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Ixodes spp. are commonly found on dogs and cats throughout the world. In the eastern United States, 16S rDNA sequence of Ixodes scapularis, the predominant species, reveals two clades—American and Southern. To confirm the species and clades of Ixodes spp. ticks submitted from pets, we examined ticks morphologically and evaluated 16S rDNA sequence from 500 ticks submitted from 253 dogs, 99 cats, 1 rabbit, and 1 ferret from 41 states. To estimate pathogen prevalence, flaB of Borrelia burgdorferi (Bb) sensu stricto and 16S rDNA of Anaplasma phagocytophilum (Ap) were amplified and sequenced. Most Ixodes spp. from the Northeast (n = 115/115; 100%) and the Midwest (n = 77/80; 96.3%) were I. scapularis, American clade. Borrelia spp. were identified in 34 of 192 (17.8%) and Ap in 5 of 192 (2.6%) I. scapularis. Two Ixodes cookei and one Ixodes texanus were identified from Ohio, Illinois, and Michigan. In contrast, 156 of 261 (59.8%) Ixodes spp. from the Southeast were I. scapularis, American clade; 86 of 261 (33.0%) were I. scapularis, Southern clade; 9 of 261 (3.4%) were Ixodes affinis; and 10 of 261 (3.8%) were I. cookei. Southern clade was significantly more common in Florida and less common in the upper South (p < 0.0001). One I. scapularis (1/242; 0.4%) from the Southeast (Kentucky) tested positive for Bb and 6 of 242 (2.5%) were positive for Ap. In the West, most (34/44; 77.3%) Ixodes spp. were Ixodes pacificus, with Ixodes angustus (n = 6) submitted from dogs in Alaska, Washington, and Oregon and Ixodes haerlei (n = 4) preliminarily identified from a dog in Montana. Pathogens were not detected in any ticks from the West. Although I. scapularis, American clade, predominated in the Northeast and Midwest, additional Ixodes spp. were found on dogs and cats in other regions and pathogens were less commonly detected. The role of less common Ixodes spp. as disease vectors, if any, warrants continued investigation. [ABSTRACT FROM AUTHOR]

Giardia duodenalis and Cryptosporidium spp. are zoonotic protozoal pathogens, spread by a fecal-oral route, which can infect a wide range of hosts including but not limited to dogs and humans. Giardia was recently estimated to be present in 37% to 50% of kennel-housed dogs. Cryptosporidium infections in kennel-housed dogs have been reported in 7% to 21% of the population. The goal of this study was to define demographic factors and fecal scores associated with positive screening test cases of Giardia and Cryptosporidium in kennel-housed laboratory dogs in the state of Texas. Fecal samples were collected from 153 clinically normal laboratory dogs at an academic research facility and a local laboratory dog supplier. We used 3 diagnostic tests evaluated in parallel to determine test positivity to each organism: a human point-of-care coproantigen test, a direct immunofluorescent assay, and an in-house polymerase chain reaction. Dogs were significantly more likely to test positive for Giardia (45%) than Cryptosporidium (7%) ( P < 0.01). Dogs that were 18 mo of age or younger had 3 times the odds ( P = 0.009) of subclinical Giardia infection compared with older dogs. We found no significant relationship between age and Cryptosporidium prevalence. Dogs with hard feces (fecal score 1-2) at the time of screening had 0.34 times lower odds ( P = 0.049) of testing positive for Giardia than dogs with normal feces, but no statistically significant relationship was found between fecal score and Cryptosporidium -positive test status. With these findings, we demonstrated the value of considering age and fecal score when choosing which dogs to screen for subclinical Giardia . Additional studies with larger sample sizes should be conducted to determine the relationship between age and fecal score and subclinical Cryptosporidium infection.

After detecting Giardia and Cryptosporidium infections and coinfections in 2 litters of puppies in our vivarium, our team realized that we needed a simple, quick, and economical point-of-care test for concurrent screening of asymptomatic dogs for both organisms. Periodic screening of colony dogs and of all dogs introduced into a colony can prevent the spread of Giardia and Cryptosporidium to immunologically naïve animals and help keep staff safe from these zoonotic organisms. To compare methods for diagnosing Giardia and Cryptosporidium spp. in dogs, we used a convenience sampling of feces from 2 popula- tions of dogs; samples were tested with a lateral-flow assay (QC), a commercially-available direct fluorescent assay (DFA), and an inhouse PCR test using established primers. QC results were analyzed in 2 ways: 1) relative to a reference standard that permitted comparative interpretation of DFA and PCR results; and 2) using Bayesian analysis for comparison independent of a reference standard. The QC test showed good specificity for the detection of Giardia according to both the reference standard (95%) and the Bayesian analysis (98%). Similarly, specificity of the QC for the detection of Cryptosporidium was 95% according to the reference standard and 97% according to Bayesian analysis. However, the sensitivity of the QC test was much lower for both Giardia (reference standard, 38%; Bayesian analysis, 48%) and Cryptosporidium (25% and 40%, respectively). This study demonstrates that the QC test can be used to detect both Giardia and Cryptosporidium in dogs and that positive results can be accepted with confidence, whereas negative tests should be confirmed through secondary testing methods.