On 9/24/93, I acquired a 4 month old Savannah Monitor (Varanus exanthematicus) lizard from a reptile distributor in Pittsburgh, PA. I do not know if this animal was captive bred / hatched, or wild caught. Being that the reptile was purchased for me as a gift (I had owned monitor lizards for 4 years, so the "gift" of a lizard was not a spur of the moment decision), I do not know what conditions the lizard was kept under before purchase, but the dealer is well known in the area for providing healthy, quality animals and maintaining a clean environment. The lizard, Zeke, was very active and defensive. He began eating from the moment I got him home (crickets, mealworms, eggs, and pinks). On 9/27/93, Zeke had his first vet visit with Dr. Robert Wagner, V.M.D. In the past, Dr. Wagner has been the veterinarian for the Pittsburgh Zoo. He had been caring for my monitors for years, and is a great reptile veterinarian. Zeke's check-up was non-remarkable, and he was in good health. A fecal check revealed giardia cysts, and he was treated with oral metronidazole liquid, (aka Flagyl) 4mg., for 7 days. At this time he weighed 173 grams Zeke next returned to the vet about a year later, on 11/17/94, for another general check-up. His physical exam was non-remarkable, and he was in good health. His weight at this visit was 1610 grams. The beginning of August, 1995, Zeke developed diarrhea. Being that I work as a veterinary technician (but not in Dr. Wagners hospital), I took a stool specimen of Zeke's to work with me and checked it for parasites. There were a few hookworm eggs. On 8/14/95, Zeke went to see Dr. Wagner for a check-up and to receive an antiparasitic medication. At this visit, he weighed 6.5 lbs. and was very healthy. He was wormed with Panacur liquid, 150mg, which was repeated in 3 weeks. On 12/13/95, I fed Zeke his dinner. At the time, he was eating canned monitor food, cooked eggs, some pinks / fuzzies once in a while. He had been on this diet since he was acquired. Zeke refused to eat and was lethargic. At the time, I had read about how some monitors will fast themselves in the winter months (although I have never had one not eat unless ill), so I was not overly concerned (just mildly concerned). Zeke continued to refuse food for 3 days. On 12/16/95, I picked Zeke up to play with him (he had become quite friendly by this time and liked human interaction). When I lifted him out of his cage, he arced his head dorsally, and flailed his front legs about. At this time, I knew that this was not some winter brumation / hibernation activity. I knew my lizard was sick. On 12/18/95, I took Zeke to see Dr. Wagner.
(Zeke with his characteristic left lateralization behavior)
The following are notes from Zeke's chart:
(Up until this time, Zeke was a healthy lizard. I routinely take my reptiles to the vet for checkups, just to be on the safe side, and to detect any abnormalities early)
12/18/96 -Not eating, lethargic. general CNS signs (progressive flailing of legs and muscular weakness). Nystagmus left eye. Diet: canned monitor and eggs. Supplements. BM on Thursday, soft but within normal limits. Possibly lateralysis to left. DDx: toxicity / botulism?, CNS infection?, nutritional deficiency? X-ray whole body = bone quality within normal limits. No trauma or metastasis. Wt: 6 lbs. In House Labs: all were within normal limits: ck - 291, sgot - 17.4, pcv - 29 total solids - 8, buffy coat estimate - 1%. Send exotic reptile profile / CBC out to lab: Results . Total bilirubin 0.1 md/dl, BUN 2.0 mg/dl, Ca++ 14.0 HI mg/dl, 7.5-13, CPK 378 IU/L,Glu 139 mg/dl, Phosphorus 2.5 mg/dl, SGOT 10 IU/L, Total Protein 8.3 g/dl, WBC 16-18 mg/dl, RBC 0.86 cu/mm, Plasma protein 8.3 cu/mm3, PCV 23 gm/dl, Buffy coat 1.0 % 0-1.0, MCV 267 cu/mm, HgB 9.1 gm/dl, MCHC 39 %, NRBC # % 0, platelets present, azurophils 5 %, bands 0 % hets/neuts 8 %, lymphocytes 77 %, monocytes 7 %, eosinophils 0 %, basophils 3 %, reactive lymphocytes 0 %, polychromasia slight, anisocytosis slight, hemoparasites 0 per oil field. Hematology comments: Toxic degran Hets Reactive lymphs. Urinalysis (in house): specific gravity: 1.020, pH: 6, protein: trace, hemolyzed blood + Treatment: Vitamin E, 0.2cc, IM, every other day for 5 treatments B-Complex with increased thiamin, .25cc/day, IM, for 7 days SMZ TMP (Ditrim) 0.4cc every other day, IM, for 4 treatments 12/21/96 -Get fax results from lab: Ca++ = 14. WBC = 16 - 18. Toxic hets and reactive lymphs. Add azium injection to tx, 0.1 - 0.2mg/day, IM -X-rays: lateral taken, ventral dorsal shows possible pulmonary vasculature calcification. DDx: may be CNS vascular calcification -if no improvement on azium (dexamethasone), try vascular dilators, Ca++ channel blockers
12/28/95 Re-check. Getting worse--> flips over on back to left side, or trying to go to the left. Decreased blink response on left side. Worse when stressed. Tx: flagyl 125mg/day for 6 days, continue B-comp, add Cardizem (Ca++ channel blocker), 5mg/day Wt: 6 lbs
1/4/96: Minimal response to treatment. Increase cardizem to 7mg/d
1/10/96: MRI, 60mg Ketamine IM ,CBC/Chem screen
1/11/96 Blood smear/CBC/profile sent out. Hemocytometer / eosinophil pipette = 108, WBC = 3600
1/12/96 Increase LDH--->Increase Ca++, decreased phosphorus, increased K--> bone inflammation? MRI negative for any large abnormalities. Consider metabolic / nutritional disease, renal disease??? Tx: force mice / monitor diet with vitamin/mineral supplement -run CPK (muscle) and Alk Phos (bone) -consider calcitonin injection and injacom. Dr. Tony Pardo (MRI) - normal except for suspicion of dilated ventricle (obstruction of overflow?)
1/18/96 Forcing food-->getting stronger Tx: -force food with Ca++ / D3 vitamin supplement, nystantin 2ml 2xdaily for 10 days , continue cardizem, .15cc injacom daily IM, for 7 days
1/25/96 fecal: neg. Gram stain, primarily gram positive rods and cocci. No yeast.
1/26/96 Jaw getting softer, +/- vascular
1/29/96 Re-check. General condition stable, still has lateralized symptoms of weakness and flexing to the left. Jaw less rubbery, but still soft and pliable. Exam: non-remarkable otherwise. Lab: Albumin - 3.92mg/dl, Ca++ = 15.25mg/dl X-rays: poorly calcified head of humerus, bilaterally Tx: continue injacom for 2 weeks, force feed, calcitonin 0.25cc/d for 7 days Wt: 5.9 lbs.
2/2/96 Dr. Marc Saunders and University Hospital of University of Pennsylvania radiologists were impressed with the amount of cerebral CSF around brain and thought this was abnormal and probably due to brain shrinkage (causes???), but consider insult such as toxin or infection. Alot of CSF would predispose brain to trauma via contra-coup affect. Dramatic finding of increased signal transmission of cerebral tissue-->possibly from previous insult. Rec repeat study later, and do a "normal" animal also.
2/8/96 More active recently; climbing; jaw firmer. Much less left lateralization
2/12/96 Continues to improve. "Looks at cat" now. Jaw definitely more firm. Minimal lagopthalmia.
2/19/96 Stable, no improvement. Is eating on own, still disoriented. Try Prednisolone 0.2cc IM, every other day for 3-4 treatments. Jaw firmer / calcified.
2/26/96 Recheck. Increased activity without cardizem--->stop. Eating well on own recently. Decreased lateralization. Jaw remains soft / rubbery, but is firmer and better calcified. Left eye slight lagopthalmus. Tx: injacom 0.1cc every 7 days for 3 treatments, Tums for Ca++ support Wt: 5.75 lbs.
3/4/96 Significant decrease in activity and appetite since off cardizem and pred injections. Re-start pred, 0.2cc IM every other day
3/11/96 Only slight increase in appetite and activity. Normal but few BM. Rec cbc / chem screen.
3/14/96 Recheck and blood work. CBC / Chem screen. Left lagopthalmia continues to improve. Left neck flexion comes and goes. Improved since on prednisolone. Good weight and activity now. Jaw remains soft, but improving or stable. Gram stain of vent: 20% gram neg rods, 80% gram positive cocci, yeast moderate. Chem screen to vet research, CBC to Avian and Exotic. PCV=26%, buffy = 1.25%, total solids = 6.8g/dl Tx: nystantin, Baytril every other day, continue pred and supplements Wt: 6 lbs.
3/18/96 Good activity, normal BM, still being force fed. Decrease pred to every third day. CBC: WBC = 19,000, toxic immature hets. Chem: Ca++ = 15, LDH = 468, globulin = 4 (down from 6.3) DDx: viral encephalitis
Since Zeke was not improving much on the medications, I decided to take him off of them, since he hated the intramuscular injections. After discontinuation of meds, Zeke improved slightly, and occasionally ate on his own. At the end of May, I noticed an increase in the left lateralization behavior once again. There are times when Zeke is very lethargic, and times when he will move about his cage. At that time, I was unsure how long I would continue to keep Zeke alive. He hates being force fed, but will not eat on his own. He has lost some weight, I estimate it to be 0.5 - 1 lb. , since he is very hard to force feed, and spit alot of the food out. I had been feeding him Hills Prescription Diet a/d, laced with canned monitor food, egg yolk, and nutrical. I began feeding him Eukanuba Recovery Formula canned food, since the texture is preferable for syringe feeding, and it contains twice the calories as the Hills. He would move about his cage to get to his water dish to drink and defecate, but that is mostly the extent of his activity.
On Thursday, July 25 1996, I arrived home to find Zeke had passed away. After crying for a while, I refrigerated his remains, and called Dr. Wagner to arrange for a post-mortem examination. The gorss anatomy showed no major abnormalities (except for an absent left kidney!). Examination of the cerebrospinal fluid revealed large amounts of gram positive cocci bacteria. This finding was thought to be a post-mortem event, and not contributing to Zeke's demise. The head and other tissues were sent to a veterinary pathologist who specializes in neurotoxicology. Results are as follows:
Clinical History: The lizard had left sided CNS signs of nine months duration. Imaging studies suggested the possibility of a decreased size in the brain / increase in the extradural or subdural space. At necropsy, a sample of cerebrospinal fluid revealed the presence of large numbers of bacteria.
Microscopic Diagnosis:
Multiple sections of brain characterized by:
Microscopic Description and Comments: Some of the major long fiber tracts are characterized by nerve fibers with markedly expanded periaxonal spaces suggestive of myelin swelling / edema. However, there is no frank evidence of myelin degeneration, and it is possible that this may be normal for a lizard of this type. (This appearance of the myelin is normal, for example, in fish) Occasional axons have undergone marked swelling, but there is no associated evidence of axonal fragmentation. Minimal inflammatory cells infiltrates surround some vessels, suggesting the presence of minimal to mild encephalitis of uncertain etiology.
Large numbers of rod shaped bacteria distend many of the vessels and are also present extensively in the meninges. These are morphogically most consistent with enteric bacteria suggesting that these bacteris migrated from the gut postmortem. There is no evidence of an associated inflammatory reaction.
The ventricles of a moderate size, and a moderate amount of space is present between the dura and underlying brain. It is not possible to state that the brain is atrophic, however, and those microscopic alterations which are present are bilaterally symmetrical in distribution.
The sections from this lizards brain will be under further study, and I will also attempt to get a second opinion on this case. It might be of particular interest to decalcify the head and look at the inner ear regions (re: the unilateral neurologic signs).
Dr. Robert Garman,Diplomate, ACVP
At this time, additional testing is being done on Zeke. I will post results when they become available. Dr. Wagner has also consulted other various reptile veterinarians.
If anyone has any information about this strange disease process, or neurological problems in monitor lizards, please contact me!!!!
I would like to thank Dr. Robert Wagner VMD and the staff at VCA Fox Chapel Animal Hospital, and UPMC for all the help and support I received during Zeke's illness!!
