SARS-CoV-2 delta variant in African lions (Panthera leo) and humans at Utah's Hogle Zoo, USA, 2021-22.

AIMS: We conducted a One Health investigation to assess the source and transmission dynamics of SARS-CoV-2 infection in African lions (Panthera leo) at Utah's Hogle Zoo in Salt Lake City from October 2021 to February 2022. METHODS AND RESULTS: Following observation of respiratory illness in the lions, zoo staff collected pooled faecal samples and individual nasal swabs from four lions. All specimens tested positive for SARS-CoV-2 by reverse transcription-polymerase chain reaction (RT-PCR). The resulting investigation included: lion observation; RT-PCR testing of lion faeces every 1-7 days; RT-PCR testing of lion respiratory specimens every 2-3 weeks; staff interviews and RT-PCR testing; whole-genome sequencing of viruses from lions and staff; and comparison with existing SARS-CoV-2 human community surveillance sequences. In addition to all five lions, three staff displayed respiratory symptoms. All lions recovered and no hospitalizations or deaths were reported among staff. Three staff reported close contact with the lions in the 10 days before lion illness onset, one of whom developed symptoms and tested positive for SARS-CoV-2 on days 3 and 4, respectively, after lion illness onset. The other two did not report symptoms or test positive. Two staff who did not have close contact with the lions were symptomatic and tested positive on days 5 and 8, respectively, after lion illness onset. We detected SARS-CoV-2 RNA in lion faeces for 33 days and in lion respiratory specimens for 14 weeks after illness onset. The viruses from lions were genetically highly related to those from staff and two contemporaneous surveillance specimens from Salt Lake County; all were delta variants (AY.44). CONCLUSIONS: We did not determine the sources of these infections, although human-to-lion transmission likely occurred. The observed period of respiratory shedding was longer than in previously documented SARS-CoV-2 infections in large felids, indicating the need to further assess duration and potential implications of shedding.

SARS-CoV-2 morbidity, treatment interventions, and vaccination practices in tigers (Panthera tigris ssp) in North American zoos.

OBJECTIVE: Evaluate SARS-CoV-2 morbidity, mortality, clinical signs, treatment interventions, and vaccination practices in tigers under professional care. ANIMALS: Amur (Panthera tigris altaica), Sumatran (Panthera tigris sumatrae), and Malayan (Panthera tigris jacksoni) tigers managed under the Tiger Species Survival Plan (SSP). METHODS: A retrospective, voluntary online survey was sent to all North American zoos holding SSP tigers between January 2020 and June 2023. RESULTS: Responses were received from 55 of 108 institutions (51%) housing 162 tigers in total, and SARS-CoV-2 infection was diagnosed in 39 tigers from 15 institutions (20 Amur, 8 Sumatran, and 11 Malayan [1 to 18 years old; 17 males and 22 females]). This corresponds to a minimum study group infection incidence of 24% over 42 months. Clinical signs included dry cough (82%), inappetence (64%), lethargy (62%), nasal discharge (46%), wheezing (31%), wet cough (18%), and ocular discharge (15%). Most cases were characterized as mild (n = 22) or moderate (14). A single case was characterized as severe. Two cases were asymptomatic. Seventeen positive tigers had been vaccinated once (n = 8) or twice (9) for SARS-CoV-2 prior to infection. No deaths due to SARS-CoV-2 were reported in the study group. Treatment interventions included antibiotics (49%), NSAIDs (18%), antiemetics (15%), and fluids (13%). No treatments were administered in 19 of 39 cases (49%). Amongst participating institutions, 69% reported fully vaccinating tigers for SARS-CoV-2 (≥ 2 doses). CLINICAL RELEVANCE: Most SARS-CoV-2-infected tigers presented with mild to moderate clinical signs and recovered with limited to no treatment interventions. Asymptomatic SARS-CoV-2 infections can occur in tigers and may be underreported. Tigers vaccinated for SARS-CoV-2 remain susceptible to infection.

Reproductive suppression of giraffe (Giraffa camelopardalis) under managed care using a GnRH immunological product.

Giraffe present unique contraception challenges as males persistently pursue females during estrus. Year-round pursuit during frequent recurring estrus can pose significant risk under slippery conditions. Complete ovarian suppression is a useful tool in giraffe because it eliminates estrous behavior, interest from the male, and controls reproduction. Effective reproduction control in giraffes has been achieved with porcine zona pellucida, oral melengestrol acetate, and depot medroxy-progesterone acetate. However, these methods allow some degree of folliculogenesis and estrous behavior. Improvest® is a gonadotropin releasing hormone (GnRH) immunological product that elicits antibodies against GnRH and abrogates the effects of endogenous GnRH. This study evaluated the efficacy of Improvest® for gonadal suppression in seven females and one male giraffe by monitoring steroid hormones. Seven female giraffe were treated intramuscularly with an initial dose, a booster at 4 weeks and maintenance boosters at 3-month intervals (600 µg/dose) for 12 months. Six females were on supplemental contraception during the induction phase because separation from males was not possible. In the male (treated with 400 µg), testosterone concentrations decreased after the second injection. However, even with low serum testosterone concentrations, mounting (of nontreated females) behavior was still observed occasionally. Ovarian activity was suppressed in all treated females and interest by the males stopped; supplemental contraceptives (during the induction phase) did not impede the effect of Improvest®. After 15.3 months (seven doses), Improvest® was discontinued in three females which no longer needed contraception. In these females, ovarian activity was noted approximately 90 days after the last dose.

Use of equine amniotic membrane free-island grafts for treatment of a midstromal corneal ulcer and descemetocele in a snow leopard (Panthera uncia).

CASE DESCRIPTION A 7-year-old sexually intact female snow leopard (Panthera uncia) was examined because of blepharospasm, periocular discharge, ventral deviation of the upper eyelid cilia, third eyelid prolapse, and corneal opacity of the right eye. CLINICAL FINDINGS An ophthalmic examination performed with the patient anesthetized revealed a 3 × 3-mm ulcer that extended approximately 60% of the depth of the right cornea and was accompanied by perilesional and intralesional cellular infiltrates and active vascularization. The upper eyelid of the right eye also had a previously repaired coloboma resulting in trichiasis. TREATMENT AND OUTCOME Surgical intervention was elected after 5 weeks of medical management including topical administration of autologous serum and topical, subconjunctival, and systemic administration of antimicrobials failed to yield any improvement in the ulcer. Equine amniotic membrane free-island graft placement and eyelid revision surgeries were performed. Two and a half weeks later, a descemetocele was diagnosed ventrolateral to the original ulcer, and a second equine amniotic membrane free-island grafting procedure was performed. Both grafts healed without further intervention. CLINICAL RELEVANCE Equine amniotic membrane free-island grafts were used to successfully repair a corneal ulcer and descemetocele in a snow leopard. The grafting procedure spared the affected globe and resulted in satisfactory cosmesis and functional vision. This procedure should be considered as an option for corneal repair in nondomestic species for which postoperative care and medical treatment options are limited.

MAMMARY GLAND ADENOCARCINOMA IN A MALE BORNEAN ORANGUTAN (PONGO PYGMAEUS).

An adult male Bornean orangutan ( Pongo pygmaeus ) was diagnosed with invasive, poorly differentiated grade 9/9 mammary gland adenocarcinoma from a subcutaneous mass that was surgically removed during a routine preventative health examination. The tumor was tested for estrogen and progesterone receptors, human epidermal growth factor receptor 2 (HER2), and HER2 fluorescence in situ hybridization (HER2 FISH). Whole blood was tested for breast cancer 1 (BRCA1) and breast cancer 2 (BRCA2) genes. The orangutan was treated orally with two common human breast cancer drugs; tamoxifen and anastrozole. The orangutan lived for 4.5 yr postdetection, dying from an unrelated cause. This is the first reported case of mammary gland adenocarcinoma in a male great ape.

Acute lymphocytic cholangitis and liver failure in an Amur tiger (Panthera tigris altaica).

An adult male Amur tiger (Panthera tigris altaica) with confirmed inflammatory bowel disease developed acute severe icterus, bilirubinuria, bilirubinemia, and elevated bile acids after a diet change. Liver biopsies showed moderate lymphoplasmacytic cholangiohepatitis (lymphocytic cholangitis). The tiger developed neurologic signs including ataxia, tremors, and seizures, as well as epistaxis. Therapy consisted of antibiotics, a steroid anti-inflammatory, vitamins, pro-coagulants, and liver-supportive medicines. The tiger improved from acute liver failure within 3 wk, while the epistaxis began at 3.5 wk and did not resolve until 10.5 wk. The long-term maintenance plan consists of oral prednisolone, metronidazole, ursodiol, and an all muscle-meat beef diet.