Abnormal Scale Dimples in snakes arising after a known viral infection

Abnormal Scale Dimples in snakes arising after a known viral infection.

Raymond Hoser

(Snakebusters)

488 Park Road, Park Orchards, Victoria, 3114, Australia.

adder@smuggled.com

Phone: +61 3 9812 3322 Mobile: +61 412 777 211 Fax: +61 3 9812 3355

Originally published in Monitor – Journal of the Victorian Herpetological Society 16(2) (October 2007):28-30.

ABSTRACT

For the first time ever this paper details scale dimpling in snakes and one or more likely causes. While no adverse affects from the dimples are known, the presence of dimples in given captive snakes may be indicative of virus, drug treatments or less likely nutritional deficiencies. Photos of the dimples are made available.

Further research into diagnosing the causal factors is required.

INTRODUCTION

In 2003, most snakes held at the author’s facility (herein called “Snakebusters”) was affected by a previously unknown reovirus (Hoser 2003a, 2003b, 2004a, 2004/5). These papers also detail viral infections in other collections, including those affected by IBD and OPMV.

All present similar symptoms in captive reptiles (that show effects of infection), including respiratory discharges, listlessness, improper posture, rapid emaciation and/or dehydration, appetite loss and other signs of ill-health.

Contrary to a lot of the considerable conflicting misinformation on the internet about these viruses, the information in the just cited papers is accurate and based on hard evidence.

In summary, the usual means of transmission of the viruses is fluid borne, including via water and cloths, reptile mites and less often shared feeding tongs.

Furthermore it is not uncommon for reptiles to carry the virus and show no symptoms. Common also is reptiles to come down “sick” with viral or secondary infections and then recover, with or without treatment.

The best treatment for affected snakes is given in Hoser 2004/5. There is no known “use-by date” for the relevant viruses and hence snakes known to be affected or exposed to these viruses should be assumed to be carriers (or potential carriers) for life.

As a result of misinformation spread on the internet to the effect that apparently healthy snakes cannot be virus infected, the spread of reovirus and other viruses in Australian collections has been rapid and to such an extent that reptiles in all states and most major collections can now be assumed to either harbour viruses and/or be at risk of acquiring stock with them.

Typically if a snake survives a bout of viral infection and associated bacterial and other infections that arise opportunistically, the snake can be expected to present as healthy and live the rest of it’s life apparently unaffected by virus.

In some cases, relapses occur, usually as a result of abnormal stress to the reptile.

Causes of this stress include temperature change (seasons) and most commonly housing more than one reptile in a cage.

The three snakes subject of this paper all suffered severely as a result of viral infection and associated complications. Post recovery all were noticed having severe scale dimpling.

While the dimpling was noticeable, especially in the affected red-bellied Black Snake (Pseudechis porphyriacus), none of these snakes appeared to be in anything other than optimal health after recovering from the viral infection symptoms.

THE AFFECTED SNAKES

Other snakes in the same collection that had similar symptoms of virus infection and that similarly recovered did not have the same scale dimpling to any degree. While the three affected snakes were all particularly sick and all came close to death, this was not a trait unique to these snakes.

Other snakes affected by the virus that also came close to death did not have the same scale dimpling after they recovered.

More significantly, while the scale dimpling appeared after a slough in each snake, this condition remained indefinitely after this time (to the date of writing this paper in May 2007), in spite of many sloughs since in each snake.

SNAKE NUMBER ONE

This was a female Red-bellied Black Snake acquired in 2003 as a sub-adult from a NSW facility (Bob Gleeson), itself recently infected by the same reovirus. This was one of three Red-bellied Black Snakes acquired at the time and in ill health from the virus and other complications.

All were treated with Baytril ® and Flagyl ® (as well as anti-parasitic drugs like Panacur ® and Droncit ®) and all made a slow and arduous recovery. They were made venomoid mid-way through the recovery phase in 2003, the rationale being that by this stage they were “out of danger” and the antibiotics in use were able to work two ways in that they also prevented infection on the post-operation snakes and would be generally given on that basis anyway. The snakes are used daily for public demonstrations (see Hoser 2004b, 2005).

The three snakes remain in peak health as of May 2007.

Only the female was noticed to have developed distinctive dimples. The two male Red-bellied Black Snakes retained their normal smooth and shiny sheen.

SNAKE NUMBER TWO

This was a two metre male “Brisbane” Carpet Python (Morelia mcdowelli) acquired from a Victorian facility (Scott Eipper). Like the Red-bellied Black Snakes, this snake had also been exposed to the same reovirus, probably in the Eipper facility, and if not there, then definitely in the Snakebusters facility.

Separate to this, prior to Snakebusters receiving this snake, it did at one stage have a severe mite infestation that was treated and “cured”. Post infestation, the snake did develop apparent hard lumps and irregularities under the skin.

This sort of problem has been reported before as a follow-on from mite infestations and the exact cause and histology isn’t known.

At the Hoser facility in 2004/5 this snake developed severe pneumonia and other signs associated with the reovirus known from the same collection.

The snake was treated for some months with Baytril and Flagyl and made a slow recovery. Please note that treatment for this and other snakes wasn’t just restricted to use of drugs. It also included a favourable temperature regime and force-feeding and force-drinking as needed.

The drugs use is highlighted as a more possible cause of the dimpling effect later seen.

Post recovery, this snake also developed distinct dimpling in the scales.

SNAKE NUMBER THREE

This was an adult male Tiger Snake (Notechis scutatus), raised from young at the Snakebusters facility. The general husbandry of this and all other snakes at the facility is detailed by Hoser (2006, or 2007) and is also inline with the general practices as outlined in Hoser (1989).

This particular Tiger Snake developed severe signs of virus infection in 2005 and was treated with Baytril and Flagyl and made a slow recovery. Post recovery the snake has been trouble free. It is not the only Tiger snake at the Hoser facility to have endured a “hit” from the virus and while recovery has been achieved in all cases (with a few close shaves), this was the only one to have ended up with scale dimpling.

The dimpling is hard to notice on this snake because the colouration of the species is not particularly glossy (as compared to the two preceding taxa), even though this particular specimen is a relatively brightly coloured animal.   The snake had been venomoid (without incident) for at least a year before the signs of viral infection appeared (the catalyst for this outbreak being unknown) and at the time of writing (2007) remains alive and well.

DISCUSSION

The dimples have not presented any husbandry or other problems in the affected snakes.

In all other manifestations they have acted and appeared normal.

Shedding has been normal for these snakes as well.

On this basis, it’s likely that similar dimpling has occurred in other people’s captive snakes and to date not been reported.

I could find no records of this in the herpetological literature or on the internet.

There is no evidence of this being seen in wild snakes.

As the dimpling is seen for the entire length of the snake’s body and effectively without exception, it is clear that the effect is a result of some systemic process.

Systemic and secondary effects of virus infections have been detailed by Hoser (2004c).

As to the likely cause of the dimpling, the most likely suspects appear to be one or more of the following:

·         Reovirus or other viral infection

·         Treatment with one or more drugs as used for viral infection (anti-bacterial drugs) and/or drugs used to treat parasite infestations or pre-emptive for them.

·         Dietary results (a deficiency in some key nutrient).

·         A combination of one or more of the above

Not mentioned so far has been the fact that the snakebusters snakes are regularly fed alternative food such as bones, chicken necks, fish and other items, besides the more typical rodent diet as seen in other collections.

Notwithstanding the above causal suspects, the problem with assigning blame to any of the above is that for each of the snakes affected, similar snakes of the same taxa with similar histories of viral exposure, infection, treatment, cure and diet have not shown any signs of dimpling.

Venomoid operations were not deemed a relevant consideration. By way of example, 9 of 10 “fixed” Tiger snakes did not get any dimples. Same for 2 of 3 “fixed” Red-bellied Blacks. Obviously the Carpet Snakes were never devenomized.

This implies that the dimpling result occurs in some individuals only under a given set of conditions rather than all snakes.

Abnormal dimpling of scales in lizards hasn’t been noted, but is presumed to be possible.

High resolution photos of some of the dimpling in the above-mentioned snakes was done at the Victorian Science Teacher’s Conference (STAVCON) in November 2006 using a Dino Digital Microscope.

ACKNOWLEDGEMENTS

All snakes referred to in the paper were provided to us for free by various licensed keepers, including from interstate. Their assistance’s in helping snakebusters remain Australia’s leading wildlife educators is appreciated. The role of the wildlife authorities in granting necessary movement and other permits is also acknowledged. The Dino Digital Microscope used in November 2006 was generously provided free of charge by Phil Jones, of Logint (website at: http://www.logint.com.au/). Other photos were taken with a Nikon D200 SLR and lenses supplied by VANBAR, Carlton, Victoria.

REFERENCES

Hoser, R. T. 1989. Australian Reptiles and Frogs. Pierson and Co., Mosman, NSW, 2088, Australia: 240 pp.

Hoser, R. T. 2003a OPMV in Australian Reptile Collections. Macarthur Herpetological Society Newsletter, June. Issue 38, pp. 2-8.

Hoser, R. T. 2003b Reovirus - Successful treatment of small elapids. Crocodilian 4(3):23-27.

Hoser, R. T. 2004a The Great Australian snake extermination. Hard Evidence 4(2):32-38 and 4(3):21-29.

Hoser, R. T. 2004b Surgical Removal of Venom Glands in Australian Elapid Snakes: The creation of venomoids. Herptile 29:1 (March):36-52.(Reprinted in Crocodilian 4(5):cover and pages 17-31 (November).

Hoser, R. T. 2004c A severe case of stomatitis (canker or mouthrot) in a Death Adder (Acanthophis antarcticus) associated with a reovirus infection. Boydii (Autumn 2004):16-17.

Hoser, R. T. 2004/5 An avoidable epidemic of reovirus in collections of Australian snakes and the wider implications of the disease in Australia and elsewhere. Herptile 29(3): 94-106, 29(4): 162-169 and 30(1): 19-28 (Sept, Dec 2004 and March 2005).

Hoser, R. T. 2005 Surgically enhanced venomous snakes. Venom glands out, silicone implants in! The creation of perfect exhibition snakes in the post HIH era. Crocodilian (2005) 5(1-3):including some cover photos.

Hoser, R. T. 2006. Successful keeping and breeding of Eastern Brown Snakes (Pseudonaja textilis) including an assessment of previously documented failures and reasons for them.
Crocodilian - Journal of the Victorian Association of Amateur Herpetologists(2006) 6(2)(August):16-28.

Hoser, R. T. 2007 Garbage Guts - Australian Tiger Snakes. Reptiles (USA) (March) 15(3):48-60.