Aural abscesses in a map turtle

21 Aural abscesses in a map turtle




INITIAL PRESENTATION


Head swellings on a map turtle.



Introduction


Exotic pet – particularly reptilian – anatomy may vary significantly from commonly treated mammalian pets. This case discusses the anatomy of the reptilian ear, describing a common condition that is often associated with poor husbandry conditions. The veterinary clinician should be prepared to gain knowledge of differing anatomy and husbandry in order to best treat exotic pets.



CASE PRESENTING SIGNS


A juvenile male map turtle (Graptemys species) (Box 21.1) presented with bilateral swellings on its head.



BOX 21.1 Ecology of map turtles



• Range in the wild covers North America from Texas to Canada

• Normal habitat: semi-aquatic, freshwater (ponds, river-bottoms and lakes). Prefer large aquatic bodies, with areas of fallen trees or other debris for basking. Several animals may congregate to bask

• Average size: adult male = 10–25 cm in length, female = 18–27 cm in length, with weight 0.5–2.5 kg

• Sexual dimorphism: female much larger than male. Carapace more oval in males, who also have longer fore claws and a longer thicker tail (to contain the phallus)

• Reproduction: mating in deep waters, nesting (May–July) in unshaded sites with sandy soil. Clutch size = 6–20 eggs. Incubation = 50–70 days. Temperature-dependent sex determination

• Free-ranging diet: omnivorous, mainly feeding in water. Invertebrates such as aquatic insects, snails, crayfish and smaller crustaceans, also dead fish and plant material. The smaller male eats mainly insects, while the female consumes more molluscs and crustaceans. Older animals eat more plant material (<50% diet)

• Captive diet: animal material (70%) – rehydrated low-fat dried cat/dog/trout pellets, small raw fish, bloodworms, earthworms; fresh food (30%) – leafy green vegetables and aquatic plants

• Longevity: over 30 years

• Dormant: November–April.


Husbandry


The client had owned the map turtle for 3 months, and housed it with a similar-sized con-specific. The enclosure was approximately 30 × 60 cm; it was constructed of a glass bottom and walls, and a plastic lid with ventilation slits. The water area had a gentle slope to permit easy access, and a maximum depth of 10 cm. An internal canister filter was present. A proportion of the water was changed weekly, equivalent to a complete water change approximately every 6 weeks. No routine water testing was carried out.


A basking area was provided, comprising a ‘land’ area with a substrate of soil and large pebbles. Some artificial plants were present, providing hiding places. A spot bulb over this area produced a basking temperature of 32°C. A small underwater heater resulted in a water temperature (measured with a digital thermometer) of 24°C, dropping to 20°C overnight. A wire enclosure around the heater ensured that the turtles could not access it directly. A UV-B strip light was attached to the lid of the enclosure, sited approximately 30 cm above the surface of the substrate.


The map turtles’ diet consisted of cat kibble (soaked in water), bloodworms and a small amount of spring greens. They were fed in their enclosure.



Case History


Two weeks prior to presentation, the owner had noticed swellings on the turtle’s head. These had gradually increased in size. No other changes in behaviour, appetite or faecal output were noted. There had been no changes in husbandry since the turtle came into in the current owners’ possession, although they did not have any details of the previous enclosure or diet.



Clinical Examination


The map turtle was examined; findings included:


• Bright, alert and reactive

• Good body condition, weighing 100 g

• Moving around well, with no locomotor problems. Supporting body weight, standing up on all four limbs. No limb swellings or discomfort were detected

• Shell quality was firm. No skin lesions were present

• A firm swelling was present laterally on either side of the map turtle’s head, caudal to the eyes. The swelling on the right protruded approximately 4 mm while that on the left extended approximately 3 mm (Fig. 21.1)

• No oral abnormalities were detected.

image

Figure 21.1 Map turtle with bilateral cephalic swellings in the region of the tympanic membranes.



DIFFERENTIAL DIAGNOSES


The differentials for cephalic swelling(s) were:


• Abscess of middle ear(s)

• Other infection: abscess, granuloma, fibriscess (granulomatous abscess); cellulitis; mycobacteria; viral (such as papillomas)

• Trauma: with haematoma formation, soft tissue damage or fractures

• Oedema

• Neoplasia (unlikely since bilateral)

• Foreign bodies (unlikely since bilateral)

• Parasites: cutaneous (such as ticks), subcutaneous (such as filarial worms, botfly)

• Sebaceous cysts.


Case Work-Up



History and clinical examination


The most important aspects of investigation of this case were the above findings. Although some precautions were in place to address hygiene, they could be improved upon (see below). The localization of the swellings on the lateral head just caudal to the eyes is the position of the ear in chelonia. Bilateral symmetrical lesions are most likely related to this anatomical structure.



Other possible investigations that were not performed in this case


Imaging, such as radiography or ultrasound, would have been useful to rule out traumatic injuries or non-infectious fluid swellings. Computed tomography (CT) may also be useful to investigate head lesions in small animals.


A fine needle aspirate may have been useful to ascertain the contents of the swellings, with microscopic examination. This would have differentiated fluids, such as blood, serous exudates, or pus, and also help to rule out neoplasia as a differential.

Related posts:

  1. Stomatitis in a Harris’ hawk
  2. The exotic pet consultation
  3. Feather plucking in a parrot
  4. Dystocia in a snake

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Sep 3, 2016 | Posted by in SMALL ANIMAL | Comments Off on Aural abscesses in a map turtle

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