractions performed during routine dental examinations in Thoroughbred racehorses. Mixed effects multiple regression analysis was used to relate the observed ages, measured in days, for PM ‘cap’ extractions simultaneously with different predictive variables. Care was taken to account for clustering of multiple observed outcomes within individual horses. Results: A total of 508 deciduous premolar ‘caps’ were removed from 207 horses, mean ages at removal from PM2, PM3 and PM4 were 35.1, 37.7 and 45.1 months, respectively. Age at which deciduous ‘cap’ removal occurred was associated significantly with tooth row, upper or lower jaw and gender of the horse concerned. There was a significant trend for later ‘cap’ extraction age with more caudal teeth, teeth in the upper jaw and female gender. Conclusions: Age at removal of deciduous premolar ‘caps’ in this population differed considerably from the ages of emergence of permanent dentition reported widely in equine publications. The results provide the first evidence of sexual dimorphism in the eruption of the permanent premolar dentition in horses. These findings strongly support a model of cheek tooth eruption in the horse in which chronology and sequence of emergence are more complex than previously thought, but which is consistent with understanding of tooth eruption in species that have been studied in greater detail. Potential relevance: Abnormalities of cheek tooth eruption are thought to be a factor in the pathogenesis of a variety of dental conditions, and a thorough understanding of the process of eruption is fundamental to the development of rational strategies for prevention and treatment.     

Clinical dental examinations of 357 donkeys in the UK. Part 1: Prevalence of dental disorders

Reasons for performing study: Dental disorders have a high prevalence in older donkeys and horses, but the nature and pathogenesis of many of these disorders have yet to be established. Objectives: The identification and determination of the prevalence of important dental disorders in different age groups in a large single population of donkeys, to establish a better understanding of the nature and pathogenesis of these disorders. Methods: A prospective cross‐sectional study was performed on the donkey population at The Donkey Sanctuary with detailed oral examinations of 357 donkeys within 7 different age groups (age range 2–53 years) recorded. Results: The prevalence of dental disease in all donkeys was 73%, increasing in prevalence from 28% in the youngest to 98% in the oldest age group. There was an increase in prevalence of commonly recognised dental disorders with increasing age, such as: diastemata (3.8% in youngest to 86% in oldest group); missing teeth (0–56%); overgrown teeth (15–86%); worn teeth (8–84%); displaced teeth (0–38%); and periodontal disease (0–28%). Conclusions: There was a significant increase in the prevalence of dental disorders with increasing age with the largest significant increase for most dental disorders occurring in the 15–20 year age group. Potential significance: Most dental disorders significantly increase in prevalence in the 15–20 year age group and, therefore, prophylactic geriatric dental treatment in donkeys should be commenced from age 15 years.     

Contamination of dog hair with eggs of Toxocara canis

Toxocara canis, the common intestinal nematode of dogs and foxes, is the parasite responsible for human toxocarosis. It has recently been shown that dogs may harbour eggs of the parasite in their fur. To further investigate this claim a population of 100 stray dogs was examined to establish the prevalence and intensity of adult toxocaral worm infection in the intestines and eggs harboured in the hair. A novel method of washing the eggs from the hair was used. Sixty-seven percent of dogs were found to have T. canis eggs on their hair with a mean egg retrieval of nearly 584 eggs per gram from positive dogs. The age of the dog was found to be the only significant factor to influence the prevalence and intensity of eggs, with 95% of all the eggs recovered found on puppies. Thirty-nine percent of dogs were found to have adult T. canis worms in their intestine, although a significantly higher percentage of puppies (80%) were infected with worms than adults (22.5%). Puppies also had more worms per infection than adults and have a strong positive correlation between egg and worms numbers whereas adults did not. These studies show that stray dogs, particularly puppies, potentially harbour considerable numbers of eggs on their hair, at densities far higher than those reported in the soil or the general environment.