Abstract

This study determined common causes of morbidity and mortality, and the effect that age, sex, and melengestrol-acetate (MGA) implants had on morbidity and mortality of captive jaguars (Panthera onca) in North America. The most common causes of morbidity in captive jaguars were found to be dental, gastrointestinal, integumentary, and musculoskeletal diseases. Prevalence of disease was shown to vary with age. However, tooth fractures, endoparasites, pododermatitis, conspecific and self-trauma, and arthritis predominated for this captive jaguar population. Other diseases or clinical signs that seemed remarkable were a high prevalence of episodes of epistaxis among jaguars. The data suggest that MGA implants increased the risk of developing female reproductive disease, and that females develop reproductive disease more frequently than males. The most common causes of mortality were reproductive disease in females and euthanasia due to musculoskeletal disease in males. Based on our findings, we present management suggestions for the captive jaguar population.

Introduction

The jaguar (Panthera onca) is a spotted South American cat, the third largest cat in the world after the lion (P. leo) and the tiger (P. tigris). Although the jaguar was once distributed from the southwestern United States through southern Argentina, its home range and population have diminished in the past century due to habitat destruction and hunting. In 1973, jaguars were placed on CITES Appendix I. The captive jaguars housed at American Zoo and Aquarium Association (AZA) institutions offer an invaluable resource for education on jaguar conservation and protection.

The primary objective of this study was to determine the most common causes of morbidity and mortality of captive jaguars held at AZA-accredited institutions in North America between 1982 and 2002. Additionally, we examined age and sex as factors of morbidity and mortality. In females, we recorded melengestrol-acetate (MGA) implant history to determine the association with reproductive disease.

Materials and Methods

We examined the medical records of 172 (84.82.6) jaguars and the necropsy reports of 84 (36.42.6) jaguars housed at 30 AZA institutions.⁴ Data were tabulated via body system, age, sex, and for adult females the MGA implant history was recorded. Prevalence of body system diseases was determined within each age group by tallying each individual that displayed a body system disease during that age range. For body system categories in which >20% of the population was diseased, the most commonly reported types of disease were determined.

Sex comparisons were made by comparing total number of males with disease of a body system to total number of females with disease of that body system. To determine the impact of implants on female reproductive disease, we recorded the number of implants received by females older than 2 yr old, and number of cases of reproductive disease. Causes and ages of mortality were recorded for males and females. Diseases that resulted in euthanasia were tallied based on the clinical signs that led the animal to be euthanatized.

Morbidity Within Age Groups

Prevalence of disease within each body system was determined (Table 1). For body systems in which >20% of the age group population displayed a disease, the most commonly reported diseases in that body system are listed below.

0 to < yr (n=85 jaguars)

Gastrointestinal—83% (15/18 cases) - Endoparasites or bacterial infection. One case each of gastric mucosal calcification, necrotic enteritis, and pancreatitis.

2 to <5 yr (n=53 jaguars)

Gastrointestinal—75% (9/12 cases) - Endoparasites or bacterial infections. One case each of chronic vomiting, GI ulcerations, and pancreatic exocrine insufficiency.

Integument—28% (5/18 cases) - Foot pad lesions (pododermatitis, cracked pads). 28% (5/18 cases) - Skin lesions due to conspecific trauma. 11% (2/18 cases) - Skin lesions due to self-trauma. 11% (2/18 cases) - Idiopathic abrasions. 11% (2/18 cases) - Dermatitis. One case each of ingrown nails and a nonspecific subcutaneous mass.

Neurologic/behavioral—100% (11/11 cases) - Self-mutilating behaviors, primarily tail sucking.

5 to <6 yr (n=99 jaguars)

Dental—49% (23/47 cases) - Tooth fractures. 38% (18/47 cases) - Moderate to severe calculus or dental caries. 9% (4/47 cases) - Periodontal disease.

Gastrointestinal—59% (22/37 cases) - Endoparasites and bacterial infections. 16% (6/37 cases) - Inflammatory diseases. One case each of ulcerations, chronic idiopathic vomiting, foreign body ingestion and pancreatic adenocarcinoma.

Integument—20% (12/61 cases) - Foot pad lesions. 18% (11/61 cases) - Conspecific trauma. 15% (9/61 cases) - Self-trauma. 15% (9/61 cases) - Inflammatory skin reactions (e.g., dermatitis, MGA implant reactions). 10% (6/61) - Ingrown nails. One case each of subcutaneous masses, lipomas, unexplained abrasions, hyperkeratosis, granulomas, and lymphosarcoma.

16 to 25 yr (n = 42 jaguars)

Dental—41% (14/34 cases) - Tooth fractures. 32% (11/34 cases) - Calculus and caries. 24% (8/34 cases) - Periodontal disease.

Gastrointestinal—35% (6/17 cases) - Endoparasites and bacterial infections. 24% (4/17 cases) - Inflammatory processes (e.g., peritonitis, gastroenteritis). 18% (3/17 cases) - Pancreatic carcinomas.

Hematologic—46% (6/13 cases) - Epistaxis. 23% (3/13 cases) - Anemia. 15% (2/13 cases) - Splenic disease. 15% (2/13 cases) - Prolonged bleeding.

Hepatic— 21% (3/14 cases) - Hepatic lipidosis. 14% (2/14 cases) - Hepatitis. 14% (2/14 cases) - Primary hepatic neoplasia. One case each of cysts, cholestasis, hepatomegaly, steroid hepatopathy, and idiopathic liver failure.

Integument—27% (9/33 cases) - Ingrown nails. 21% (7/33 cases) - Inflammatory processes (e.g., dermatitis, reactions to MGA implants). 18% (6/33 cases) - Self-trauma (especially to tail). One case each of foot pad lesions, sebaceous cysts, lipomas, and hyperkeratosis.

Musculoskeletal/neuromuscular—36% (9/25 cases) - Joint diseases (e.g., arthritis, degenerative joint disease, trauma). 36% (9/25 cases) - Generalized signs (e.g., ataxia, progressive hindlimb weakness, unexplained lameness). 12% (3/25 cases) - Bone lesions (e.g., fractures, osteomyelitis). 16% (4/25 cases) - Diseases of spinal processes (e.g., intervertebral disc disease, spondylosis).

Neurologic/behavioral—71% (10/14 cases) - Behavioral (e.g., psychogenic feline alopecia, tail sucking, pacing). One case each of encephalitis, head tremors, seizures, and encephalomalacia. Renal—29% (6/21 cases) - Idiopathic “renal disease” or “renal failure”. 24% (5/21 cases) - Glomerulonephritis or interstitial nephritis. 14% (3/21 cases) - Renal cysts. 10% (2/21 cases) - Hydronephrosis. 10% (2/21 cases) - Cystitis. 10% (2/21 cases) - Pyelonephritis. 5% (1/21 cases) - Renal hypertension.

Reproductive (female)—71% (15/21 cases) - Neoplasia. 19% (4/21 cases) - Hyperplasia or cysts. One case each of pyometra and mineralization of the uterus.

Respiratory—36% (4/11 cases) - Pneumonia. 18% (2/11 cases) - Rhinitis. 18% (2/11 cases) - Atelectasis. One case each of emphysema, sinusitis, and granulomas.

Table 1. Prevalence of disease (%) within age groups of captive jaguars (Panthera onca)

Morbidity Associated with Sex and MGA Implant History

Our data suggest that females have a significantly higher prevalence over males of reproductive disease (33% vs. 5%). Sixty percent of females that had received at least one MGA implant (n=25) developed some form of hormonally linked reproductive tract or mammary disease, compared to 32% of non-implanted females (n=37). The diseases that were most frequently represented in this population include endometrial hyperplasia, pyometra, ovarian cysts, ovarian papillary cystadenocarcinoma, and mammary adenocarcinoma.

Mortality

Reproductive disease (18%), musculoskeletal disease (13%), and stillbirths/perinatal deaths (10%) were the top 3 causes of mortality in captive jaguars. For males, the most common cause of death was euthanasia due to musculoskeletal disease (22%). For females, reproductive disease was the most common cause of mortality, accounting for 36% of deaths. Interestingly, 47% of the females that died from reproductive disease had never received an MGA implant. Causes of death for eleven jaguars were unspecified in the records.

Discussion

Gastrointestinal disease represented a significant portion of jaguar morbidity in all age groups. The primary cause of gastrointestinal health problems was parasite infestations. In most instances, these infestations were treated with anthelminthics and cleared before clinical signs became apparent. The prevalence of inflammatory gastrointestinal diseases such as peritonitis and gastroenteritis increased with age.

Integument diseases, frequently seen in jaguars over 2 yr old, included cracked pads, pododermatitis, dermatitis, abscesses, trauma from cage-mates, ingrown nails, and self-trauma. Cracked pads may be related to concrete enclosures, and pododermatitis can be caused by Staphylococcus aureus infections or immune-mediated processes.¹ Inflammatory responses to MGA implants were reported fairly frequently in adults. Lacerations and bite wounds from cage-mates may have occurred due to territorial disputes, and could be prevented by housing jaguars separately or providing more individual space. In older cats, ingrown nails became a problem. Nails should be trimmed regularly. Self-trauma, classified as a neurologic/behavioral disease in this study, often resulted in secondary integumentary damage, causing a raw, inflamed tail. Enrichment devices and activities should be supplemented and the cats should be provided adequate space and areas to hide to prevent self-trauma from boredom or stress.

Dental disease was very common in jaguars 5 yr and older. Fractured canines were the most common dental lesion, followed by moderate to heavy tartar. Periodontal disease was seen in older jaguars. Annual exams should always include a dental exam and treatment, when deemed necessary. Chewing on bars and fencing promotes tooth fractures, and enrichment devices should be given to encourage jaguars to chew dental-friendly items.

Musculoskeletal, reproductive, renal, hematologic, hepatic, and respiratory diseases were important causes of morbidity in animals 16–25 yr old. Musculoskeletal diseases observed included arthritis, spondylosis, and intervertebral disc disease. Arthritis can be immune-mediated or degenerative. Arthritis may also be related to cement housing.¹ Obesity should be prevented as it can also be a contributing factor to developing arthritis and other musculoskeletal diseases. Reproductive diseases were highly prevalent in females between 16–25 yr, well beyond the age of last reproduction of wild jaguars (8 yr).² We suggest that MGA contraceptive implants, as indicated in other studies,³ may increase the risk of reproductive disease. Additionally, females who received at least one MGA implant appeared to be more likely to acquire reproductive disease than those who had never received an MGA implant. MGA implants appear to increase risk of developing reproductive tract disease, and should be seriously considered before being used as a contraceptive device. The most common report of renal disease in geriatric jaguars was renal failure of unknown etiology. Cystitis and glomerulonephritis were also reported in several jaguars. Hematologic diseases, such as anemia and epistaxis, became more prevalent in geriatrics. Epistaxis was a surprisingly common problem in these jaguars, and was present through all age groups. Due to the high frequency of epistaxis in the population, and because epistaxis can indicate a primary bleeding disorder, future cases of epistaxis should be worked up for etiology. Hepatic lipidosis was the most frequently reported liver problem, possibly related to problems of obesity in captive jaguars. Other hepatic diseases included hepatitis and primary hepatic neoplasia. Pneumonia was a common respiratory diagnosis. Of the infectious pneumonias, Actinomyces israelii, Flavobacterium spp., Pasteurella spp., Penicillium spp., Candida spp., and Aspergillus spp. were cultured from the lungs.

Episodes of mortality in jaguars less than 2 yr old tended to be due to stillbirths, trauma, or pneumonia. Jaguars older than 5 yr tended to die from reproductive tract disease or musculoskeletal/neuromuscular disease.

Based on the findings of this study, we present the following management suggestions:

• Full dental exam and treatment performed at every annual exam. Avoid types of fencing or bars in enclosure that may contribute to fractured teeth.
• Early diagnosis and aggressive treatment for pododermatitis and cracked pads.
• Thorough workups of epistaxis and anemia cases.
• Solitary housing with enrichment for aggressive animals.
• Use a softer substrate rather than housing animals on cement.
• Avoid using MGA implants—Ovariohysterectomies recommended instead.
• Keep complete medical records. Include pathology and necropsy reports for every animal.

Acknowledgments

The authors thank the Friends of the National Zoo, Bob Wiese, Abilene Zoological Gardens, Akron Zoological Park, Audubon Zoo, Caldwell Zoo, Denver Zoo, Elmwood Park Zoo, Erie Zoological Gardens, Fort Worth Zoo, Gladys Porter Zoo, Granby Zoo, Henry Doorly Zoo, Houston Zoo, Jacksonville Zoological Gardens, Knoxville Zoo, Lee Richardson Zoo, Louisville Zoological Gardens, Memphis Zoo, Milwaukee County Zoo, Smithsonian’s National Zoological Park, Oklahoma City Zoo, Palm Beach Zoo, Philadelphia Zoo, Rio Grande Zoo, Sacramento Zoo, Saint Louis Zoological Park, Salisbury Zoo, San Antonio Zoo, San Diego Zoo, Tulsa Zoo, and Woodland Park Zoological Gardens.

Literature Cited

1.  Baker, W.K. 2003. Natural history, behavior, and social organization of the jaguar. In: Law, C. (Ed.) Jaguar Species Survival Plan Guidelines for Captive Management of Jaguars. Pp. 8–16.

2.  Eisenberg, J.F. 1986. Life history strategies of the Felidae: variations on a common theme. In: Miller, S.D. and Everett, D.D. (eds.). Cats of the World: Biology, Conservation and Management. Natl. Wildl. Fed. Washington, DC. Pp. 293–303.

3.  Munson, L., A. Gardner, R.J. Mason, L.M. Chassy, and U.S. Seal. 2002. Endometrial hyperplasia and mineralization in zoo felids treated with melengestrol-acetate contraceptive. Vet. Pathol. 39:419–427.

4.  Wiese, R.J. 2000. AZA North American Regional Studbook for the Jaguar (Panthera onca).