Detection of Hammondia heydorni-like oocysts in feces of a dog with recurrent diarrhea

Abstract

We report a male, 15-month-old American Canadian White Shepherd dog suffering from recurrent diarrhea and anorexia. Fecal analysis revealed coccidian oocysts of small size. Their morphology was similar to those of Hammondia (H.) heydorni and Neospora (N.) caninum isolates. Unsporulated oocysts had a mean length of 11.8 ± 0.96 µm and a mean width of 11.9 ± 0.96 µm. H. heydorni infection was suggested based on the larger size compared with N. caninum oocysts. Additionally, real time PCR analysis for N. caninum from the fecal sample was negative. After a single anti-coccidian treatment (0.45 mg/kg emodepside + 9 mg/kg toltrazuril) accompanied by amoxicillin (12 mg/kg twice daily for 6 days) the dog recovered very quickly from the disease. This case demonstrates that H. heydorni-like oocysts may be associated with gastrointestinal disease in canine species.

Biliary protozoa in a dog with acute cholangiohepatitis fed a raw food diet

“…Hammondia was historically not believed to be associated with disease in dogs, but recent literature suggests this organism may be an emerging pathogen 1,3,4 . Hammondiasis has been reported infrequently, often is associated with diarrhea, 4,11 and has been identified in dogs fed raw meat 11 . Infection secondary to feeding a raw meat diet in the dog described here would be compatible with the obligate 2‐host life cycle of Hammondia , 2 with small rodents and ruminants usually acting as intermediate hosts, and dogs and other canids as definitive hosts in natural infection.…”

“…Sarcocystidae species have been described as a causative factor in hepatitis affecting companion animals, namely Toxoplasma in cats, and Sarcocystis and Neospora in dogs. Hammondia was historically not believed to be associated with disease in dogs, but recent literature suggests this organism may be an emerging pathogen 1,3,4 . Hammondiasis has been reported infrequently, often is associated with diarrhea, 4,11 and has been identified in dogs fed raw meat 11 .…”

“…1,2 Little is known about the pathogenicity of the Sarcocystid coccidian protozoa H. heydorni in dogs, but diarrhea is the most frequently reported clinical sign in clinical cases. 3,4 Other Sarcocystid coccidian protozoa have been associated with hepatitis in dogs, 5,6 with the presence of Hammondia species identified in bile from a dog with acute hepatitis 7 and Isospora spp. also documented in canine bile, 8 but the clinical relevance of these biliary protozoa is unclear.…”

Molecular detection of Hammondia heydorni in dogs in Mosul city

“…Oocyst can excrete by definitive hosts and sporulated within 3 days (4). The infection with H. heydorni of the definitive hosts is characterized by subclinical course, some times the animals suffer from anorexia, severe diarrhea or recurrent diarrhea, unresponsive specially in puppies and immune compromised dogs, sometimes neurological signs have been observed (5).…”

Analytical sensitivity of a multiplex quantitative PCR for Toxoplasma gondii and Neospora caninum

“…qPCR allowed for the rapid and specific detection of DNA in organisms such as T. gondii and N. caninum (Fekkar et al 2008;Ghalmi et al 2008). Alongside T. gondii and N. caninum, animals can also be infected with Hammondia spp., an organism that is often considered non-pathogenic, yet some case reports suggest otherwise (Allan et al 2022;Reichel et al 2007;Schares et al 2021;Šlapeta et al 2002;Steffl and Nautscher 2019). A highly specific qPCR assay for Hammondia hammondi, based on the repetitive element Hhamm222, has recently been developed (Schares et al 2021).…”