Is tick fever curable in dogs?

Ehrlichiosis moves through phases. The European guideline for vets, by Sainz and colleagues, says dogs treated in the acute phase improve quickly, within 24 to 48 hours, and their prognosis is good if they complete the full course. In the chronic phase, dogs can develop bone marrow hypoplasia and severe pancytopenia, a fall in all blood cell types, and the guideline describes the prognosis of the chronic severe form as grave.

The usual treatment is a course of an antibiotic lasting about four weeks, chosen and dosed by your vet. The guideline favours the full four weeks because shorter treatment in experimental infections left some dogs as silent carriers. Stopping when the dog looks better is the commonest way a 'cure' fails.

Even then, cure is hard to prove. The guideline says some dogs may remain persistently infected after appropriate treatment, and that earlier infection does not give permanent immunity, so a dog can be reinfected by another tick.

TroCCAP's tropical guidelines say few, if any, of the drugs used against Babesia sterilise the infection, and most treated dogs still harbour parasites when treatment ends. They can become lifelong carriers despite appropriate treatment, and parasites can return to the bloodstream at any time, triggered by stress, other illness or medicines that suppress the immune system.

Merck describes Babesia gibsoni as causing a chronic disease with progressive, severe anaemia that is not readily treated with the usual drugs. For very anaemic animals, it notes, a blood transfusion may be lifesaving. B. gibsoni also spreads in ways other than ticks: TroCCAP lists transfusion, mother to puppies, and fighting.

Merck says ehrlichiosis can be prevented by controlling dogs' exposure to ticks. For babesiosis it is more cautious, saying chemical tick control cannot be relied on to prevent transmission, while TroCCAP still recommends long-acting registered tick products to prevent or reduce exposure. Read together: tick prevention lowers the risk a great deal but is not a guarantee, so keep watching for signs even in a protected dog.