Skip to main content

Restoring vision after cat bite: a case report on successful diagnostic and therapeutic regimen for Capnocytophaga endophthalmitis



Capnocytophaga is a bacterium frequently found in the oral flora of dogs and cats (e.g. Capnocytophaga canimorsus) and humans (e.g. Capnocytophaga gingivalis). Among Capnocytophaga related ocular infections, fulminant endophthalmitis is a rare but sight-threatening clinical manifestation.

Case presentation

A 35-year-old previously healthy patient presented after a cat bite into the left upper and lower eyelid and nasal part of the conjunctiva of the left eye. At initial consultation, the corrected visual acuity was 0.8 in decimal scale and a detailed clinical examination revealed no evidence of ocular penetration. However, daily follow-up examinations under local therapy revealed a progressive intraocular inflammation, therefore the decision was made to perform a diagnostic vitrectomy with intravitreal and systemic antibiotic treatment. Capnocytophaga felis was detected as the cause of endophthalmitis and the initiated treatment resulted in quick morphological and functional recovery of the left eye. After surgery of secondary cataract, visual acuity improved from hand motion preoperatively to 1.0 postoperatively.


Early recognition as well as prompt and effective treatment of animal bite associated endophthalmitis is essential for good visual recovery and functional outcome. Furthermore, this case highlights the importance of daily follow-up examinations, even in the absence of signs of ocular penetration and intraocular inflammation, to enable prompt and effective treatment initiation. Given the negative results in bacterial culture, we additionally emphasize the value of sequencing-based microbiological diagnostics in unclear cases.


Capnocytophaga spp. are capnophilic, microaerophilic, gram-negative bacilli, frequently found in the oral flora of dogs and cats (e.g. Capnocytophaga canimorsus [1, 2]) and humans (e.g. Capnocytophaga gingivalis [3, 4]). Predominantly in the course of bites, scratches, licks or mere exposure to these animals, Capnocytophaga can lead to various types of local and systemic infections, including lethal sepsis [5, 6]. First cases of endophthalmitis caused by Capnocytophaga were published in 1993 and only a limited cumulative number of eight cases of Capnocytophaga related endophthalmitis have been described so far [7,8,9,10,11,12]. Here we present a clinical case of a successful diagnostic and therapeutic approach to Capnocytophaga endophthalmitis after a cat bite.

Case presentation

A 35-year-old previously healthy patient presented after a cat bite into the left upper and lower eyelid and nasal part of the conjunctiva of the left eye. At initial consultation, the corrected visual acuity was 0.8 in decimal scale. Clinical examination revealed scratches of the lids and a conjunctival tear of approximately 3 mm in length with conjunctival injection and chemosis (Fig. 1). Although a sclera wound after a cat bite is not always easy to identify, we decided to perform a sclera exploration in operating theater. During this procedure, no signs of penetration could be seen. The patient described that he had got bitten into his left eye during play with his own cat. He had been vaccinated against tetanus and his cat had got all regular vaccinations. Since initially no intraocular inflammation was seen, the affected eye was treated with moxifloxacin eye drops (5 mg/ml) and the eyelids with gentamicin eye ointment (5 mg/g), each applied five times a day. The following day, mild inflammation of the anterior chamber was detected. Therefore, dexamethasone (1 mg/ml) four times a day was added to the local antibiotic therapy. Despite local treatment, the intraocular inflammation increased rapidly, showing anterior chamber inflammation with a hypopyon (Fig. 2) and vitreous infiltration (Fig. 3) on the second day after injury. We admitted the patient and initiated intravenous wide spectrum antibiotic treatment with ceftazidime 1 g twice a day and imipenem/cilastatin 1 g three times a day. At that point, visual acuity was reduced to perception of hand motion only. To avoid posterior synechiae formation, we added cyclopentolate 10 mg/ml twice a day to the local therapy. On the fourth day after injury, a diagnostic pars plana vitrectomy was performed in order to obtain samples for microbiological analysis. During vitrectomy, vancomycin (1 mg/0.1 ml) and ceftazidime (2.25 mg/0.1 ml) were applied intravitreally. The patient recovered quickly after surgery and empiric antibiotic treatment. The vitreous punctate was subjected to culture analysis for aerobic, anaerobic and fungal pathogens, yielding negative results in the absence of antimicrobial substances. Utilizing the Sanger sequencing method for 16S rDNA and species identification through both NCBI (non-curated database) and EzBioCloud (curated database), we identified Capnocytophaga felis as the cause of endophthalmitis. We changed the therapeutic regimen accordingly from intravenous to oral treatment with clindamycin 600 mg three times a day and discharged the patient five days after surgery. A secondary cataract was identified three weeks after the injury (Fig. 4). Since during the vitrectomy, no signs of any lens touch or penetration could be seen, we strongly believe that the rapid cataract development was associated with the primary injury. A cataract surgery was performed. During surgery, a penetration of the posterior capsule was observed, confirming our hypothesis of the injury having caused the cataract development. An implantation of the intraocular lens into the sulcus was therefore necessary (Fig. 5). Already one day after cataract surgery, visual acuity improved to 1.0 in decimal scale and remained stable during follow up examinations.

Fig. 1
figure 1

Conjunctival tear of approximately 3 mm in length with conjunctival injection and chemosis at initial consultation (slit lamp examination)

Fig. 2
figure 2

Anterior chamber inflammation with a hypopyon on the second day after injury (slit lamp examination)

Fig. 3
figure 3

Infiltration of the vitreous on the second day after injury (ocular ultrasound)

Fig. 4
figure 4

Secondary cataract three weeks after injury (slit lamp examination)

Fig. 5
figure 5

Result after cataract surgery with implantation of the intraocular lens into the sulcus (slit lamp examination)

Discussion and conclusions

In the presented case, early recognition along with prompt and effective treatment of the intraocular Capnocytophaga infection were crucial to preserve visual outcome. Even though no signs of ocular penetration were visible in the first place, clinical aspects, e.g. massive intravitreal inflammation despite intensive local antibiotic treatment and the rapid development of a secondary cataract after the trauma with a capsular defect diagnosed later, strongly suggested an eye penetration during cat bite injury. Initial daily follow-up examinations allowed us to respond quickly to the developing endophthalmitis, which otherwise would have potentially led to irreversible visual loss. Therefore, we recommend a strict control regimen after bite injuries, even if no obvious signs of ocular penetration can be detected.

Due to its rapid and aggressive progression, infectious endophthalmitis is a severe vision threatening disease [13]. In order to avoid retinal toxicity, an initial empiric treatment with local broad-spectrum antibiotic, like moxifloxacin, as well as intravitreal and intravenous treatments with broad-spectrum antibiotics can be necessary. Due to a progressive intraocular inflammation, we treated the patient with intravenous ceftazidime and imipenem/cilastatin. This combination has high potency especially in gram-negative endophthalmitis, including Capnocytophaga related endophthalmitis [7, 14, 15]. The combination of intravitreally applied vancomycin and ceftazidime covers a broad gram-positive and gram-negative spectrum and is known to be an ideal empiric treatment of endophthalmitis [15], under which the patient was already recovering well. As comprehensive culture analysis of vitreous punctate for aerobic, anaerobic and fungal pathogens did not show any growth, sequencing-based diagnostic was crucial in this case to detect Capnocytophaga felis, a recently newly described species isolated from the oral cavity of cats [16], as the cause of endophthalmitis. This was especially important to optimize antibiotic regimen to oral treatment with clindamycin, as recommended for the treatment of Capnocytophaga related ocular infections [9, 17] in order to prevent severe systemic infections, e.g. Capnocytophaga associated lethal sepsis [6]. Taken together, early recognition as well as prompt and effective diagnosis and treatment of the developing endophthalmitis were key to achieve best therapeutic outcome.

Availability of data and materials

The datasets used and analyzed during the current study are available from the corresponding author on reasonable request.


  1. Brenner DJ, Hollis DG, Fanning GR, Weaver RE (1989) Capnocytophaga canimorsus sp. nov. (formerly cdc group df-2), a cause of septicemia following dog bite, and c. cynodegmi sp. nov., a cause of localized wound infection following dog bite. J Clin Microbiol 27:231–235.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Gaastra W, Lipman LJ (2010) Capnocytophaga canimorsus. Vet Microbiol 140:339–346.

    Article  PubMed  Google Scholar 

  3. Socransky SS, Holt SC, Leadbetter ER, Tanner AC, Savitt E, Hammond BF (1979) Capnocytophaga: new genus of gram-negative gliding bacteria. iii. physiological characterization. Arch Microbiol 122:29–33.

    Article  CAS  PubMed  Google Scholar 

  4. London J, Celesk RA, Kagermeier A, Johnson JL (1985) Emended description of capnocytophaga gingivalis. Int J Syst Bacteriol 35:369–370.

    Article  Google Scholar 

  5. Lion C, Escande F, Burdin JC (1996) Capnocytophaga canimorsus infections in human: review of the literature and cases report. Eur J Epidemiol 12:521–533.

    Article  CAS  PubMed  Google Scholar 

  6. Handrick W, Schwede I, Steffens U (2010) Letal verlaufende capnocytophaga-canimorsus-sepsis nach hundebiss. Med Klinik 105:739–741.

    Article  Google Scholar 

  7. Rubsamen PE, McLeish WM, Pflugfelder S, Miller D (1993) Capnocytophaga endophthalmitis. Ophthalmology 100:456–459.

    Article  CAS  PubMed  Google Scholar 

  8. Zimmer-Galler IE, Pach JM (1996) Capnocytophaga canimorsus endophthalmitis. Retina (Philadelphia, Pa) 16:163–164.

    Article  CAS  PubMed  Google Scholar 

  9. Phipps SE, Tamblyn DM, Badenoch PR (2002) Capnocytophaga canimorsus endophthalmitis following cataract surgery. Clin Exp Ophthalmol 30:375–377.

    Article  PubMed  Google Scholar 

  10. Papadaki TG, Moussaoui RE, Ketel RJV, Verbraak FD, Tan HS (2008) Capnocytophaga canimorsus endogenous endophthalmitis in an immunocompetent host. Brit J Ophthalmol 92:1566–1567.

    Article  CAS  Google Scholar 

  11. Muen WJ, Bal AM, Wheelan S, Green F (2009) Bilateral endophthalmitis due to dog bite. Ophthalmology 116:1420–1421.

    Article  PubMed  Google Scholar 

  12. Thommen F, Opota O, Greub G, Jaton K, Guex-Crosier Y, Wolfensberger TJ, Matet A (2020) Capnocytophaga canimorsus endophthalmitis after cataract surgery linked to salivary dog-to-human transmission. Retin Cases Brief Rep 14:183–186.

    Article  PubMed  Google Scholar 

  13. Lee JJ, Jo YJ, Lee JS (2022) Clinical characteristics and risk factors for visual prognosis according to the types of infectious endophthalmitis. PLoS ONE 17:e0278625.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Irvine WD, Flynn HW, Miller D, Pflugfelder SC (1992) Endophthalmitis caused by gram-negative organisms. Arch Ophthalmol (Chicago, Ill : 1960) 110:1450–1454.

    Article  CAS  Google Scholar 

  15. Gentile RC, Shukla S, Shah M, Ritterband DC, Engelbert M, Davis A, Hu DN (2014) Microbiological spectrum and antibiotic sensitivity in endophthalmitis: a 25-year review. Ophthalmology 121:1634–1642.

    Article  PubMed  Google Scholar 

  16. Suzuki M, Umeda K, Kimura M, Imaoka K, Morikawa S, Maeda K (2020) Capnocytophaga felis sp. nov. isolated from the feline oral cavity. Int J Syst Evol Microbiol 70:3355–3360.

    Article  CAS  PubMed  Google Scholar 

  17. Alexandrakis G, Palma LA, Miller D, Alfonso EC (2000) Capnocytophaga keratitis. Ophthalmology 107:1503–1506.

    Article  CAS  PubMed  Google Scholar 

Download references


Not applicable.


We acknowledge support from the Open Access Publication Fund of the University of Tübingen. Open Access funding enabled and organized by Projekt DEAL.

Author information

Authors and Affiliations



LW drafted the manuscript. LW, DAM, JN and SD revised the manuscript. LW, JN and SD examined and treated the patient and collected the data. All authors contributed significantly to the work and approved the final manuscript for submission.

Corresponding author

Correspondence to Lasse Wolfram.

Ethics declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Obtained from patient.

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wolfram, L., Merle, D., Neubauer, J. et al. Restoring vision after cat bite: a case report on successful diagnostic and therapeutic regimen for Capnocytophaga endophthalmitis. J Ophthal Inflamm Infect 14, 3 (2024).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: