436
The Biology of Sea Turtles, Vol. II
16.12.1.3 Respiratory Infections
Bacterial and fungal respiratory infections are not as common as dermal and gastrointestinal infections (Glazebrook et al., 1993; Leong et al., 1989) in sea turtles,
but should be suspected if a turtle is lethargic and floating on its side. Tiltedswimming or side-floating turtles should be quarantined immediately because respiratory infections (bacterial and fungal) are most often fatal and may be contagious.
Leong et al. (1989) described mycobacterial pneumonia (MP) infections as a cause
of tilted-swimming, and found that antibiotic treatment of MP with streptomycin
was ineffective. The NMFS STF has been identifying and treating tilted-swimming
turtles with 5 mg/kg injectable enrofloxacin (Baytril ® , Bayer Corp., Shawnee, KS)
with promising results. Although an MP or fungal infection is suspected, in most
cases, limited attempts are made to isolate the infectious agent because of the
intrusive nature of obtaining samples from the lungs. The MP or fungal infection
may be secondary to a bacterial pneumonia infection.
16.12.1.4 Viral Infections and Gray-Patch Disease (GPD)
The herpesvirus is believed to cause cutaneous lesions on the flippers and neck of
green sea turtle hatchlings. At the Cayman Turtle Farm, GPD has been reported to
infect 65–95% of green turtle hatchlings. Although it appears to be cutaneous in
nature, infecting only the epidermal layers, it can be fatal (Haines, 1978; Haines
and Kleese, 1977). GPD occurs in two forms: pustular-like (blister) lesions that
resolve spontaneously with time, and extensive gray-patch lesions that may spread
to cover large areas of skin (Haines, 1978). The latter form is often lethal (Haines
and Kleese, 1977).
Recovery from pustular GPD results from spontaneous healing by the time the
turtles reach 12 months of age (Haines, 1978). Poor water quality, most notably
elevated water temperature (>30°C), and overcrowding (stress) may trigger the
manifestation of both forms of GPD. Infection rates and severity vary with age, with
hatchlings being most susceptible (Glazebrook et al., 1990; Leong et al. 1989;
Haines, 1978).
16.12.2 BLOATING–FLOATING
Loggerheads fed a commercially prepared pellet diet can develop floating–bloating
problems even at levels not considered to be overfeeding. Overfeeding Kemp’s
ridley hatchlings or post-hatchlings can cause bloating (Fontaine et al., 1985).
Pelagic loggerhead hatchlings and yearlings are the most susceptible to the condition, and the condition is exacerbated by low water temperature and a short
photoperiod, with the problem being more prevalent in the winter months. The
exact cause is unknown, and no bacterial or viral pathogens have ever been isolated.
Permanent carapace and plastron deformation occurs with growth. The problem
can become chronic without treatment. Increasing the size of the rearing container
volume (a minimum of three times), increasing water depth (a minimum of two
times), temporarily switching the diet from pellet food to squid or fish, offering
1123_C16 Page 436 Tuesday, November 12, 2002 8:28 AM
The Biology of Sea Turtles, Vol. II
16.12.1.3 Respiratory Infections
Bacterial and fungal respiratory infections are not as common as dermal and gastrointestinal infections (Glazebrook et al., 1993; Leong et al., 1989) in sea turtles,
but should be suspected if a turtle is lethargic and floating on its side. Tiltedswimming or side-floating turtles should be quarantined immediately because respiratory infections (bacterial and fungal) are most often fatal and may be contagious.
Leong et al. (1989) described mycobacterial pneumonia (MP) infections as a cause
of tilted-swimming, and found that antibiotic treatment of MP with streptomycin
was ineffective. The NMFS STF has been identifying and treating tilted-swimming
turtles with 5 mg/kg injectable enrofloxacin (Baytril ® , Bayer Corp., Shawnee, KS)
with promising results. Although an MP or fungal infection is suspected, in most
cases, limited attempts are made to isolate the infectious agent because of the
intrusive nature of obtaining samples from the lungs. The MP or fungal infection
may be secondary to a bacterial pneumonia infection.
16.12.1.4 Viral Infections and Gray-Patch Disease (GPD)
The herpesvirus is believed to cause cutaneous lesions on the flippers and neck of
green sea turtle hatchlings. At the Cayman Turtle Farm, GPD has been reported to
infect 65–95% of green turtle hatchlings. Although it appears to be cutaneous in
nature, infecting only the epidermal layers, it can be fatal (Haines, 1978; Haines
and Kleese, 1977). GPD occurs in two forms: pustular-like (blister) lesions that
resolve spontaneously with time, and extensive gray-patch lesions that may spread
to cover large areas of skin (Haines, 1978). The latter form is often lethal (Haines
and Kleese, 1977).
Recovery from pustular GPD results from spontaneous healing by the time the
turtles reach 12 months of age (Haines, 1978). Poor water quality, most notably
elevated water temperature (>30°C), and overcrowding (stress) may trigger the
manifestation of both forms of GPD. Infection rates and severity vary with age, with
hatchlings being most susceptible (Glazebrook et al., 1990; Leong et al. 1989;
Haines, 1978).
16.12.2 BLOATING–FLOATING
Loggerheads fed a commercially prepared pellet diet can develop floating–bloating
problems even at levels not considered to be overfeeding. Overfeeding Kemp’s
ridley hatchlings or post-hatchlings can cause bloating (Fontaine et al., 1985).
Pelagic loggerhead hatchlings and yearlings are the most susceptible to the condition, and the condition is exacerbated by low water temperature and a short
photoperiod, with the problem being more prevalent in the winter months. The
exact cause is unknown, and no bacterial or viral pathogens have ever been isolated.
Permanent carapace and plastron deformation occurs with growth. The problem
can become chronic without treatment. Increasing the size of the rearing container
volume (a minimum of three times), increasing water depth (a minimum of two
times), temporarily switching the diet from pellet food to squid or fish, offering
1123_C16 Page 436 Tuesday, November 12, 2002 8:28 AM