- Dogs should be tested for gastrointestinal parasites at least once every 3 months to monitor the efficacy of parasite control regimes and owner compliance.
- Standard or modified faecal flotation using a solution with specific gravity of between (1.18-1.20) is recommended for the diagnosis of the majority of gastrointestinal parasites of dogs.
- Clinical signs might occur prior to shedding of parasite stages in the faeces, in which case, history and clinical signs should guide treatment decisions.
- Diagnosis of gastrointestinal parasitic infections may be complicated by an absence of, or intermittent egg/ larvae shedding in the faeces, even in symptomatic cases. Testing three or more samples, on alternate days, may increase the probability of finding diagnostic stages in the faeces.
- Blood or buffy coat smears from animals suspected of haemoparasitic infections, should be performed using capillary blood collected via ear-tip or outer lip margin.
- In some cases, ancillary tests (e.g. blood counts, urinalysis, x-ray, and echocardiography) should be conducted to better guide treatment and management of the patient. In some instances, imaging tools may also be helpful to confirm the diagnosis; e.g. echocardiography may reveal the presence of heartworms in the right ventricle and computed tomography scan may indicate the presence of Onchocerca lupi in the retrobulbar space.
- TroCCAP does not recommend the off-label use of drugs for controlling parasites in dogs. In cases where a registered product is not available (e.g. heartworm adulticides are not available in many heartworm endemic countries), the off-label use of alternative protocols (e.g. slow-killing therapy for heartworm infections) may be the only option.
- The decision of using off-label drugs or protocols should rely on the recommendation of the veterinary practitioner in charge. The veterinarian should apply caution when recommending off-label use of drugs and closely monitor the dog for any unexpected adverse events; the responsibility for any adverse event related to the off-label use of drugs and doses lies with the prescribing veterinarian.
- Generic brands are often available and more accessible. However, veterinarians should be cautious when prescribing generic products. TroCCAP advocates the use of products for which information on efficacy, safety, and quality control is available from the manufacturer.
- Caution should be applied when using off-label macrocyclic lactones, especially in dogs with the MDR1 gene mutation (e.g. Collies). Toxicity is also dependent on dose and route of administration, with topical application being better tolerated than oral and injectable ones.
- Care should be taken to minimize the risk of parasite transmission and morbidity, especially in puppies, by improving nutrition, environmental hygiene, and avoiding overcrowding and other stressors.
- Anthelminthic therapy should be combined with supportive care (e.g. electrolyte fluid therapy, blood transfusion and iron supplementation and high protein diet) where necessary.
- All dogs and where applicable, cats, should be treated at the same time when residing in the same household.
- Blood donor dogs should be in optimal health and blood screened using PCR and serological tests to rule out the presence/exposure to blood-borne pathogens such as Babesia spp., Anaplasma platys, Ehrlichia canis, haemotropic mycoplasmas and Hepatozoon canis and where endemic, Brucella canis. For further information on blood transfusions can be found at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4913655/pdf/JVIM-30-015.pdf
- Crystalline fluid therapy should be avoided in severely anaemic patients unless the patient is significantly dehydrated. In this case, pack-cell volume must be closely monitored.
Prevention and control
- Puppies and adult dogs should be dewormed with an adulticide fortnightly or with a larvicidal monthly (moxidectin) at recommended doses.
- Prompt, daily removal and disposal of faeces is recommended.
- Concrete and paved surfaces may be disinfected with 1% sodium hypochlorite solution (bleach), to kill or at least reduce the viability of helminth eggs and larvae.
- Disinfection of gravel, loam surfaces or lawns with sodium borate (5 kg/m2) will kill larvae, but will also destroy vegetation.
- Do not feed raw meat or allow dogs to hunt as many animals and birds act as intermediate or paratenic hosts for some gastrointestinal parasites.
Public health considerations
- Several parasites of dogs (e.g. roundworms, hookworms and filarial spp.) are zoonotic and their control is also important from a public health perspective.
- Veterinarians and public health workers should educate dog owners regarding the potential risks of improper parasite control in dogs. Many parasites are zoonotic and may affect especially young children and immunocompromised individuals.
- Veterinarians should also advocate good hygienic practices (e.g. hand washing, wearing footwear while outdoors, and prompt removal of dogs faeces) for dog owners to minimize the risks of zoonotic parasite transmission.