Diseases of the Integumentary System

Chapter 42 Diseases of the Integumentary System



SNAKES


As in other animals, the skin of the reptile is the largest organ of the body and is important for protection of the internal structures, to prevent drying, and to prevent invasion by bacterial, fungal, and viral organisms. Normal reptile skin consists of two layers, the epidermis and dermis. The epidermis is covered completely by keratin, forming scales and joints. The dorsal skin of some reptiles may be ornamental or defensive in structure (as in horned lizards). The ventral surface skin is thin in some species and thick in others. The dermis consists of connective tissue and may contain small bones called osteoderms. Normal reptile skin heals more slowly than mammalian skin, with lesions often taking up to 6 weeks to heal, and the speed of healing can be related to environmental temperatures. (Healing is faster at greater temperatures.)


Reptiles shed their skin periodically in a process known as ecdysis. The frequency of shedding is related to species, age, state of nutrition, reproductive status, parasite load, ambient temperature, and humidity. In snakes, the process normally replicates existing skin and replaces the entire epidermis with shedding of the old skin, usually in one piece. The process takes about 2 weeks. The animal may not feed and be cranky, so owners should limit handling during this time. During ecdysis, the skin is much more permeable, and topical medications may be more readily absorbed.



Dysecdysis (Difficult or Incomplete Shed)


Difficulty shedding or failure to completely shed is a common problem in snakes kept in excessively dry environments (Fig. 42-1). Areas of old scar tissue, suture lines, or areas heavily parasitized may also fail to shed completely.


image

Figure 42-1 Dysecdysis, or abnormal shedding, has many causes.


(From Mader DR: Reptile medicine and surgery, ed 2, St. Louis, 2006, Saunders, by permission.)



CLINICAL SIGNS



• Dry, flaky skin

• Skin appears to be firmly attached at some points, loose at others

• Retained spectacles


DIAGNOSIS



• Physical examination

• History of recent shed


TREATMENT



• Soak snake in warm-water baths until skin loosens

• Gently remove the retained skin

• Improve the environmental humidity to prevent recurrence


INFORMATION FOR CLIENTS



• Snakes preparing to shed will often appear dull in color and be irritable.

• Keep the environmental humidity within the proper limits for the species.

• Placing a rough object into the cage (carpet, a brick, rough wood) will help the snake shed.

• Avoid using any topical medications during the shedding period.


Abscesses


Abscesses are one of the more common dermatologic problems seen in captive reptiles (see Color Plate 25). Bite wounds, cage trauma, prey bites, and attacks from cage mates can all result in infection with Gram-negative bacteria. Reptiles, like birds, form caseous abscesses; they contain inspissated or dry pus that must be removed surgically. Culture and sensitivity is necessary for proper treatment.



CLINICAL SIGNS



• Firm, swollen mass on the surface of the animal; commonly on the head or trunk


DIAGNOSIS



• Physical examination and history of trauma or fighting

• Complete blood cell count (CBC)
Needle aspirate

Culture/sensitivity

• Radiology or ultrasound


TREATMENT



• Surgical curettage of the abscess

• Flushing of the capsule until healing is well under way

• Topical antibiotics: silver sulfadiazine (Silvadene) ointment or other antibiotic ointment


INFORMATION FOR CLIENTS



• Avoid housing species together.

• Feed only killed or recently killed prey; avoid live prey.

• Some animals will bang their nose against glass or wire in an attempt to escape. This may cause a rostral abscess.


Discolorations


Discolorations frequently occur in animals with infections, trauma, or metabolic disease. The most common discolorations are brownish, greenish, reddish, or yellowish discolorations of the scales.



CLINICAL SIGNS



• Discoloration of scales in a previous healthy-appearing animal

• Clinical signs of other disease problems


DIAGNOSIS



• Physical examination and history

• CBC, serum chemistry

• Culture/sensitivity of discolored areas


TREATMENT



• Depends on the diagnostic workup results


Information for Clients



• If you treat the problem, the discoloration may disappear with the next shed.


Parasites


The most common dermal parasites seen in snakes are the tick (Ixodes, Argasidae, Amblyomma) (Fig. 42-2) and the mite (Ophionyssus natricis; the snake mite). Numerous species inhabit reptiles, but the treatment is the same.


image

Figure 42-2 A hard-shelled tick under the scale of a ball python.


(From Mader DR: Reptile medicine and surgery, ed 2, St. Louis, 2006, Saunders, by permission.)



CLINICAL SIGNS



• Scales that are lifted from the surface (ticks)

• Small red or brown dots moving under scales or between scales, especially around the eyes and cloaca (mites)

• Snake may rub or twist their bodies or remain in water for extended periods

• Anemia (both)


DIAGNOSIS



• Observation of the parasite on the surface of the skin


TREATMENT



• Ticks: Manually remove all ticks.
Treat the area topically with antibacterial ointment

+/− Systemic antibiotics

• Mites: Place animal in 5% Sevin dust for 4 to 5 hours; then rinse the animal with a 1% ivermectin spray (prepared by mixing 5 mg ivermectin with 1 quart water).

• Thoroughly clean and disinfect the cage and cage furniture; remove any wood where mites might hide.


INFORMATION FOR CLIENTS



• Prevent parasites by housing the reptile in a clean environment.

• Treat all new additions to the collection before adding them to the cage.

• Examine your reptile frequently for external parasites.

• Never add caught wild snakes to your collection.


TRAUMA


Types of trauma commonly seen in reptile patients include cage trauma (usually to the nose and facial area), prey trauma (due to prey attacking the snake), and thermal trauma (burns from hot rocks or heating lamps). As a result of the snake’s environment, almost all wounds become infected and will require treatment. Bacteria such as Aeromonas, Corynebacteria, Mycobacterium, Pseudomonas, and Salmonella have been associated with both abscesses and superficial lesions in snakes.



Prey Trauma


Trauma from prey occurs when a live animal is fed to the snake and ends up attacking the snake instead (Fig. 42-3). Wounds may be superficial, but snakes may be critically injured or even killed by larger prey with a desire to survive. This type of trauma can be prevented by feeding killed or stunned prey and carefully monitoring the feeding process until finished.


image

Figure 42-3 A, Multiple rat bite wounds in a boa constrictor. B, Close-up of some of the wounds on the same snake.


(From Mader DR: Reptile medicine and surgery, ed 2, St. Louis, 2006, Saunders, by permission.)



CLINICAL SIGNS



• Fresh wounds anywhere on the body immediately after feeding


DIAGNOSIS



• History and physical examination

• Culture/sensitivity if infected


TREATMENT



• Wet-to-dry bandages of all wounds

• Surgical repair if necessary to close the wounds

• New-Skin (Prestigebrands, Irving, NY) has been used to protect the healing tissues

• Antibiotics (systemic) if needed


INFORMATION FOR CLIENTS



• Never leave live rodents in a reptile cage overnight or preferably feed only killed or stunned prey.

• Serious wounds are an emergency and should be seen by your veterinarian immediately.

• Most of these lesions will heal well given time and proper treatment.


Cage Trauma


Cage trauma is usually the result of the active snake attempting to escape confinement by butting or hitting the cage with its nose, resulting in abrasions that can become infected. These infections often spread to the oral cavity if untreated.



CLINICAL SIGNS



• Abrasions or abscesses in the rostral area

• Swelling/inflammation of the oral, nasal tissues


DIAGNOSIS



• Observation of the traumatic behavior

• Physical examination

• Culture/sensitivity if infected


TREATMENT



• Clean wounds.

You may also need

Tags:
Aug 31, 2016 | Posted by in GENERAL | Comments Off on Diseases of the Integumentary System

Full access? Get Clinical Tree
Get Clinical Tree app for offline access