Sirenia Flashcards
Dugong tusks are modifications of which tooth type?
Incisors (F8)
What type of GI tract do Sirenia have?
hindgut fermenters (F8)
Name 3 sequelae of boat strike injury in sirenia
Pneumothorax, spinal trauma, rib transection (head injury, abdominal ST damage, hemothorax, diaphragmatic hernia etc) (F8)
Which Sirenia are polyphyodonts?
Manatees (dugongs are not) (West)
What environmental factor is most important to control during a manatee procedure?
Temperature (low metabolic rate, limited capacity for thermogenesis, sensitive to cold stress) (West)
What are the common venipuncture sites in sirenia?
caudal tail ventral vertebral arch vascular bundle and brachial vascular bundle (West)
What type of intubation is most common in sirenia?
Nasal intbuation, most often done with rhinoscopic assistance (West)
Which cell type is the first to respond to stress in the sirenian immune system?
Lymphocytes (Terio)
Which sirenians have heterophils?
Florida manatees and dugongs (Terio)
How is the sirenian lung anatomy different from a typical mammal?
Dorsal bilateral pleural cavities divided by two separate hemidiaphragms that contain the lungs, which extend almost the entire length of the body (Terio)
What type of skin lesions are typical of cold stress syndrome in sirenia?
Marked epidermal hyperplasia characterized by irregular, verruciform, pale grey plaques that are often fissured (Terio)
What viral disease causes hyperplastic skin lesions in sirenia?
Trichechus manatus latirostris papillomaviruses (TmPV) (Terio)
What type of bones do sirenia have?
Pachyosteosclerotic: densely mineralized bones aid in buoyancy control (CRC)
What is the most sensitive indicator of systemic inflammation in sirenia?
Serum amyloid A, WBC count is not sensitive as it does not increase significnatly (CRC)
Name 3 common sequelae of cold stress syndrome in sirenia
GI stasis, DIC, dermatitis (others including pneumonia, emaciation, myocardial degeneration, renal failure, etc) (CRC)
What is the nasopharyngeal trematode found in manatees?
Cochleotrema cochleotrema (CRC)
What type of lesions have been associated with Trichechid herpesvirus 1 (TrHV1)?
Dermattis
Mass mortalities in sirenians have been associated with what toxin produced by dinoflagellates?
Brevetoxin
Describe the taxonomy of manatees and dugongs.
What are the two families?
What are the closest living relatives to sirenians?
What is the scientific name for the Florida manatee?
What about the Dugong?
Introduction
- Order: Sirenia
- Two families:
- Dugongidae – dugong, extinct Steller’s sea cow
- Trichechidae – Amazonian manatee, West African manatee, two subspecies of West Indian manatee (Antillean and Florida)
- Closest taxonomic relative: elephant (Proboscidae) and hyrax (Hyracoidea)
- All extant species are Vulnerable
Describe the natural history of sirenians.
What sort of environment do they live in?
What are their predators?
What is their genetics and metabolism like?
How long do they live?
Natural History
- Tropical and subtropical climates
- Florida manatees “threatened” in US
- Marine, brackish, freshwater
- Depth: 1-4 meters
- Coastal seagrass beds and rivers
- No predators
- Low genetic diversity
- Low metabolic rates
- Lifespan: >50 yr
- FL manatees are semi-social
- Cows/calves form bonds for 1-2 years
Describe the external features of sirenians.
Which is the largest species? Is there sexual dimorphism?
Which species have flukes? Which have paddles?
How do you sex a sirenian?
What is unique about their skin?
How do they close their nostrils when diving?
What are two features of the skeletal system?
- Large and fusiform
- Manatees – round, dorsoventrally flattened tail fluke/peduncle
- Dugongs – laterally compressed peduncle and forked flukes
- FL manatee is largest extant species
- Females larger than males
- Males
- Genital opening just caudal to umbilicus
- Longer pectoral flippers for grasping females
- Females
- Genital openings just cranial to anus
- Gross features
- Densely mineralized bones (pachyosteosclerotic) – buoyancy control
- Thin epidermis and very thick dermis
- Highly tactile lips with perioral bristles (modified vibrissae)
- Flexible and prehensile upper lip
- Dorsally located nostrils with valves that close during diving
- Manatees (but NOT dugongs) have only 6 cervical vertebrae
Describe the ocular anatomy of sirenians.
Which species have vascular corneas?
Which speices have conjunctival associated lymphoid tissue?
Do sirenians have nasolacrimal systems?
Describe the muscular anatomy of their eyelids.
- Eyes
- Small and nearly spherical
- Florida and Antillean manatees – vascularized corneas
- Dugongs do not have these
- Does not appear to impact vision
-
T. manatus have modified ocular glands and prominent conjunctival-associated lymphoid tissue
- Lack traditional nasolacrimal system
- Modified extraocular muscles
- Palpebral fissure closes to a small round point (like a miotic pupil)
Describe the gastrointestinal anatomy of sirenians.
How do the teeth of manatees differ from dugongs?
The tusks of dugongs are what type of modified tooth?
What is the general digestive strategy of sirenians?
What is their normal GI transit time?
Describe the anatomy of the duodenum and cecum specifically.
GI System
- Manatees
- Molariform teeth
- Lack canines and incisors (replaced by gingival plates)
- Undergo molar progression
- Most rostral teeth are replaced by new teeth behind
- Unlimited supply
- Dugongs
- Tusks (incisors) – erupt at puberty in males and some very old females
- Hindgut fermenters
- GI transit time = 7 days
- Discrete accessory digestive gland (cardiac gland) in stomach
- Unique gastric mucosal histology and glands
- Large duodenal ampulla and diverticulae
- Large cecum with diverticulae (also called horns or accessory sacs)
- Prominent colon
Describe the thoracic anatomy of manatees.
Describe the arrangement and functions of the diaphragm and transverse septum?
Thorax (manatees)
- Two single-lobed, elongate lungs
- Lay dorsally
- Each has its own horizontal pleural cavity
- Diaphragm in a horizontal plane
- Dorsal to the heart
- Does not attach to the sternum
- Extends entire length of body cavity (40% of the total body length)
- Attaches medially to bony projections that extend ventrally from vertebral bodies 🡪 two distinct hemi-diaphragms
- Transverse septum
- Perpendicular to the diaphragm
- Separates heart from liver and viscera
- Heart is dorsoventrally flattened
- Distinct external separation between ventricles, often occupied by fat 🡪 double ventricular apex
What are the two vascular access sites in sirenians?
Describe the techniques.
Vascular access
- Brachial vascular bundle–a rete of veins and arteries in the interosseus space between the radius and ulna
- Can be accessed from the medial or lateral sides of the pectoral flipper
- Caudal tail ventral vertebral arch vascular bundle is also used, especially in younger animals where the pectoral vessels are small
- Not generally used in awake animals due to potential danger from movement of the fluke
- Spinal needles can be used to obtain IV access for drug and fluid administration in anesthetized adults in the caudal tail vascular bundle
- Blood collection
- Brachial vascular bundle
- Interosseous space b/w radius and ulna
- Medial or lateral approach to pectoral flipper
- Flipper firmly restrained 🡪 elbow and carpal joints identified 🡪 radius and ulna palpated 🡪 locate space between then 🡪 middle portion of flipper midway between elbow and carpus is surgically scrubbed
- 18-20G, 1-2in needle attached to extension line and syringe or vacutainer
- Calves
- 25-21G butterfly set with ¾-in needle
- Lateral aspect is easier due to minimal abduction of pectoral flipper
- Blood clots quickly 🡪 heparinize needle
- Caudal vascular bundle
- Ventral to the vertebral column in the paddle
- Difficult to access safely in awake animals
- Use only in anesthetized or very ill animals
- Brachial vascular bundle
What is the leading cause of mortality of manatees in Florida and Puerto Rico?
Describe the lesions typically associated with trauma?
How are these manatees managed?
- Watercraft injuries
- Common cause of death of FL manatees and T. manatus in Puerto Rico
- 22% of reported carcasses annually
- Injuries on dorsum
- Blunt trauma – boat hulls
- Sharp/shearing trauma – propeller blades and lower motor units
- Death from blunt trauma more common
- Severe internal hemorrhage with minimal external wounds
- Skin, diaphragm, and lung lacerations
- Skeletal damage (rib or spinal fractures)
- Hemothorax
- Pyothorax
- Pneumothorax
- Hemoabdomen
- Kidney damage
- Pneumothorax
- Clinical signs: increased RR and effort, listing, excessive buoyancy
- Confirm with radiographs/ultrasound or air on thoracocentesis
- Flotation devices may be necessary
- Thoracocentesis
- Diagnostic and therapeutic
- Serial thoracocentesis can be successful for resolution
- Remove smaller amounts over multiple procedures
- If you remove to much, there will be immediate refilling of potential space
- Chest tubes – challenging to maintain
- Most resolve with supportive care and time
- Thoracocentesis may not be indicated if animal is eating and breathing normally with no respiratory distress
-
Boat strike is one of the most common causes of morbidity/mortality
- Death can result from sharp penetrating trauma from propellers and/or blunt trauma from the boat hull
- Significant sequelae include hydrothorax, SQ emphysema, pneumothorax, secondary infections resulting in sepsis, pyothorax, pleuritis and peritonitis
- Diaphragmatic hernias can also occur
- Lungs often injured due to dorsal anatomic location
- Fractures and luxations also occur
Watercraft injury
- One of the largest cases of rescue and mortality
- Presence of external wounds in an animal with abnormal buoyancy is highly suggestive of traumatic pneumothorax
- Excess intestinal gas from enterocolitis or constipation can also mimic these signs
- Radiography to confirm
- May need to tap repeatedly, severe cases may require the use of a flotation jacket to equalize the animal in the water column
- Chest drains have had mixed results
- Animals not responding to treatment after 4-6 weeks may have a severe tear in the lung tissue which may require surgical intervention
- Head injury, spinal injury, and abdominal ST damage are also common sequela of boats trike
- Propeller wounds are characteristic and can also cause rib transection
- Proper wound care is key
Cold Stress Syndrome in manatees occurs at what temperature?
What demographic groups are most susceptible?
What are the clinical signs in acute versus chronic cases?
What clinicopathologic changes are common with cold stress sydrome?
What are the histologic lesions of the skin? Compare acute versus chronic cases.
What are the lesions in other organs?
Cold Stress Syndrome (CRC)
- Prolonged exposure to temperatures < 20C (68F)
- Common in manatees, may also occur in dugongs
- One of the major threats to free-ranging FL manatee populations
- Sub-adults more commonly affected than adults
- > surface area:volume
- Lack maternal care
- Orphan calves susceptible due to lower fat mass
- Acute exposure 🡪 lethargy and fatal hypothermia
- Chronic exposure
- Emaciation, depletion of fat stores, serous fat atrophy, lymphoid depletion, epidermal hyperplasia, pustular dermatitis, enterocolitis, myocardial degeneration
- Opportunistic infections and secondary diseases
- Bacteremia, dehydration, hypoglycemia, renal failure
- Clin path
- Thromboembolic disease
- Hypercoagulability and have longer PT and PTT, increased D-dimer and fibrinogen, thrombocytopenia
- Severe acidemia, metabolic acidosis, abnormal electrolyte findings
- Leukocytosis
- Elevated LDH, CK, creatinine, serum amyloid A
- Thromboembolic disease
- Clinical signs
- Skin lesions and poor body condition
- Early skin lesions: epidermal bleaching of extremities and muzzle
- Chronic skin lesions: hyperkeratosis, diffuse pustules, ulcerative lesions
- Muzzle, head, and extremities most severely affected
- GI stasis, constipation, absence of gut sounds or flatulence, pneumonia
Cold stress syndrome (CSS) (ZP)
- A range of clinical and acute and chronic disease processes that can occur in manatees following exposure to water temps below 20 C (68 F)
- Emaciation is noted in most chronic cases of CSS
- Marked epidermal hyperplasia characterized by irregular, verruciform, pale grey plaques that are often fissured are commonly noted
- Multifocal cutaneous ulceration and/or cutaneous pustules or abscesses
- Histologically there is moderate to severe lymphoid depletion in LN, spleen, gut and respiratory mucosa
- Myocardial degeneration
- Heterophilic and histiocytic colitis or enteritis
- Chronic-active suppurative bronchopneumonia
- Pancreatic zymogen granule depletion
- Acute skin lesions—vasculitis and vascular necrosis
What are some common diseases of neonatal manatees presenting to rehab facilities?
What is pneumatosis intestinalis?
How is it treated?
Neonatal, maternally dependent calves
- Orphans present to rehab facilities not uncommonly
- Calves may suffer from complications related to prematurity, inanition, poor adaption, watercraft injury, and infection such as omphalitis, which includes hypoglycemia, dehydration, constipation, enterocolitis, and pneumatosis intestinalis.
- Congenital defects in rescued calves have included ectrodactyly of the pectoral flippers digits, atresia ani, and omphalocele or exteriorization of the intestinal tract at the umbilicus
-
Pneumatosis intestinalis
- GI gas within the wall of the GI tract
- Secondary to necrotic enterocolitis, GI obstruction, GI ischemia, sepsis
- Interactions with mucosal integrity, intraluminal pressure, bacterial flora, and intraluminal gas play roles in development
- Treatment
- Oral aminoglycosides
- Metronidazole
- Pepto-Bismol
- Changing diet to elemental human infant formula
Describe the physical examination of manatees
How is body condition determined?
What can be appreciated on auscultation?
Physical Examination
- RR: 3-5 breaths/ 5 mintues
- Examine ventrum when dry-docked
- Place straps under the axilla and cranial to the peduncle to facilitate rolling
- Body condition
- Malnourished
- Distinct neck due to loss of nuchal fat (“peanut-head”)
- Prominent scapulae, hips, spine
- Flat (thin) or conave (very thin) ventrum
- Longitudinal skin folds (emaciated)
- Malnourished
- Oral exam with digital palpation of molars
- Thoracic and abdominal auscultation
- Normal sinus rhythm
- HR: 40-60 bpm
- Calves: 60-75 bpm
- Percussion useful for GI tract
- Gas and peristaltic intestinal sounds are normal
- Hindgut fermentation produces large volumes of colonic gas
- Absence is abnormal
Normal stool is formed, but not dry
- If no feces, perform rectal exam
A recent study created a scoring system for DIC in Florida manatees.
What diseases of manatees are commonly associated with DIC? Is there a common disease that is not associated with it?
How is diagnosis of DIC achieved?
What test specifically provides negative prognostic information? At what value?
Barratclough, A., Ball, R. L., Floyd, R. F., Reep, R. L., & Conner, B. J. (2017). Proposal and application of a novel disseminated intravascular coagulation scoring system in the Florida manatee (Trichechus manatus latirostris). Journal of Zoo and Wildlife Medicine, 48(1), 152-158.
Abstract: Disseminated intravascular coagulopathy (DIC) is an acquired disorder of hemostasis resulting in activation of the coagulation and fibrinolytic pathways. It is reported secondarily to multiple disease processes and can be associated with increased mortality. Previous research at Tampa’s Lowry Park Zoo (LPZ) demonstrated that Florida manatees (Trichechus manatus latirostris) with cold stress syndrome (CSS) demonstrated thromboembolic disease. The object of this retrospective study was to establish the presence and clinical relevance of DIC in Florida manatees admitted to LPZ for rehabilitation from 07 March 2010 to 15 August 2015. A coagulation panel, including prothrombin time, partial thromboplastin time, platelet count, fibrinogen level, and D-dimer level was used to diagnose DIC. There were 100 cases identified in the study period: 35 trauma, 43 CSS, 17 secondary to harmful algae blooms (HAB), and five miscellaneous. Manatees with CSS had the highest incidence of DIC with 24 of 43 cases (56%) affected, followed by trauma with 18 of 35 cases (52%) affected. None of the manatees with HAB were found to have DIC. Manatees that developed DIC during rehabilitation or when DIC progressed did not survive. Due to the clinical implications of DIC, identifying its presence and recognizing its severity could improve clinical outcomes by enabling more intensive treatment protocols.
- Disseminated intravascular coagulation (DIC): Acquired disorder of hemostasis
- Always secondary to another cause (e.g. sepsis, trauma, neoplasia, immune-mediated disorders)
- Diagnosis achieved through combination of tests
- Coagulation panel: PT, PTT, D-dimers, fibrinogen, platelet count
- Human ER medicine has validated a scoring system
- Low fibrinogen is possible due to consumption
- Developed a modified scoring system based on humans, cats, dogs. Combined score ≥ 4 is associated with DIC
- Cold stress syndrome (CSS) and trauma are likely associated with DIC (56% and 52% of cases, respectively)
- DIC was not found in harmful algal bloom (brevetoxicosis) cases
- Trauma had the highest mortality rates compared to CSS and HAB cases. Reduced survival in trauma manatees with DIC.
- In CSS, DIC is common (56%) though survival probability is not related to DIC presence or absence
- Can correct underlying problem with supportive care and resolution of hypothermia
- If repeat coag panels, a change in DIC score was a better predictor of outcome
- D dimers were best standalone indicator for long-term prognosis
- > 1,500 ng/mL = poor w/ only one survivor (3200 ng/mL)
Summary: Over half of cold-stressed manatees had DIC but it was not associated with poorer long-term outcome. Over half of trauma cases had DIC and it was associated with reduced survival. There was no DIC in brevetoxicosis cases. D-dimers were the best single test for predicting outcome.
A recent study compared temperature measurement methods in manatees.
What were the two temperature measurement techniques?
Which measurement technique was most reliable?
How did core body temperatures differ between healthy and cold-stunned manatees?
Martony, M. E., Isaza, R., Erlacher-Reid, C. D., Peterson, J., & Stacy, N. I. (2020). Esophageal measurement of core body temperature in the florida manatee (trichechus manatus latirostris). Journal of Wildlife Diseases, 56(1), 27-33.
ABSTRACT: Cold-stress syndrome (CSS) is one of the leading natural threats to free-ranging Florida manatees (Trichechus manatus latirostris). Cold water exposure below the species’ acceptable physiologic range is a frequent occurrence for manatees during cold weather months causing CSS induced systemic illness and significant annual mortality. Although CSS is a commonly presented condition at manatee rehabilitation facilities, the core body temperatures in CSS manatees are currently unknown due to the lack of clinically applicable and accurate temperature measurement methodologies. Our objective was to establish a clinically applicable measurement methodology of core body temperature in manatees. A novel, minimally invasive temperature technique to obtain esophageal temperature by placing a temperature sensor through an oro-gastric tube was compared to current oral and nasal methods in 20 clinically healthy manatees. Results identified the esophageal measurement as the best performing and most precise temperature methodology. The superior performance of esophageal temperature measurements differed significantly from both nasal and oral measurements, while nasal and oral measurements did not differ when compared with each other. The esophageal measurements were consistent with manatee core body temperature, facilitating generation of a reference interval for core body temperature in healthy manatees (35.0– 35.8 C). Four CSS medical cases were evaluated with the newly validated esophageal temperature method, facilitating diagnosis of hypothermia. The application of this temperature measurement technique to CSS manatees in field or rehabilitation settings will help in understanding CSS pathophysiology, improve medical assessments during rehabilitation, and contribute to conservation efforts.
Intro
- Cold stress syndrome (CSS) is one of the leading threats to wild Florida manatees
- No accurate method for assessing core body temp in manatees exist
- objective was to establish a clinically applicable measurement methodology of core body temperature in manatees
M&M
- n = 20 healthy manatees
- Measurement of esophageal temps via orogastric tube with a digisense thermometer. This was compared to oral and nasal measurements
- Temperatures from 4 manatees that were clinical for CSS were also measured via esophageal method and were compared to the healthy manatee measurements
Results and discussion
- The esophageal measurement was significantly different (higher) from oral and nasal
- Also consistent with core body temperatures measured in research settings with more invasive techniques
- Oral and nasal were not significantly different from each other
- The reference interval for core body temperature as measured by esophageal temperature for the healthy manatees was 35.0–38.5 C (95-100.4 F)
- The esophageal temperatures of all 4 CSS manatees were below this reference range by at least 1.2 deg C
- The procedure was well tolerated by all manatees and temperatures were attained quickly and remained stable over a 2-minute period
- Note that measurements were taken after 5 minutes out of water, so could be some environmental impact (warmer air compared to the water leading to increase core temp) on temperature though none was identified
Takeaway: Esophageal temperature measurements is an accurate and non-invasive way to measure core body temperature in florida manatees
A recent study evaluated the pharmacokinetics of tulathromycin in manatees.
What is tulathromycin - how does it last so long?
How long does a single dose of 2.5 mg/kg last?
What is a proposed multidose dosing interval?
EVALUATION OF THE PHARMACOKINETIC BEHAVIOR OF TULATHROMYCIN (DRAXXIN) IN FLORIDA MANATEES (TRICHECHUS MANATUS LATIROSTRIS) UNDERGOING MEDICAL REHABILITATION.
Smith LN, Bublitz C, Nixon E, Yeatts J, Ball RL, Baynes RE.
Journal of Zoo and Wildlife Medicine. 2021;52(3):880-885.
Florida manatees (Trichechus manatus latirostris) frequently present to rehabilitation care facilities for various conditions, including boat strike trauma, cold stress syndrome, and brevetoxicosis. Throughout the course of treatment, antimicrobial use to treat respiratory disease is frequently warranted. To date, clinicians have extrapolated dosages based on established information available in bovine and equine medicine. The routes of administration, efficacy, and treatment intervals are considerations in dealing with critical wild animals. The use of tulathromycin, a triamilide antibiotic, has been studied in multiple domestic species of economic importance, including cattle, small ruminants, and swine, and has revealed efficacy against respiratory diseases. Given this information, this antibiotic has also been used in manatees with positive clinical outcomes. This study employed sparse sampling and evaluated banked plasma samples at various time intervals post–tulathromycin administration obtained during the clinical treatment course of nine animals during their rehabilitation. Preliminary pharmacokinetic analysis following administration of a single dose estimated a half-life of 33.75 h and volume of distribution per fraction absorbed (Vz/F = 4.29 L/kg). The pharmacokinetic behavior of tulathromycin in Florida manatees can be used to optimize dosage regimens in this species.
Background
- FL manatee down-listed from endangered to threatened in 2017; no PK studies in manatees
- Tulathromycin: macrolide, high concentrations in lungs compared to plasma in pigs, mice, horse, and cattle
- Accumulates in neutrophils and alveolar macs
- Current tulathromycin dose routinely used in manatees: 2.5 mg/kg SQ q7d
- Respiratory isolates in a study of Antillean manatees: G- (E coli, Enterobacter sakasakii, Providencia rettgeri, Stenotrophomonas maltophilia)
Key Points
- 1-3 retrospective samples from each time point, some different and some the same animals, animals were sick (brevetoxin, entanglement, boat strike, cold stress, orphaned calf)
- Single dose 2.5 mg/kg SQ: rapid elimination and short half life (34 hr), fell below 0.1 ug/ml by 120h
- Shorter than cattle (44-90h depending on age and route of admin)
- Two doses 9 days apart: prolonged elimination phase and long half life (280 hr), fell below 0.1 ug/ml after 216h
- Large volume of distribution supports hypothesis that despite dropping plasma levels, may concentrate in tissues, especially lungs
- Unknown if tulathromycin accumulates in heterophils of manatees like it does in neutrophils of cattle
Conclusions
- Tulathromycin can reach clinically applicable PK values in the manatee (above 0.03 ug/ml for 5 days)
- Multidose regimen (2.5 mg/kg q7-9d) is supported based on extended half life and plasma conc (9days)
A recent report described the management of dental pad fractures in Florida manatees.
Describe the dental pad anatomy of manatees.
How were these fractures managed?
What husbandry modifications were made to allow these animals to heal?
PRESENTATION AND MANAGEMENT OF DENTAL PAD FRACTURES IN TWO FLORIDA MANATEES (TRICHECHUS MANATUS LATIROSTRIS)
Journal of Zoo and Wildlife Medicine 52(3): 1084–1089, 2021
Abstract: The Florida manatee (Trichechus manatus latirostris) has well-developed keratinized dental pads at the most rostral aspect of their mouth to assist with mastication. This unique development is thought to be an adaptive response to their highly abrasive diets that contain phytoliths and sediments that may accelerate dental wear. In May 2013, two Florida manatees presented with multiple fractures in their inferior dental pads. The fractures were successfully managed with nutritional modifications, dental pad trimming, and vigilant monitoring through behavioral husbandry training. Signs of spontaneous healing were observed as early as 60 days after initial presentation with subsequent full resolution. Although surgical intervention was planned, the spontaneous healing mitigated significant health risks associated with the procedure. To the authors’ knowledge, these are the first reported cases of dental pad fractures and their spontaneous healing and resolution in manatees.
Intro
- Manatees have well-developed keratinized dental pads at the front of their mandibles, rostral to the cheek-teeth
- These heavily cornified pads provide a hard surface area to mechanically break down sea grasses during mastication and before transit to the cheek-teeth
Animal 1
- 33 yo MI florida manatee
- Presented with 2 fractures of the inferior dental pad during a routine session
- Weekly trimming under behavioral restraint was implemented
- Appeared visually healed at day 60 aside from a hairline fracture mark
- Fully resolved 3 months later
Animal 2
- 36 yo MI florida manatee
- Lived in managed care, cohabitates with animal 1
- Inferior dental pad fracture observed during routine training session (2 weeks after animal 1)
- By day 60 the pad was visually normal
- No further fractures for more than 5 years
Treatment and management
- Food items were tailored to minimize pressure points during mastication (ie lettuce offered as leaves only with the based removed, monkey biscuits soaked etc)
- Close examination of enrichment items was performed to ensure that the manatees couldn’t bite them and cause further damage
- Because Animal 1 had fractures that were more severe and chronic, the loose part of the fracture did not wear down on its own and thus required dental pad trimming on a weekly basis to prevent a fulcrum
- Although surgery to remove the loose tissue on Animal 1 was planned, both initial fractures spontaneously healed after 60 days, making surgical intervention no longer necessary
Discussion
- this case study demonstrates that dental pads can spontaneously heal without the need for surgical intervention.
- It is unknown if there are genetic or nutritional risk factors involved or what the frequency of this clinical presentation may be in the wild, but the authors hypothesize that this may be underdiagnosed, and it warrants further exploration.
- A possible etiology for the dental pad fractures is that the manatees may have been cribbing more frequently because of discomfort from an underlying tooth issue.
- Cribbing was observed from both animals, which sparked the initial examination, but no other clinical or behavioral concerns were identified.
- Because both animals presented with the condition very close in time, another possible etiology is that new enrichment items or some other husbandry issue were introduced and caused trauma to the dental pads.
