Cat Bite Research Articles

Atypical presentation of bartonellosis with hepatolienal lesions

Cat scratch disease is caused by the gram-negative intracellular bacterium Bartonella henselae (B. henselae). Human infection occurs mainly through cat scratches and bites. In typical cases, the clinical course is presented by a primary affect on the skin and regional lymphadenitis. The atypical presentation of infection can occur with fever, abdominal, ocular and neurological manifestations. A special feature of the abdominal form is the presence of solitary or multiple hypo/anechoic foci of different size and shape in the liver and spleen. B. henselae infection is one of the most common mimics of malignant lymphoma, when the spleen is involved in combination with B symptoms (weight loss, night sweats and prolonged fever). A history of recent contact with cats and diagnostic IgG titers to B. henselae indicate infection. There is no consensus on the choice of antimicrobial drug and the duration of therapy for systemic forms. The article presents its own experience in the diagnosis and treatment of such patients. The patient's parents agreed to use the information, including the child's photo, in scientific research and publications.

Profile of Animal Bite Cases in a Tertiary Care Hospital in Mysuru

Animal bites cause a big burden worldwide in terms of morbidity and mortality. As per WHO, dog bites are the cause of major animal bite injuries followed by snake bites, cat bites, and monkey bites. Annually about 55,000–60,000 persons die of rabies, of which nearly one-third are from India alone. Rabies, though being a 100% fatal disease, is also a potentially preventable disease. Objective: To estimate the proportion of animal bites in patients attending anti-rabies clinic of a tertiary hospital, Mysuru. Material & Methods: A cross-sectional study was carried out during the period of June 2018 - May 2019. Secondary data was collected from the registers available at the anti-rabies clinic in KR Hospital, Mysuru, using a pretested proforma. This information was compiled in an excel sheet and analysed using simple measures like proportions, percentages, and graphs. Results: A total of 3861 animal bite cases were reported, out of which, 69.1% were males and 30.9% were females. Dog bites contributed the highest (92.1%) followed by cat bites (5.2%). As per the category of wounds, 59.6% were Category 2 and 36.2% were Category 3 wounds. Conclusion: Dog bite is the commonest animal bite which needs to be addressed as a priority with appropriate preventive strategies. There is a pressing need to create awareness among the general population about the need for timely health care seeking behaviour and to avail the benefit of free anti-rabies vaccination in the public health sector in order to prevent the risk of fatal events.

Restorative management of human bite injuries to the face: Case series

Facial skin wounds are common problems seen and treated by emergency centers around the world. Among all wounds, cat and dog bites are frequently seen. Human bite injuries are both deceptive and difficult in their presentation and management. The injuries have a disfiguration effect with possible psychological impact on the patient.The aim of this paper is to compare experience with human bites of the face in our surgical unit, with other similar trials in term of reasons for the circumstances of injuries, age, and sex of the patients, site of injury, pan-time between consultation and treatment, incidence of infection and surgical management.Data in terms of age, gender distribution, circumstances of injury, location of injuries, evolution of surgical management and complications were recorded.We report here a series of 10 cases of human bite wounds to the face, admitted to our department, and treated with different reconstruction procedures.

Cat scratch disease

Cat scratch disease is a usually harmless infectious disease caused by Bartonella henselae bacteria. These bacteria are transmitted to humans by a cat scratch or bite. Its typical presentation is a self-limiting lymphadenitis of regional lymph nodes, mostly in the neck. The disease is especially prevalent in children and young adults. Cat scratch disease can be associated with fever, headaches, and malaise, sometimes present itself atypically and in only a few cases expand as a disseminated disease. A swelling in the neck can be caused by many different disorders. In patients with lymphadenitis in the neck and a cat scratch or bite in their recent history, the probable diagnosis cat scratch disease can be made on the basis of clinical findings. Diagnostic testing should be performed when required. For patients with a typical manifestation of cat scratch disease, a wait-and-see policy can be considered. For patients with atypical manifestations, further diagnostic testing and treatment with antibiotics are recommended.

In silico Analysis of Pasteurella multocida PlpE Protein Epitopes As Novel Subunit Vaccine Candidates.

Background: Pasteurella multocida is a Gram-negative, non-motile, non-spore forming, and aerobic/anaerobic cocobacillus known as the causative agent of human and animal diseases. Humans can often be affected by cat scratch or bite, which may lead to soft tissue infections and in rare cases to bacteremia and septicemia. Commercial vaccines against this agent include inactivated, live attenuated, and non-pathogenic bacteria. Current vaccines have certain disadvantages such as reactogenicity or reversion to virulence. Therefore, the aim of this study was to reach a multi-epitope vaccine candidate that could be serotype independent and covers most incident serotypes of P. multocida. Methods:In this study, reverse vaccinology strategy was used to identify potentially immunogenic and protective epitopes. First, multiple alignments of different sequences of PlpE from various serotypes of P. multocida were analyzed to identify the conserved regions. Bioinformatics tools were then applied to predict and select epitopes for further studies. Results:Three different conserved immunogenic regions were selected according to the selected criteria, and their various sequential orders were evaluated structurally by in silico tools to find the best order. Conclusion:In searching the epitopes of PlpE to design a new vaccine candidate against pasteurellosis, we found the region 1 + region 2 + region 3 (without any linker between regions) of epitope, including the regions of PlpE protein of P. multocida, as the appropriate serotype independent vaccine candidate against pasteurellosis.

Demographic Profiles of Animal Bite Cases at a Dedicated Anti-Rabies Hospital in Dhaka City of Bangladesh

Background: Animal bite management are very crucial part in the post prophylaxis treatment.
 Objective: The purpose of the present study was to see the demographic profile of animal bite cases at a dedicated anti-rabies hospital.
 Methodology: This retrospective chart review based on secondary data received from animal bite register was conducted in the Department of Microbiology at National Institute of Neurosciences & Hospital, Dhaka, Bangladesh from January 2014 to December 2015 for a period of two years. All relevant data were noted from the registered record.
 Result: A total number of 17688 cases were collected from the register log book of animal bite. The mean age with standard deviation was 24.42±17.22 with the range of 1 to 99 years. The ratio between male and female was 2.33:1. The most common animal bite was dog bite which was 13574(76.7%) cases followed by cat, monkey, fox and weasel bite which were 3667(20.7%) cases, 163(0.9%) cases, 39(0.2%) cases and 22(0.1%) cases respectively. Lower extremity was the most site of bite by the animals which was 12936(73.1%) cases followed by upper extremity, waist, head & neck, face and trunk which were 3592(20.3%) cases, 428(2.4%) cases, 155(0.9%) cases, 116(0.7%) and 114(0.6%) cases respectively. The most common category of bite was category II which was 11800(66.7%) cases.
 Conclusion: In conclusion male young adult person bite by dog with category II are the most common victims of animal bites seeking for treatment.
 Journal of National Institute of Neurosciences Bangladesh, 2020;6(2): 135-139

Allergic Reaction to Rabies Vaccine in a 4-Year-Old Girl during Post-Exposure Rabies Prophylaxis: A Case Report

Adverse events to vaccine or vaccine induced reactions and particularly hypersensitivity post-vaccination reactions to the rabies vaccine, are very rare. Therefore, we wanted to show a case of a four-year-old girl who developed an allergic reaction after a dog and cat bite during rabies postexposure prophylaxis. Sensitization to some component of the infectious agent of the rabies vaccine, grown on purified chick embryo cells but also on human diploid cells, has been proven. Although, allergic reactions to the rabies vaccine are extremely rare, vaccination can be done following the official WHO guide for pre-exposure and post/exposure prophylaxis in humans.

Neurorretinitis por Bartonella henselae en Gipuzkoa, 2014-2019

IntroductionBartonella henselae causes cat scratch disease (CSD), spread by a cat scratch or bite. Cats are its main reservoir. This sometimes results in optic neuritis or neuroretinitis. ObjectiveTo review these conditions in Gipuzkoa (Spain), 2014-2019. MethodsA retrospective review of serology and clinical records, selecting those with consistent clinical signs, contact with cats and positive serology for B. henselae (IgG-IFA≥1/256). ResultsSixty-four patients had CSD. Of these, one had optic neuritis and 3 had neuroretinitis (4/64; 6.3%). In 3 patients, flu-like symptoms preceded eye symptoms. Two suffered from loss of visual acuity at discharge, despite prolonged treatment with antibiotics and corticosteroids. ConclusionOptic neuritis and neuroretinitis caused by B. henselae are severe complications with a non-negligible incidence among patients with CSD in Gipuzkoa. We recommend ruling out CSD in patients with symptoms of optic neuritis or neuroretinitis (sudden vision loss, etc.) and contact with cats.

Characterizing trends in human-wildlife conflicts in the American Midwest using wildlife rehabilitation records.

Human-wildlife conflict is difficult to measure, but the analysis of records from wildlife rehabilitation facilities has shown potential as a technique for characterizing human impacts on wildlife. To examine the value of wildlife rehabilitation records for characterizing local human-wildlife conflicts and prevalence of select wildlife diseases, we reviewed 45,668 records representing over 280 species admitted to a wildlife rehabilitation facility over a 10-year period (2005–2014). We identified the most frequently recorded causes of admission for commonly admitted species, and evaluated how causes of admission may vary across taxa throughout the year. Our analyses support the value of wildlife rehabilitation facility data for characterizing some pressures from human-wildlife conflict and select disease trends for certain taxa, as well as utility for informing topics to emphasize in local conservation education efforts. For example, orphaned neonatal wildlife accounted for the largest proportion of admissions to this facility, and highlights a opportunity for conservation education regarding when wildlife is truly orphaned and requires professional intervention. Additionally, domestic dog attack cases accounted for a proportion of admissions comparable to that of domestic cat attacks, demonstrating a need for the conversation surrounding the impact of domestic pets on local wildlife to expand to include dogs in addition to cats.

Pasteurella multocida Mycotic Aortic Aneurysm in a Man After a Healed Canine Bite

Abstract Pasteurella multocida is most commonly associated with cat bites leading to skin and soft tissue infections, including joint and bone infections, with or without concomitant bacteremia. Mycotic aneurysm secondary to P. multocida bacteremia is a rare complication. However, because of its high morbidity and mortality, as well as the bacterium's high virulence and predilection for endothelium, this is an entity clinicians should be aware of. Because of limited data and very few reported cases in the literature, little is known regarding risk factors, clinical presentation, and treatment. All those cases presented insidiously and with nonspecific symptoms; therefore, a high degree of clinical suspicion is necessary to make the diagnosis. We present a case of an immunocompetent patient that presented with P. multocida bacteremia complicated by mycotic aneurysm of a native vessel. A review of the literature on the topic is also discussed.

犬咬創の2週間後に突然発症したCapnocytophaga canimorsusによる敗血症の1例(Sepsis caused by Capnocytophaga canimorsus two weeks after dog bites: a case report)

要旨Capnocytophaga canimorsus感染症は犬・猫による咬掻創感染症の一つであり，多くが敗血症を呈し死亡率約30%に達する。本邦での報告は大変稀であったが，近年報告数が増えつつある。症例は70歳の女性。来院2週間前，飼い犬に右手指を咬まれて数日で自然治癒した。来院前日より発熱・下痢が出現，来院当日12時頃に不穏状態となったため当院へ救急搬送された。血液検査で炎症反応上昇と凝固能障害，およびCTで腸管浮腫と脾臓低形成以外の有意所見を認めず，明らかな熱源は同定できなかった。当初は感染性腸炎による敗血症・DICと診断し，抗菌薬投与含め全身管理を開始した。第1病日より人工呼吸管理を必要としたが，全身状態は経時的に軽快し，第33病日に自宅退院となった。血液培養でグラム陰性桿菌を検出し，犬咬創歴が入院後判明したことから，下痢症状とあわせてC. canimorsusを疑った。第18病日に遺伝子検査で菌が同定され，C. canimorsus感染症による敗血症性DICと確定診断した。本症例は犬咬創後2週間経過しており，受傷痕もなく早期診断は困難であったが，動物咬創歴が診断の鍵となった。感染源不明の敗血症・DICの原因として，C. canimorsus感染症は鑑別に挙げる必要がある。

Severe recurrent Streptobacillus moniliformis endocarditis in a pregnant woman, and review of the literature

BackgroundRat bite fever is a systemic febrile illness caused by infection with the Gram-negative bacillus Streptobacillus moniliformis following a bite, scratch, or contact with excrement. Only 26 cases of native valve endocarditis have been reported to date. We could find no other reports of severe Streptobacillus endocarditis requiring valve replacement in a young, pregnant patient.Case presentationA pregnant patient sought care for right leg pain, fevers, left upper quadrant pain, generalized weakness, fatigue, and inability to bear weight on her right leg. She had a syncopal episode 9 months earlier, resulting in a mandibular fracture and internal fixation hardware. Her pregnancy was complicated by hyperemesis and weight loss. Her pets included a rescued wild bird, a cat, and four rats. Her parents rescued stray cats, and she recalled multiple cat bites and scratches since childhood. She denied injection drug use. Ultrasound indicated a right popliteal artery thrombus. Transesophageal echocardiogram revealed a 2 cm × 0.7 cm vegetation. Angiography demonstrated multiple splenic infarcts and bilateral renal infarcts. She underwent mitral valve repair. The mitral valve Gram stain demonstrated 2+ Gram-negative rods, rare Gram-positive rods, and moderate white blood cells. Propionibacterium spp. was isolated from the mitral valve tissue on Columbia agar incubated anaerobically. Anaerobic and aerobic cultures of the valve tissue on all other broths and agars remained negative at 14 days. Hematoxylin and eosin stains showed a fibro-inflammatory vegetation. Aggregates of rod-shaped bacteria were identified on Warthin Starry/Steiner stain. Bartonella titers were positive for B. henselae IgG 1:256, IgM < 1:20. Brown-Hopps Gram stain, AFB, and GMS stains for bacterial and fungal microorganisms were negative. Broad range bacterial PCR and sequencing of a segment of 16 s rRNA gene of the valve tissue matched to Streptobacillus sp. (genus level) and most closely related to Streptobacillus moniliformis.ConclusionThis case demonstrates diagnostic and therapeutic challenges associated with a relatively uncommon cause of endocarditis. The diagnosis of rat bite fever was delayed due to symptoms of a concomitant pregnancy. Other confounders included possible alternative sources or co-infections with another zoonosis from multiple pets, and an odontogenic source due to presence of exposed jaw hardware.

Using Surveillance of Animal Bite Patients to Decipher Potential Risks of Rabies Exposure From Domestic Animals and Wildlife in Brazil.

Direct contact with domestic animals and wildlife is linked to zoonotic spillover risk. Patients presenting with animal-bite injuries provide a potentially valuable source of surveillance data on rabies viruses that are transmitted primarily by animal bites. Here, we used passive surveillance data of bite patients to identify areas with high potential risk of rabies transmission to humans across Brazil, a highly diverse and populous country, where rabies circulates in a range of species. We analyzed one decade of bite patient data from the national health information system (SINAN) comprising over 500,000 patients attending public health facilities after being bitten by a domestic or wild animal. Our analyses show that, between 2008 and 2016, patients were mostly bitten by domestic dogs (average annual dog bite patients: 502,043 [436,391–544,564], annual incidence per state: 258 dog bites/100,000 persons) and cats (76,512 [56,588–97,580] cat bites, 41 cat bites/100,000/year), but bites from bats (4,172 [3,351–5,365] bat bites, 2.3/100,000/year), primates (3,320 [3,013–3,710] primate bites, 2.0/100,000/year), herbivores (1,908 [1,492–2,298] herbivore bites, 0.9/100,000/year) and foxes (883 [609–1,086] fox bites, 0.6/100,000/year) were also considerable. Incidence of bites due to dogs and herbivores remained relatively stable over the last decade. In contrast bites by cats and bats increased while bites by primates and foxes decreased. Bites by wild animals occurred in all states but were more frequent in the North and Northeast of Brazil, with over 3-fold differences in incidence between states across all animal groups. Most bites reported from domestic animals and wildlife occurred in urban settings (71%), except for bites from foxes, which were higher in rural settings (57%). Based upon the Ministry of Health guidelines, only half of patients received the correct Post-Exposure Prophylaxis following a bite by a suspect rabid animal. We identified areas and species of high-risk for potential zoonotic transmission of rabies in Brazil and reveal that, despite increasing human encroachment into natural ecosystems, only patients reporting bites by bats increased. Our study calls for future research to identity the socio-ecological factors underlying bites and the preventive measures needed to reduce their incidence and potential risk of rabies transmission.

Death by cat bite: Pasteurella multocida: Autopsy findings and review of the literature

Pasteurella multocida, a gram-negative bacillus, is present in the oropharyngeal secretions of livestock, wild animals, and domesticated pets and can cause infection in humans. The most common route of entry has been shown to be via an animal bite, but a significant portion of cases of human infection lack evidence of such a wound. Review of the literature reveals that patients with a history of an animal bite tend to have a less aggressive clinical course than patients without an animal source of infection. We present a case, however, of Pasteurella multocida bacteremia which resulted in the death of an immunocompromised 80-year old woman in which the route of infection was found at autopsy to be a cat bite. This case highlights the importance of educating patients, particularly those with underlying immunocompromised conditions, of the possible lethal complications that can result from animal inflicted wounds and the importance of seeking medical assistance should a bite occur.

Analysis of Bacteriological Infected Dog and Cat Bite Wounds in Veterinary Medical Staff

Bite wounds, human and animal origin, can lead to significant complications if appropriate therapy is not undertaken timeously. The major risk of these aggressions is given by the possibility of systemic propagation of the bacteria involved in the wound and the appearance of complications such as osteomyelitis, septic arthritis, bacterial endocarditis, etc. The identification of pathogenic germs and antibiotic sensitivity test were the key points for a specific therapy that could prevent the spread of infection in the deep tissues. Twenty five biological samples collected from various wounds produced by dogs and cats bites over the veterinary personnel during the medical evaluated. Various aerobic pathogenic and conditional pathogenic bacteria (Staphylococcus aureus, Staphylococcus pseudo intermedius, Staphylococcus intermedius, Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus xylosus, Staphylococcus warneri, Micrococcus roseus, Streptococcus sp. gr.B, Streptococcus sp. gr.F, Streptococcus sp. gr.G, Enterococcus faecalis, Enterococcus faecium, Trueperella pyogenes, Corynebacterium sp., Bacillus cereus, Pasteurella multocida, Pasteurella canis, Mannheimia haemolitica, Escherichia coli, Pseudomonas aeruginosa, Actinobacillus sp., Neisseria sp) and anaerobic bacteria (Clostridium perfringens, Bacteroides sp.) were isolated. The bacterial drug sensitivity was fluctuating, observing the variations influenced by the natural and acquired resistance of the tested bacterial species. The wounds produced by the bites of dogs and cats have aerobic and anaerobic polymicrobial etiology.

Pasteurella multocida Infections with Unusual Modes of Transmission from Animals to Humans: A Study of 79 Cases with 34 Nonbite Transmissions.

Pasteur discovered the causative agent of fowl cholera (Pasteurella multocida) in 1880. Since then, multiple zoonotic infections affecting humans have been reported. P. multocida infections usually result from bites of cats or dogs. The earliest reports of nonbite transmissions (NBTs) were attributed to cat scratches and lung colonization. More recently, multiple modes of unusual NBTs have been reported, including animal exposures with no direct contact. Here, we report 79 cases of pet-associated infections, with 34 NBTs. Previously unreported and unsuspected, novel modes of NBTs presented include stepping on dog drool infecting a submetatarsal ulcer, contamination of a wound by socks covered with cat hair and dander resulting in P. multocida bacteremia, stumbling over a dog and falling while drunk and abrasions contaminated with dog saliva resulting in wound infection, and severe epiglottitis and supraglottitis after eating peanut butter and crackers half eaten by a dog. Cat bites were more common than dog bites. Both bite and nonbite infections were more common in the elderly, with more older patients in the nonbite group. Upper extremity bites were more than lower extremity bites for both cats and dogs. NBTs were associated with more co-morbidities and resulted in more life-threatening infections than bites, confirming the findings of a prior smaller series. Open wounds were the most common point of entry for nonbite infections, with majority in the lower extremity. Based on this study and prior reports, pet owners must protect open wounds and individuals with certain underlying conditions and infants should avoid pet exposure completely. Our findings and animal transmission of bite and nonbite P. multocida infections reported in literature are summarized.

Pasteurella Multocida tenosynovitis of the flexor pollicis longus caused by a rabbit bone wound

A 29-year-old man was admitted to our emergency department with a painful thumb, feverredness, and swelling and limited function. Five days before he was wounded with a rabbitbone. He was given amoxicillin-clavulanate with a lack of improvement. He was admitted forhospitalization and an ultrasound confirmed tenosynovitis as well as subcutaneous edema, sosurgical debridement was performed. Cultures were positive to Pasteurella multocida.Hospital stay was 9 days, and he continued oral antibiotic for 10 days after discharge. Fourmonths postoperatively, the patient had complete function and didn’t show evidence ofrecurrence. To conclude, rapidly developing cellulitis, tenosynovitis, fever and drainage fromhand wounds after a cat or dog bites should suggest Pasteurella multocida infection.However, P. multocida tenosynovitis can be also produced after a rabbit bone wound.Absence of response after 24-48 of antibiotic treatment, especially if cellulitis has progressedto tenosynovitis, is an indication for surgery.

Pediatric Bartonella Infection (Cat Scratch Disease) Presenting as Inguinal Lymphadenopathy

Cat scratch disease is an infectious disease resulting from inoculation of Bartonella species through a cat scratch or bite, often presenting as an erythematous papule at the site of inoculation with nearby painful lymphadenopathy. The diagnosis of this disease is complicated by a wide variety of clinical presentations, as the primary lesion may not be initially noticed. Furthermore, cervical and axillary lymph nodes are the most commonly involved regions of tender lymphadenopathy, but there have been reported cases that do not fit the typical clinical picture – such the case discussed in this report of a pediatric Bartonella henselae infection that initially presented as left inguinal lymphadenopathy with underlying necrosis and abscess formation. In this case, a 9-year-old boy presented to the ED with a 4-day history of increasing mass in the left groin, as well as a subjective fever for the previous 2 days. An ultrasound revealed a necrotic abscess in the left inguinal lymph node which necessitated empiric antibiotic therapy and surgical excision; titers revealed a recent infection with Bartonella henselae. Atypical presentations of cat scratch disease, such as inguinal lymphadenopathy, have historically confounded the diagnosis. However, positive serology studies ultimately yielded the correct diagnoses in these children. Given that cat scratch disease can present in an atypical fashion in approximately 5 - 25% of cases, physicians should keep the disease on the differential even when presented with rare presentations such as inguinal lymphadenopathy; serological testing for B. henselae can be utilized once more likely etiologies have been ruled out.

"Cat and dog bite injuries of the hand: early versus late treatment".

Animal bites of the hand are common injuries in the emergency department. Serious complications may occur if those injuries are not treated adequately. The purpose of the study was to examine if there is a difference between the treatment of animal bite injuries at an early stage (first treatment within the first 24h after injury, group I) versus a later stage (first treatment more than 24h after injury, group II) retrospectively. Between January 2010 and March 2016, a total of 69 patients with cat and dog bite injuries were treated in our hospital emergency room (ER). 45 patients arrived at the ER within 24h after the injury (group I). 24 patients were treated more than 24h after injury for the first time (group II). A retrospective study with evaluation of the clinical data including wound aspect, tissue damage, treatment, and antibiotics was performed. In group I, 27 were outpatients and 18 were in-house patients with an average hospitalization period of 3.3days ± 1.12days. 16 patients were treated conservatively. An operation was performed in 29 patients and in 3 patients a second look surgery was necessary. In group II, 5 patients were outpatients and 19 were inpatients with an average hospitalization period of 5.8days ± 1.9days. An operation was performed in 22 patients, and 2 were treated conservatively. In five patients, a second look surgery was necessary in group II. The study demonstrates that an early treatment of cat and dog bite injuries leads to less second-look operations and a shorter hospitalization. Hence, animal bite injuries of the hands should be treated immediately to avoid further complications. Level 3, therapeutic.

Childhood Cat Bites Relate to Increased Adulthood Severity of Schizotypy, Psychotic-Like Experiences, and Social Anhedonia in a Transdiagnostic Psychiatric Sample

Introduction: Previous research has linked childhood cat scratches and bites to an increased risk for depression, and childhood cat ownership to increased risk of schizophrenia, bipolar disorder, and social anhedonia. Our group previously reported that childhood cat bites, but not ownership, related to increased schizotypy severity in an undergraduate sample. Methods: The current study expands this research by inquiring about cat bites and ownership in a transdiagnostic adult sample (N = 162; 51% female; mean age = 38.15, SD = 10.65), composed of schizophrenia spectrum disorders (n = 30), bipolar disorders (n = 30), unipolar depression (n = 23), and nonpsychiatric participants (n = 79). Participants completed a diagnostic interview, scales of symptom severity, and a cat interaction history interview. Results: Across the entire sample, self-report of cat bites prior to age 13, but not after, related to greater current severity of overall schizotypy, self-reported and clinician-rated psychotic-like symptoms, and social anhedonia, when compared to individuals who reported no lifetime cat bites. Cat bites prior to age 13 did not relate to severity of depression, non-social anhedonia, or clinician-rated negative symptoms. Self-report of residing with a cat prior to age 13, or a first cat bite after age 12, did not relate to any symptom severity measure examined. Conclusions: One theory for these findings is that an unknown infectious agent common in cat saliva interacted with brain development in childhood to increase the likelihood of these symptoms. A novel theory for the infectious agent Pasteurella multocidais discussed. Future research can examine candidate infectious agents to identify potential causal mechanisms for these relationships.