Haw’s Syndrome Associated with Giardiasis in a Cat
Authors: Mendoça Agnes Prieto , Silva Thaíz Furtado , Moraes Reiner Silveira de , Amaral Andréia Vitor Couto do , Ramos Dirceu Guilherme de Souza 
Published: May 2022

Background: Haw’s syndrome results in bilateral projection of the third eyelid, which is caused by a dysfunction of the sympathetic innervation in the region, not accompanied by other ocular changes. It has been mostly seen in cats, under 2-year-old and, it usually shows an acute presentation. It is believed that the disorder may be self-limiting, but several infectious etiologies have been proposed, together with diarrhea. The aim of the study was to report a case of a 2-year-old mixed breed male feline, castrated and diagnosed with Haw’s syndrome, associated with an infectious condition given the presence of Giardia sp.Case: A 2-year-old male, mixed-breed cat and orchiectomized, was admitted and treated at the Veterinary Hospital of the Federal University of Jataí. In the anamnesis, the owner complained that the cat had had pasty brown diarrhea for 4 days and a projection of the third eyelid. He emphasized that the animal used to have some episodes of diarrhea sporadically and the last deworming was carried out 3 months ago from that day. He reported contact with other random street and outdoorcats. On the physical examination, bilateral projection of the third eyelid was observed without any other visible alteration. The third eyelid projection was responsive to the mydriatic and adrenergic [phenylephrine 10%] eye drops instillation test. Complete blood count and serum biochemical evaluation of creatinine, alkaline phosphatase (ALP) and alanine aminotransferase (ALT) concentrations were performed. In addition, abdominal ultrasound and parasitological examination of feces were requested. Complete blood count showed eosinophilia and serum biochemical evaluations were within reference values. The coproparasitological examination detected Giardia sp. On the ultrasound, no significant changes were observed. The recommended treatment was anthelmintic [fenbendazole 50 mg/kg, SID, for 5 days]. However, one week later, the coproparasitological examination still showed Giardia sp. Given this scenario, the chosen treatment was the use of nitazoxanide [25 mg/kg, BID, for 7 days]. Therefore, the patient presented emesis and the treatment with nitazoxanide had to be suspended. Thus, metronidazole [25 mg/kg, BID, for 7 days] was prescribed, in addition to the environmental disinfection and daily litter box cleaning, all performed with quaternary ammonia. After 1 week of treatment with metronidazole, the patient’s clinical improvement and reversal of the third eyelid projection were observed.Discussion: This case proved to be consistent with the data found in the literature, in which cats younger than 2-year-old are affected by Haw’s syndrome and may present concomitant diarrhea. On the physical examination, the parameters evaluated were within normal reference for the cat species and the bilateral projection of the third eyelid was the only alteration found in the patient. The prognosis for the patient with Haw’s syndrome and concomitant giardiasis is favorable, as longas the intestinal infection is treated briefly, in order to prevent the chronicity of the enteroparasitosis. The need of more studies is evident in order to explain the Haw’s syndrome pathology and so, clarify the real cause of this disease. Since the syndrome is mostly, a self-limiting disease, interventions with topical ocular drugs are not necessary. However, in the event of a concomitant disease, infection or underlying cause, it must be treated correctly. Attention is drawn to the need of feces examination through coproparasitological evaluation in cases of diarrhea.
Keywords: cat, diarrhea, intestinal parasitosis, nict membrane.