Graphical abstractHighlights► Rhipicephalus evertsi evertsi and Amblyomma hebraeum are abundant on wild African buffalo. ► The two tick species do not affect each other’s abundance. ► Strong differences in attachment site preference suggest spatial niche segregation. ► Host traits (immunity, age, pregnancy status, body condition) drive tick abundance. ► Buffalo with stronger innate immunity have fewer ticks.

Callitrichids are commonly exhibited species in zoological institutions. Retrospective mortality studies allow institutions to evaluate health trends in captive populations and have the potential to advance zoological medicine and husbandry practices. In this single institution, retrospective study, histopathologic records were reviewed for 166 callitrichids comprising six species. For all species and age-groups combined, trauma was the leading cause of death followed by enteritis and stillbirth. In adults and juveniles, the leading cause of death was enteritis, with neonates dying primarily from trauma. Neonatal mortality was high for most species, ranging from 12.5% to 60%, with most neonatal loss in Geoffroy's and pied tamarins. Twin births were commonly associated with neonatal mortality in most species. Intestinal adenocarcinoma was a common finding for adult Geoffroy's tamarin, and hemosiderosis was also identified in this species. Renal disease was a common finding in adult callitrichids and was the second most common cause of death in this age-group. Mortality in the juvenile period (>30 days-1 yr) was uncommon, comprising only 8.4% of the data set. Although capable of surviving into advanced age (>20 yr for one animal), the average age at death for all age classes was 3.84 yr and 9.31 yr for adults. This study contributes to the current knowledge regarding trends in callitrichid health and husbandry and can be used to investigate health trends in this group.

There is growing information available regarding duration of immunity for core vaccines in both domestic and nondomestic species. Vaccination protocols in nondomestic canids have frequently followed guidelines developed for the domestic dog; however, these protocols can be inappropriate for nondomestic canids such as the African wild dog (Lycaon pictus), leaving some animals susceptible to infectious disease and others at risk for contracting vaccine-induced disease. In this study, red wolves (Canis rufus) were vaccinated against canine distemper virus (CDV) and canine parvovirus (CPV) and vaccination titers were followed annually for 3 yr. One hundred percent of wolves developed and maintained a positive titer to CDV for 3 yr and 96.9% of wolves developed and maintained a positive titer to CPV for 3 yr. Seroconversion for canine adenovirus was sporadic. The results of this study support decreasing the frequency of vaccine administration in the red wolf population to a triennial basis.

An 8 yr, intact male red-rumped agouti ( Dasyprocta leporina) was evaluated for weight loss. Examination revealed poor body condition, hypercalcemia, elevated serum 25-hydroxyvitamin D, metastatic calcification of soft tissues, and hyperechoic kidneys. The diet, formulated for laboratory rodents, contained elevated levels of vitamin D. Histopathology from a female conspecific that died 5 mo prior identified dystrophic mineralization and nephrosclerosis, suggestive of a vitamin D toxicity. The male agouti responded well to a dietary reduction in vitamin D and calcium. Six months into therapy, progressive renal failure was identified and was further managed with enalapril, phosphorus binders, and dietary manipulation. Suspected vitamin D toxicity has been reported in pacas ( Cuniculus paca) and agouti and has been linked to exposure to New World primate diets. In this brief communication, an agouti developed suspected hypervitaminosis D after receiving a commercial rodent diet commonly fed to this species in captivity.

Capturing disease trends among different species has indisputable value to both veterinary clinicians and zoo managers for improving the welfare and management of zoo species. The causes of mortality for eight species of gazelle (addra gazelle, Nanger dama; dorcas gazelle, Gazella dorcas; Grant's gazelle, Nanger granti; sand gazelle, Gazella leptoceros; Saudi goitered gazelle, Gazella subgutturosa; Soemmerring's gazelle, Nanger soemmerringii; Thomson's gazelle, Eudorcas thomsonii; and Speke's gazelle, Gazella spekei) are presented from an 18-yr period (1996 2014). The leading cause of mortality for all species was trauma, followed by bronchopneumonia, and failure to thrive/maternal neglect. Nephritis and rumenitis/abomasitis/enteritis were common ancillary lesions across all species. On average, female gazelle lived twice as long as male gazelle, with an average overall adult survival time of 9.3 yr. Dorcas, Thomson's and addra gazelle females had the longest average survival time (10-13 yr). Calves up to 6 mo of age died most frequently from failure of passive transfer or maternal neglect. Thyroid carcinoma was frequently identified in Thomson's gazelle. Sand and Speke's gazelle frequently died from systemic amyloidosis, and Saudi goitered gazelle were more likely to have renal amyloidosis. Hematuria syndrome was the second most common cause of death in Grant's gazelle. The majority of lesions identified in this study that cause or contribute to mortality are preventable with appropriate management. Knowledge of disease trends in captive gazelle populations can help guide veterinary care, management decisions, and collection management planning.

Pyometra is a serious, life-threatening disease of both domestic and non-domestic species often requiring ovariohysterectomy to preserve the life of the animal. Medical management of pyometra has been successful in domestic and non-domestic species, and the consideration of such treatment is of marked importance in a critically endangered species. Of the canids, the red wolf (Canis rufus) is second only to African hunting dogs (Lycaon pictus) in terms of the prevalence of both cystic endometrial hyperplasia and pyometra. In this report, three red wolves were medically managed for pyometra. Aside from vaginal discharge, none of the wolves exhibited clinical signs, nor were there reflective inflammatory changes in the laboratory findings. All wolves received standard treatment for pyometra, including prostaglandin F2alpha and antibiotic therapy, while one wolf was more aggressively managed with uterine lavage. Pyometra recurred in two of the treated wolves, while the most aggressively managed wolf continues to show ultrasonographic resolution 2 yr posttreatment. Aggressive medical management of pyometra should be considered a treatment option in certain red wolf females, as it may preserve the animal's reproductive potential.

CASE DESCRIPTION 10 large felids at 8 facilities were determined or suspected to have developed gastric dilatation with or without enterotoxemia over a 20-year period. Four felids were found dead with no premonitory signs. CLINICAL FINDINGS 4 felids (2 male snow leopards [Uncia uncia], 1 male Amur tiger [Panthera tigris altaica], and 1 male Sumatran tiger [Panthera tigris sumatrae]) were found dead or died before they could be evaluated. Six felids had hematemesis (1 male and 1 female African lion [Panthera leo] and 1 male jaguar [Panthera onca]) or abdominal distention and signs of lethargy with or without vomiting (1 male African lion, 1 male Malayan tiger [Panthera tigris jacksoni], and 1 female Sumatran tiger). Gastric dilatation was radiographically and surgically confirmed in the male Malayan and female Sumatran tigers and the jaguar. TREATMENT AND OUTCOME In 3 felids with an antemortem diagnosis, the gastric dilatation resolved with decompressive laparotomy but then recurred in 1 felid, which subsequently died. Three others died at various points during hospitalization. Although Clostridium perfringens type A was recovered from 3 of the 5 felids for which microbial culture was performed, and 2 felids had a recent increase in the amount fed, no single factor was definitively identified that might have incited or contributed to the gastric dilatation. CLINICAL RELEVANCE Gastric dilatation was a life-threatening condition in the large felids of this report, causing sudden death or clinical signs of hematemesis, abdominal distention, or vomiting. Even with rapid diagnosis and surgical decompression, the prognosis was poor. Research is needed into the factors that contribute to this emergent condition in large felids so that preventive measures might be taken.

The family Lemuridae is considered prone to hemosiderosis and hemochromatosis, which delayed rapid diagnosis and treatment of the lemur's disease. Apparent hepatic injury following iron dextran injections further complicated treatment. Findings for this lemur support the use of species-specific total iron binding capacity and total serum iron and ferritin concentrations in evaluation of an animal with suspected iron deficiency.