Eyevet Services Ltd., Feilding, New Zealand.
New Zealand Veterinary Pathology, Palmerston North, New Zealand.
N Z Vet J. 2023 Nov;71(6):321-328. doi: 10.1080/00480169.2023.2248066. Epub 2023 Sep 4.
Medical records of four dogs diagnosed with protothecosis in New Zealand were reviewed. The dogs were aged between 4 and 9 years and three of the four dogs were female. Breeds were one Labrador, one Miniature Schnauzer and two crossbreeds. The reasons for initial veterinary evaluation were a cough and opaque appearance of the right eye (Case 1), diarrhoea (Cases 2 and 3), and cutaneous disease (Case 4).
The ocular signs were characterised by panuveitis, retinal detachment and secondary glaucoma. Gastrointestinal signs included chronic haemorrhagic diarrhoea due to colitis. Three cases had disseminated infection and developed both bilateral, blinding, ocular disease and chronic gastrointestinal disease. Cutaneous signs consisted of draining fistulae over the olecranon, multifocal cutaneous nodules, and ulceration and tracts of the foot pads. Disseminated protothecosis was confirmed by histopathology of biopsied ocular tissues in Cases 1 and 2 and by gastrointestinal biopsies in Case 3. spp. were also identified in cytological specimens from Cases 1 and 4 and recovered by culture in Cases 2 and 4. Cutaneous protothecosis was diagnosed in Case 4 initially by cytology and histopathology of skin lesions, and was confirmed by PCR of cultured organisms.
Prior to diagnosis of protothecosis, a variety of treatments were prescribed to treat the gastrointestinal and ocular signs. After diagnosis, only Cases 2 and 4 received medication aimed at treating the protothecal infection, which was itraconazole in both cases. Following the progression of clinical signs and concerns about quality of life, all four dogs were euthanised.
Disseminated protothecosis in three dogs, cutaneous protothecosis in one dog.
Canine protothecosis is rarely reported, despite the ubiquity of the causal algae, and the disease usually carries an extremely grave prognosis when infection is generalised. In New Zealand, protothecosis should be considered as a differential diagnosis in dogs with panuveitis, chorioretinitis or retinal detachment, colitis, or nodular, ulcerative or fistulating cutaneous lesions.
对新西兰 4 只诊断为原藻病的犬的医学记录进行了回顾。这些犬的年龄在 4 至 9 岁之间，其中 3 只为雌性。品种包括 1 只拉布拉多犬、1 只迷你雪纳瑞犬和 2 只混种犬。最初兽医评估的原因是咳嗽和右眼不透明外观（病例 1）、腹泻（病例 2 和 3）和皮肤疾病（病例 4）。
眼部体征表现为全葡萄膜炎、视网膜脱离和继发性青光眼。胃肠道体征包括结肠炎引起的慢性出血性腹泻。3 例发生播散性感染，同时出现双侧、致盲性眼部疾病和慢性胃肠道疾病。皮肤病变包括肘突上方有渗出性瘘管、多发性皮肤结节、脚垫溃疡和窦道。病例 1 和 2 的眼部组织活检和病例 3 的胃肠道活检证实为播散性原藻病。病例 1 和 4 的细胞学标本中也发现了 spp.，并在病例 2 和 4 中通过培养物得到证实。病例 4 最初通过皮肤病变的细胞学和组织病理学诊断为皮肤原藻病，PCR 证实为培养物。
在诊断为原藻病之前，曾针对胃肠道和眼部症状开具了多种治疗方案。确诊后，只有病例 2 和 4 接受了针对原藻感染的药物治疗，两种情况均使用伊曲康唑。随着临床症状的进展和对生活质量的担忧，这 4 只犬均被安乐死。
3 只犬为播散性原藻病，1 只犬为皮肤原藻病。
尽管致病藻类无处不在，但犬原藻病的报道很少见，当感染广泛时，该病通常预后极差。在新西兰，当犬出现全葡萄膜炎、脉络膜视网膜炎或视网膜脱离、结肠炎或结节性、溃疡性或瘘管性皮肤病变时，应将原藻病视为鉴别诊断。
