Abstract
Between April 1998 and June 1999, eight palm vipers (Bothriechis marchi) were diagnosed with a disease similar to inclusion body disease (IBD) of boid snakes.1,2 Signalments and clinical signs are summarized in Table 1. Six palm vipers were captive bred and two palm vipers were wild caught. All palm vipers were adults at time of death with a mean age of 8.6 years. Three palm vipers were found dead with no premonitory clinical signs and five palm vipers had one or more of the following clinical signs: anorexia, regurgitation, paresis, and dehydration. All palm vipers had intracytoplasmic, round to oval, single to multiple, eosinophilic inclusion bodies in hepatocytes and renal tubular epithelial cells. Inclusion bodies were distributed in other organs with varying frequency. The distribution of inclusions in affected vipers is summarized in Table 2. Concurrent histologic lesions are summarized in Table 3 and included urate nephrosis, septic thrombi, and hepatocellular degeneration. Ultrastructural features of the inclusions had features similar to inclusions in boid snakes with IBD.2 Figure 1 depicts a flow chart pedigree analysis of the affected palm vipers. Based upon pedigree analysis, there appears to be a familial tendency for this disease in this population of palm vipers.
Acknowledgments
We thank Dr. Suzan Murray (Fort Worth Zoo), Dr. Wynona Shellabarger and Dr. Tim Reichard (The Toledo Zoo), Dr. Scott Gearhart and Dr. Gary West (San Antonio Zoo), Dr. Ann Duncan (Detroit Zoo), and David Heckard (Abilene Zoo) for case submissions.
Table 1. Breed, gender, age, and clinical signs of eight palm vipers (Bothriechis marchi) with inclusion body disease
Case number
|
Gender
|
Age (years)a
|
Clinical signs
|
1
|
Mb
|
5
|
Regurgitation, anorexia
|
2
|
Uc
|
Adult
|
Anorexia
|
3
|
Fd
|
13
|
Paresis, anorexia
|
4
|
M
|
Adult
|
None
|
5
|
F
|
8
|
None
|
6
|
M
|
8
|
Anorexia
|
7
|
F
|
9
|
Dehydration, anorexia
|
8
|
F
|
Adult
|
None
|
aAge at time of death.
bMale.
cUndetermined.
dFemale.
Table 2. Distribution of inclusion bodies in eight palm vipers (Bothriechis marchi) categorized according to frequency
Location of ICIBa
|
Cases
|
Location of ICIB
|
Cases
|
Hepatocytes
|
8
|
Glomerular mesangial cells
|
4
|
Renal tubular epithelial cells
|
8
|
Myenteric ganglia
|
3
|
Respiratory epithelial cells
|
6
|
Oviductal epithelial cells
|
3
|
Biliary ductal epithelial cells
|
6
|
Pancreatic acinar cells
|
2
|
Gastric mucosal cells
|
5
|
Esophageal mucosal cells
|
3
|
Intestinal mucosal cells
|
4
|
Epididymal epithelial cells
|
2
|
Striated myofibers cells
|
4
|
Thymic/splenic lymphoid cells
|
2
|
Smooth myofibers
|
5
|
Adrenal cells
|
1
|
Thyroid follicular cells
|
3
|
Pancreatic ductular cells
|
1
|
aICIB= intracytoplasmic inclusion body.
Table 3. Concurrent histologic lesions in eight palm vipers (Bothriechis marchi) with inclusion body disease
Histologic lesion
|
Cases
|
Histologic lesion
|
Cases
|
Urate nephrosis
|
5
|
Hepatitis
|
2
|
Intravascular septic thrombi
|
5
|
Gastroenteritis
|
2
|
Hepatocellular degeneration
|
5
|
Aortic mineralization
|
2
|
Biliary ductal hyperplasia
|
3
|
Interstitial pneumonia
|
2
|
Granulomasa
|
3
|
Hepatic melanosis
|
2
|
aGranulomas located in one or more of the following: skin, stomach, thyroid gland, intestine, lung, and heart.
Figure 1
Flow chart depicting the distribution of the original wild-caught palm vipers (Bothriechis marchi) and the subsequent generations to different zoological parks.
Literature Cited
1. Axthelm MK. Clinicopathologic and virologic observations of a probable viral disease affecting boid snakes. In: Proceedings from the American Association of Zoo Veterinarians. 1985:108–109.
2. Schumacher J, Jacobson ER, Homer BL, Gaskin JM. Inclusion body disease in boid snakes. J Zoo Wildl Med. 1994;25:511–524.