Disease threats to the endangered Iberian lynx (Lynx pardinus)

The Iberian lynx, (Lynx pardinus), is the most endangered felid in the world. To determine whether sympatric carnivores are reservoirs of pathogens posing a disease risk for the lynx, evidence of exposure to 17 viral, bacterial and protozoan agents was investigated in 176 carnivores comprising 26 free-living lynx, 53 domestic cats, 28 dogs, 33 red foxes (Vulpes vulpes), 24 Egyptian mongooses (Herpestes ichneumon), 10 common genets (Genetta genetta) and 2 Eurasian badgers (Meles meles) in the areas inhabited by the last two populations of Iberian lynx, both in Andalusia (South-Western Spain).The results indicated that the lynx had low rates of contact with viral pathogens, with one seropositive finding each for feline leukemia virus, parvovirus and canine adenovirus-1, whereas contact with bacteria and protozoa appeared more frequent. Active infections with parvovirus, Ehrlichia spp., Mycobacterium bovis, Leptospira interrogans and Cytauxzoon spp. were confirmed. In contrast, 53% of the domestic cats were exposed to some infectious agent (prevalence range 4.5–11.4%). Antibodies to canine distemper virus and parvovirus were frequently found in dogs (32% and 42%, respectively) and foxes (30% and 12%). Past or present infections with parvovirus, Ehrlichia spp., Chlamydophila spp., M. bovis, Salmonella enterica, L. interrogans, Toxoplasma gondii, and Neospora caninum were also detected in these and other species surveyed.Questionnaires to owners revealed that 14% of the dogs but none of the cats had been vaccinated, and no cat had been neutered. Based on the apparent absence of acquired immunity of the lynx against infectious agents, the frequent detection of agents among sympatric carnivores, and the reported lack of immunocompetence of the Iberian lynx, a disease outbreak among the local abundant carnivores may pose a serious disease risk for lynx conservation.     

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.     

Resorptive tooth root lesions in the Malayan tapir (Tapirus indicus)

Facial abscessation and osteomyelitis due to dental disease is commonly seen in the Malayan tapir (Tapirus indicus), but little is known about the prevalence or etiology of these lesions. To determine the prevalence of dental ailments, 56 skulls and mandibles of deceased Malayan tapirs were visually and radiographically evaluated. Dental lesions were scored according to severity, and individuals were classified according to their age (juvenile/ young adult/adult) and origin (captive/free ranging). All of the lesions identified were of a resorptive nature. seemingly originating at the cementoenamel junction and burrowing towards the center of the tooth. Overall, 27% of the investigated skulls presented radiolucent dental lesions. The prevalence among captive animals was 52% (13/25), while only 6% (2/31) of the free-ranging tapirs had dental lesions. The second, third, and fourth premolars and first molar were the teeth most commonly affected, and the mandibular teeth were more often involved than the maxillary dentition. This study demonstrates a high prevalence of resorptive dental lesions in captive Malayan tapirs and provides a strong indication that age and captivity are significant risk factors in the development of these lesions. Dental disease, Malayan tapir, radiology, resorptive lesions, Tapirus indicus.     

Antibodies to selected canine pathogens and infestation with intestinal helminths in golden jackals (Canis aureus) in Israel.

Blood and fecal samples, collected from 46 healthy adult free-ranging golden jackals captured in two different locations in Israel, were examined. A serological Study was conducted to investigate the prevalence of circulating antibodies reacting with four common canine pathogens: canine distemper virus (CDV), canine parvovirus (CPV), Ehrlichia canis and Leishmania infantum. Faecal flotation and haematological tests were also performed. The seroprevalence of CPV, E. canis, CDV, and L. infantum were 72.3% (34/47), 54.3% (25/46), 52.2% (24/46), and 6.5% (3/46) respectively. Faecal flotation tests revealed a high prevalence of Ancylostoma caninum (13/17, 76%) and a low prevalence of Dipilidium caninum infestation. Examination of blood smears revealed Hepatazoon canis gamonts in one jackal. Golden jackals are among the most common free-ranging carnivores in Israel and neighboring countries. Their habitats are in proximity to densely populated areas and they bear close phylogenic relation to the domestic dog. These facts, combined with the high prevalence of the jackals' exposure to the major canine pathogens demonstrated in this study, suggest that they may serve as a reservoir for the transmission of certain diseases to domestic dogs.     

Significant association between tooth extrusion and tooth resorption in domestic cats

Abnormal extrusion of canine teeth is often noted in middle-aged and geriatric domestic cats. The same age group of cats also is commonly affected by tooth resorption (TR). This study explored the relationship between these two phenomena of unknown etiology. Using digital radiography, the distance between the alveolar margin (AM) and cementoenamel junction (CEJ), referred to as the AM-CEJ distance, was measured in clinically and radiographically healthy maxillary canine teeth of 24 TR-affected and 29 TR-free cats. The mean AM-CEJ distance of maxillary canine teeth of cats with and cats without TR was 2.68-mm and 2.22-mm, respectively. An analysis of covariance adjusting for age revealed a significant correlation (p = 0.02) between tooth extrusion and TR. Extrusion of the maxillary canine teeth became clinically apparent when an AM-CEJ distance of 2.5-mm or greater was evident in the absence of horizontal or vertical alveolar bone loss. Based on this criterion, 15 of 24 cats with TR (63.0 %) exhibited extrusion of maxillary canine teeth, compared to 9 of 29 cats without TR (31.0 %). Four extruded and five non-extruded maxillary canine teeth were evaluated histologically. Cementum of extruded teeth was significantly thicker compared to that of non-extruded teeth. Four of 4 canine teeth with extrusion (100 %) showed histological evidence of resorption, compared to 1 of 5 canine teeth without extrusion (20.0 %). These results suggest that tooth extrusion is linked to or may be caused by similar factors responsible for the development of TR.     

Allogeneic tooth transplantation in the dog

Allogeneic tooth transplantation was evaluated as a functional and aesthetic treatment for dental fracture in the dog. Of 7 dogs that received tooth transplants, 5 were research animals and 2 were clinical patients. Canine teeth were transplanted immediately after extraction in the research dogs. Endodontic therapy had been performed on the affected canine tooth of one clinical patient. The other clinical patient had bilateral maxillary canine fractures 2 months earlier. One of the research dog transplants failed at 3 weeks as a result of improper surgical technique. Four of the research dogs had a solid implant for 18 months, after which time the dogs were euthanatized serially. All transplanted teeth were anchored firmly into the alveoli, but were nonviable. Root resorption, with bone replacement, was first noticed at 24 months. The transplanted tooth in the first clinical patient remained functional for 3 months, after which time the tooth was fractured. The right canine transplant in the second clinical patient failed by 3 months, probably because of preexisting periapical inflammation. The left transplanted tooth remains stable at 38 months. It was concluded that allogeneic tooth transplantation may have merit as a rapid and inexpensive method for replacement of fractured teeth in the dog. Function is compromised gradually as a result of root resorption and ankylosis, with tooth fracture likely to occur after 2 years.     

Comparative observation of skeletal-dental abnormalities in wild, domestic, and laboratory rabbits

Dietary habits must be considered as one of the major potential factors resulting in acquired malocclusions in rabbits. Although the dentition of the wild rabbit and the domesticated laboratory rabbit are basically identical, dietary habits are noticeably different. Therefore, the prevalence of tooth problems between these lagomorph species were investigated anatomically and radiographically. Mean measurements of the skull and dental arches suggested that wild rabbits have slightly shorter and wider skulls and dental arches compared with domestic laboratory rabbits. Root elongation of incisors and check teeth, and periodontal disease were more frequently observed in domestic laboratory rabbits. Diagnostic radiographs from domestic pet rabbits showed relatively higher crowns, severe root elongation, and advanced periodontitis. These results do not provide definitive evidence that dietary habits cause malocclusions, however they suggest that diet is a major factor in the initiation of malocclusions in rabbits.     

Molecular evidence of shared hookworm Ancylostoma tubaeforme haplotypes between the critically endangered Iberian lynx and sympatric domestic cats

Hookworms of the genus Ancylostoma are the most pathogenic parasites of young cats, and A. tubaeforme may cause morbidity or mortality in young individuals of the most endangered felid species in the world, the Iberian lynx (Lynx pardinus). Since the transmission of monoxenous parasites is related to host density and remaining lynx populations are currently very small, the presence of reservoir hosts may be necessary for the maintenance of the hookworm life-cycle, the domestic cat being the most likely reservoir of A. tubaeforme. In order to confirm this hypothesis, the mitochondrial cytochrome c oxidase subunit I gene (Cox I) sequences of three A. tubaeforme specimens from a road-killed Iberian lynx from Do?ana were compared with 14 specimens retrieved from five sympatric free-roaming cats from the same area, and with six specimens from three free-roaming cats from the Mediterranean island of Mallorca. Gene fragments (300 bp) from 23 A. tubaeforme individuals representing 16 different haplotypes were obtained. A statistical parsimony haplotype network analysis showed that the three specimens infecting an Iberian lynx corresponded to two different haplotypes, one of which was identical to a specimen in a cat found only 10 km from the lynx. Specimens from the Iberian lynx and those from cats in Do?ana were only 1.03% genetically divergent, whereas specimens from Mallorca cats and those from Do?ana cats and the lynx diverged by 1.33% and 1.36%, respectively. The existence of shared haplotypes of hookworms between lynx and cat reinforces the hypothesis that the abundant sympatric domestic cat population is acting as a reservoir for A. tubaeforme infection in the endangered Iberian lynx.     

Regional anesthesia of the infraorbital and inferior alveolar nerves during noninvasive tooth pulp stimulation in halothane-anesthetized cats

OBJECTIVE: To determine whether anesthesia of the infraorbital and inferior alveolar nerves abolishes reflex-evoked muscle action potentials (REMP) during tooth-pulp stimulation in halothane-anesthetized cats. ANIMALS: 8 healthy adult cats. PROCEDURE: In halothane-anesthetized cats, an anodal electrode was attached to the tooth to be stimulated and a platinum needle cathodal electrode was inserted in adjacent gingival mucosa. Cathodal and anodal electrodes were moved to the upper and lower canine, upper fourth premolar, and lower first molar teeth for stimulation; baseline REMP was recorded. A 25-gauge 1-cm needle was inserted 0.5 cm into the infraorbital canal. A 25-gauge 1-cm needle was inserted 1 cm rostral to the angular process of the ramus, and advanced 0.5 cm along the medial aspect. Chloroprocaine was injected at each site. Each tooth was stimulated every 10 minutes for 90 minutes. RESULTS: REMP was abolished within 10 minutes for all upper teeth, except for the upper canine tooth in 1 cat, and abolished within 10 minutes for lower teeth in 4 cats. In 1 cat, REMP was not abolished in the lower first molar tooth. In 3 cats, REMP was not abolished in the lower canine and first molar teeth. At 90 minutes, REMP was restored for all teeth except the lower canine tooth in 1 cat, for which REMP was restored at 120 minutes. CONCLUSIONS AND CLINICAL RELEVANCE: Regional anesthesia of the infraorbital and inferior alveolar nerves may provide dental analgesia in cats.     

Nasolacrimal obstruction caused by root abscess of the upper canine in a cat

A 10‐year‐old, castrated male domestic short hair cat was presented to the Small Animal Clinic at the Western College of Veterinary Medicine with a presenting complaint of chronic, ocular discharge from the left eye. Ocular examination confirmed epiphora and mucopurulent discharge but there were no apparent reasons for the ocular discharge, and nasolacrimal obstruction was suspected. The cat had swelling of the left side of the face, severe periodontal disease and a fractured upper left canine tooth with pulpal exposure. Dacryocystorhinography revealed narrowing of the nasolacrimal duct above the root of the fractured upper left canine and dental radiographs showed a severe periapical lucency at the apex of the upper left canine tooth. The fractured canine tooth was removed. Subsequently, the ocular discharge and facial swelling resolved. After 2 years, the epiphora has never reoccurred. This is a noteworthy case because a suspected root abscess resulted in extralumenal compression of the nasolacrimal duct, which shows the importance of a thorough oral examination when nasolacrimal obstruction is evident.     

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.     

Relationship between diet, dental calculus and periodontal disease in domestic and feral cats in Australia

Objective To compare the dental calculus scores and prevalence of periodontal disease in domestic cats eating commercially available canned and dry foods with those in feral cats consuming a diet consisting of small mammals, birds, reptiles and insects.
Animals Twenty-nine feral cats and 20 domestic cats were included in the study.
Procedure A dental chart and dental calculus scores were recorded using the maxillary canine, maxillary third and fourth premolar, mandibular canine, mandibular fourth premolar and first molar teeth on both sides. Periodontal disease was recorded using gingival recession, increased periodontal pocket formation, radiographic alveolar bone loss, osteomyelitis, furcation and root exposure, and the presence of calculus as indicators.
Results Dental calculus scores were significantly higher in domestic cats than in feral cats. There was no statistical difference in the prevalence of periodontal disease between the two groups.
Conclusion It can be inferred that diet may play a role in the accumulation of calculus, but a diet based on live prey does not protect cats against periodontal disease.     

Oral examination results in rescued ferrets: clinical findings

Ferrets have increased in popularity as pets, and a growing number are seen in companion animal practice. Domestic ferrets are commonly used as animal models for research of human oral conditions. The present study evaluated the prevalence of oral pathology in rescued ferrets which - to the authors' knowledge - has not yet been described in the scientific literature. Conscious oral examination was performed on 63 ferrets, of which 49 underwent general anesthesia for further examination. The most common clinical findings included malocclusion of mandibular second incisor teeth (95.2%); extrusion of canine teeth (93.7%); and abrasion and attrition of teeth (76.2%). Tooth fractures were exclusively associated with canine teeth and found in 31.7% of ferrets. Pulp exposure was confirmed in 60.0% of fractured teeth. The normal gingival sulcus depth measured < 0.5-mm in 87.8% of anesthetized ferrets. Clinical evidence of periodontal disease was present in 65.3% of anesthetized ferrets (gingivitis or probing depths > 0.5-mm), however advanced periodontal disease (i.e. periodontal pockets > 2-mm or stage 3 furcation exposure) was not found upon clinical examination. There was no evidence of tooth resorption, dental caries, stomatitis, or oral tumors in the examined group of ferrets.     

Reattachment of tooth fragment: an in vitro study

Canine tooth fracture is common in dogs. Application of an esthetic and durable restoration may be challenging in veterinary dental practice. This study used traditional human dental laboratory methods to evaluate fracture strength of intact dog canine teeth and fractured teeth that had been restored by reattachment of the tooth fragment. The results showed that the teeth restored by reattachment of the tooth fragment supported a test load equal to 45.4 % of the load necessary to fracture intact canine teeth.     

Prevalence of odontoclastic resorptive lesions in a population of clinically healthy cats

The prevalence of odontoclastic resorptive lesions (ORLs) was determined in a clinically healthy cat population (228 cats) using both clinical (oral examination) and radiographic (full-mouth series with intraorally positioned dental film) methods. The overall prevalence rate was 29 per cent (mean age of the cat population 4.9 years). The mandibular third premolars (307, 407) were the most commonly affected tooth and the pattern of ORL development was symmetrical in most cats. The risk of having ORLs was found to increase with increasing age and cats with clinically and radiographically missing teeth were more likely to have the condition. Neutering, gender, age at neutering or mean whole mouth gingivitis index did not affect the prevalence of ORLs.     

Equine odontoclastic tooth resorption and hypercementosis

A poorly described, painful disorder of incisor and canine teeth, variably causing periodontitis, with resorptive or proliferative changes of the calcified dental tissues, has recently been documented in aged horses. No plausible aetiopathogenesis for this syndrome has been recorded. Eighteen diseased teeth from eight horses were examined grossly and microscopically and showed the presence of odontoclastic cells by tartrate resistant acid phosphatase (TRAP) staining. A chronological sequence of odontoclastic resorption followed by hypercementosis was demonstrated and, consequently, the term equine odontoclastic tooth resorption and hypercementosis (EOTRH) is proposed for this disorder. EOTRH shares many features with similar dental syndromes described in humans and cats. An aetiological hypothesis proposes mechanical stress of the periodontal ligament as the initiating factor.     

Results of root canal treatment in dogs: 127 cases (1995-2000)

OBJECTIVE: To evaluate results of root canal treatment in dogs. DESIGN: Retrospective study. SAMPLE POPULATION: 127 tooth roots in 64 dogs. PROCEDURE: Radiographs obtained before surgery, immediately after surgery, and during follow-up examinations after surgery were evaluated by 2 individuals. Treatment was considered successful if the periodontal ligament space was normal and possible preoperative root resorption, if present, had ceased. Treatment was considered to show no evidence of failure if possible preoperative root resorption had ceased but a preexisting periapical lesion had remained the same or only decreased in size and not complete resolved. Treatment was considered to have failed if a periapical lesion or root resorption developed subsequent to endodontic treatment, if a preexisting periapical lesion had increased in size, or if possible preoperative root resorption appeared to continue after endodontic treatment. RESULTS: Follow-up time ranged from 1 to 60 months (mean, 13 months). Treatment was classified as successful for 87 (69%) roots, as showing no evidence of failure for 33 (26%) roots, and as having failed for 7 (6%) roots. The success rate was lower for canine teeth than for maxillary fourth premolar teeth. Roots with a preexisting periapical lucency or preexisting root resorption had lower success rates. The use of intracanal medication and the method and quality of obturation were not associated with outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that root canal treatment offers a viable option for salvage of periodontally sound but endodontically diseased teeth in dogs.     

Occlusal angles of cheek teeth in normal horses and horses with dental disease

The angle between the occlusal surface of the tooth and the horizontal plane of 687 cheek teeth from the skulls of 22 horses without gross dental disorders and 11 horses with dental disorders were measured by using stiff malleable wire as an imprint. Each measurement was repeated five times and the mean angle was recorded. In the normal skulls, the mean occlusal angles of the mandibular cheek teeth ranged from 19.2 degrees at the Triadan 06 position to 30 degrees at the 11 position, and these angles were significantly greater than the occlusal angles of the opposing maxillary cheek teeth (range 12.5 degrees to 18 degrees) at all the positions except the 06. The rostral mandibular cheek teeth had significantly lower occlusal angles than the caudal mandibular cheek teeth, but the converse was true for the maxillary teeth. In the skulls with dental disorders the occlusal angles of the mandibular cheek teeth ranged from 15.6 degrees to 28.5 degrees , and of the maxillary cheek teeth from 9.2 degrees to 16.4 degrees. They were not significantly different from the angles of the teeth from the normal skulls, except at the 06 position, where they were smaller.     

Surgical exposure and orthodontic extrusion of an impacted canine tooth in a cat: a case report

A 7 month-old, male domestic shorthaired cat was referred because of facial swelling, an operculated cystic oral mass, and impaction of the associated maxillary left canine tooth. Surgical exposure and realignment failed to result in eruption. Surgical reexposure and orthodontic extrusion resulted in a functional alignment of the tooth within the dental arch. Follow up evaluations over the 5 ensuing years indicated persistence of the facial deformation, no evidence of ameloblastic biotransformation, and a healthy tooth.