Use of ponazuril paste to treat coccidiosis in shelter-housed cats and dogs

Acute phase response and oxidative stress in coccidiosis: A review in domestic animals

Coccidiosis is a highly significant disease in domestic animals due to its global distribution and economic impact. The occurrence of oxidative stress (OS) and the acute phase response (APR) play crucial roles in the development of coccidiosis, thereby contributing to the pathogenicity of coccidia. A range of triggers including parasitic infection, can induce the APR. This response encompasses a set of hormonal and metabolic changes to restore body stability and improve the body's healing capabilities. Ovine coccidiosis has the potential to cause OS, which can be prevented and treated through the use of dietary additives. By including Curcuma longa in the diets of infected sheep, it is possible to reduce lipid peroxidation (LPO) and nitric oxide (NO) production, while simultaneously improving serum antioxidant capacity and interleukin-10 (IL-10) levels. Caprine coccidiosis can activate the APR. Research indicated that goats suffering from coccidiosis exhibited elevated concentrations of malondialdehyde (MDA) and total homocysteine, along with reduced levels of some enzymes such as superoxide dismutase (SOD) and glutathione reductase (GR), as well as decreased levels of zinc (Zn), manganese (Mn), selenium (Se), vitamin C, and total antioxidant capacity (TAC). Bovine coccidiosis is linked to elevated MDA concentrations and reduced serum glutathione (GSH) and TAC levels. Eimeria can induce OS and inflammatory damage in infected birds by releasing pro-inflammatory mediators from cells, resulting in a significant increase in CAT and SOD activity, lipid peroxidation and damage to the intestinal epithelium. To promote the antioxidant system of infected birds, some herbal food additives such as grape seed proanthocyanidine extract, Curcuma longa and Rumex nervosus leaf extract, can be used. Research on the APR in birds is not as extensive as in ruminants. Currently, there is a lack of studies on the occurrence of OS and APR in camels, horses, dogs, and cats with coccidiosis.

Cystoisospora spp. infection at a dog breeding facility in the Madrid region: Infection rate and clinical management based on toltrazuril metaphylaxis

Canine coccidiosis caused by Cystoisospora canis and Cystoisospora ohioensis-complex is common in kennels. While often underestimated, coccidiosis may cause severe clinical signs in puppies and sometimes even lead to death, so preventative measures are important. This study examines Cystoisospora spp. infection at a Labrador retriever breeding facility in Madrid, Spain. To identify environmental factors associated with infection, dams were examined throughout a reproductive cycle (from oestrus to 60 days postpartum) and their puppies during their first 60 days of life. Also assessed was the efficacy of combined treatment with emodepside (0.9 mg/ml) and toltrazuril (18 mg/ml) at a dose of 0.5 ml/kg of weight, equivalent to 0.45 mg/kg and 9 mg/kg, respectively, in puppies on day 35 of life. Oocyst shedding was detected in 4.6-18.6% of 45 dams examined and in 2.2-9.1% of their litters (315 puppies). In both cases, peak opg elimination was recorded on day 30 postpartum/of life. The species of Cystoisospora detected were C. canis (91.3%) and C. ohioensis-complex (8.7%). While in both dams and puppies opg counts were higher in autumn when rainfall was at its highest, correlation between opg and rainfall emerged as significant only in puppies (p = 0.031). The treatment of 35 day-old puppies with toltrazuril was 100% effective in controlling this infection in the kennel. Our findings therefore suggest the need for a strict hygiene regime and the use of toltrazuril as blanket treatment to reduce Cystoisospora transmission in dog breeding facilities.

Ponazuril: Clinical efficacy, ultrastructure, and histopathology studies of in vivo anticoccidial action against Eimeria tenella

Ponazuril, a novel antiprotozoal drug in the class of triazine, has shown a promising application on apicomplexan infections in poultry and livestock. However, the effect and mechanism of action of ponazuril against Eimeria tenella (E. tenella) are unclear. The efficacy against E. tenella was initially studied by administering different doses of ponazuril in drinking water. The treated stage and site of ponazuril on E. tenella were observed through ultrastructural and histopathological analyses. Chicks were orally treated with a dose of 15 mg/kg body weight of ponazuril at different endogenous stages of E. tenella post-infection. According to the clinical study, the values of anticoccidial indices (ACI) were 157.0, 162.3, 196.9, 194.5, and 190.9, respectively, when the ponazuril was administered in drinking water at doses of 5, 10, 20, 40, and 50 mg/L for two consecutive days after infection. Among them, the 20 mg/L ponazuril group showed the best anticoccidial effect, which was superior to that of the toltrazuril treatment group, with an ACI value of 191.7. Histological analysis indicated that ponazuril effectively relieved cecal lesions, and decreased the number of merozoites. Transmission electron micrographs (TEM) observed that merozoites became irregular in shape, and some apparent protrusions of the outer membrane were presented especially the second-generation merozoites. Additionally, abnormalities in the development of WFBI and WFBII in the macrogametocyte were observed, which may affect the formation of the ovule wall. Moreover, merozoites in the treated group showed uneven and marginalized chromatin and mitochondrial swelling. These results suggested ponazuril is a potential anticoccidial drug, providing information on the mechanism of anticoccidial effects.

Pharmacokinetics of orally administered single‐dose ponazuril in cats

Cats and kittens in animal shelters and catteries regularly suffer from severe gastrointestinal coccidiosis, which can be fatal, and there are no drugs labeled for feline coccidiosis in the United States. Ponazuril, a triazine‐class drug, is increasingly used at a dose of 50 mg/kg/d, orally, for three to five days in shelter environments for coccidiosis. A single oral dose of ponazuril paste 15% (Marquis^®; Merial) at 50 mg/kg was administered to six healthy adult cats. Sample analysis was completed via high‐performance liquid chromatography. Plasma concentrations peaked at 7.49 ± 2.06 µg/ml at 14.67 ± 7.45 hr post‐administration. This study shows that ponazuril achieved a plasma concentration that inhibits growth of similar organisms after a single oral dose in cats. Further studies are necessary to optimize dosing for the treatment of clinical coccidiosis in cats.

Bioanalytical RP-HPLC method for the determination of ponazuril in plasma

The goal of this investigation was to establish a reliable technique for the quantitation of ponazuril in limited sample volumes. Samples were extracted with chloroform and separation was achieved with a Symmetry RP₁₈ column. Ultraviolet absorption was measured at 254 nm. A combination of 0.1% formic acid and acetonitrile (50:50) was used as the mobile phase. The calibration curve was linear from 0.1-25 μg/mL, with a lower limit of quantification of 0.1 μg/mL with a 100 μL sample. The precision and accuracy were well within the range set by the Food and Drug Administration and the recovery was over 95%. This technique was used to analyze ponazuril samples and found to be appropriate for pharmacokinetic studies.

USE OF CLINDAMYCIN IN PALLAS' CATS [OTOCOLOBUS (FELIS) MANUL] TO REDUCE JUVENILE TOXOPLASMOSIS-ASSOCIATED MORTALITY RATES

Pallas' cat [Otocolobus (Felis) manul] experiences a high mortality rate from toxoplasmosis. During the period 2006-2016, the overall mortality rate for this species from all causes during the first year of life was 71.59% in European Association of Zoos and Aquaria institutions, with the most significant infectious cause from systemic toxoplasmosis (20.6%) as confirmed by postmortem examination and histopathology. Clindamycin was used starting in 2014 in two collections that had previously experienced 100% mortality rates by toxoplasmosis in kittens less than one year of age, covering key Toxoplasma gondii exposure periods for kittens (n = 17) as a prophylactic measure. This protocol resulted in a 67.03% (95% confidence interval 41.76-78.61%) reduction in the first year mortality rate over a two-year period to 5.88% in those animals treated.

Interventions and observations associated with survival of orphaned shelter kittens undergoing treatment for diarrhea

OBJECTIVES

The objective of this study was to identify significant associations between treatment interventions and survival of orphaned shelter kittens with diarrhea.

METHODS

Orphaned kittens admitted to a large open-intake municipal animal shelter and entering a volunteer foster care provider network between April 2016 and July 2017 were studied. Individual orphaned kittens for which the care provider sought examination by shelter veterinarians because of clinical signs of diarrhea were included. Treatments administered were recorded and their association with kitten survival to adoption or transfer to a rescue partner was statistically examined.

RESULTS

A total of 1718 orphaned kittens were fostered, among which 220 kittens (12.8%) from 118 different litters were presented for evaluation of diarrhea. A total of 172 (78.2%) kittens underwent treatment for their diarrhea, among which 153 (89.0%) survived to adoption or transfer to a rescue partner and 19 (11.0%) died or were humanely euthanized. Kittens with diarrhea that were ⩾4 weeks of age were 24.8 times more likely to survive (95% confidence interval [CI] 6.8-89.8; P <0.0001). While controlling for age, kittens that received a vitamin and mineral supplement were 12.8 times more likely to survive (95% CI 3.1-52.5; P = 0.0004) than kittens with diarrhea that did not receive the supplement. Treatment with subcutaneous fluids, penicillin G, tube feeding, a probiotic containing Enterococcus faecium SF68, ponazuril or metronidazole did not statistically significantly increase the survival of kittens with diarrhea.

CONCLUSIONS AND RELEVANCE

Age ⩾4 weeks and treatment of diarrhea with a vitamin and mineral supplement favorably improves survival of orphaned kittens to adoption. Application of these findings are likely to improve the health and welfare of this population and contribute to a refinement in use of shelter resources.

A review of Cystoisospora felis and C. rivolta-induced coccidiosis in cats

Until the discovery of Toxoplasma gondii oocysts in cat feces in 1970, little was known of coccidiosis in cats. Until 1970, three coccidian parasites based on different sized oocysts were recognized, the parasite with large oocysts (∼40 μm long and called Isospora felis), medium sized oocysts (∼25 μm long, called Isospora rivolta), and small sized oocysts (14 μm or less, called Isospora bigemina) were known and they were considered not host-specific. Later, it was demonstrated that these parasites were host-specific and had also extra-intestinal stages. The Isospora bigemina turned out to be more than 25 organisms belonging to T. gondii, Hammondia spp., Sarcocystis spp., Besnoitia spp., and Neospora spp.; these subjects have been reviewed previously in detail. The present paper summarizes biology of Isospora felis, and I. rivolta (now transferred to genus Cystoisospora), including taxonomy, life cycle, diagnosis, and treatment. Re-excretion of T. gondii oocysts from chronically infected cats after superinfection with Cystoisospora felis oocysts is discussed. There are only two species of Cystoisospora species in cats, C. felis and C. rivolta; Isospora novocati and Cystoisospora frenkeli named for I. rivolta-like parasites of cats are considered synonym of C. rivolta. Clinical coccidiosis occurs more commonly in recently weaned kittens and C. felis infections are more prevalent than C. rivolta.

Prevalence of enteropathogens in cats with and without diarrhea in four different management models for unowned cats in the southeast United States

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Most cats in shelters, sanctuaries, foster homes, and trap-neuter-return programs carried at least one enteropathogen.

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Tritrichomonas foetus and coronavirus were more common in cats with diarrhea.

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Other bacterial, viral, protozoal, and helminth enteropathogens were present in cats with normal feces and diarrhea.

The objective of this study was to determine the prevalence of enteropathogens in cats with and without diarrhea in four different models for managing unowned cats: short-term animal shelter, long-term sanctuary, home-based foster care, and trap-neuter-return. Fecal samples from 482 cats, approximately half of the cats with normal fecal consistency and half with diarrhea, were tested by zinc sulfate centrifugation and by real-time PCR for a panel of enteropathogens.

At least one enteropathogen of feline or zoonotic importance was detected in a majority of cats, regardless of management model. For most enteropathogens, the presence or absence of diarrhea was not significantly associated with infection, the exceptions being Tritrichomonas foetus in sanctuary cats with diarrhea (26%) and normal fecal consistency (10%), respectively (P ≤ 0.04), and feline coronavirus in foster cats (80% and 58%) (P ≤ 0.001). The types of enteropathogens detected were related to the type of management model, e.g., viral and protozoal infections were most common in shelters, sanctuaries, and foster homes (confinement systems), whereas helminth infections were most common in trap-neuter-return programs (free-roaming cats).

These results suggest that management practices for unowned cats are inadequate for control of enteropathogens and that the presence of diarrhea is a poor indicator of enteropathogen carriage. Risk-management strategies to reduce transmission to people and other animals should focus on sanitation, housing, compliance with preventive care guidelines, periodic surveillance, response to specific enteropathogens, humane population management of free-roaming community cats, public health education, and minimizing the duration and number of cats in mass confinement.