A Peek at MN Moose Health and Mortalities. Erika Butler Wildlife Veterinarian MN DNR

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1 A Peek at MN Moose Health and Mortalities Erika Butler Wildlife Veterinarian MN DNR

2 Quick overview of what s to come Mortality results from the NW study Mortality results from the NE study The NE health assessment project What the results from all 3 studies mean The Wildlife Health Program s prespective

3 Why the Wildlife Health Program Got Involved Average Adult Non-Hunting Mortality Alaska & Canada Northwestern Minnesota Northeastern Minnesota 8 12% 21% (16 26%) 21% (5 35%)

4 The NW Study Study initiated in 1995 response to declining #s beginning in mid-1980s 152 adult cows and juveniles radio-collared Goal was to determine survival, productivity and causes of mortality.

5 Some of the health findings from the NW Poor adult cow and yearling survival Good calf survival Low pregnancy (48%) and twinning rates (19%) 87% of mortality related to parasites and infectious diseases Apparent Cu and Se deficiencies Cu deficiency: causes faulty hoof growth, poor coat, lowered reproductive rates, etc; subclinical can cause poor health and opportunistic infections Se deficiency: white muscle disease; predisposes to infectious diseases

6 Causes of NW MN Mortality in Study Animals (n = 76) Unknown 25% Poaching 3% Accidents 4% Predation 7% Liver Flukes likely 31% Brainworm likely 5% Disease/Starved likely 25%

7 NW Anecdotal Mortality (n = 56) unknown 7% Liver flukes likely 11% Disease/Starved likely 52% Brainworm likely 30%

8 The NE Study ( ) Cooperative effort between the MN DNR, Fond du Lac Band of Lake Superior Chippewa, US Geological Survey, 1854 Treaty Authority, and Natural Resources and Research Institute Response to apparently stable moose numbers after mild winters of and the results of the NW study 150 adult bulls and cows collared since still on the air

9 Northeastern Minnesota Study Area Koochiching Lake Cook Itasca St. Louis Study Area Counties in Minnesota N Aitkin Carlton # Duluth W E S

10 Health Results from the NE Study Poor adult survival Calf survival of 35% Pregnancy rate of 83% and twinning rate of 30% 58% of mortality described as unknown but likely health related

11 Causes of NE MN Mortality in Study Animals (n = 87) Poached 2% Accidents 11% Hunters 18% Unknown 58% Wolves 10% Bacterial Meningitis 1%

12 NE Anecdotal Mortality (n = 23) Multiple Problems 22% Unknown 9% Brainworm likely 35% Winter Ticks 4% Liver Flukes 4% Brainworm possible 26%

13 Some of the Strange Findings Some often appeared to have simply tipped over Poor Antler Development (Arterial worm? Liver Flukes?) Emaciation (even during the good times ) Less than expected rump fat documented during captures Timing of non-hunting mortality

14 Timing of Non-anthropogenic Mortality February March April May June July August September October November December January

15 Tipover Disease

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17 P. tenuis serology results from Indicates exposure, not infection or illness - 18/109 NE MN captures + ELISA test for P. tenuis - 13 of 18 died (3 months - 4+ years later) - COD = wolves, trains, hunters, unknown - 1 carcass showed possible cranial evidence of worm - 5 still alive, some for 5+ years - 1 produced twins for 3 years in a row 2005 Captures

18 Our NE Moose Health Assessment Project Screen hunter harvested (presumably healthy) moose for a variety of disease agent Goal = obtain normal values for healthy moose in this population allowing better interpretation of results from non-hunting mortalities Negative results don t mean the disease isn t out there

19 Had hunters collect fixed and frozen liver and lung, feces, blood (for serum), hair, teeth, and any unusual things Staffed registration stations to collect obex and cranial lymph nodes Sample Collection

20 Quality of Kit Submissions in 2007 Hunter cooperation was excellent 118 full sample kits 24 partial kits 4 Teeth/hair only Veterinary Diagnostic Lab reported that the majority of the samples were quite good! Examples of some errors: Spleen or blood clot collected instead of liver Insufficient amount of a sample collected

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22 What did we do with the samples? Obex and LN s CWD and TB Serum EEE, WNV, MCF, Johne s, Anaplasmosis, Brucella, BTV, BVD 1 & 2, EHD, IBR, Lepto, Neospora, PI 3 Lung, Liver, and Feces Parasit, Sedimentation, Cultures, Johne s, Mycoplasma, and Salmonella

23 Year 1 Results The Negatives! Mycoplasma (119) Mycobacterium paratuberculosis (90 fecal cultures, 118 fecal PCRs, 121 Biocor serology) Brucellosis (112) Bovine herpes virus (120) Blue tongue virus (121) Epizootic hemorrhagic disease (121) Neospora (122) CWD (14 obexes, 23 RLN) Bovine TB (# s currently unknown)

24 The Positives from 2007 EEE (5/116; 4.3%) 2 at at >= 100 WNV (45/117; 38.5%) 32 at 10 6 at at >= 100 Both tests used virus neutralization Results at >= 100 are STRONGLY positive Little known about effects on moose; EEE poses greater mortality threat Could be impacted by climate change

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26 More Positives from 2007 MCF (8/117; 6.8%) 4 at 1:100 4 at 1:20 Documented to cause death in moose/other ruminants; neurological effects, go blind, thrash, go down Need whole blood to determine the strain Anaplasmosis (1/117; 0.9%) Moose known to be susceptible; causes anemia and weakens immune system

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28 Some more positives BVD 1 & 2 (2/120; 1.7%) 1 at 1024/ at 128/256 Known to affect moose PI 3 (1/122; 0.8%) 1 at 10

29 Still more positives Leptospira sp. L. bratislava: 4/121 (3.3%) 2 at 100, 2 at 200 L. canicola: 2/121 (1.7%) 1 at 100, 1 at 200 L. grippothyphosa: 3/121 (2.5%) 2 at 100, 1 at 200 L. hardjo: 0/121 L. interrogans icterohaemorrhagicae: 2/121 (1.7%) 1 at 100, 1 at 200 L. pomona: 10/121 (8.3%) 4 at 100, 1 at 200, 5 at 400

30 Fecal Floatation Fecal Parasitology 5 Nematodirus 5 Moniezia 6 Strongyle type ova One Dictyolcaulus One Nematodirus/Moniezia

31 Bacterial Cultures Liver 119: no significant growth 1 E. coli, 1 Pantoea sp. Lung 124: no significant growth 1 E. coli Other Abscess- Arcanobacterium Spleen- 1 Pantoea sp.

32 Histology Results- Liver 114 samples NSF lipidosis (due to rut?) 17 with hepatitis or perihepatitis (flukes??) 4 fluke or fluke material Hydatid cysts, fibrosis, peritonitis, lymphoid hyperplasia

33 Histology Results- Lung 126 samples NSF 93 Hydatid cysts in 5 Lymphoid hyperplasia in 6 Chronic pleuritis in 4 Varying types/degrees of pneumonia in 4 Bronchitis, emphysema, and granuloma

34 Other Results Colon and Small Intestine Histopathology 1 sample examined, enteritis Results of liver ICP not yet analyzed but some low copper levels exist

35 Year 2 Major Changes Asked hunters to take pictures of cut surface of liver and heart Collected larger tissue/fecal samples We wanted brains!! We know moose can survive P. tenuis infection, but not how many normal moose have chronic migration tracts Whole blood and smears Allows for investigation into tickborne diseases (anaplasma, babesia, etc)

36 What We Collected in 2008 Collected kits from 120 hunters 21 brains!! 113 serum samples Samples submitted to Diagnostic lab in October and November, results should be available in the next month

37 And now, it s time for our opinion

38 What do the results of these studies mean?? MN moose are being exposed to a wide array of diseases Deficiencies of copper and selenium exist Obviously diseases are playing a role in nonhunting mortality A lot of unknowns out there

39 Issues with P. tenuis Clear that P. tenuis is a mortality factor of MN moose Serology indicates that some are surviving Visibility of brainworm moose may cause a sightability bias Not all circling moose are P. tenuis (anything that causes neuro. disease like EEE and MCF) Extremely difficult to diagnose, results difficult to interpret Migration tract vs nematode, chronic vs acute, what does an adult in the meninges mean? Brains from 2008 hunters should give us a better idea of how to interpret migration tracts

40 Copper, Selenium, and Other Heavy Metals Difficult to determine what the normal range is for moose Subclinical deficiencies could be predisposing them to opportunistic infections NE herd health assessment should help establish normals for that region

41 Authors of the NW Study thought they played a large role in mortalities Often subjective; do see heavy loads and major aberrant migration, but difficult to determine whether it caused a mortality Liver Flukes

42 Problems with determining cause of mortality Need fresh carcasses from collared animals (sightability bias) Need better monitoring (better collars or daily monitoring), more complete and timely sample collection, and faster delivery time to the dlab Need more complete disease screening Very little virus isolation completed, very little done with the tick diseases

43 Burning questions Why now?? NW moose dissappeared in a short amount of time NE moose look like they are heading in the same direction If P. tenuis has is the problem, what has changed lately (it has been around for a long time)?? If climate change is the problem, why is it so dramatic? If we suspect heat stress is playing a role, why are we not getting internal temperatures of the moose?

44 In Summary Nutrition, habitat, deer densities, climate change, heat stress, disease??? There is no smoking gun it could be any of these things or a combination Without a thorough investigation we may never know the ultimate cause of our moose decline